Merge pull request #27676 from vespa-engine/hmusum/vdslib-cleanup-1

Cleanup, simplify, remove dead code. No functional changes

19 files changed, 215 insertions, 333 deletions

diff --git a/vdslib/src/main/java/com/yahoo/vdslib/BucketDistribution.java b/vdslib/src/main/java/com/yahoo/vdslib/BucketDistribution.java
index c49fdb93d20..ba17b947bb8 100644
--- a/vdslib/src/main/java/com/yahoo/vdslib/BucketDistribution.java
+++ b/vdslib/src/main/java/com/yahoo/vdslib/BucketDistribution.java
@@ -4,6 +4,7 @@ package com.yahoo.vdslib;
 import com.yahoo.document.BucketId;
 
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
 import java.util.logging.Level;
 import java.util.logging.Logger;
@@ -14,16 +15,16 @@ import java.util.logging.Logger;
 public class BucketDistribution {
 
     // A logger object to enable proper logging.
-    private static Logger log = Logger.getLogger(BucketDistribution.class.getName());
+    private static final Logger log = Logger.getLogger(BucketDistribution.class.getName());
 
     // A map from bucket id to column index.
-    private int[] bucketToColumn;
+    private final int[] bucketToColumn;
 
     // The number of columns to distribute to.
     private int numColumns;
 
     // The number of bits to use for bucket identification.
-    private int numBucketBits;
+    private final int numBucketBits;
 
     /**
      * Constructs a new bucket distribution object with a given number of columns and buckets.
@@ -68,7 +69,7 @@ public class BucketDistribution {
      * @return The bucket distribution.
      */
     private static List<Integer> getBucketCount(int numColumns, int numBucketBits) {
-        List<Integer> ret = new ArrayList<Integer>(numColumns);
+        List<Integer> ret = new ArrayList<>(numColumns);
         int cnt = getNumBuckets(numBucketBits) / numColumns;
         int rst = getNumBuckets(numBucketBits) % numColumns;
         for (int i = 0; i < numColumns; ++i) {
@@ -100,9 +101,7 @@ public class BucketDistribution {
      * that it all buckets point to that single column.
      */
     public void reset() {
-        for (int i = 0; i < bucketToColumn.length; ++i) {
-            bucketToColumn[i] = 0;
-        }
+        Arrays.fill(bucketToColumn, 0);
         numColumns = 1;
     }
 
@@ -152,32 +151,6 @@ public class BucketDistribution {
     }
 
     /**
-     * Sets the number of buckets to use for this document distribution object. This will reset and setup this object
-     * from scratch. The original number of columns is maintained.
-     *
-     * @param numBucketBits The new number of bits to use for bucket id.
-     */
-    public synchronized void setNumBucketBits(int numBucketBits) {
-        if (numBucketBits == this.numBucketBits) {
-            return;
-        }
-        this.numBucketBits = numBucketBits;
-        bucketToColumn = new int[getNumBuckets(numBucketBits)];
-        int numColumns = this.numColumns;
-        reset();
-        setNumColumns(numColumns);
-    }
-
-    /**
-     * Returns the number of bits used for bucket identifiers.
-     *
-     * @return The number of bits.
-     */
-    public int getNumBucketBits() {
-        return numBucketBits;
-    }
-
-    /**
      * Returns the number of buckets available using the configured number of bucket bits.
      *
      * @return The number of buckets.
diff --git a/vdslib/src/main/java/com/yahoo/vdslib/DocumentSummary.java b/vdslib/src/main/java/com/yahoo/vdslib/DocumentSummary.java
index ab5fe0d9a86..4371e19d090 100644
--- a/vdslib/src/main/java/com/yahoo/vdslib/DocumentSummary.java
+++ b/vdslib/src/main/java/com/yahoo/vdslib/DocumentSummary.java
@@ -5,7 +5,8 @@ import com.yahoo.vespa.objects.BufferSerializer;
 import com.yahoo.vespa.objects.Deserializer;
 
 import java.nio.ByteOrder;
-import java.io.UnsupportedEncodingException;
+
+import static java.nio.charset.StandardCharsets.UTF_8;
 
 public class DocumentSummary {
 
@@ -27,23 +28,14 @@ public class DocumentSummary {
                 int summarySize = buf.getInt(null);
                 int end = start;
                 while (cArr[end++] != 0);
-                try {
-                    byte [] sb = new byte [summarySize];
-                    System.arraycopy(cArr, end, sb, 0, summarySize);
-                    summaries[i] = new Summary(new String(cArr, start, end-start-1, "utf-8"), sb);
-                    start = end + summarySize;
-                } catch (UnsupportedEncodingException e) {
-                    throw new RuntimeException("UTF-8 apparently not supported");
-                }
+                byte [] sb = new byte [summarySize];
+                System.arraycopy(cArr, end, sb, 0, summarySize);
+                summaries[i] = new Summary(new String(cArr, start, end-start-1, UTF_8), sb);
+                start = end + summarySize;
             }
         }
     }
 
-    /** Constructs a new message from a byte buffer. */
-    public DocumentSummary(byte[] buffer) {
-        this(BufferSerializer.wrap(buffer));
-    }
-
     final public int getSummaryCount()         { return summaries.length; }
     final public Summary getSummary(int hitNo) { return summaries[hitNo]; }
 
@@ -63,7 +55,6 @@ public class DocumentSummary {
 
         final public String getDocId()           { return docId; }
         final public byte [] getSummary()        { return summary; }
-        final public void setSummary(byte [] summary) { this.summary = summary; }
 
         public int compareTo(Summary s) {
             return getDocId().compareTo(s.getDocId());
diff --git a/vdslib/src/main/java/com/yahoo/vdslib/MetaEntry.java b/vdslib/src/main/java/com/yahoo/vdslib/MetaEntry.java
deleted file mode 100644
index a05f746fe48..00000000000
--- a/vdslib/src/main/java/com/yahoo/vdslib/MetaEntry.java
+++ /dev/null
@@ -1,52 +0,0 @@
-// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-package com.yahoo.vdslib;
-
-import com.yahoo.io.GrowableByteBuffer;
-
-import java.nio.ByteBuffer;
-import java.nio.ByteOrder;
-
-public class MetaEntry {
-    public static int REMOVE_ENTRY = 1;
-    public static int BODY_STRIPPED = 2;
-    public static int BODY_IN_HEADER = 4;
-    public static int UPDATE_ENTRY = 8;
-    public static int COMPRESSED = 16;
-
-    public static int SIZE = 32;
-
-    public long timestamp = 0;
-    public int headerPos = 0;
-    public int headerLen = 0;
-    public int bodyPos = 0;
-    public int bodyLen = 0;
-    public byte flags = 0;
-
-    public MetaEntry() {
-    }
-
-    public MetaEntry(byte[] buffer, int position) {
-        ByteBuffer buf = ByteBuffer.wrap(buffer, position, SIZE);
-        buf.order(ByteOrder.LITTLE_ENDIAN);
-
-        timestamp = buf.getLong();
-        headerPos = buf.getInt();
-        headerLen = buf.getInt();
-        bodyPos = buf.getInt();
-        bodyLen = buf.getInt();
-        flags = buf.get();
-    }
-
-    public void serialize(GrowableByteBuffer buf) {
-        ByteOrder originalOrder = buf.order();
-        buf.order(ByteOrder.LITTLE_ENDIAN);
-        buf.putLong(timestamp); // 8
-        buf.putInt(headerPos); // 12
-        buf.putInt(headerLen); // 16
-        buf.putInt(bodyPos); // 20
-        buf.putInt(bodyLen); // 24
-        buf.putInt(flags); // 28 (written as little-endian int, this is on purpose)
-        buf.putInt(0); // 32
-        buf.order(originalOrder);
-    }
-}
diff --git a/vdslib/src/main/java/com/yahoo/vdslib/SearchResult.java b/vdslib/src/main/java/com/yahoo/vdslib/SearchResult.java
index b7c9b1b71b5..c89abf87970 100644
--- a/vdslib/src/main/java/com/yahoo/vdslib/SearchResult.java
+++ b/vdslib/src/main/java/com/yahoo/vdslib/SearchResult.java
@@ -1,19 +1,22 @@
 // Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vdslib;
+
 import com.yahoo.data.access.helpers.MatchFeatureData;
 import com.yahoo.vespa.objects.BufferSerializer;
 import com.yahoo.vespa.objects.Deserializer;
 
-import java.io.UnsupportedEncodingException;
 import java.nio.ByteOrder;
 import java.util.ArrayList;
 import java.util.Map;
 import java.util.Optional;
 import java.util.TreeMap;
 
+import static java.nio.charset.StandardCharsets.UTF_8;
+
 public class SearchResult {
+
     public static class Hit implements Comparable<Hit> {
-        private String docId;
+        private final String docId;
         private double rank;
         private MatchFeatureData.HitValue matchFeatures;
         public Hit(Hit h) {
@@ -40,7 +43,7 @@ public class SearchResult {
         }
     }
     public static class HitWithSortBlob extends Hit {
-        private byte [] sortBlob;
+        private final byte [] sortBlob;
         public HitWithSortBlob(Hit h, byte [] sb) {
             super(h);
             sortBlob = sb;
@@ -57,12 +60,12 @@ public class SearchResult {
             return sortBlob.length - b.sortBlob.length;
         }
     }
-    private int    totalHits;
-    private Hit[]  hits;
-    private TreeMap<Integer, byte []> aggregatorList;
-    private TreeMap<Integer, byte []> groupingList;
-    private static int EXTENSION_FLAGS_PRESENT = -1;
-    private static int MATCH_FEATURES_PRESENT_MASK = 1;
+    private final int    totalHits;
+    private final Hit[]  hits;
+    private final TreeMap<Integer, byte []> aggregatorList;
+    private final TreeMap<Integer, byte []> groupingList;
+    private static final int EXTENSION_FLAGS_PRESENT = -1;
+    private static final int MATCH_FEATURES_PRESENT_MASK = 1;
 
     public SearchResult(Deserializer buf) {
         BufferSerializer bser = (BufferSerializer) buf; // TODO: dirty cast. must do this differently
@@ -76,17 +79,13 @@ public class SearchResult {
         }
         hits = new Hit[numHits];
         if (numHits != 0) {
-            int docIdBufferLength = buf.getInt(null);
+            int docIdBufferLength = buf.getInt(null);  // Unused, but need to call getInt() to advance buffer
             byte[] cArr = bser.getBuf().array();
             int start = bser.getBuf().arrayOffset() + bser.position();
             for(int i=0; i < numHits; i++) {
                 int end = start;
                 while (cArr[end++] != 0);
-                try {
-                    hits[i] = new Hit(new String(cArr, start, end-start-1, "utf-8"), 0);
-                } catch (UnsupportedEncodingException e) {
-                    throw new RuntimeException("UTF-8 apparently not supported");
-                }
+                hits[i] = new Hit(new String(cArr, start, end-start-1, UTF_8), 0);
                 start = end;
             }
             bser.position(start - bser.getBuf().arrayOffset());
@@ -104,8 +103,9 @@ public class SearchResult {
             hits[i] = new HitWithSortBlob(hits[i], buf.getBytes(null, size[i]));
         }
 
+        // Unused, but need to call getInt() to advance buffer
         int numAggregators = buf.getInt(null);
-        aggregatorList = new TreeMap<Integer, byte []>();
+        aggregatorList = new TreeMap<>();
         for (int i = 0; i < numAggregators; i++) {
             int aggrId = buf.getInt(null);
             int aggrLength = buf.getInt(null);
@@ -113,7 +113,7 @@ public class SearchResult {
         }
 
         int numGroupings = buf.getInt(null);
-        groupingList = new TreeMap<Integer, byte []>();
+        groupingList = new TreeMap<>();
         for (int i = 0; i < numGroupings; i++) {
             int aggrId = buf.getInt(null);
             int aggrLength = buf.getInt(null);
@@ -159,18 +159,8 @@ public class SearchResult {
         return featureType == 0;
     }
 
-    /**
-     * Constructs a new message from a byte buffer.
-     *
-     * @param buffer A byte buffer that contains a serialized message.
-     */
-    public SearchResult(byte[] buffer) {
-        this(BufferSerializer.wrap(buffer));
-    }
-
     final public int getHitCount()      { return hits.length; }
     final public int getTotalHitCount() { return (totalHits != 0) ? totalHits : getHitCount(); }
     final public Hit getHit(int hitNo)  { return hits[hitNo]; }
-    final public Map<Integer, byte []> getAggregatorList() { return aggregatorList; }
     final public Map<Integer, byte []> getGroupingList() { return groupingList; }
 }
diff --git a/vdslib/src/main/java/com/yahoo/vdslib/distribution/ConfiguredNode.java b/vdslib/src/main/java/com/yahoo/vdslib/distribution/ConfiguredNode.java
index 92cf8b025e9..965dd018c4f 100644
--- a/vdslib/src/main/java/com/yahoo/vdslib/distribution/ConfiguredNode.java
+++ b/vdslib/src/main/java/com/yahoo/vdslib/distribution/ConfiguredNode.java
@@ -7,31 +7,28 @@ package com.yahoo.vdslib.distribution;
  *
  * @author bratseth
  */
-public class ConfiguredNode implements Comparable<ConfiguredNode> {
+public record ConfiguredNode(int index, boolean retired) implements Comparable<ConfiguredNode> {
 
-    private final int index;
-
-    private final boolean retired;
-
-    public ConfiguredNode(int index, boolean retired) {
-        this.index = index;
-        this.retired = retired;
-    }
-
-    /** Return the index (distribution key) of this node */
-    public int index() { return index; }
+    /**
+     * Return the index (distribution key) of this node
+     */
+    @Override
+    public int index() {return index;}
 
-    /** Returns whether the node is configured to be retired */
-    public boolean retired() { return retired; }
+    /**
+     * Returns whether the node is configured to be retired
+     */
+    @Override
+    public boolean retired() {return retired;}
 
     @Override
-    public int hashCode() { return index; }
+    public int hashCode() {return index;}
 
     @Override
     public boolean equals(Object other) {
         if (other == this) return true;
-        if ( ! (other instanceof ConfiguredNode)) return false;
-        return ((ConfiguredNode)other).index == this.index;
+        if (! (other instanceof ConfiguredNode)) return false;
+        return ((ConfiguredNode) other).index == this.index;
     }
 
     @Override
diff --git a/vdslib/src/main/java/com/yahoo/vdslib/distribution/Distribution.java b/vdslib/src/main/java/com/yahoo/vdslib/distribution/Distribution.java
index a83e2a4f89c..bfa7e919514 100644
--- a/vdslib/src/main/java/com/yahoo/vdslib/distribution/Distribution.java
+++ b/vdslib/src/main/java/com/yahoo/vdslib/distribution/Distribution.java
@@ -26,14 +26,7 @@ import java.util.concurrent.atomic.AtomicReference;
 
 public class Distribution {
 
-    private static class Config {
-        Config(Group nodeGraph, int redundancy) {
-            this.nodeGraph = nodeGraph;
-            this.redundancy = redundancy;
-        }
-
-        private final Group nodeGraph;
-        private final int redundancy;
+    private record Config(Group nodeGraph, int redundancy) {
     }
 
     private ConfigSubscriber configSub;
@@ -197,8 +190,8 @@ public class Distribution {
     }
 
     private static class ScoredGroup implements Comparable<ScoredGroup> {
-        Group group;
-        double score;
+        final Group group;
+        final double score;
 
         ScoredGroup(Group g, double score) { this.group = g; this.score = score; }
 
@@ -266,8 +259,8 @@ public class Distribution {
     }
 
     private static class ResultGroup implements Comparable<ResultGroup> {
-        Group group;
-        int redundancy;
+        final Group group;
+        final int redundancy;
 
         ResultGroup(Group group, int redundancy) {
             this.group = group;
@@ -489,14 +482,11 @@ public class Distribution {
 
     public Set<ConfiguredNode> getNodes() {
         final Set<ConfiguredNode> nodes = new HashSet<>();
-        GroupVisitor visitor = new GroupVisitor() {
-            @Override
-            public boolean visitGroup(Group g) {
-                if (g.isLeafGroup()) {
-                    nodes.addAll(g.getNodes());
-                }
-                return true;
+        GroupVisitor visitor = g -> {
+            if (g.isLeafGroup()) {
+                nodes.addAll(g.getNodes());
             }
+            return true;
         };
         visitGroups(visitor);
         return nodes;
diff --git a/vdslib/src/main/java/com/yahoo/vdslib/distribution/Group.java b/vdslib/src/main/java/com/yahoo/vdslib/distribution/Group.java
index b926ee3be8d..c1c2eef5c8f 100644
--- a/vdslib/src/main/java/com/yahoo/vdslib/distribution/Group.java
+++ b/vdslib/src/main/java/com/yahoo/vdslib/distribution/Group.java
@@ -9,13 +9,13 @@ import java.text.ParseException;
  */
 public class Group implements Comparable<Group> {
 
-    private String name;
+    private final String name;
     private Group parent = null;
-    private int index;
+    private final int index;
     private int distributionHash;
-    private Distribution distribution = null;
+    private final Distribution distribution;
     private double capacity;
-    private Map<Integer, Group> subgroups;
+    private final Map<Integer, Group> subgroups;
     private List<ConfiguredNode> nodes;
 
     public Group(int index, String name) {
@@ -63,8 +63,7 @@ public class Group implements Comparable<Group> {
     @Override
     public boolean equals(Object o) {
         if (o == this) return true;
-        if ( ! (o instanceof Group)) { return false; }
-        Group other = (Group) o;
+        if ( ! (o instanceof Group other)) { return false; }
         if ( ! name.equals(other.name)
             || index != other.index
             || (distribution == null ^ other.distribution == null)
@@ -210,7 +209,7 @@ public class Group implements Comparable<Group> {
             for (int i=0; i<distributionSpec.length; ++i) {
                 String token = st.nextToken();
                 try{
-                    distributionSpec[i] = (token.equals("*") ? 0 : Integer.valueOf(token));
+                    distributionSpec[i] = (token.equals("*") ? 0 : Integer.parseInt(token));
                 } catch (NumberFormatException e) {
                     throw new ParseException("Illegal distribution spec \"" + serialized + "\". Copy counts must be integer values in the range 1-255.", i);
                 }
@@ -243,9 +242,9 @@ public class Group implements Comparable<Group> {
             int asterixCount = distributionSpec.length - firstAsterix;
             int[][] preCalculations = new int[maxRedundancy + 1][];
             for (int i=1; i<=maxRedundancy; ++i) {
-                List<Integer> spec = new ArrayList<Integer>();
-                for (int j=0; j<distributionSpec.length; ++j) {
-                    spec.add(distributionSpec[j]);
+                List<Integer> spec = new ArrayList<>();
+                for (int k : distributionSpec) {
+                    spec.add(k);
                 }
                 int remainingRedundancy = i;
                 for (int j=0; j<firstAsterix; ++j) {
@@ -277,8 +276,7 @@ public class Group implements Comparable<Group> {
         @Override
         public boolean equals(Object o) {
             if (o == this) return true;
-            if ( ! (o instanceof Distribution)) return false;
-            Distribution other = (Distribution) o;
+            if ( ! (o instanceof Distribution other)) return false;
             return (distributionSpec == other.distributionSpec && preCalculatedResults.length == other.preCalculatedResults.length);
         }
 
diff --git a/vdslib/src/main/java/com/yahoo/vdslib/distribution/GroupVisitor.java b/vdslib/src/main/java/com/yahoo/vdslib/distribution/GroupVisitor.java
index df5a6e5a9d1..1108ce7507d 100644
--- a/vdslib/src/main/java/com/yahoo/vdslib/distribution/GroupVisitor.java
+++ b/vdslib/src/main/java/com/yahoo/vdslib/distribution/GroupVisitor.java
@@ -3,6 +3,6 @@ package com.yahoo.vdslib.distribution;
 
 public interface GroupVisitor {
 
-    public boolean visitGroup(Group g);
+    boolean visitGroup(Group g);
 
 }
diff --git a/vdslib/src/main/java/com/yahoo/vdslib/state/ClusterState.java b/vdslib/src/main/java/com/yahoo/vdslib/state/ClusterState.java
index 4bf305e65e0..30a209b6754 100644
--- a/vdslib/src/main/java/com/yahoo/vdslib/state/ClusterState.java
+++ b/vdslib/src/main/java/com/yahoo/vdslib/state/ClusterState.java
@@ -24,7 +24,7 @@ public class ClusterState implements Cloneable {
 
     /**
      * Maintains a bitset where all non-down nodes have a bit set. All nodes that differ from defaultUp
-     * and defaultDown are store explicit in a hash map.
+     * and defaultDown are stored explicitly in a hash map.
      */
     private static class Nodes {
         private int logicalNodeCount;
diff --git a/vdslib/src/main/java/com/yahoo/vdslib/state/Diff.java b/vdslib/src/main/java/com/yahoo/vdslib/state/Diff.java
index f4eb9ff8dde..8a4bedddaeb 100644
--- a/vdslib/src/main/java/com/yahoo/vdslib/state/Diff.java
+++ b/vdslib/src/main/java/com/yahoo/vdslib/state/Diff.java
@@ -8,8 +8,9 @@ import java.util.List;
  * TODO: document this
  */
 public class Diff {
+
     public static class Entry {
-        String id;
+        final String id;
             // Values set for entries that contain diff themselves
         String preContent;
         String postContent;
@@ -32,22 +33,22 @@ public class Diff {
         public Entry bold() { bold = true; return this; }
         public Entry splitLine() { splitLine = true; return this; }
     }
-    private List<Entry> diff = new LinkedList<Entry>();
+    private final List<Entry> diff = new LinkedList<>();
 
     public void add(Entry e) { diff.add(e); }
 
     public boolean differs() { return (!diff.isEmpty()); }
 
-    class PrintProperties {
+    static class PrintProperties {
         boolean insertLineBreaks = false;
-        boolean ommitGroupForSingleEntries = true;
+        final boolean ommitGroupForSingleEntries = true;
         String lineBreak = "\n";
-        String entrySeparator = ", ";
-        String idValueSeparator = ": ";
+        final String entrySeparator = ", ";
+        final String idValueSeparator = ": ";
         String keyValueSeparator = " => ";
-        String singleGroupSeparator = "";
-        String groupStart = "[";
-        String groupStop = "]";
+        final String singleGroupSeparator = "";
+        final String groupStart = "[";
+        final String groupStop = "]";
         String indent = "  ";
         String boldStart = "";
         String boldStop = "";
diff --git a/vdslib/src/test/java/com/yahoo/vdslib/BucketDistributionTestCase.java b/vdslib/src/test/java/com/yahoo/vdslib/BucketDistributionTestCase.java
index 7257bf0cc7f..59b5a7ae55a 100644
--- a/vdslib/src/test/java/com/yahoo/vdslib/BucketDistributionTestCase.java
+++ b/vdslib/src/test/java/com/yahoo/vdslib/BucketDistributionTestCase.java
@@ -25,7 +25,7 @@ public class BucketDistributionTestCase {
             BucketDistribution bd = new BucketDistribution(NUM_COLUMNS, numBucketBits);
             for (int i = 0; i < bd.getNumBuckets(); ++i) {
                 if (i % 32 == 0) {
-                    System.out.println("");
+                    System.out.println();
                     System.out.print("                ");
                 }
                 System.out.print(bd.getColumn(new BucketId(16, i)));
@@ -37,7 +37,7 @@ public class BucketDistributionTestCase {
             if (numBucketBits < MAX_BUCKETBITS) {
                 System.out.print(",");
             }
-            System.out.println("");
+            System.out.println();
         }
         System.out.println("        };");
     }
diff --git a/vdslib/src/test/java/com/yahoo/vdslib/SearchResultTestCase.java b/vdslib/src/test/java/com/yahoo/vdslib/SearchResultTestCase.java
index 3f3e8fd0f8b..b675798b374 100644
--- a/vdslib/src/test/java/com/yahoo/vdslib/SearchResultTestCase.java
+++ b/vdslib/src/test/java/com/yahoo/vdslib/SearchResultTestCase.java
@@ -17,12 +17,12 @@ public class SearchResultTestCase {
         SearchResult.Hit b = new SearchResult.Hit("b", 0.1);
         SearchResult.Hit c = new SearchResult.Hit("c", 1.0);
         SearchResult.Hit bb = new SearchResult.Hit("b2", 0.1);
-        assertTrue(a.compareTo(a) == 0);
+        assertEquals(0, a.compareTo(a));
         assertTrue(a.compareTo(b) > 0);
         assertTrue(a.compareTo(c) > 0);
         assertTrue(b.compareTo(a) < 0);
-        assertTrue(b.compareTo(bb) == 0);
-        assertTrue(bb.compareTo(b) == 0);
+        assertEquals(0, b.compareTo(bb));
+        assertEquals(0, bb.compareTo(b));
         assertTrue(b.compareTo(c) > 0);
         assertTrue(c.compareTo(a) < 0);
         assertTrue(c.compareTo(b) < 0);
@@ -47,7 +47,7 @@ public class SearchResultTestCase {
         SearchResult.Hit h5 = new SearchResult.HitWithSortBlob(a, b5);
         SearchResult.Hit h6 = new SearchResult.HitWithSortBlob(a, b6);
 
-        assertTrue(h1.compareTo(h1) == 0);
+        assertEquals(0, h1.compareTo(h1));
         assertTrue(h1.compareTo(h2) < 0);
         assertTrue(h1.compareTo(h3) < 0);
         assertTrue(h1.compareTo(h4) < 0);
@@ -55,7 +55,7 @@ public class SearchResultTestCase {
         assertTrue(h1.compareTo(h6) < 0);
 
         assertTrue(h2.compareTo(h1) > 0);
-        assertTrue(h2.compareTo(h2) == 0);
+        assertEquals(0, h2.compareTo(h2));
         assertTrue(h2.compareTo(h3) < 0);
         assertTrue(h2.compareTo(h4) < 0);
         assertTrue(h2.compareTo(h5) < 0);
@@ -63,7 +63,7 @@ public class SearchResultTestCase {
 
         assertTrue(h3.compareTo(h1) > 0);
         assertTrue(h3.compareTo(h2) > 0);
-        assertTrue(h3.compareTo(h3) == 0);
+        assertEquals(0, h3.compareTo(h3));
         assertTrue(h3.compareTo(h4) < 0);
         assertTrue(h3.compareTo(h5) < 0);
         assertTrue(h3.compareTo(h6) < 0);
@@ -71,7 +71,7 @@ public class SearchResultTestCase {
         assertTrue(h4.compareTo(h1) > 0);
         assertTrue(h4.compareTo(h2) > 0);
         assertTrue(h4.compareTo(h3) > 0);
-        assertTrue(h4.compareTo(h4) == 0);
+        assertEquals(0, h4.compareTo(h4));
         assertTrue(h4.compareTo(h5) < 0);
         assertTrue(h4.compareTo(h6) < 0);
 
@@ -79,7 +79,7 @@ public class SearchResultTestCase {
         assertTrue(h5.compareTo(h2) > 0);
         assertTrue(h5.compareTo(h3) > 0);
         assertTrue(h5.compareTo(h4) > 0);
-        assertTrue(h5.compareTo(h5) == 0);
+        assertEquals(0, h5.compareTo(h5));
         assertTrue(h5.compareTo(h6) < 0);
 
         assertTrue(h6.compareTo(h1) > 0);
@@ -87,6 +87,6 @@ public class SearchResultTestCase {
         assertTrue(h6.compareTo(h3) > 0);
         assertTrue(h6.compareTo(h4) > 0);
         assertTrue(h6.compareTo(h5) > 0);
-        assertTrue(h6.compareTo(h6) == 0);
+        assertEquals(0, h6.compareTo(h6));
     }
 }
diff --git a/vdslib/src/test/java/com/yahoo/vdslib/distribution/CrossPlatformTestFactory.java b/vdslib/src/test/java/com/yahoo/vdslib/distribution/CrossPlatformTestFactory.java
index 70a11ff530f..90128c7c04b 100644
--- a/vdslib/src/test/java/com/yahoo/vdslib/distribution/CrossPlatformTestFactory.java
+++ b/vdslib/src/test/java/com/yahoo/vdslib/distribution/CrossPlatformTestFactory.java
@@ -20,36 +20,29 @@ public abstract class CrossPlatformTestFactory {
 
     public String getName() { return name; }
 
-    public boolean loadTestResults() throws Exception {
+    public void loadTestResults() throws Exception {
         File reference = new File(directory, name + ".reference.results");
         if (!reference.exists()) {
-            return false;
+            return;
         }
-        BufferedReader br = new BufferedReader(new FileReader(reference));
-        StringBuilder sb = new StringBuilder();
-        try{
-            while(true) {
+        try (BufferedReader br = new BufferedReader(new FileReader(reference))) {
+            StringBuilder sb = new StringBuilder();
+            while (true) {
                 String line = br.readLine();
                 if (line == null) break;
                 sb.append(line);
             }
             parse(sb.toString());
-        } finally {
-            br.close();
         }
-        return true;
     }
 
     public void recordTestResults() throws Exception {
         File results = new File(directory, name + ".java.results");
-        FileWriter fw = new FileWriter(results);
-        try{
+        try (FileWriter fw = new FileWriter(results)) {
             fw.write(serialize());
-        } finally {
-            fw.close();
         }
     }
 
-    public abstract String serialize() throws Exception;
+    public abstract String serialize();
     public abstract void parse(String serialized) throws Exception;
 }
diff --git a/vdslib/src/test/java/com/yahoo/vdslib/distribution/DistributionTestCase.java b/vdslib/src/test/java/com/yahoo/vdslib/distribution/DistributionTestCase.java
index 19c9c79522d..6dfffa23aed 100644
--- a/vdslib/src/test/java/com/yahoo/vdslib/distribution/DistributionTestCase.java
+++ b/vdslib/src/test/java/com/yahoo/vdslib/distribution/DistributionTestCase.java
@@ -30,26 +30,27 @@ import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;
 
 public class DistributionTestCase {
+
+    private static final int minUsedBits = 16;
+
     private DistributionTestFactory test;
     /** Build a set of buckets to test that should represent the entire bucket space well. */
-    private static List<BucketId> getTestBuckets() { return getTestBuckets(16); }
-    private static List<BucketId> getTestBuckets(int minUsedBits) {
+    private static List<BucketId> getTestBuckets() {
         List<BucketId> buckets = new ArrayList<>();
-        assertTrue(minUsedBits <= 16);
-            // Get a set of buckets from the same split level
-        for (int i=16; i<=18; ++i) {
-            for (int j=0; j<20; ++j) {
+        // Get a set of buckets from the same split level
+        for (int i = 16; i <= 18; ++ i) {
+            for (int j = 0; j < 20; ++ j) {
                 buckets.add(new BucketId(i, j));
             }
         }
-            // Get a few random buckets at every split level.
+        // Get a few random buckets at every split level.
         Random randomized = new Random(413);
         long randValue = randomized.nextLong();
-        for (int i=minUsedBits; i<58; ++i) {
+        for (int i = minUsedBits; i < 58; ++ i) {
             buckets.add(new BucketId(i, randValue));
         }
         randValue = randomized.nextLong();
-        for (int i=minUsedBits; i<58; ++i) {
+        for (int i = minUsedBits; i < 58; ++ i) {
             buckets.add(new BucketId(i, randValue));
         }
         return Collections.unmodifiableList(buckets);
@@ -230,7 +231,7 @@ public class DistributionTestCase {
     }
 
     @Test
-    public void testSplitBeyondSplitBitDoesntAffectDistribution() throws Exception {
+    public void testSplitBeyondSplitBitDoesntAffectDistribution() {
         Random randomized = new Random(7123161);
         long val = randomized.nextLong();
         test = new DistributionTestFactory("abovesplitbit");
@@ -325,7 +326,7 @@ public class DistributionTestCase {
     }
 
     @Test
-    public void testHierarchicalDistribution() throws Exception {
+    public void testHierarchicalDistribution() {
         test = new DistributionTestFactory("hierarchical-grouping")
                 .setDistribution(buildHierarchicalConfig(6, 3, 1, "1|2|*", 3));
         for (BucketId bucket : getTestBuckets()) {
diff --git a/vdslib/src/test/java/com/yahoo/vdslib/distribution/DistributionTestFactory.java b/vdslib/src/test/java/com/yahoo/vdslib/distribution/DistributionTestFactory.java
index 78b548e5925..e94e4f04199 100644
--- a/vdslib/src/test/java/com/yahoo/vdslib/distribution/DistributionTestFactory.java
+++ b/vdslib/src/test/java/com/yahoo/vdslib/distribution/DistributionTestFactory.java
@@ -21,7 +21,7 @@ import static org.junit.Assert.assertTrue;
 // TODO: Use config builder instead of ConfigGetter to create test config.
 public class DistributionTestFactory extends CrossPlatformTestFactory {
 
-    ObjectMapper mapper = new ObjectMapper();
+    final ObjectMapper mapper = new ObjectMapper();
 
     private static final String testDirectory = "src/tests/distribution/testdata";
     private int redundancy;
@@ -32,14 +32,14 @@ public class DistributionTestFactory extends CrossPlatformTestFactory {
     private String upStates;
 
     private int testsRecorded = 0;
-    private List<Test> results = new ArrayList<>();
+    private final List<Test> results = new ArrayList<>();
     private int testsVerified = 0;
 
-    enum Failure { NONE, TOO_FEW_BITS, NO_DISTRIBUTORS_AVAILABLE };
+    enum Failure { NONE, TOO_FEW_BITS, NO_DISTRIBUTORS_AVAILABLE }
 
     static public class Test {
-        private BucketId bucket;
-        private List<Integer> nodes;
+        private final BucketId bucket;
+        private final List<Integer> nodes;
         private Failure failure;
 
         public Test(BucketId bucket) {
@@ -50,8 +50,7 @@ public class DistributionTestFactory extends CrossPlatformTestFactory {
 
         @Override
         public boolean equals(Object other) {
-            if (!(other instanceof Test)) return false;
-            Test t = (Test) other;
+            if (!(other instanceof Test t)) return false;
             return (bucket.equals(t.bucket)
                     && nodes.equals(t.nodes)
                     && failure.equals(t.failure));
@@ -81,19 +80,14 @@ public class DistributionTestFactory extends CrossPlatformTestFactory {
             return nodes;
         }
 
-        public Test assertFailure(Failure f) {
-            assertEquals(f, failure);
-            return this;
-        }
         public Test assertNodeCount(int count) {
             if (count > 0) assertEquals(toString(), Failure.NONE, failure);
             assertEquals(toString(), count, nodes.size());
             return this;
         }
-        public Test assertNodeUsed(int node) {
+        public void assertNodeUsed(int node) {
             assertEquals(toString(), Failure.NONE, failure);
             assertTrue(toString(), nodes.contains(node));
-            return this;
         }
     }
 
@@ -166,9 +160,7 @@ public class DistributionTestFactory extends CrossPlatformTestFactory {
                 int node = d.getIdealDistributorNode(state, bucket, upStates);
                 t.nodes.add(node);
             } else {
-                for (int i : d.getIdealStorageNodes(state, bucket, upStates)) {
-                    t.nodes.add(i);
-                }
+                t.nodes.addAll(d.getIdealStorageNodes(state, bucket, upStates));
             }
         } catch (Distribution.TooFewBucketBitsInUseException e) {
             t.failure = Failure.TOO_FEW_BITS;
@@ -184,7 +176,7 @@ public class DistributionTestFactory extends CrossPlatformTestFactory {
         return t;
     }
 
-    public String serialize() throws Exception {
+    public String serialize() {
         ObjectNode test = new ObjectNode(mapper.getNodeFactory())
                 .put("cluster-state", state.toString())
                 .put("distribution", new StorDistributionConfig(distributionConfig).toString())
diff --git a/vdslib/src/test/java/com/yahoo/vdslib/distribution/GroupTestCase.java b/vdslib/src/test/java/com/yahoo/vdslib/distribution/GroupTestCase.java
index 353f2bf4ebc..ce9d4dcedff 100644
--- a/vdslib/src/test/java/com/yahoo/vdslib/distribution/GroupTestCase.java
+++ b/vdslib/src/test/java/com/yahoo/vdslib/distribution/GroupTestCase.java
@@ -31,7 +31,7 @@ public class GroupTestCase {
 
     private void assertDistributionFailure(String spec, int redundancy, String expectedError) {
         try{
-            Group.Distribution distribution = new Group.Distribution(spec, redundancy);
+            new Group.Distribution(spec, redundancy);
             fail("Failed to fail parsing of spec \"" + spec + "\", redundancy " + redundancy + " with failure: " + expectedError);
         } catch (Exception e) {
             assertEquals(expectedError, e.getMessage());
diff --git a/vdslib/src/test/java/com/yahoo/vdslib/state/ClusterStateTestCase.java b/vdslib/src/test/java/com/yahoo/vdslib/state/ClusterStateTestCase.java
index 77dd37b3ebf..c4ff28b75b1 100644
--- a/vdslib/src/test/java/com/yahoo/vdslib/state/ClusterStateTestCase.java
+++ b/vdslib/src/test/java/com/yahoo/vdslib/state/ClusterStateTestCase.java
@@ -9,7 +9,9 @@ import java.util.function.BiFunction;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotEquals;
 import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
 
 public class ClusterStateTestCase{
 
@@ -55,16 +57,16 @@ public class ClusterStateTestCase{
         assertEquals(state, new ClusterState("storage:0"));
         assertEquals(state, new ClusterState("distributor:0"));
 
-        assertFalse(state.equals(new ClusterState("version:1")));
-        assertFalse(state.equals(new ClusterState("cluster:d")));
-        assertFalse(state.equals(new ClusterState("bits:20")));
-        assertFalse(state.equals(new ClusterState("storage:1")));
-        assertFalse(state.equals(new ClusterState("distributor:1")));
+        assertNotEquals(state, new ClusterState("version:1"));
+        assertNotEquals(state, new ClusterState("cluster:d"));
+        assertNotEquals(state, new ClusterState("bits:20"));
+        assertNotEquals(state, new ClusterState("storage:1"));
+        assertNotEquals(state, new ClusterState("distributor:1"));
 
         {
             ClusterState state1 = new ClusterState("distributor:3 .1.s:d .2.s:m storage:3 .1.s:i .2.s:r");
             ClusterState state2 = new ClusterState("distributor:3 .1.s:d .2.s:m storage:3 .1.s:i .2.s:m");
-            assertFalse(state1.equals(state2));
+            assertNotEquals(state1, state2);
             assertFalse(state1.similarTo(state2));
             assertFalse(state1.similarToIgnoringInitProgress(state2));
         }
@@ -72,7 +74,7 @@ public class ClusterStateTestCase{
         {
             ClusterState state1 = new ClusterState("cluster:d");
             ClusterState state2 = new ClusterState("cluster:d version:1 bits:20 distributor:1 storage:1 .0.s:d");
-            assertFalse(state1.equals(state2));
+            assertNotEquals(state1, state2);
             assertTrue(state1.similarTo(state2));
             assertTrue(state1.similarToIgnoringInitProgress(state2));
         }
@@ -80,12 +82,12 @@ public class ClusterStateTestCase{
         {
             ClusterState state1 = new ClusterState("distributor:3 .1.s:d .2.s:m storage:3 .1.s:i .2.s:r");
             ClusterState state2 = new ClusterState("distributor:3 storage:3");
-            assertFalse(state1.equals(state2));
+            assertNotEquals(state1, state2);
             assertFalse(state1.similarTo(state2));
             assertFalse(state1.similarToIgnoringInitProgress(state2));
         }
 
-        assertFalse(state.equals("class not instance of ClusterState"));
+        assertNotEquals("class not instance of ClusterState", state);
         assertFalse(state.similarTo("class not instance of ClusterState"));
 
         assertEquals(state, state);
@@ -200,36 +202,39 @@ public class ClusterStateTestCase{
         ClusterState state3 = new ClusterState("distributor:9 storage:2");
 
         assertEquals("storage: [4: Down => Up, 5: Down => Up], distributor: [7: Up => Down, 8: Up => Down]", state1.getTextualDifference(state2));
-        assertEquals("storage: [<br>\n" +
-                "&nbsp;4: <b>Down</b> =&gt; <b>Up</b>, <br>\n" +
-                "&nbsp;5: <b>Down</b> =&gt; <b>Up</b><br>\n" +
-                "], distributor: [<br>\n" +
-                "&nbsp;7: <b>Up</b> =&gt; <b>Down</b>, <br>\n" +
-                "&nbsp;8: <b>Up</b> =&gt; <b>Down</b><br>\n" +
-                "]", state1.getHtmlDifference(state2));
+        assertEquals("""
+                             storage: [<br>
+                             &nbsp;4: <b>Down</b> =&gt; <b>Up</b>, <br>
+                             &nbsp;5: <b>Down</b> =&gt; <b>Up</b><br>
+                             ], distributor: [<br>
+                             &nbsp;7: <b>Up</b> =&gt; <b>Down</b>, <br>
+                             &nbsp;8: <b>Up</b> =&gt; <b>Down</b><br>
+                             ]""", state1.getHtmlDifference(state2));
         assertEquals("storage: [2: Up => Down, 3: Up => Down, 4: Up => Down, 5: Up => Down], distributor: [7: Down => Up, 8: Down => Up]", state2.getTextualDifference(state3));
-        assertEquals("storage: [<br>\n" +
-                "&nbsp;2: <b>Up</b> =&gt; <b>Down</b>, <br>\n" +
-                "&nbsp;3: <b>Up</b> =&gt; <b>Down</b>, <br>\n" +
-                "&nbsp;4: <b>Up</b> =&gt; <b>Down</b>, <br>\n" +
-                "&nbsp;5: <b>Up</b> =&gt; <b>Down</b><br>\n" +
-                "], distributor: [<br>\n" +
-                "&nbsp;7: <b>Down</b> =&gt; <b>Up</b>, <br>\n" +
-                "&nbsp;8: <b>Down</b> =&gt; <b>Up</b><br>\n" +
-                "]", state2.getHtmlDifference(state3));
+        assertEquals("""
+                             storage: [<br>
+                             &nbsp;2: <b>Up</b> =&gt; <b>Down</b>, <br>
+                             &nbsp;3: <b>Up</b> =&gt; <b>Down</b>, <br>
+                             &nbsp;4: <b>Up</b> =&gt; <b>Down</b>, <br>
+                             &nbsp;5: <b>Up</b> =&gt; <b>Down</b><br>
+                             ], distributor: [<br>
+                             &nbsp;7: <b>Down</b> =&gt; <b>Up</b>, <br>
+                             &nbsp;8: <b>Down</b> =&gt; <b>Up</b><br>
+                             ]""", state2.getHtmlDifference(state3));
 
         state1.setVersion(123);
         state1.setNodeState(new Node(NodeType.STORAGE, 2), new NodeState(NodeType.STORAGE, State.INITIALIZING).setInitProgress(0.2f).setDescription("Booting"));
         state2.setDistributionBits(21);
         assertEquals("version: 123 => 0, bits: 16 => 21, storage: [2: [Initializing => Up, description: Booting => ], 4: Down => Up, 5: Down => Up], distributor: [7: Up => Down, 8: Up => Down]", state1.getTextualDifference(state2));
-        assertEquals("version: 123 =&gt; 0, bits: 16 =&gt; 21, storage: [<br>\n" +
-                "&nbsp;2: [<b>Initializing</b> =&gt; <b>Up</b>, description: Booting =&gt; ], <br>\n" +
-                "&nbsp;4: <b>Down</b> =&gt; <b>Up</b>, <br>\n" +
-                "&nbsp;5: <b>Down</b> =&gt; <b>Up</b><br>\n" +
-                "], distributor: [<br>\n" +
-                "&nbsp;7: <b>Up</b> =&gt; <b>Down</b>, <br>\n" +
-                "&nbsp;8: <b>Up</b> =&gt; <b>Down</b><br>\n" +
-                "]", state1.getHtmlDifference(state2));
+        assertEquals("""
+                             version: 123 =&gt; 0, bits: 16 =&gt; 21, storage: [<br>
+                             &nbsp;2: [<b>Initializing</b> =&gt; <b>Up</b>, description: Booting =&gt; ], <br>
+                             &nbsp;4: <b>Down</b> =&gt; <b>Up</b>, <br>
+                             &nbsp;5: <b>Down</b> =&gt; <b>Up</b><br>
+                             ], distributor: [<br>
+                             &nbsp;7: <b>Up</b> =&gt; <b>Down</b>, <br>
+                             &nbsp;8: <b>Up</b> =&gt; <b>Down</b><br>
+                             ]""", state1.getHtmlDifference(state2));
     }
 
     @Test
@@ -254,40 +259,40 @@ public class ClusterStateTestCase{
 
         try {
             new ClusterState("badtokenwithoutcolon");
-            assertTrue("Should fail", false);
-        } catch (Exception e) {}
+            fail("Should fail");
+        } catch (Exception ignored) {}
         try {
             new ClusterState(".0.s:d");
-            assertTrue("Should fail", false);
-        } catch (Exception e) {}
+            fail("Should fail");
+        } catch (Exception ignored) {}
         try {
             new ClusterState("cluster:badvalue");
-            assertTrue("Should fail", false);
-        } catch (Exception e) {}
+            fail("Should fail");
+        } catch (Exception ignored) {}
         try {
             new ClusterState("cluster:m");
-            assertTrue("Should fail", false);
-        } catch (Exception e) {}
+            fail("Should fail");
+        } catch (Exception ignored) {}
         try {
             new ClusterState("version:badvalue");
-            assertTrue("Should fail", false);
-        } catch (Exception e) {}
+            fail("Should fail");
+        } catch (Exception ignored) {}
         try {
             new ClusterState("distributor:badvalue");
-            assertTrue("Should fail", false);
-        } catch (Exception e) {}
+            fail("Should fail");
+        } catch (Exception ignored) {}
         try {
             new ClusterState("storage:badvalue");
-            assertTrue("Should fail", false);
-        } catch (Exception e) {}
+            fail("Should fail");
+        } catch (Exception ignored) {}
         try {
             new ClusterState("distributor:2 .3.s:d");
-            assertTrue("Should fail", false);
-        } catch (Exception e) {}
+            fail("Should fail");
+        } catch (Exception ignored) {}
         try {
             new ClusterState("storage:2 .3.s:d");
-            assertTrue("Should fail", false);
-        } catch (Exception e) {}
+            fail("Should fail");
+        } catch (Exception ignored) {}
     }
 
     @Test
diff --git a/vdslib/src/test/java/com/yahoo/vdslib/state/NodeStateTestCase.java b/vdslib/src/test/java/com/yahoo/vdslib/state/NodeStateTestCase.java
index 1ce3655b394..3eff07e80b9 100644
--- a/vdslib/src/test/java/com/yahoo/vdslib/state/NodeStateTestCase.java
+++ b/vdslib/src/test/java/com/yahoo/vdslib/state/NodeStateTestCase.java
@@ -4,11 +4,12 @@ package com.yahoo.vdslib.state;
 import org.junit.Test;
 
 import java.text.ParseException;
-import java.util.List;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotEquals;
 import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
 
 public class NodeStateTestCase {
 
@@ -56,36 +57,36 @@ public class NodeStateTestCase {
         assertEquals(ns, NodeState.deserialize(NodeType.STORAGE, ": s:m sbadkey:u bbadkey:2 cbadkey:2.0 rbadkey:2 ibadkey:0.5 tbadkey:2 mbadkey:message dbadkey:2 unknownkey:somevalue"));
         try {
             NodeState.deserialize(NodeType.STORAGE, "s:m badtokenwithoutcolon");
-            assertTrue("Should fail", false);
-        } catch (Exception e) {}
+            fail("Should fail");
+        } catch (Exception ignored) {}
         try {
             NodeState.deserialize(NodeType.STORAGE, "s:m c:badvalue");
-            assertTrue("Should fail", false);
-        } catch (Exception e) {}
+            fail("Should fail");
+        } catch (Exception ignored) {}
         try {
             NodeState.deserialize(NodeType.STORAGE, "s:m i:badvalue");
-            assertTrue("Should fail", false);
-        } catch (Exception e) {}
+            fail("Should fail");
+        } catch (Exception ignored) {}
         try {
             NodeState.deserialize(NodeType.STORAGE, "s:m t:badvalue");
-            assertTrue("Should fail", false);
-        } catch (Exception e) {}
+            fail("Should fail");
+        } catch (Exception ignored) {}
         try {
             NodeState.deserialize(NodeType.STORAGE, "s:m t:-1");
-            assertTrue("Should fail", false);
-        } catch (Exception e) {}
+            fail("Should fail");
+        } catch (Exception ignored) {}
         try {
             NodeState.deserialize(NodeType.STORAGE, "s:m d:badvalue");
-            assertTrue("Should fail", false);
-        } catch (Exception e) {}
+            fail("Should fail");
+        } catch (Exception ignored) {}
         try {
             NodeState.deserialize(NodeType.STORAGE, "s:m d.badkey:badvalue");
-            assertTrue("Should fail", false);
-        } catch (Exception e) {}
+            fail("Should fail");
+        } catch (Exception ignored) {}
         try {
             NodeState.deserialize(NodeType.STORAGE, "s:m d.1:badindex");
-            assertTrue("Should fail", false);
-        } catch (Exception e) {}
+            fail("Should fail");
+        } catch (Exception ignored) {}
 
         ns = new NodeState(NodeType.STORAGE, State.UP).setDescription("Foo bar");
         assertEquals("", ns.serialize(2, false));
@@ -127,11 +128,11 @@ public class NodeStateTestCase {
             assertTrue(ns1.similarToIgnoringInitProgress(ns4));
             assertTrue(ns2.similarToIgnoringInitProgress(ns4));
 
-            assertFalse(ns1.equals(ns2));
-            assertFalse(ns2.equals(ns3));
-            assertFalse(ns3.equals(ns4));
+            assertNotEquals(ns1, ns2);
+            assertNotEquals(ns2, ns3);
+            assertNotEquals(ns3, ns4);
 
-            assertFalse(ns1.equals("class not instance of NodeState"));
+            assertNotEquals("class not instance of NodeState", ns1);
             assertFalse(ns1.similarTo("class not instance of NodeState"));
         }
         {
@@ -139,7 +140,7 @@ public class NodeStateTestCase {
             NodeState ns2 = new NodeState(NodeType.STORAGE, State.UP).setMinUsedBits(18);
             assertTrue(ns1.similarTo(ns2));
             assertTrue(ns1.similarToIgnoringInitProgress(ns2));
-            assertFalse(ns1.equals(ns2));
+            assertNotEquals(ns1, ns2);
         }
     }
 
@@ -163,12 +164,12 @@ public class NodeStateTestCase {
     public void testValidInClusterState() {
         try{
             new NodeState(NodeType.DISTRIBUTOR, State.UNKNOWN).verifyValidInSystemState(NodeType.DISTRIBUTOR);
-            assertTrue("Should not be valid", false);
-        } catch (Exception e) {}
+            fail("Should not be valid");
+        } catch (Exception ignored) {}
         try{
             new NodeState(NodeType.DISTRIBUTOR, State.UP).setCapacity(3).verifyValidInSystemState(NodeType.DISTRIBUTOR);
-            assertTrue("Should not be valid", false);
-        } catch (Exception e) {}
+            fail("Should not be valid");
+        } catch (Exception ignored) {}
     }
 
 }
diff --git a/vdslib/src/test/java/com/yahoo/vdslib/state/NodeTest.java b/vdslib/src/test/java/com/yahoo/vdslib/state/NodeTest.java
index 971b4782ab0..e3fc0faecd5 100644
--- a/vdslib/src/test/java/com/yahoo/vdslib/state/NodeTest.java
+++ b/vdslib/src/test/java/com/yahoo/vdslib/state/NodeTest.java
@@ -5,7 +5,9 @@ import org.junit.Test;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotEquals;
 import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
 
 public class NodeTest {
 
@@ -29,23 +31,23 @@ public class NodeTest {
         assertEquals(n3, n3);
         assertEquals(n4, n4);
 
-        assertFalse(n1.equals(n2));
-        assertFalse(n1.equals(n3));
-        assertFalse(n1.equals(n4));
+        assertNotEquals(n1, n2);
+        assertNotEquals(n1, n3);
+        assertNotEquals(n1, n4);
 
-        assertFalse(n2.equals(n1));
-        assertFalse(n2.equals(n3));
-        assertFalse(n2.equals(n4));
+        assertNotEquals(n2, n1);
+        assertNotEquals(n2, n3);
+        assertNotEquals(n2, n4);
 
-        assertFalse(n3.equals(n1));
-        assertFalse(n3.equals(n2));
-        assertFalse(n3.equals(n4));
+        assertNotEquals(n3, n1);
+        assertNotEquals(n3, n2);
+        assertNotEquals(n3, n4);
 
-        assertFalse(n4.equals(n1));
-        assertFalse(n4.equals(n2));
-        assertFalse(n4.equals(n3));
+        assertNotEquals(n4, n1);
+        assertNotEquals(n4, n2);
+        assertNotEquals(n4, n3);
 
-        assertFalse(n1.equals("class not instance of Node"));
+        assertNotEquals("class not instance of Node", n1);
     }
 
     @Test
@@ -62,19 +64,19 @@ public class NodeTest {
 
         try {
             new Node("nodewithoutdot");
-            assertTrue("Method expected to throw IllegalArgumentException", false);
+            fail("Method expected to throw IllegalArgumentException");
         } catch (IllegalArgumentException e) {
             assertEquals("Not a legal node string 'nodewithoutdot'.", e.getMessage());
         }
         try {
             new Node("fleetcontroller.0");
-            assertTrue("Method expected to throw IllegalArgumentException", false);
+            fail("Method expected to throw IllegalArgumentException");
         } catch (IllegalArgumentException e) {
             assertEquals("Unknown node type 'fleetcontroller'. Legal values are 'storage' and 'distributor'.", e.getMessage());
         }
         try {
             new Node("storage.badindex");
-            assertTrue("Method expected to throw NumberFormatException", false);
+            fail("Method expected to throw NumberFormatException");
         } catch (NumberFormatException e) {
             assertEquals("For input string: \"badindex\"", e.getMessage());
         }