Avoid using temporary arrays on frequently called code. Just do what you need.

Also chain StringBuilder.append for readability and unify on simple ternary operator.

3 files changed, 30 insertions, 57 deletions

diff --git a/component/src/main/java/com/yahoo/component/ComponentId.java b/component/src/main/java/com/yahoo/component/ComponentId.java
index e1e1b43c08a..05c710e3fc1 100644
--- a/component/src/main/java/com/yahoo/component/ComponentId.java
+++ b/component/src/main/java/com/yahoo/component/ComponentId.java
@@ -87,9 +87,9 @@ public final class ComponentId implements Comparable<ComponentId> {
         if (namespace == null) {
             return this;
         } else {
-            ComponentId newNamespace = getNamespace() == null ?
-                    namespace :
-                    getNamespace().nestInNamespace(namespace);
+            ComponentId newNamespace = (getNamespace() == null)
+                    ? namespace
+                    : getNamespace().nestInNamespace(namespace);
             return new ComponentId(getName(), getVersion(), newNamespace);
         }
     }
diff --git a/component/src/main/java/com/yahoo/component/SpecSplitter.java b/component/src/main/java/com/yahoo/component/SpecSplitter.java
index 07d5c573140..6bc4bed4094 100644
--- a/component/src/main/java/com/yahoo/component/SpecSplitter.java
+++ b/component/src/main/java/com/yahoo/component/SpecSplitter.java
@@ -1,9 +1,6 @@
 // Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.component;
 
-import java.util.Arrays;
-import java.util.List;
-
 /**
  * Splits and component id or component specification string into their constituent parts.
  * 
@@ -16,30 +13,28 @@ class SpecSplitter {
     final ComponentId namespace;
 
     SpecSplitter(String spec) {
-        List<String> idAndNamespace = splitFirst(spec, '@');
-        List<String> nameAndVersion = splitFirst(idAndNamespace.get(0), ':');
-
-        name = nameAndVersion.get(0);
-        version = second(nameAndVersion);
-        namespace = ComponentId.fromString(second(idAndNamespace));
-    }
-
-    private String second(List<String> components) {
-        return components.size() == 2?
-                components.get(1) :
-                null;
-    }
+        int indexOfAlpha = spec.indexOf('@');
+        String nameAndVersion = spec;
+        if (indexOfAlpha != -1) {
+            if (indexOfAlpha == spec.length() - 1) {
+                throw new RuntimeException("Expected characters after '@'");
+            }
+            nameAndVersion = spec.substring(0, indexOfAlpha);
+            namespace = ComponentId.fromString(spec.substring(indexOfAlpha + 1));
+        } else {
+            namespace = null;
+        }
 
-    private static List<String> splitFirst(String string, char c) {
-        int index = string.indexOf(c);
-        if (index != -1) {
-            if (index == string.length() - 1) {
-                throw new RuntimeException("Expected characters after '" + c + "'");
+        int indexOfColon = nameAndVersion.indexOf(':');
+        if (indexOfColon != -1) {
+            if (indexOfColon == nameAndVersion.length() - 1) {
+                throw new RuntimeException("Expected characters after ':'");
             }
-            return Arrays.asList(string.substring(0, index),
-                    string.substring(index + 1));
+            name = nameAndVersion.substring(0, indexOfColon);
+            version = nameAndVersion.substring(indexOfColon+1);
         } else {
-            return Arrays.asList(string, null);
+            name = nameAndVersion;
+            version = null;
         }
     }
 
diff --git a/component/src/main/java/com/yahoo/component/Version.java b/component/src/main/java/com/yahoo/component/Version.java
index e0ed3f03f7e..7c98af55be3 100644
--- a/component/src/main/java/com/yahoo/component/Version.java
+++ b/component/src/main/java/com/yahoo/component/Version.java
@@ -193,11 +193,7 @@ public final class Version implements Comparable<Version> {
 
     /** Returns new Version(versionString), or Version.emptyVersion if the input string is null or "" */
     public static Version fromString(String versionString) {
-        if (versionString == null) {
-            return emptyVersion;
-        } else {
-            return new Version(versionString);
-        }
+        return (versionString == null) ? emptyVersion :new Version(versionString);
     }
 
     /**
@@ -225,23 +221,11 @@ public final class Version implements Comparable<Version> {
     private String toStringValue() {
         StringBuilder b = new StringBuilder();
         if (! qualifier.isEmpty()) {
-            b.append(getMajor());
-            b.append(".");
-            b.append(getMinor());
-            b.append(".");
-            b.append(getMicro());
-            b.append(".");
-            b.append(qualifier);
+            b.append(getMajor()).append(".").append(getMinor()).append(".").append(getMicro()).append(".").append(qualifier);
         } else if (getMicro() != 0) {
-            b.append(getMajor());
-            b.append(".");
-            b.append(getMinor());
-            b.append(".");
-            b.append(getMicro());
+            b.append(getMajor()).append(".").append(getMinor()).append(".").append(getMicro());
         } else if (getMinor() != 0) {
-            b.append(getMajor());
-            b.append(".");
-            b.append(getMinor());
+            b.append(getMajor()).append(".").append(getMinor());
         } else if (getMajor() != 0) {
             b.append(getMajor());
         }
@@ -256,11 +240,7 @@ public final class Version implements Comparable<Version> {
      */
     public String toFullString() {
         StringBuilder b = new StringBuilder();
-        b.append(getMajor());
-        b.append(".");
-        b.append(getMinor());
-        b.append(".");
-        b.append(getMicro());
+        b.append(getMajor()).append(".").append(getMinor()).append(".").append(getMicro());
 
         if (! qualifier.isEmpty()) {
             b.append(".");
@@ -382,11 +362,9 @@ public final class Version implements Comparable<Version> {
 
     /** Creates a version specification that only matches this version */
     public VersionSpecification toSpecification() {
-        if (this == emptyVersion)
-            return VersionSpecification.emptyVersionSpecification;
-        else {
-            return new VersionSpecification(getMajor(), getMinor(), getMicro(), getQualifier());
-        }
+        return (this == emptyVersion)
+                ? VersionSpecification.emptyVersionSpecification
+                : new VersionSpecification(getMajor(), getMinor(), getMicro(), getQualifier());
     }
 
 }