Provide a (non-working) encoder by default

1 files changed, 48 insertions, 0 deletions

diff --git a/container-core/src/main/java/com/yahoo/language/provider/DefaultEncoderProvider.java b/container-core/src/main/java/com/yahoo/language/provider/DefaultEncoderProvider.java
new file mode 100644
index 00000000000..9b07ee55bd8
--- /dev/null
+++ b/container-core/src/main/java/com/yahoo/language/provider/DefaultEncoderProvider.java
@@ -0,0 +1,48 @@
+// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.language.provider;
+
+import com.google.inject.Inject;
+import com.yahoo.container.di.componentgraph.Provider;
+import com.yahoo.language.Language;
+import com.yahoo.language.process.Encoder;
+import com.yahoo.tensor.Tensor;
+import com.yahoo.tensor.TensorType;
+
+import java.util.List;
+
+/**
+ * Provides the default encoder implementation if no encoder component has been explicitly configured
+ * (dependency injection will fallback to providers if no components of the requested type is found).
+ *
+ * @author bratseth
+ */
+@SuppressWarnings("unused") // Injected
+public class DefaultEncoderProvider implements Provider<Encoder> {
+
+    // Use lazy initialization to avoid expensive (memory-wise) instantiation
+    private static final Encoder failingEncoder = new FailingEncoder();
+
+    @Inject
+    public DefaultEncoderProvider() { }
+
+    @Override
+    public Encoder get() { return failingEncoder; }
+
+    @Override
+    public void deconstruct() {}
+
+    public static class FailingEncoder implements Encoder {
+
+        @Override
+        public List<Integer> encode(String text, Language language) {
+            throw new IllegalStateException("No encoder has been configured");
+        }
+
+        @Override
+        public Tensor encode(String text, Language language, TensorType tensorType) {
+            throw new IllegalStateException("No encoder has been configured");
+        }
+
+    }
+
+}