HADOOP-3180. Add name of missing class to WritableName.getClass

IOException. (Pete Wyckoff via omalley)


git-svn-id: https://svn.apache.org/repos/asf/hadoop/core/trunk@700253 13f79535-47bb-0310-9956-ffa450edef68

CHANGES.txt

@@ -17,6 +17,9 @@ Trunk (unreleased changes)
     HADOOP-4244. Change test-patch.sh to check Eclipse classpath no matter
     it is run by Hudson or not. (szetszwo)
 
+    HADOOP-3180. Add name of missing class to WritableName.getClass 
+    IOException. (Pete Wyckoff via omalley)
+
   OPTIMIZATIONS
 
   BUG FIXES

src/core/org/apache/hadoop/io/WritableName.java

@@ -70,7 +70,7 @@ public class WritableName {
     try {
       return conf.getClassByName(name);
     } catch (ClassNotFoundException e) {
-      IOException newE = new IOException("WritableName can't load class");
+      IOException newE = new IOException("WritableName can't load class: " + name);
       newE.initCause(e);
       throw newE;
     }

src/test/org/apache/hadoop/io/TestWritableName.java

@@ -0,0 +1,107 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.hadoop.io;
+
+import java.io.*;
+import java.util.Random;
+
+import org.apache.hadoop.conf.Configurable;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.util.ReflectionUtils;
+
+import junit.framework.TestCase;
+
+/** Unit tests for WritableName. */
+public class TestWritableName extends TestCase {
+  public TestWritableName(String name) { 
+    super(name); 
+  }
+
+  /** Example class used in test cases below. */
+  public static class SimpleWritable implements Writable {
+    private static final Random RANDOM = new Random();
+
+    int state = RANDOM.nextInt();
+
+    public void write(DataOutput out) throws IOException {
+      out.writeInt(state);
+    }
+
+    public void readFields(DataInput in) throws IOException {
+      this.state = in.readInt();
+    }
+
+    public static SimpleWritable read(DataInput in) throws IOException {
+      SimpleWritable result = new SimpleWritable();
+      result.readFields(in);
+      return result;
+    }
+
+    /** Required by test code, below. */
+    public boolean equals(Object o) {
+      if (!(o instanceof SimpleWritable))
+        return false;
+      SimpleWritable other = (SimpleWritable)o;
+      return this.state == other.state;
+    }
+  }
+
+  private static final String testName = "mystring";
+
+  public void testGoodName() throws Exception {
+    Configuration conf = new Configuration();
+    Class<?> test = WritableName.getClass("long",conf);
+    assertTrue(test != null);
+  }
+
+  public void testSetName() throws Exception {
+    Configuration conf = new Configuration();
+    WritableName.setName(SimpleWritable.class, testName);
+
+    Class<?> test = WritableName.getClass(testName,conf);
+    assertTrue(test.equals(SimpleWritable.class));
+  }
+
+
+  public void testAddName() throws Exception {
+    Configuration conf = new Configuration();
+    String altName = testName + ".alt";
+
+    WritableName.addName(SimpleWritable.class, altName);
+
+    Class<?> test = WritableName.getClass(altName, conf);
+    assertTrue(test.equals(SimpleWritable.class));
+
+    // check original name still works
+    test = WritableName.getClass(testName, conf);
+    assertTrue(test.equals(SimpleWritable.class));
+
+  }
+
+  public void testBadName() throws Exception {
+    Configuration conf = new Configuration();
+    try {
+      Class<?> test = WritableName.getClass("unknown_junk",conf);
+      assertTrue(false);
+    } catch(IOException e) {
+      assertTrue(e.getMessage().matches(".*unknown_junk.*"));
+    }
+  }
+	
+}