Author: cutting
Date: Tue Sep 18 11:25:56 2007
New Revision: 577010
URL: http://svn.apache.org/viewvc?rev=577010&view=rev
Log:
HADOOP-120. In ArrayWritable, prevent creation with null value class and
improve documentation. Contributed by Cameron Pope.
Added:
lucene/hadoop/trunk/src/test/org/apache/hadoop/io/TestArrayWritable.java
Modified:
lucene/hadoop/trunk/CHANGES.txt
lucene/hadoop/trunk/src/java/org/apache/hadoop/io/ArrayWritable.java
Modified: lucene/hadoop/trunk/CHANGES.txt
URL:
http://svn.apache.org/viewvc/lucene/hadoop/trunk/CHANGES.txt?rev=577010&r1=577009&r2=577010&view=diff
==============================================================================
--- lucene/hadoop/trunk/CHANGES.txt (original)
+++ lucene/hadoop/trunk/CHANGES.txt Tue Sep 18 11:25:56 2007
@@ -249,6 +249,9 @@
HADOOP-1878. Add space between priority links on job details
page. (Thomas Friol via cutting)
+ HADOOP-120. In ArrayWritable, prevent creation with null value
+ class, and improve documentation. (Cameron Pope via cutting)
+
Release 0.14.1 - 2007-09-04
Modified: lucene/hadoop/trunk/src/java/org/apache/hadoop/io/ArrayWritable.java
URL:
http://svn.apache.org/viewvc/lucene/hadoop/trunk/src/java/org/apache/hadoop/io/ArrayWritable.java?rev=577010&r1=577009&r2=577010&view=diff
==============================================================================
--- lucene/hadoop/trunk/src/java/org/apache/hadoop/io/ArrayWritable.java
(original)
+++ lucene/hadoop/trunk/src/java/org/apache/hadoop/io/ArrayWritable.java Tue
Sep 18 11:25:56 2007
@@ -21,16 +21,29 @@
import java.io.*;
import java.lang.reflect.Array;
-/** A Writable for arrays containing instances of a class. */
+/**
+ * A Writable for arrays containing instances of a class. The elements of this
+ * writable must all be instances of the same class. If this writable will be
+ * the input for a Reducer, you will need to create a subclass that sets the
+ * value to be of the proper type.
+ *
+ * For example:
+ * <code>
+ * public class IntArrayWritable extends ArrayWritable {
+ * public IntArrayWritable() {
+ * super(IntWritable.class);
+ * }
+ * }
+ * </code>
+ */
public class ArrayWritable implements Writable {
private Class valueClass;
private Writable[] values;
- public ArrayWritable() {
- this.valueClass = null;
- }
-
public ArrayWritable(Class valueClass) {
+ if (valueClass == null) {
+ throw new IllegalArgumentException("null valueClass");
+ }
this.valueClass = valueClass;
}
@@ -46,13 +59,6 @@
}
}
- public void setValueClass(Class valueClass) {
- if (valueClass != this.valueClass) {
- this.valueClass = valueClass;
- this.values = null;
- }
- }
-
public Class getValueClass() {
return valueClass;
}
Added: lucene/hadoop/trunk/src/test/org/apache/hadoop/io/TestArrayWritable.java
URL:
http://svn.apache.org/viewvc/lucene/hadoop/trunk/src/test/org/apache/hadoop/io/TestArrayWritable.java?rev=577010&view=auto
==============================================================================
--- lucene/hadoop/trunk/src/test/org/apache/hadoop/io/TestArrayWritable.java
(added)
+++ lucene/hadoop/trunk/src/test/org/apache/hadoop/io/TestArrayWritable.java
Tue Sep 18 11:25:56 2007
@@ -0,0 +1,64 @@
+/**
+ * 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 junit.framework.TestCase;
+
+/** Unit tests for ArrayWritable */
+public class TestArrayWritable extends TestCase {
+
+ static class TextArrayWritable extends ArrayWritable {
+ public TextArrayWritable() {
+ super(Text.class);
+ }
+ }
+
+ public TestArrayWritable(String name) {
+ super(name);
+ }
+
+ /**
+ * If valueClass is undefined, readFields should throw an exception
indicating
+ * that the field is null. Otherwise, readFields should succeed.
+ */
+ public void testThrowUndefinedValueException() throws IOException {
+ // Get a buffer containing a simple text array
+ Text[] elements = {new Text("zero"), new Text("one"), new Text("two")};
+ TextArrayWritable sourceArray = new TextArrayWritable();
+ sourceArray.set(elements);
+
+ // Write it to a normal output buffer
+ DataOutputBuffer out = new DataOutputBuffer();
+ DataInputBuffer in = new DataInputBuffer();
+ sourceArray.write(out);
+
+ // Read the output buffer with TextReadable. Since the valueClass is
defined,
+ // this should succeed
+ TextArrayWritable destArray = new TextArrayWritable();
+ in.reset(out.getData(), out.getLength());
+ destArray.readFields(in);
+ Writable[] destElements = destArray.get();
+ assertTrue(destElements.length == elements.length);
+ for (int i = 0; i < elements.length; i++) {
+ assertEquals(destElements[i],elements[i]);
+ }
+ }
+}
