src/test/org/apache/nutch/util/WritableTestUtils.java

/*
 * 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.nutch.util;

import org.apache.hadoop.io.*;
import org.apache.hadoop.conf.*;
import org.junit.Assert;

public class WritableTestUtils {

  /** Utility method for testing writables. */
  public static void testWritable(Writable before) throws Exception {
    testWritable(before, null);
  }

  /** Utility method for testing writables. */
  public static void testWritable(Writable before, Configuration conf)
      throws Exception {
    Assert.assertEquals(before, writeRead(before, conf));
  }

  /** Utility method for testing writables. */
  public static Writable writeRead(Writable before, Configuration conf)
      throws Exception {

    DataOutputBuffer dob = new DataOutputBuffer();
    before.write(dob);

    DataInputBuffer dib = new DataInputBuffer();
    dib.reset(dob.getData(), dob.getLength());

    Writable after = (Writable) before.getClass().getConstructor().newInstance();
    if (conf != null) {
      ((Configurable) after).setConf(conf);
    }
    after.readFields(dib);
    return after;
  }

}