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Lucene example source code file (TestSetOnce.java)

This example Lucene source code file (TestSetOnce.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - Lucene tags/keywords

exception, exception, integer, integer, interruptedexception, override, rand, setonce, setonce, setoncethread, setoncethread, test, testsetonce, thread, util

The Lucene TestSetOnce.java source code

package org.apache.lucene.util;

 * 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,
 * See the License for the specific language governing permissions and
 * limitations under the License.

import java.util.Random;

import org.apache.lucene.util.SetOnce.AlreadySetException;
import org.junit.Test;

public class TestSetOnce extends LuceneTestCase {

  private static final class SetOnceThread extends Thread {
    SetOnce<Integer> set;
    boolean success = false;
    final Random RAND;
    public SetOnceThread(Random random) {
      RAND = new Random(random.nextLong());
    public void run() {
      try {
        sleep(RAND.nextInt(10)); // sleep for a short time
        set.set(new Integer(Integer.parseInt(getName().substring(2))));
        success = true;
      } catch (InterruptedException e) {
        // ignore
      } catch (RuntimeException e) {
        // TODO: change exception type
        // expected.
        success = false;
  public void testEmptyCtor() throws Exception {
    SetOnce<Integer> set = new SetOnce();
  public void testSettingCtor() throws Exception {
    SetOnce<Integer> set = new SetOnce(new Integer(5));
    assertEquals(5, set.get().intValue());
    set.set(new Integer(7));
  public void testSetOnce() throws Exception {
    SetOnce<Integer> set = new SetOnce();
    set.set(new Integer(5));
    assertEquals(5, set.get().intValue());
    set.set(new Integer(7));
  public void testSetMultiThreaded() throws Exception {
    final SetOnce<Integer> set = new SetOnce();
    SetOnceThread[] threads = new SetOnceThread[10];
    for (int i = 0; i < threads.length; i++) {
      threads[i] = new SetOnceThread(random);
      threads[i].setName("t-" + (i+1));
      threads[i].set = set;
    for (Thread t : threads) {

    for (Thread t : threads) {
    for (SetOnceThread t : threads) {
      if (t.success) {
        int expectedVal = Integer.parseInt(t.getName().substring(2));
        assertEquals("thread " + t.getName(), expectedVal, t.set.get().intValue());

Other Lucene examples (source code examples)

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