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Lucene example source code file (TestIndexWriterOnJRECrash.java)

This example Lucene source code file (TestIndexWriterOnJRECrash.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

arraylist, bufferedinputstream, exception, exception, file, file, io, ioexception, object, override, override, processbuilder, reflection, thread, util, verbose, verbose

The Lucene TestIndexWriterOnJRECrash.java source code

package org.apache.lucene.index;

 *  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.

import java.io.BufferedInputStream;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;

import org.apache.lucene.store.Directory;
import org.apache.lucene.store.MockDirectoryWrapper;
import org.apache.lucene.util.Constants;
import org.apache.lucene.util._TestUtil;

 * Runs TestNRTThreads in a separate process, crashes the JRE in the middle
 * of execution, then runs checkindex to make sure its not corrupt.
public class TestIndexWriterOnJRECrash extends TestNRTThreads {
  private File tempDir;
  public void setUp() throws Exception {
    tempDir = _TestUtil.getTempDir("jrecrash");
  public void testNRTThreads() throws Exception {
    String vendor = Constants.JAVA_VENDOR;
    assumeTrue(vendor + " JRE not supported.", 
        vendor.startsWith("Sun") || vendor.startsWith("Apple"));
    // if we are not the fork
    if (System.getProperty("tests.crashmode") == null) {
      // try up to 10 times to create an index
      for (int i = 0; i < 10; i++) {
        // if we succeeded in finding an index, we are done.
        if (checkIndexes(tempDir))
    } else {
      // we are the fork, setup a crashing thread
      final int crashTime = _TestUtil.nextInt(random, 3000, 4000);
      Thread t = new Thread() {
        public void run() {
          try {
          } catch (InterruptedException e) {}
      // run the test until we crash.
      for (int i = 0; i < 1000; i++) {
  /** fork ourselves in a new jvm. sets -Dtests.crashmode=true */
  public void forkTest() throws Exception {
    List<String> cmd = new ArrayList();
        + System.getProperty("file.separator")
        + "bin"
        + System.getProperty("file.separator")
        + "java");
    // passing NIGHTLY to this test makes it run for much longer, easier to catch it in the act...
    cmd.add("-DtempDir=" + tempDir.getPath());
    cmd.add("-Dtests.seed=" + random.nextLong() + ":" + random.nextLong());
    ProcessBuilder pb = new ProcessBuilder(cmd);
    Process p = pb.start();
    InputStream is = p.getInputStream();
    BufferedInputStream isl = new BufferedInputStream(is);
    byte buffer[] = new byte[1024];
    int len = 0;
    if (VERBOSE) System.err.println(">>> Begin subprocess output");
    while ((len = isl.read(buffer)) != -1) {
      if (VERBOSE) {
        System.err.write(buffer, 0, len);
    if (VERBOSE) System.err.println("<<< End subprocess output");
   * Recursively looks for indexes underneath <code>file,
   * and runs checkindex on them. returns true if it found any indexes.
  public boolean checkIndexes(File file) throws IOException {
    if (file.isDirectory()) {
      MockDirectoryWrapper dir = newFSDirectory(file);
      dir.setCheckIndexOnClose(false); // don't double-checkindex
      if (IndexReader.indexExists(dir)) {
        if (VERBOSE) {
          System.err.println("Checking index: " + file);
        return true;
      for (File f : file.listFiles())
        if (checkIndexes(f))
          return true;
    return false;
   * currently, this only works/tested on Sun and IBM.
  public void crashJRE() {
    try {
      Class<?> clazz = Class.forName("sun.misc.Unsafe");
      // we should use getUnsafe instead, harmony implements it, etc.
      Field field = clazz.getDeclaredField("theUnsafe");
      Object o = field.get(null);
      Method m = clazz.getMethod("putAddress", long.class, long.class);
      m.invoke(o, 0L, 0L);
    } catch (Exception e) { e.printStackTrace(); }

Other Lucene examples (source code examples)

Here is a short list of links related to this Lucene TestIndexWriterOnJRECrash.java source code file:

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