java内存溢出异常解决方案

文章关键字:|java|内存|溢出|异常|方案|

  下面是具体的代码实现

  package com.free;

  import java.io.File;

  import java.io.FileInputStream;

  import java.io.FileNotFoundException;

  import java.io.FileOutputStream;

  import java.io.IOException;

  import java.io.ObjectInputStream;

  import java.io.ObjectOutputStream;

  import java.math.BigInteger;

  import java.util.ArrayList;

  import java.util.List;

  /**

  * @author free

  * springcomingagain@gmail.com

  */

  public class OutMemorySolution {

  /***

  * Change JVM Arguments

  * 调整 虚拟机参数

  *
  * First Try
  *
  * -Xloggc:gc.log
  * -Xms256M
  * -Xmx256M
  *
  * throw java.lang.OutOfMemoryError: Java heap space
  *
  *
  * Second Try
  *
  * -Xloggc:gc.log
  * -Xms512M
  * -Xmx512M
  *
  *
  */

    public static void changeJVMArguments() {

      long startTime = System.currentTimeMillis();

      System.out.println("Start : " + startTime);

      List list = new ArrayList(0);

      for (int i = 0; i < 5000000; i++) {

        list.add(new BigInteger("1000000"));

      }

      long endTime = System.currentTimeMillis();

      System.out.println("End.. : " + endTime + " Cost : " + (endTime - startTime));

    }

  /**

  * Release Object Immediate

  * 立即 释放无用的对象

  *


  *
  *  Release Object
  *
  *
  * //First Release Object
  * BigInteger temp1 = null;
  * for (int i = 0; i < 1200000; i++) {
  *     temp1 = array1[i];
  *     temp1 = null;
  *     array1[i] = null;
  * }
  * array1 = null;
  * ...
  * //Second Release Object
  * temp1 = null;
  * for (int i = 0; i < 1200000; i++) {
  *     temp1 = array2[i];
  *     temp1 = null;
  *     array2[i] = null;
  * }
  * array2 = null;
  *
  *
  */

    public static void releaseObjectImmediate() {

      long startTime = System.currentTimeMillis();

      System.out.println("First Start : " + startTime);

      BigInteger[] array1 = new BigInteger[1200000];

      for (int i = 0; i < 1200000; i++) {

        array1[i] = new BigInteger("10000000");

      }

      // First Release Object

      BigInteger temp1 = null;

      for (int i = 0; i < 1200000; i++) {

        temp1 = array1[i];

        temp1 = null;

        array1[i] = null;

      }

      array1 = null;

      long endTime = System.currentTimeMillis();

      System.out.println("First End.. : " + endTime + " Cost : " + (endTime - startTime));

      // do something start

      // do something end..

      startTime = System.currentTimeMillis();

      System.out.println("Second Start : " + startTime);

      BigInteger[] array2 = new BigInteger[1200000];

      for (int i = 0; i < 1200000; i++) {

        array2[i] = new BigInteger("10000000");

      }

      // Second Release Object

      temp1 = null;

      for (int i = 0; i < 1200000; i++) {

        temp1 = array2[i];

        temp1 = null;

        array2[i] = null;

      }

      array2 = null;

      endTime = System.currentTimeMillis();

      System.out.println("Second End.. : " + endTime + " Cost : " + (endTime - startTime));

    }



原文地址:http://www.evget.com/zh-CN/Info/ReadInfo.aspx?id=9280

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