PermGen space错误解决方法，java.lang.OutOfMemoryError

转自：
http://www.cnblogs.com/xwdreamer/archive/2011/11/21/2296930.html

1.报错：
Exception in thread "DispatcherThread" java.lang.OutOfMemoryError: PermGen space
Exception in thread "ContainerBackgroundProcessor[StandardEngine[Catalina]]" java.lang.OutOfMemoryError: PermGen space
Exception in thread "State Saver" java.lang.OutOfMemoryError: PermGen space
Exception in thread "AWT-Windows" java.lang.OutOfMemoryError: OutOfMemoryError

2.原因：
PermGen space的全称是Permanent Generation space,是指内存的永久保存区域,这块内存主要是被JVM存放Class和Meta信息的,Class在被Loader时就会被放到PermGen space中,它和存放类实例(Instance)的Heap区域不同,GC(Garbage Collection)不会在主程序运行期对PermGen space进行清理，所以如果你的应用中有很多CLASS的话,就很可能出现PermGen space错误,这种错误常见在web服务器对JSP进行pre compile的时候。如果你的WEB APP下都用了大量的第三方jar, 其大小超过了jvm默认的大小(4M)那么就会产生此错误信息了。


3.解决方法1：
手动设置MaxPermSize大小，如果是linux系统，修改TOMCAT_HOME/bin/catalina.sh，如果是windows系统，修改TOMCAT_HOME/bin/catalina.bat，
在“echo "Using CATALINA_BASE: $CATALINA_BASE"”上面加入以下行：
JAVA_OPTS="-server -XX:PermSize=64M -XX:MaxPermSize=128m
建议：将相同的第三方jar文件移置到tomcat/shared/lib目录下，这样可以达到减少jar 文档重复占用内存的目的。

4.解决方法2
修改eclipse.ini文件，修改如下：


-vmargs
-Dosgi.requiredJavaVersion=1.5
-Xms128m
-Xmx512m
-XX:PermSize=64M
-XX:MaxPermSize=128M如果还报错，可以考虑如下修改


-vmargs
-Dosgi.requiredJavaVersion=1.5
-Xms512m
-Xmx1024m
-XX:PermSize=256M
-XX:MaxPermSize=512M


报错：
2011-11-21 21:10:46 org.apache.catalina.loader.WebappClassLoader clearReferencesJdbc
严重: The web application [/Application] registered the JDBC driver [com.mysql.jdbc.Driver] but failed to unregister it when the web application was stopped. To prevent a memory leak, the JDBC Driver has been forcibly unregistered.
2011-11-21 21:10:46 org.apache.catalina.loader.WebappClassLoader clearReferencesThreads
严重: The web application [/Application] appears to have started a thread named [MySQL Statement Cancellation Timer] but has failed to stop it. This is very likely to create a memory leak.
2011-11-21 21:10:46 org.apache.catalina.loader.WebappClassLoader clearReferencesThreads
严重: The web application [/Application] appears to have started a thread named [AWT-Windows] but has failed to stop it. This is very likely to create a memory leak.
2011-11-21 21:10:46 org.apache.catalina.loader.WebappClassLoader clearReferencesThreads
严重: The web application [/Application] appears to have started a thread named [Thread-14] but has failed to stop it. This is very likely to create a memory leak.
2011-11-21 21:10:46 org.apache.catalina.loader.WebappClassLoader clearThreadLocalMap
严重: The web application [/Application] created a ThreadLocal with key of type [net.sf.json.AbstractJSON$1] (value [net.sf.json.AbstractJSON$1@3661eeb]) and a value of type [java.util.HashSet] (value [[]]) but failed to remove it when the web application was stopped. This is very likely to create a memory leak.
2011-11-21 21:10:50 org.apache.catalina.core.ApplicationContext log
信息: Initializing Spring FrameworkServlet 'Dispatcher'修改catalina.bat

添加
JAVA_OPTS="-Djava.awt.headless=true -Dfile.encoding=UTF-8
-server -Xms1536m -Xmx1536m
-XX:NewSize=256m -XX:MaxNewSize=256m -XX:PermSize=256m
-XX:MaxPermSize=256m -XX:+DisableExplicitGC"


样例
#   JSSE_HOME       (Optional) May point at your Java Secure Sockets Extension
#                   (JSSE) installation, whose JAR files will be added to the
#                   system class path used to start Tomcat.
#
#   CATALINA_PID    (Optional) Path of the file which should contains the pid
#                   of catalina startup java process, when start (fork) is used
#
# $Id: catalina.sh 609438 2008-01-06 22:14:28Z markt $
# -----------------------------------------------------------------------------

JAVA_OPTS="-Djava.awt.headless=true -Dfile.encoding=UTF-8 -server -Xms1536m
-Xmx1536m -XX:NewSize=256m -XX:MaxNewSize=256m -XX:PermSize=256m
-XX:MaxPermSize=256m -XX:+DisableExplicitGC"


# OS specific support.  $var _must_ be set to either true or false.
cygwin=false
os400=false
darwin=false
case "`uname`" in
CYGWIN*) cygwin=true;;
OS400*) os400=true;;
Darwin*) darwin=true;;
esac

# resolve links - $0 may be a softlink
PRG="$0"


具体参数根据自己机器情况而定
JAVA_OPTS="-Djava.awt.headless=true -Dfile.encoding=UTF-8 -server -Xms512m
-Xmx512m -XX:NewSize=256m -XX:MaxNewSize=256m -XX:PermSize=256m
-XX:MaxPermSize=256m -XX:+DisableExplicitGC"