我正在开发一个由 Struts、Spring 和 Hibernate 组成的 Java EE Web 应用程序。在那里，我反复遇到以下异常（每天至少一次）。
例外 1：
Exception in thread "Timer-0" java.lang.OutOfMemoryError: Java heap space
at java.util.LinkedHashMap.createEntry(LinkedHashMap.java:424)
at java.util.LinkedHashMap.addEntry(LinkedHashMap.java:406)
at java.util.HashMap.put(HashMap.java:385)
at sun.util.resources.OpenListResourceBundle.loadLookup(OpenListResourceBundle.java:118)
at sun.util.resources.OpenListResourceBundle.loadLookupTablesIfNecessary(OpenListResourceBundle.java:97)
at sun.util.resources.OpenListResourceBundle.handleGetObject(OpenListResourceBundle.java:58)
at sun.util.resources.TimeZoneNamesBundle.handleGetObject(TimeZoneNamesBundle.java:59)
at java.util.ResourceBundle.getObject(ResourceBundle.java:368)
at java.util.ResourceBundle.getObject(ResourceBundle.java:371)
at java.util.ResourceBundle.getStringArray(ResourceBundle.java:351)
at sun.util.TimeZoneNameUtility.retrieveDisplayNames(TimeZoneNameUtility.java:100)
at sun.util.TimeZoneNameUtility.retrieveDisplayNames(TimeZoneNameUtility.java:81)
at java.util.TimeZone.getDisplayNames(TimeZone.java:399)
at java.util.TimeZone.getDisplayName(TimeZone.java:350)
at java.text.SimpleDateFormat.subFormat(SimpleDateFormat.java:1110)
at java.text.SimpleDateFormat.format(SimpleDateFormat.java:899)
at java.text.SimpleDateFormat.format(SimpleDateFormat.java:869)
at java.text.DateFormat.format(DateFormat.java:316)
at org.apache.log4j.helpers.PatternParser$DatePatternConverter.convert(PatternParser.java:443)
at org.apache.log4j.helpers.PatternConverter.format(PatternConverter.java:65)
at org.apache.log4j.PatternLayout.format(PatternLayout.java:506)
at org.apache.log4j.WriterAppender.subAppend(WriterAppender.java:310)
at org.apache.log4j.DailyRollingFileAppender.subAppend(DailyRollingFileAppender.java:369)
at org.apache.log4j.WriterAppender.append(WriterAppender.java:162)
at org.apache.log4j.AppenderSkeleton.doAppend(AppenderSkeleton.java:251)
at org.apache.log4j.helpers.AppenderAttachableImpl.appendLoopOnAppenders(AppenderAttachableImpl.java:66)
at org.apache.log4j.Category.callAppenders(Category.java:206)
at org.apache.log4j.Category.forcedLog(Category.java:391)
at org.apache.log4j.Category.log(Category.java:856)
at com.mchange.v2.log.log4j.Log4jMLog$Log4jMLogger.log(Log4jMLog.java:161)
at com.mchange.v2.log.log4j.Log4jMLog$Log4jMLogger.warning(Log4jMLog.java:221)
at com.mchange.v2.async.ThreadPoolAsynchronousRunner$DeadlockDetector.run(ThreadPoolAsynchronousRunner.java:624)
例外 2：
Exception in thread "com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread-#1" java.lang.OutOfMemoryError: GC overhead limit exceeded
at java.util.HashMap.addEntry(HashMap.java:753)
at java.util.HashMap.put(HashMap.java:385)
at java.util.HashSet.add(HashSet.java:200)
at com.mchange.v2.c3p0.util.ConnectionEventSupport.addConnectionEventListener(ConnectionEventSupport.java:39)
at com.mchange.v2.c3p0.impl.NewPooledConnection.addConnectionEventListener(NewPooledConnection.java:237)
at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.refurbishResourceOnCheckin(C3P0PooledConnectionPool.java:292)
at com.mchange.v2.resourcepool.BasicResourcePool.attemptRefurbishResourceOnCheckin(BasicResourcePool.java:1606)
at com.mchange.v2.resourcepool.BasicResourcePool.access$200(BasicResourcePool.java:32)
at com.mchange.v2.resourcepool.BasicResourcePool$1RefurbishCheckinResourceTask.run(BasicResourcePool.java:1228)
at com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:547)
Exception in thread "com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread-#4" java.lang.OutOfMemoryError: GC overhead limit exceeded
Exception in thread "Task-Thread-for-com.mchange.v2.async.ThreadPerTaskAsynchronousRunner@6c8bb765" java.lang.OutOfMemoryError: GC overhead limit exceeded
Exception in thread "com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread-#3" java.lang.OutOfMemoryError: GC overhead limit exceeded
Exception in thread "com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread-#2" java.lang.OutOfMemoryError: GC overhead limit exceeded
Exception in thread "Task-Thread-for-com.mchange.v2.async.ThreadPerTaskAsynchronousRunner@6c8bb765" java.lang.OutOfMemoryError: GC overhead limit exceeded
Exception in thread "Task-Thread-for-com.mchange.v2.async.ThreadPerTaskAsynchronousRunner@6c8bb765" java.lang.OutOfMemoryError: GC overhead limit exceeded
Exception in thread "Timer-0" java.lang.OutOfMemoryError: Java heap space
Exception in thread ""http-bio-8080"-exec-2" java.lang.OutOfMemoryError: Java heap space
Exception in thread ""http-bio-8443"-Acceptor-0" java.lang.OutOfMemoryError: Java heap space
Exception in thread ""http-bio-8080"-exec-3" java.lang.OutOfMemoryError: Java heap space
Exception in thread "com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread-#4" java.lang.OutOfMemoryError: GC overhead limit exceeded
这是我的配置：
-server -Xms2048m -Xmx2048m
-XX:NewSize=1024m -XX:MaxNewSize=1024m -XX:PermSize=512m
-XX:MaxPermSize=1024m -XX:+DisableExplicitGC"
谁能指出我是否因为这种配置或其他任何原因而出现此异常？
我知道我的代码中存在一些问题，但我如何预测找出这些问题？我尝试过 Eclipse MAT 来分析内存转储，但没有任何想法。
我已经尝试为此增加内存，但除了减少此异常的频率外，它并没有太大帮助。
请帮忙。提前致谢。