好久没有使用MyEclipse10了，今天打开看了以前大学的项目，在Tomcat7中发布启动，我嚓嘞，报错：

SEVERE: Exception initializing random number generator using algorithm [SHA1PRNG]java.security.NoSuchAlgorithmException: SHA1PRNG SecureRandom not available    at sun.security.jca.GetInstance.getInstance(Unknown Source)    at java.security.SecureRandom.getInstance(Unknown Source)    at org.apache.catalina.util.SessionIdGeneratorBase.createSecureRandom(SessionIdGeneratorBase.java:210)    at org.apache.catalina.util.SessionIdGeneratorBase.getRandomBytes(SessionIdGeneratorBase.java:174)    at org.apache.catalina.util.StandardSessionIdGenerator.generateSessionId(StandardSessionIdGenerator.java:34)    at org.apache.catalina.util.SessionIdGeneratorBase.generateSessionId(SessionIdGeneratorBase.java:167)    at org.apache.catalina.util.SessionIdGeneratorBase.startInternal(SessionIdGeneratorBase.java:256)    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:145)    at org.apache.catalina.session.ManagerBase.startInternal(ManagerBase.java:714)    at org.apache.catalina.session.StandardManager.startInternal(StandardManager.java:461)    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:145)    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5643)    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:145)    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:899)    at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:875)    at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:652)    at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1260)    at org.apache.catalina.startup.HostConfig$DeployDirectory.run(HostConfig.java:2002)    at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)    at java.util.concurrent.FutureTask$Sync.innerRun(Unknown Source)    at java.util.concurrent.FutureTask.run(Unknown Source)    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)    at java.lang.Thread.run(Unknown Source)

 看到这个错误，一头雾水，从来没有见过这个错误，以为是tomcat7的缘故，又换位tomcat6，发布启动之后，我叉，有出现错误：

SEVERE: Cannot find message associated with key managerBase.digestjava.security.NoSuchAlgorithmException: MD5 MessageDigest not available    at sun.security.jca.GetInstance.getInstance(Unknown Source)    at java.security.Security.getImpl(Unknown Source)    at java.security.MessageDigest.getInstance(Unknown Source)    at org.apache.catalina.session.ManagerBase.getDigest(ManagerBase.java:478)    at org.apache.catalina.session.ManagerBase.generateSessionId(ManagerBase.java:1220)    at org.apache.catalina.session.StandardManager.start(StandardManager.java:636)    at org.apache.catalina.core.ContainerBase.setManager(ContainerBase.java:448)    at org.apache.catalina.core.StandardContext.start(StandardContext.java:4665)    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:803)    at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:780)    at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:583)    at org.apache.catalina.startup.HostConfig.deployDescriptor(HostConfig.java:676)    at org.apache.catalina.startup.HostConfig.deployDescriptors(HostConfig.java:602)    at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:503)    at org.apache.catalina.startup.HostConfig.start(HostConfig.java:1322)    at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:325)    at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:142)    at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1069)    at org.apache.catalina.core.StandardHost.start(StandardHost.java:822)    at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1061)    at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:463)    at org.apache.catalina.core.StandardService.start(StandardService.java:525)    at org.apache.catalina.core.StandardServer.start(StandardServer.java:759)    at org.apache.catalina.startup.Catalina.start(Catalina.java:595)    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)    at java.lang.reflect.Method.invoke(Unknown Source)    at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:289)    at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:414)

然后，干脆就去掉项目，单独的启动tomcat6 和 tomcat7，我叉，还是一样的错误，这说明 原来的项目是没有问题的，那就是 MyEclipse10 和 tomcat的原因了。

因为tomcat6和tomcat7 依赖的是 JDK7，所以报了这个错，原因还不清楚，但是在eclipse中 tomcat6 和 tomcat7 是可以使用JDK7的。于是，把tomcat6 和 tomcat7 依赖的JDK7换为 MyEclipse10自带的JDK6，重新启动tomcat，我叉，真的就没有问题了。