有时会遇到一个问题，系统运行时忽然退出，怀疑执行了System.exit方法，但是无法排查是哪里调用。可通过java的SecurityManager机制来进行检查。
实现一个继承SecurityManager的子类，重写checkExit方法，并通过 -Djava.security.manager设置，就可监测到哪里执行了System.exit方法。
如下列代码，将执行了System.exit方法打印出来
public class ExitPRintSecurityManager extends SecurityManager { private final int runtimeStackIndex = 3; @Override public void checkExit(int paramInt) { String exitName = "Runtime.exit"; StackTraceElement[] stack = Thread.currentThread().getStackTrace(); if (stack.length > runtimeStackIndex) { int sourceIndex = runtimeStackIndex; StackTraceElement source = stack[sourceIndex]; if ("java.lang.System".equals(source.getClassName()) && "exit".equals(source.getMethodName())) { source = stack[++sourceIndex]; exitName = "System.exit"; } System.out.println(exitName + " in " + source); System.out.println("Stack trace as follows:"); printStack(sourceIndex, stack); } else { System.out.println("Can not print System.exit"); } } private void printStack(int sourceIndex, StackTraceElement[] stack){ for (int i = sourceIndex - 1; i < stack.length; i++) { System.out.println(" " + stack[i]); } } @Override public void checkPermission(Permission perm, Object context) { // allow anything. } @Override public void checkPermission(Permission paramPermission) { // allow anything. }}新闻热点
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