| kTraceElement = false;
private static Method getStackTrace = null;
private static Method getClassName = null;
private static Method getFileName = null;
private static Method getMethodName = null;
private static Method getLineNumber = null;
…. // 以下代码省略
可以看到，Log4J 1.3仍然兼容JDK1.3，而且为JDK1.4也做了相应的优化。
Java线程运行栈信息的获取(4)
时间:2011-02-13
五、JDK1.5的Thread Stack Trace
JDK1.5在Thread类里面引入了getStackTrace()和getAllStackTraces()两个方法。这下子，我们不用 (new Throwable()).getStackTrace ();可以调用
Thread.getCurrentThread().getStackTrace()来获得当前线程的运行栈信息。不仅如此，只要权限允许，还可以获得其它线程的运行栈信息。
/**
* Returns an array of stack trace elements representing the stack dump
* of this thread. This method will return a zero-length array if
* this thread has not started or has terminated.
* If the returned array is of non-zero length then the first element of
* the array represents the top of the stack, which is the most recent
* method invocation in the sequence. The last element of the array
* represents the bottom of the stack, which is the least recent method
* invocation in the sequence.
*
*
If there is a security manager, and this thread is not
* the current thread, then the security managers
* checkPermissionmethod is called with a
* RuntimePermission("getStackTrace")permission
* to see if its ok to get the stack trace.
*
*
Some virtual machines may, under some circumstances, omit one
* or more stack frames from the stack trace. In the extreme case,
* a virtual machine that has no stack trace information concerning
* this thread is permitted to return a zero-length array from this
* method.
*
* @return an array of StackTraceElement,
* each represents one stack frame.
*
* @since 1.5
*/
public StackTraceElement[] getStackTrace() {
if (this != Thread.currentThread()) {
// check for getStackTrace permission
SecurityManager security = System.getSecurityManager();
if (security != null) {
security.checkPermission(
SecurityConstants.GET_STACK_TRACE_PERMISSION);
}
}
if (!isAlive()) {
return EMPTY_STACK_TRACE;
}
Thread[] threads = new Thread[1];
threads[0] = this;
StackTraceElement[][] result = dumpThreads(threads);
return result[0];
}
/**
* Returns a map of stack traces for all live threads.
*
* @since 1.5
*/
public static Map getAllStackTraces() {
// check for getStackTrace permission
// Get a snapshot of the list of all threads
}
六、总结
从总的发展趋势来看，JDK不仅提供越来越多、越来越强的功能，而且暴露给用户的控制方法越来越多，越来越强大。
文章来源:http://blog.csdn.net/buaawhl/archive/2005/01/18/257653.aspx |
