Can I get details of the call stack in Java, such as to find where a method was called from?

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Oct 13

Can I get details of the call stack in Java, such as to find where a method was called from?

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The StackTraceElement class can be used to get details about the call stack.

The following example shows how it can be used to view the call stack and determine where a method was called from.


public class WhoCalledMe
{

	public static void main(String[] args)
	{
		f();
	}

	public static void f()
	{
		g();
	}

	public static void g()
	{
		showCallStack();
		System.out.println();
		System.out.println(
			"g() was called by "+whoCalledMe());
	}

	public static String whoCalledMe()
	{
		StackTraceElement[] stackTraceElements =
			Thread.currentThread().getStackTrace();
		StackTraceElement caller = stackTraceElements[4];
	    String classname = caller.getClassName();
	    String methodName = caller.getMethodName();
	    int lineNumber = caller.getLineNumber();
		return classname+"."+methodName+":"+lineNumber;
	}

	public static void showCallStack()
	{
		StackTraceElement[] stackTraceElements =
			Thread.currentThread().getStackTrace();
		for (int i=2 ; i<stackTraceElements.length; i++)
		{
			StackTraceElement ste = stackTraceElements[i];
		    String classname = ste.getClassName();
		    String methodName = ste.getMethodName();
		    int lineNumber = ste.getLineNumber();
		    System.out.println(
		    	classname+"."+methodName+":"+lineNumber);
		}
	}
}