Java Thread getStackTrace() Method

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Description

The Java Thread getStackTrace() method returns an array of stack trace elements representing the stack dump of this thread.This 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.

Declaration

Following is the declaration for java.lang.Thread.getStackTrace() method

public StackTraceElement[] getStackTrace()

Parameters

NA

Return Value

This method returns an array of StackTraceElement, each represents one stack frame.

Exception

SecurityException − if a security manager exists and its checkPermission method doesn't allow getting the stack trace of thread.

Example: Getting StackTrace in Single Threaded Environment

The following example shows the usage of Java Thread getStackTrace() method. In this program, we've created a class ThreadDemo. In main method,ThreadDemo instace method getStackTrace() is called which in turn retrieves the currentThread and using getStackTrace() get the stack trace and print the classname.

package com.tutorialspoint;

public class ThreadDemo {

   public static void main(String[] args) {
      new ThreadDemo().getStackTrace();
   }

   public void getStackTrace() {
      System.out.println(Thread.currentThread().getStackTrace()[3].getClassName());
   }
} 

Output

Let us compile and run the above program, this will produce the following result −

com.tutorialspoint.ThreadDemo

Example: Getting StackTrace in Multi-Threaded Environment

The following example shows the usage of Java Thread activeCount() method. In this program, we've created a thread class ThreadDemo by implementing Runnable interface. In constructor, current thread is retrieved using currentThread() method and a new thread is created using new Thread. Using getStackTrace() get the stack trace and print the classname.

package com.tutorialspoint;

public class ThreadDemo implements Runnable {

   ThreadDemo() {     
      // thread created
      Thread t = new Thread(this, "Admin Thread");
      
      // this will call run() function
      t.start();

	  System.out.println(Thread.currentThread().getStackTrace()[2].getClassName());
   }

   public void run() {
      System.out.println("This is run() method");
   }

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

Output

Let us compile and run the above program, this will produce the following result −

This is run() method
com.tutorialspoint.ThreadDemo