Extract information about current method in Java

Say you wish to get some simple information about the currently running function in your Java program. The stacktrace of the current thread can help you find that.

Here’s a simple snippet to print the class name, the file name, the line number and the method name:

public class Person
{
    public void sayHello(int homeManyTimes)
    {
        for (int i = 0; i < homeManyTimes; i++)
        {
            System.out.println("Hello!");
        }
        StackTraceElement[] stackTrace = Thread.currentThread().getStackTrace();
        StackTraceElement currentStackTrance = stackTrace[1];
        System.out.println(currentStackTrance.getClassName());
        System.out.println(currentStackTrance.getFileName());
        System.out.println(currentStackTrance.getLineNumber());
        System.out.println(currentStackTrance.getMethodName());
    }
}

If you call the sayHello function…

Person person = new Person();
person.sayHello(10);

…then you might get an output similar to the following:

com.mycompany.domainobjects.Person
Person.java
20
sayHello

Note that the class name will be the fully qualified name including the namespace.

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