THE PACKAGE JAVA.LANG

java.lang.Throwable

 and its Subclasses

20.22

The name of the actual class of this object

": "

 (a colon and a space)

The result of the

getMessage

 method ( 20.22.3) for this object

If this

Throwable

 object was created with no error message string ( 20.22.1),

then the name of the actual class of this object is returned.

20.22.5

public Throwable fillInStackTrace()

This method records within this

Throwable

 object information about the current

state of the stack frames for the current thread.

20.22.6

public void printStackTrace()

This method prints a stack trace for this

Throwable

 object on the error output

stream that is the value of the field

System.err

 ( 20.18.3). The first line of output

contains the result of the

toString

 method ( 20.22.4) for this object. Remaining

lines represent data previously recorded by the method

fillInStackTrace

( 20.22.5). The format of this information depends on the implementation, but the

following example may be regarded as typical:

java.lang.NullPointerException

at MyClass.mash(MyClass.java:9)

at MyClass.crunch(MyClass.java:6)

at MyClass.main(MyClass.java:3)

This example was produced by running the program:

class MyClass {

public static void main(String[] argv) {

crunch(null);

}

static void crunch(int[] a) {

mash(a);

}

static void mash(int[] b) {

System.out.println(b[0]);

}

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