20.21

java.lang.ThreadGroup

THE PACKAGE JAVA.LANG

20.21.2

public ThreadGroup(ThreadGroup parent, String name)

throws NullPointerExpression, SecurityException,

IllegalThreadStateException

First, the

checkAccess

 method ( 20.21.4) of the

parent

 thread group is called

with no arguments.

If

parent

 is

null

, then a

NullPointerExpression

 is thrown. If

parent

 is a

ThreadGroup

 that has been destroyed by method

destroy

 ( 20.21.11), then an

IllegalThreadStateException

 is thrown.

This constructor initializes a newly created

ThreadGroup

 object so that it has

the specified

name

 as its name and belongs to the thread group represented by

parent

.

The maximum priority for the newly created thread group is set equal to the

maximum priority of

parent

. The method

setMaxPriority

 ( 20.21.13) may be

used to change the maximum priority to a lower value.

The newly created thread group is initially marked as being a daemon thread

group if and only

parent

 is a daemon thread group. The method

setDaemon

( 20.21.15) may be used to change whether or not a thread group is a daemon

thread group.

20.21.3

public String toString()

The returned value is a concatenation of the following six strings:

The name of the class of this thread group object

  "[name="

The name ( 20.21.5) of this thread group

  ",maxpri="

The current maximum priority ( 20.21.12) for this thread group, as a decimal

numeral

  "]"

All literal characters mentioned above are from the ASCII subset of Unicode.

Overrides the

toString

 method of

Object

 ( 20.1.3).

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