ExitUtil (Apache Hadoop Common 3.4.1.300-dep-1001 API)

java.lang.Object
- org.apache.hadoop.util.ExitUtil

```
@LimitedPrivate({"HDFS","MapReduce","YARN"})
@Unstable
public final class ExitUtil
extends java.lang.Object
```
Facilitates hooking process termination for tests, debugging and embedding. Hadoop code that attempts to call System.exit(int) or Runtime.halt(int) MUST invoke it via these methods.

Nested Class Summary

Nested Classes
Modifier and Type	Class	Description
`static class`	`ExitUtil.ExitException`	An exception raised when a call to `terminate(int)` was called and system exits were blocked.
`static class`	`ExitUtil.HaltException`	An exception raised when a call to `terminate(int)` was called and system halts were blocked.

Field Summary

Fields
Modifier and Type	Field	Description
`static java.lang.String`	`EXIT_EXCEPTION_MESSAGE`	Message raised from an exit exception if none were provided: "ExitException".
`static java.lang.String`	`HALT_EXCEPTION_MESSAGE`	Message raised from a halt exception if none were provided: "HaltException".

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method	Description
`static void`	`disableSystemExit()`	Disable the use of System.exit for testing.
`static void`	`disableSystemHalt()`	Disable the use of `Runtime.getRuntime().halt()` for testing.
`static ExitUtil.ExitException`	`getFirstExitException()`
`static ExitUtil.HaltException`	`getFirstHaltException()`
`static void`	`halt(int status)`	Forcibly terminates the currently running Java virtual machine.
`static void`	`halt(int status, java.lang.String message)`	Forcibly terminates the currently running Java virtual machine.
`static void`	`halt(int status, java.lang.Throwable t)`	Forcibly terminates the currently running Java virtual machine.
`static void`	`halt(ExitUtil.HaltException he)`	Halts the JVM if halt is enabled, rethrow provided exception or any raised error otherwise.
`static boolean`	`haltCalled()`
`static void`	`haltOnOutOfMemory(java.lang.OutOfMemoryError oome)`	Handler for out of memory events -no attempt is made here to cleanly shutdown or support halt blocking; a robust printing of the event to stderr is all that can be done.
`static void`	`resetFirstExitException()`	Reset the tracking of process termination.
`static void`	`resetFirstHaltException()`	Reset the tracking of process termination.
`static void`	`terminate(int status)`	Like `terminate(int, Throwable)` without a message.
`static void`	`terminate(int status, java.lang.String msg)`	Terminate the current process.
`static void`	`terminate(int status, java.lang.Throwable t)`	Like `terminate(int, String)` but uses the given throwable to build the message to display or throw as an `ExitUtil.ExitException`.
`static void`	`terminate(ExitUtil.ExitException ee)`	Exits the JVM if exit is enabled, rethrow provided exception or any raised error otherwise.
`static boolean`	`terminateCalled()`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - EXIT_EXCEPTION_MESSAGE
```
public static final java.lang.String EXIT_EXCEPTION_MESSAGE
```
    Message raised from an exit exception if none were provided: "ExitException".
    
    See Also:
    
    Constant Field Values
  - HALT_EXCEPTION_MESSAGE
```
public static final java.lang.String HALT_EXCEPTION_MESSAGE
```
    Message raised from a halt exception if none were provided: "HaltException".
    
    See Also:
    
    Constant Field Values
- Method Detail
  - disableSystemExit
```
public static void disableSystemExit()
```
    Disable the use of System.exit for testing.
  - disableSystemHalt
```
public static void disableSystemHalt()
```
    Disable the use of Runtime.getRuntime().halt() for testing.
  - terminateCalled
```
public static boolean terminateCalled()
```
    Returns:
    
    true if terminate has been called.
  - haltCalled
```
public static boolean haltCalled()
```
    Returns:
    
    true if halt has been called.
  - getFirstExitException
```
public static ExitUtil.ExitException getFirstExitException()
```
    Returns:
    
    the first ExitException thrown, null if none thrown yet.
  - getFirstHaltException
```
public static ExitUtil.HaltException getFirstHaltException()
```
    Returns:
    
    the first HaltException thrown, null if none thrown yet.
  - resetFirstExitException
```
public static void resetFirstExitException()
```
    Reset the tracking of process termination. This is for use in unit tests where one test in the suite expects an exit but others do not.
  - resetFirstHaltException
```
public static void resetFirstHaltException()
```
    Reset the tracking of process termination. This is for use in unit tests where one test in the suite expects a halt but others do not.
  - terminate
```
public static void terminate(ExitUtil.ExitException ee)
                      throws ExitUtil.ExitException
```
    Exits the JVM if exit is enabled, rethrow provided exception or any raised error otherwise. Inner termination: either exit with the exception's exit code, or, if system exits are disabled, rethrow the exception.
    
    Parameters:
    
    ee - exit exception
    
    Throws:
    
    ExitUtil.ExitException - if System.exit(int) is disabled and not suppressed by an Error
    
    java.lang.Error - if System.exit(int) is disabled and one Error arise, suppressing anything else, even ee
  - halt
```
public static void halt(ExitUtil.HaltException he)
                 throws ExitUtil.HaltException
```
    Halts the JVM if halt is enabled, rethrow provided exception or any raised error otherwise. If halt is disabled, this method throws either the exception argument if no error arise, the first error if at least one arise, suppressing he. If halt is enabled, all throwables are caught, even errors.
    
    Parameters:
    
    he - the exception containing the status code, message and any stack trace.
    
    Throws:
    
    ExitUtil.HaltException - if Runtime.halt(int) is disabled and not suppressed by an Error
    
    java.lang.Error - if Runtime.halt(int) is disabled and one Error arise, suppressing anyuthing else, even he
  - terminate
```
public static void terminate(int status,
                             java.lang.Throwable t)
                      throws ExitUtil.ExitException
```
    Like terminate(int, String) but uses the given throwable to build the message to display or throw as an ExitUtil.ExitException.
    
    Parameters:
    
    status - exit code to use if the exception is not an ExitException.
    
    t - throwable which triggered the termination. If this exception is an ExitUtil.ExitException its status overrides that passed in.
    
    Throws:
    
    ExitUtil.ExitException - if System.exit(int) is disabled.
  - halt
```
public static void halt(int status,
                        java.lang.Throwable t)
                 throws ExitUtil.HaltException
```
    Forcibly terminates the currently running Java virtual machine.
    
    Parameters:
    
    status - exit code to use if the exception is not a HaltException.
    
    t - throwable which triggered the termination. If this exception is a ExitUtil.HaltException its status overrides that passed in.
    
    Throws:
    
    ExitUtil.HaltException - if System.exit(int) is disabled.
  - terminate
```
public static void terminate(int status)
                      throws ExitUtil.ExitException
```
    Like terminate(int, Throwable) without a message.
    
    Parameters:
    
    status - exit code
    
    Throws:
    
    ExitUtil.ExitException - if System.exit(int) is disabled.
  - terminate
```
public static void terminate(int status,
                             java.lang.String msg)
                      throws ExitUtil.ExitException
```
    Terminate the current process. Note that terminate is the *only* method that should be used to terminate the daemon processes.
    
    Parameters:
    
    status - exit code
    
    msg - message used to create the ExitException
    
    Throws:
    
    ExitUtil.ExitException - if System.exit(int) is disabled.
  - halt
```
public static void halt(int status)
                 throws ExitUtil.HaltException
```
    Forcibly terminates the currently running Java virtual machine.
    
    Parameters:
    
    status - status code
    
    Throws:
    
    ExitUtil.HaltException - if Runtime.halt(int) is disabled.
  - halt
```
public static void halt(int status,
                        java.lang.String message)
                 throws ExitUtil.HaltException
```
    Forcibly terminates the currently running Java virtual machine.
    
    Parameters:
    
    status - status code
    
    message - message
    
    Throws:
    
    ExitUtil.HaltException - if Runtime.halt(int) is disabled.
  - haltOnOutOfMemory
```
public static void haltOnOutOfMemory(java.lang.OutOfMemoryError oome)
```
    Handler for out of memory events -no attempt is made here to cleanly shutdown or support halt blocking; a robust printing of the event to stderr is all that can be done.
    
    Parameters:
    
    oome - out of memory event

Class ExitUtil

Nested Class Summary

Field Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

EXIT_EXCEPTION_MESSAGE

HALT_EXCEPTION_MESSAGE

Method Detail

disableSystemExit

disableSystemHalt

terminateCalled

haltCalled

getFirstExitException

getFirstHaltException

resetFirstExitException

resetFirstHaltException

terminate

halt

terminate

halt

terminate

terminate

halt

halt

haltOnOutOfMemory