javax.realtime

Class IllegalTaskStateException

java.lang.Object

java.lang.Throwable

java.lang.Exception

java.lang.RuntimeException

java.lang.IllegalArgumentException

java.lang.IllegalThreadStateException

javax.realtime.IllegalTaskStateException

All Implemented Interfaces:

Serializable, StaticThrowable<IllegalTaskStateException>

Direct Known Subclasses:

CeilingViolationException, ProcessorAffinityException

public class IllegalTaskStateException
extends IllegalThreadStateException
implements StaticThrowable<IllegalTaskStateException>

The exception thrown when a Schedulable instance attempts an operation which is illegal in its current state. For instance, changing parameters on such instances are only allowed when the scheduler is not active or the new parameters are consistent with the current scheduler.

Since:

RTSJ 2.0

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from interface javax.realtime.StaticThrowable

StaticThrowable.Hidden

Method Summary

Modifier and Type	Method and Description
Throwable	fillInStackTrace() Fills in the execution stack trace.
static IllegalTaskStateException	get() Gets the preallocated version of this Throwable.
Throwable	getCause() Returns the cause of this throwable or null if the cause is nonexistent or unknown.
String	getLocalizedMessage() Creates a localized description of this throwable.
String	getMessage() Returns the detail message string of this throwable.
IllegalTaskStateException	getSingleton() For the case of legacy code that creates an RTSJ exception explicity, this provides a means of obtaining its singleton version.
StackTraceElement[]	getStackTrace() Provides programmatic access to the stack trace information printed by Throwable.printStackTrace().
Throwable	initCause(Throwable causingThrowable) Initializes the cause of this throwable to the specified value.
void	printStackTrace() Prints this throwable and its backtrace to the standard error stream.
void	printStackTrace(PrintStream stream) Prints this throwable and its backtrace to the specified print stream.
void	printStackTrace(PrintWriter writer) Prints this throwable and its backtrace to the specified print writer.
void	setStackTrace(StackTraceElement[] new_stackTrace) Sets the stack trace elements that will be returned by Throwable.getStackTrace() and printed by Throwable.printStackTrace() and related methods.

Methods inherited from class java.lang.Throwable

addSuppressed, getSuppressed, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface javax.realtime.StaticThrowable

init, init, init, init, writeReplace

Method Detail

get

public static IllegalTaskStateException get()

Gets the preallocated version of this Throwable. Allocation is done in memory that acts like ImmortalMemory. The message and cause are cleared and the stack trace is filled out.

Returns:

the preallocated exception.

getSingleton

public IllegalTaskStateException getSingleton()

Description copied from interface: StaticThrowable

For the case of legacy code that creates an RTSJ exception explicity, this provides a means of obtaining its singleton version.

Specified by:

getSingleton in interface StaticThrowable<IllegalTaskStateException>

Returns:

the singleton version of this exception.

getMessage

public String getMessage()

Description copied from class: Throwable

Returns the detail message string of this throwable.

Specified by:

getMessage in interface StaticThrowable<IllegalTaskStateException>

Overrides:

getMessage in class Throwable

Returns:

the detail message string of this Throwable instance (which may be null).

getLocalizedMessage

public String getLocalizedMessage()

Description copied from class: Throwable

Creates a localized description of this throwable. Subclasses may override this method in order to produce a locale-specific message. For subclasses that do not override this method, the default implementation returns the same result as getMessage().

Specified by:

getLocalizedMessage in interface StaticThrowable<IllegalTaskStateException>

Overrides:

getLocalizedMessage in class Throwable

Returns:

The localized description of this throwable.

initCause

public Throwable initCause(Throwable causingThrowable)

Description copied from class: Throwable

Initializes the cause of this throwable to the specified value. (The cause is the throwable that caused this throwable to get thrown.)

This method can be called at most once. It is generally called from within the constructor, or immediately after creating the throwable. If this throwable was created with Throwable.Throwable(Throwable) or Throwable.Throwable(String,Throwable), this method cannot be called even once.

An example of using this method on a legacy throwable type without other support for setting the cause is:

 try {
     lowLevelOp();
 } catch (LowLevelException le) {
     throw (HighLevelException)
           new HighLevelException().initCause(le); // Legacy constructor
 }
 

Specified by:

initCause in interface StaticThrowable<IllegalTaskStateException>

Overrides:

initCause in class Throwable

Parameters:

causingThrowable - the cause (which is saved for later retrieval by the Throwable.getCause() method). (A null value is permitted, and indicates that the cause is nonexistent or unknown.)

Returns:

a reference to this Throwable instance.

getCause

public Throwable getCause()

Description copied from class: Throwable

Returns the cause of this throwable or null if the cause is nonexistent or unknown. (The cause is the throwable that caused this throwable to get thrown.)

This implementation returns the cause that was supplied via one of the constructors requiring a Throwable, or that was set after creation with the Throwable.initCause(Throwable) method. While it is typically unnecessary to override this method, a subclass can override it to return a cause set by some other means. This is appropriate for a "legacy chained throwable" that predates the addition of chained exceptions to Throwable. Note that it is not necessary to override any of the PrintStackTrace methods, all of which invoke the getCause method to determine the cause of a throwable.

Specified by:

getCause in interface StaticThrowable<IllegalTaskStateException>

Overrides:

getCause in class Throwable

Returns:

the cause of this throwable or null if the cause is nonexistent or unknown.

fillInStackTrace

public Throwable fillInStackTrace()

Description copied from class: Throwable

Fills in the execution stack trace. This method records within this Throwable object information about the current state of the stack frames for the current thread.

If the stack trace of this Throwable is not writable, calling this method has no effect.

Specified by:

fillInStackTrace in interface StaticThrowable<IllegalTaskStateException>

Overrides:

fillInStackTrace in class Throwable

Returns:

a reference to this Throwable instance.

See Also:

Throwable.printStackTrace()

setStackTrace

public void setStackTrace(StackTraceElement[] new_stackTrace)
                   throws NullPointerException

Description copied from class: Throwable

Sets the stack trace elements that will be returned by Throwable.getStackTrace() and printed by Throwable.printStackTrace() and related methods. This method, which is designed for use by RPC frameworks and other advanced systems, allows the client to override the default stack trace that is either generated by Throwable.fillInStackTrace() when a throwable is constructed or deserialized when a throwable is read from a serialization stream.

If the stack trace of this Throwable is not writable, calling this method has no effect other than validating its argument.

Specified by:

setStackTrace in interface StaticThrowable<IllegalTaskStateException>

Overrides:

setStackTrace in class Throwable

Throws:

NullPointerException - if stackTrace is null or if any of the elements of stackTrace are null

Parameters:

new_stackTrace - the stack trace elements to be associated with this Throwable. The specified array is copied by this call; changes in the specified array after the method invocation returns will have no affect on this Throwable's stack trace.

getStackTrace

public StackTraceElement[] getStackTrace()

Description copied from class: Throwable

Provides programmatic access to the stack trace information printed by Throwable.printStackTrace(). Returns an array of stack trace elements, each representing one stack frame. The zeroth element of the array (assuming the array's length is non-zero) represents the top of the stack, which is the last method invocation in the sequence. Typically, this is the point at which this throwable was created and thrown. The last element of the array (assuming the array's length is non-zero) represents the bottom of the stack, which is the first method invocation in the sequence.

Some virtual machines may, under some circumstances, omit one or more stack frames from the stack trace. In the extreme case, a virtual machine that has no stack trace information concerning this throwable is permitted to return a zero-length array from this method. Generally speaking, the array returned by this method will contain one element for every frame that would be printed by printStackTrace. Writes to the returned array do not affect future calls to this method.

Specified by:

getStackTrace in interface StaticThrowable<IllegalTaskStateException>

Overrides:

getStackTrace in class Throwable

Returns:

an array of stack trace elements representing the stack trace pertaining to this throwable.

printStackTrace

public void printStackTrace()

Description copied from class: Throwable

Prints this throwable and its backtrace to the standard error stream. This method prints a stack trace for this Throwable object on the error output stream that is the value of the field System.err. The first line of output contains the result of the Throwable.toString() method for this object. Remaining lines represent data previously recorded by the method Throwable.fillInStackTrace(). 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[] args) {
         crunch(null);
     }
     static void crunch(int[] a) {
         mash(a);
     }
     static void mash(int[] b) {
         System.out.println(b[0]);
     }
 }
 

The backtrace for a throwable with an initialized, non-null cause should generally include the backtrace for the cause. The format of this information depends on the implementation, but the following example may be regarded as typical:

 HighLevelException: MidLevelException: LowLevelException
         at Junk.a(Junk.java:13)
         at Junk.main(Junk.java:4)
 Caused by: MidLevelException: LowLevelException
         at Junk.c(Junk.java:23)
         at Junk.b(Junk.java:17)
         at Junk.a(Junk.java:11)
         ... 1 more
 Caused by: LowLevelException
         at Junk.e(Junk.java:30)
         at Junk.d(Junk.java:27)
         at Junk.c(Junk.java:21)
         ... 3 more
 

Note the presence of lines containing the characters "...". These lines indicate that the remainder of the stack trace for this exception matches the indicated number of frames from the bottom of the stack trace of the exception that was caused by this exception (the "enclosing" exception). This shorthand can greatly reduce the length of the output in the common case where a wrapped exception is thrown from same method as the "causative exception" is caught. The above example was produced by running the program:

 public class Junk {
     public static void main(String args[]) {
         try {
             a();
         } catch(HighLevelException e) {
             e.printStackTrace();
         }
     }
     static void a() throws HighLevelException {
         try {
             b();
         } catch(MidLevelException e) {
             throw new HighLevelException(e);
         }
     }
     static void b() throws MidLevelException {
         c();
     }
     static void c() throws MidLevelException {
         try {
             d();
         } catch(LowLevelException e) {
             throw new MidLevelException(e);
         }
     }
     static void d() throws LowLevelException {
        e();
     }
     static void e() throws LowLevelException {
         throw new LowLevelException();
     }
 }

 class HighLevelException extends Exception {
     HighLevelException(Throwable cause) { super(cause); }
 }

 class MidLevelException extends Exception {
     MidLevelException(Throwable cause)  { super(cause); }
 }

 class LowLevelException extends Exception {
 }
 

As of release 7, the platform supports the notion of suppressed exceptions (in conjunction with the try-with-resources statement). Any exceptions that were suppressed in order to deliver an exception are printed out beneath the stack trace. The format of this information depends on the implementation, but the following example may be regarded as typical:

 Exception in thread "main" java.lang.Exception: Something happened
  at Foo.bar(Foo.java:10)
  at Foo.main(Foo.java:5)
  Suppressed: Resource$CloseFailException: Resource ID = 0
          at Resource.close(Resource.java:26)
          at Foo.bar(Foo.java:9)
          ... 1 more
 

Note that the "... n more" notation is used on suppressed exceptions just at it is used on causes. Unlike causes, suppressed exceptions are indented beyond their "containing exceptions."

An exception can have both a cause and one or more suppressed exceptions:

 Exception in thread "main" java.lang.Exception: Main block
  at Foo3.main(Foo3.java:7)
  Suppressed: Resource$CloseFailException: Resource ID = 2
          at Resource.close(Resource.java:26)
          at Foo3.main(Foo3.java:5)
  Suppressed: Resource$CloseFailException: Resource ID = 1
          at Resource.close(Resource.java:26)
          at Foo3.main(Foo3.java:5)
 Caused by: java.lang.Exception: I did it
  at Foo3.main(Foo3.java:8)
 

Likewise, a suppressed exception can have a cause:

 Exception in thread "main" java.lang.Exception: Main block
  at Foo4.main(Foo4.java:6)
  Suppressed: Resource2$CloseFailException: Resource ID = 1
          at Resource2.close(Resource2.java:20)
          at Foo4.main(Foo4.java:5)
  Caused by: java.lang.Exception: Rats, you caught me
          at Resource2$CloseFailException.<init>(Resource2.java:45)
          ... 2 more
 

Specified by:

printStackTrace in interface StaticThrowable<IllegalTaskStateException>

Overrides:

printStackTrace in class Throwable

printStackTrace

public void printStackTrace(PrintStream stream)

Description copied from class: Throwable

Prints this throwable and its backtrace to the specified print stream.

Specified by:

printStackTrace in interface StaticThrowable<IllegalTaskStateException>

Overrides:

printStackTrace in class Throwable

Parameters:

stream - PrintStream to use for output

printStackTrace

public void printStackTrace(PrintWriter writer)

Description copied from class: Throwable

Prints this throwable and its backtrace to the specified print writer.

Specified by:

printStackTrace in interface StaticThrowable<IllegalTaskStateException>

Overrides:

printStackTrace in class Throwable

Parameters:

writer - PrintWriter to use for output