Package java.lang

Class Throwable

java.lang.Object
java.lang.Throwable
All Implemented Interfaces:
Serializable
Direct Known Subclasses:
Error, Exception
public class Throwable
extends Object
implements Serializable
The superclass of all classes which can be thrown by the VM. The two direct subclasses are recoverable exceptions (Exception) and unrecoverable errors (Error). This class provides common methods for accessing a string message which provides extra information about the circumstances in which the Throwable was created (basically an error message in most cases), and for saving a stack trace (that is, a record of the call stack at a particular point in time) which can be printed later.

A Throwable can also include a cause, which is a nested Throwable that represents the original problem that led to this Throwable. It is often used for wrapping various types of errors into a common Throwable without losing the detailed original error information. When printing the stack trace, the trace of the cause is included.

See Also:
Error, Exception, RuntimeException, Serialized Form

  • Constructor Summary

    Constructors
    Modifier Constructor Description
      Throwable()
    Constructs a new Throwable that includes the current stack trace.
      Throwable​(String detailMessage)
    Constructs a new Throwable with the current stack trace and the given detail message.
      Throwable​(String detailMessage, Throwable cause)
    Constructs a new Throwable with the current stack trace, the given detail message and cause.
    protected Throwable​(String detailMessage, Throwable cause, boolean enableSuppression, boolean writableStackTrace)
    Constructs a new Throwable with the current stack trace, the specified detail message and the specified cause.
      Throwable​(Throwable cause)
    Constructs a new Throwable with the current stack trace and the given cause.

  • Method Summary

    Modifier and Type Method Description
    void addSuppressed​(Throwable throwable)
    Adds throwable to the list of throwables suppressed by this.
    Throwable fillInStackTrace()
    Records the stack trace from the point where this method has been called to this Throwable.
    Throwable getCause()
    Returns the cause of this Throwable, or null if there is no cause.
    String getLocalizedMessage()
    Returns the detail message which was provided when this Throwable was created.
    String getMessage()
    Returns the detail message which was provided when this Throwable was created.
    StackTraceElement[] getStackTrace()
    Returns a clone of the array of stack trace elements of this Throwable.
    Throwable[] getSuppressed()
    Returns the throwables suppressed by this.
    Throwable initCause​(Throwable throwable)
    Initializes the cause of this Throwable.
    void printStackTrace()
    Writes a printable representation of this Throwable's stack trace to the System.err stream.
    void printStackTrace​(PrintStream err)
    Writes a printable representation of this Throwable's stack trace to the given print stream.
    void printStackTrace​(PrintWriter err)
    Writes a printable representation of this Throwable's stack trace to the specified print writer.
    void setStackTrace​(StackTraceElement[] trace)
    Sets the array of stack trace elements.
    String toString()
    Returns a string containing a concise, human-readable description of this object.

    Methods inherited from class java.lang.Object

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

  • Constructor Details

    • Throwable

      public Throwable()
      Constructs a new Throwable that includes the current stack trace.

    • Throwable

      public Throwable​(String detailMessage)
      Constructs a new Throwable with the current stack trace and the given detail message.

    • Throwable

      public Throwable​(String detailMessage, Throwable cause)
      Constructs a new Throwable with the current stack trace, the given detail message and cause.

    • Throwable

      public Throwable​(Throwable cause)
      Constructs a new Throwable with the current stack trace and the given cause.

    • Throwable

      protected Throwable​(String detailMessage, Throwable cause, boolean enableSuppression, boolean writableStackTrace)
      Constructs a new Throwable with the current stack trace, the specified detail message and the specified cause.
      Parameters:
      enableSuppression - if false, addSuppressed(Throwable) will be a no-op.
      writableStackTrace - if false, fillInStackTrace() will not be called, this object's stackTrace will be null, calls to fillInStackTrace() and setStackTrace(java.lang.StackTraceElement[]) will be no-ops, and getStackTrace() will return a zero-length array.
      Since:
      1.7

  • Method Details

    • fillInStackTrace

      public Throwable fillInStackTrace()
      Records the stack trace from the point where this method has been called to this Throwable. This method is invoked by the Throwable constructors.

      This method is public so that code (such as an RPC system) which catches a Throwable and then re-throws it can replace the construction-time stack trace with a stack trace from the location where the exception was re-thrown, by calling fillInStackTrace.

      This method is non-final so that non-Java language implementations can disable VM stack traces for their language. Filling in the stack trace is relatively expensive. Overriding this method in the root of a language's exception hierarchy allows the language to avoid paying for something it doesn't need.

      Returns:
      this Throwable instance.

    • getMessage

      public String getMessage()
      Returns the detail message which was provided when this Throwable was created. Returns null if no message was provided at creation time.

    • getLocalizedMessage

      public String getLocalizedMessage()
      Returns the detail message which was provided when this Throwable was created. Returns null if no message was provided at creation time. Subclasses may override this method to return localized text for the message. Android returns the regular detail message.

    • getStackTrace

      public StackTraceElement[] getStackTrace()
      Returns a clone of the array of stack trace elements of this Throwable. Each StackTraceElement represents an entry in the call stack. The element at position 0 is the top of the stack, that is, the stack frame where this Throwable is thrown.
      See Also:
      printStackTrace()

    • setStackTrace

      public void setStackTrace​(StackTraceElement[] trace)
      Sets the array of stack trace elements. Each StackTraceElement represents an entry in the call stack. A copy of the specified array is stored in this Throwable. will be returned by getStackTrace() and printed by printStackTrace().
      Parameters:
      trace - the new array of StackTraceElements. A copy of the array is stored in this Throwable, so subsequent changes to trace will not change the call stack stored in this Throwable.
      Throws:
      NullPointerException - if any element in trace is null.
      See Also:
      printStackTrace()

    • printStackTrace

      public void printStackTrace()
      Writes a printable representation of this Throwable's stack trace to the System.err stream.

    • printStackTrace

      public void printStackTrace​(PrintStream err)
      Writes a printable representation of this Throwable's stack trace to the given print stream. If the Throwable contains a cause, the method will be invoked recursively for the nested Throwable.

    • printStackTrace

      public void printStackTrace​(PrintWriter err)
      Writes a printable representation of this Throwable's stack trace to the specified print writer. If the Throwable contains a cause, the method will be invoked recursively for the nested Throwable.
      Parameters:
      err - the writer to write the stack trace on.

    • toString

      public String toString()
      Description copied from class: Object
      Returns a string containing a concise, human-readable description of this object. Subclasses are encouraged to override this method and provide an implementation that takes into account the object's type and data. The default implementation is equivalent to the following expression: 
         getClass().getName() + '@' + Integer.toHexString(hashCode())

      See Writing a useful toString method if you intend implementing your own toString method.

      Overrides:
      toString in class Object
      Returns:
      a printable representation of this object.

    • initCause

      public Throwable initCause​(Throwable throwable)
      Initializes the cause of this Throwable. The cause can only be initialized once.
      Parameters:
      throwable - the cause of this Throwable.
      Returns:
      this Throwable instance.
      Throws:
      IllegalArgumentException - if Throwable is this object.
      IllegalStateException - if the cause has already been initialized.

    • getCause

      public Throwable getCause()
      Returns the cause of this Throwable, or null if there is no cause.

    • addSuppressed

      public final void addSuppressed​(Throwable throwable)
      Adds throwable to the list of throwables suppressed by this. The throwable will included when this exception's stack trace is printed.
      Throws:
      IllegalArgumentException - if throwable == this.
      NullPointerException - if throwable == null.
      Since:
      1.7

    • getSuppressed

      public final Throwable[] getSuppressed()
      Returns the throwables suppressed by this.
      Since:
      1.7