public class WrappedRuntimeException extends RuntimeException
Modifier and Type | Method and Description |
---|---|
boolean |
equals(Object obj)
Indicates whether some other object is "equal to" this one.
|
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.
|
StackTraceElement[] |
getStackTrace()
Provides programmatic access to the stack trace information printed by
Throwable.printStackTrace() . |
int |
hashCode()
Returns a hash code value for the object.
|
void |
printStackTrace()
Prints this throwable and its backtrace to the
standard error stream.
|
void |
printStackTrace(PrintStream s)
Prints this throwable and its backtrace to the specified print stream.
|
void |
printStackTrace(PrintWriter s)
Prints this throwable and its backtrace to the specified
print writer.
|
void |
setStackTrace(StackTraceElement[] stackTrace)
Sets the stack trace elements that will be returned by
Throwable.getStackTrace() and printed by Throwable.printStackTrace()
and related methods. |
String |
toString()
Returns a short description of this throwable.
|
addSuppressed, fillInStackTrace, getSuppressed, initCause
public void printStackTrace()
java.lang.Throwable
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:
This example was produced by running the program:java.lang.NullPointerException at MyClass.mash(MyClass.java:9) at MyClass.crunch(MyClass.java:6) at MyClass.main(MyClass.java:3)
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 moreNote 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$CloseFailException: Resource ID = 0 at Resource.close(Resource.java:26) at Foo.bar(Foo.java:9) ... 1 moreNote that the "... n more" notation is used on suppressed exceptions just at it is used on causes. Unlike causes, suppressed exceptions are indented beyond their "containing exceptions."
An exception can have both a cause and one or more suppressed exceptions:
Exception in thread "main" java.lang.Exception: Main block at Foo3.main(Foo3.java:7) Suppressed: Resource$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
printStackTrace
in class Throwable
public void printStackTrace(PrintStream s)
java.lang.Throwable
printStackTrace
in class Throwable
s
- PrintStream
to use for outputpublic void printStackTrace(PrintWriter s)
java.lang.Throwable
printStackTrace
in class Throwable
s
- PrintWriter
to use for outputpublic Throwable getCause()
java.lang.Throwable
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.
public String getLocalizedMessage()
java.lang.Throwable
getMessage()
.getLocalizedMessage
in class Throwable
public String getMessage()
java.lang.Throwable
getMessage
in class Throwable
Throwable
instance
(which may be null
).public StackTraceElement[] getStackTrace()
java.lang.Throwable
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.
getStackTrace
in class Throwable
public void setStackTrace(StackTraceElement[] stackTrace)
java.lang.Throwable
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.
setStackTrace
in class Throwable
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.public String toString()
java.lang.Throwable
Throwable.getLocalizedMessage()
method
getLocalizedMessage
returns null
, then just
the class name is returned.public boolean equals(Object obj)
java.lang.Object
The equals
method implements an equivalence relation
on non-null object references:
x
, x.equals(x)
should return
true
.
x
and y
, x.equals(y)
should return true
if and only if
y.equals(x)
returns true
.
x
, y
, and z
, if
x.equals(y)
returns true
and
y.equals(z)
returns true
, then
x.equals(z)
should return true
.
x
and y
, multiple invocations of
x.equals(y)
consistently return true
or consistently return false
, provided no
information used in equals
comparisons on the
objects is modified.
x
,
x.equals(null)
should return false
.
The equals
method for class Object
implements
the most discriminating possible equivalence relation on objects;
that is, for any non-null reference values x
and
y
, this method returns true
if and only
if x
and y
refer to the same object
(x == y
has the value true
).
Note that it is generally necessary to override the hashCode
method whenever this method is overridden, so as to maintain the
general contract for the hashCode
method, which states
that equal objects must have equal hash codes.
equals
in class Object
obj
- the reference object with which to compare.true
if this object is the same as the obj
argument; false
otherwise.Object.hashCode()
,
HashMap
public int hashCode()
java.lang.Object
HashMap
.
The general contract of hashCode
is:
hashCode
method
must consistently return the same integer, provided no information
used in equals
comparisons on the object is modified.
This integer need not remain consistent from one execution of an
application to another execution of the same application.
equals(Object)
method, then calling the hashCode
method on each of
the two objects must produce the same integer result.
Object.equals(java.lang.Object)
method, then calling the hashCode
method on each of the
two objects must produce distinct integer results. However, the
programmer should be aware that producing distinct integer results
for unequal objects may improve the performance of hash tables.
As much as is reasonably practical, the hashCode method defined by
class Object
does return distinct integers for distinct
objects. (This is typically implemented by converting the internal
address of the object into an integer, but this implementation
technique is not required by the
Java™ programming language.)
hashCode
in class Object
Object.equals(java.lang.Object)
,
System.identityHashCode(java.lang.Object)