dk.rode.thesis.meta.util.Throwables
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Evaluating Software Design Patterns — the "Gang of Four" patterns implemented in Java 6 |
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java.lang.Object
public class Throwables
Utilities to manipulate throwable types and objects.
| Constructor Summary | |
|---|---|
private |
Throwables()
Private off-limit constructor. |
| Method Summary | ||
|---|---|---|
static List<Throwable> |
getCauses(Throwable throwable)
Returns a list containing the throwable cause chain acquired from throwable. |
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static List<Exception> |
getCheckedExceptions(Collection<?> objects)
Returns a list containing the checked exceptions from objects. |
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static List<Exception> |
getCheckedExceptions(Object... objects)
Returns a list containing the checked exceptions from objects. |
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static List<Class<? extends Exception>> |
getCheckedExceptionTypes(Class<?>... types)
Returns a list containing the checked exception types from types. |
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static List<Class<? extends Exception>> |
getCheckedExceptionTypes(Collection<Class<?>> types)
Returns a list containing the checked exception types from types. |
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static int |
getIndex(StackTraceElement[] trace,
CharSequence... tokens)
Returns the last index + 1 in the supplied stack trace where one of the supplied tokens is found. |
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static List<Throwable> |
getUncheckedThrowables(Collection<?> objects)
Returns a list containing the unchecked throwables from objects. |
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static List<Throwable> |
getUncheckedThrowables(Object... objects)
Returns a list containing the unchecked throwables from objects. |
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static List<Class<? extends Throwable>> |
getUncheckedThrowableTypes(Class<?>... types)
Returns a list containing the unchecked throwable types from types. |
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static List<Class<? extends Throwable>> |
getUncheckedThrowableTypes(Collection<Class<?>> types)
Returns a list containing the unchecked throwable types from types. |
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static boolean |
isChecked(Throwable throwable)
Returns true if throwable is a checked exception, false if not. |
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static Exception |
toCheckedException(Throwable throwable)
Returns a checked exception based on throwable. |
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static Exception |
toCheckedException(Throwable throwable,
boolean unwind)
Returns a checked exception based on throwable. |
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static
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toCheckedException(Throwable throwable,
Class<T> type)
Returns a checked exception of the type supplied as type
based on throwable. |
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static
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toCheckedException(Throwable throwable,
Class<T> type,
boolean unwind)
Returns a checked exception of the type supplied as type
based on throwable. |
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static RuntimeException |
toRuntimeException(Throwable throwable)
Returns a runtime exception based on throwable. |
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static RuntimeException |
toRuntimeException(Throwable throwable,
boolean unwind)
Returns a runtime exception based on throwable. |
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static
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toRuntimeException(Throwable throwable,
Class<T> type)
Returns a runtime exception of the type supplied as type
based on throwable. |
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static
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toRuntimeException(Throwable throwable,
Class<T> type,
boolean unwind)
Returns a runtime exception of the type supplied as type
based on throwable. |
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static CharSequence |
toStackTrace(Throwable throwable)
Serializes the stack trace from throwable into
the returned char sequence. |
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static
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toThrowableType(Throwable throwable,
Class<T> type)
Returns a throwable of the type supplied as type
based on throwable. |
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static
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toThrowableType(Throwable throwable,
Class<T> type,
boolean unwind)
Returns a throwable of the type supplied as type
based on throwable. |
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static
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unwind(Throwable throwable,
Class<T> type)
Returns the first throwable assignable to type in the
cause chain acquired from throwable, if any. |
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| Methods inherited from class java.lang.Object |
|---|
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
| Constructor Detail |
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private Throwables()
| Method Detail |
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public static final List<Throwable> getCauses(Throwable throwable)
throwable.
The first index contains throwable, the second index
the cause A of throwable, the third the cause B
of A, etc.
throwable - The throwable to supply the cause chain; cannot be null.
NullPointerException - If throwable is null.public static final List<Exception> getCheckedExceptions(Collection<?> objects)
objects. The returned list may contain duplicates.
objects - The objects; cannot be null, but may contain null entries.
objects; never null.
NullPointerException - If objects is null.public static final List<Exception> getCheckedExceptions(Object... objects)
objects. The returned list may contain duplicates.
objects - The objects; cannot be null, but may contain null entries.
objects; never null.
NullPointerException - If objects is null.public static final List<Class<? extends Exception>> getCheckedExceptionTypes(Class<?>... types)
types. The returned list may contain duplicates.
types - The types; cannot be null, but may contain null entries.
types; never null.
NullPointerException - If types is null.public static final List<Class<? extends Exception>> getCheckedExceptionTypes(Collection<Class<?>> types)
types. The returned list may contain duplicates.
types - The types; cannot be null, but may contain null entries.
types; never null.
NullPointerException - If types is null.
public static final int getIndex(StackTraceElement[] trace,
CharSequence... tokens)
The search for a token is done in the class name available via
a stack trace element using
Strings.indexOfIgnoreCase(CharSequence, CharSequence).
Hence, the search is case-insensitive, and the search for tokens
is done in the order the tokens are supplied.
trace - The stack trace; cannot be null.tokens - The list of tokens to search for.
trace.length
if no token could be found.
NullPointerException - If trace is null.public static final List<Throwable> getUncheckedThrowables(Collection<?> objects)
objects. The returned list may contain duplicates.
objects - The objects; cannot be null, but may contain null entries.
objects; never null.
NullPointerException - If objects is null.public static final List<Throwable> getUncheckedThrowables(Object... objects)
objects. The returned list may contain duplicates.
objects - The objects; cannot be null, but may contain null entries.
objects; never null.
NullPointerException - If objects is null.public static final List<Class<? extends Throwable>> getUncheckedThrowableTypes(Class<?>... types)
types. The returned list may contain duplicates.
types - The types; cannot be null, but may contain null entries.
types; never null.
NullPointerException - If types is null.public static final List<Class<? extends Throwable>> getUncheckedThrowableTypes(Collection<Class<?>> types)
types. The returned list may contain duplicates.
types - The types; cannot be null, but may contain null entries.
types; never null.
NullPointerException - If types is null.public static final boolean isChecked(Throwable throwable)
throwable is a checked exception, false if not.
throwable - The throwable to test; can be null, in which case false is returned.
throwable is a checked exception, false if not.public static final Exception toCheckedException(Throwable throwable)
throwable.
If throwable is already a checked exception, it will
simply be returned. Otherwise a new checked exception is
created, throwable is set as the cause, and the
created checked exception is returned.
throwable - The throwable; cannot be null.
NullPointerException - If throwable is null.
public static final Exception toCheckedException(Throwable throwable,
boolean unwind)
throwable.
If throwable is already a checked exception,
it will simply be returned. If not and if unwind
is true, a checked exception is tried unwound from the cause chain
acquired from throwable and if found
returned. Otherwise a new checked exception is created,
throwable is set as the cause, and the created checked
exception is returned.
throwable - The throwable; cannot be null.unwind - True to try and unwind a checked exception from cause
chain, false to create a new checked exception if needed
(a new instance will also be created if no checked
exception can be found in the cause chain).
NullPointerException - If throwable is null.
public static final <T extends Exception> T toCheckedException(Throwable throwable,
Class<T> type)
type
based on throwable.
If throwable is already a checked exception of
the desired type, it will simply be returned. Otherwise a new
checked exception of the desired type is created, throwable
is set as the cause, and the created checked exception is returned.
T - The type of throwable.throwable - The throwable; cannot be null.type - The specific checked exception type as a class token;
cannot be null.
NullPointerException - If either parameter is null.
RuntimeException - If the current context to does have
access to create a checked exception of the desired type;
or if the desired type does not have a default constructor,
or the construction fails.
public static final <T extends Exception> T toCheckedException(Throwable throwable,
Class<T> type,
boolean unwind)
type
based on throwable.
If throwable is already a checked exception of the desired type,
it will simply be returned. If not and if unwind is true, a
checked exception of the desired type is tried unwound
from the cause chain acquired from throwable and if found
returned. Otherwise a new checked exception of the desired type is created,
throwable is set as the cause, and the created checked
exception is returned.
T - The type of throwable.throwable - The throwable; cannot be null.type - The specific runtime exception type as a class token;
cannot be null.unwind - True to try and unwind a checked exception of the desired
type from cause chain, false to create such a new checked exception
if needed (a new instance will also be created if no such checked
exception can be found in the cause chain).
NullPointerException - If either parameter is null.
RuntimeException - If the current context to does have
access to create a checked exception of the desired type;
or if the desired type does not have a default constructor,
or the construction fails.public static final RuntimeException toRuntimeException(Throwable throwable)
throwable.
If throwable is already a runtime exception, it will
simply be returned. Otherwise a new runtime exception is
created, throwable is set as the cause, and the
created runtime exception is returned.
throwable - The throwable; cannot be null.
NullPointerException - If throwable is null.
public static final RuntimeException toRuntimeException(Throwable throwable,
boolean unwind)
throwable.
If throwable is already a runtime exception,
it will simply be returned. If not and if unwind
is true, a runtime exception is tried unwound from the cause chain
acquired from throwable and if found
returned. Otherwise a new runtime exception is created,
throwable is set as the cause, and the created runtime
exception is returned.
throwable - The throwable; cannot be null.unwind - True to try and unwind a runtime exception from cause
chain, false to create a new runtime exception if needed
(a new instance will also be created if no runtime
exception can be found in the cause chain).
NullPointerException - If throwable is null.
public static final <T extends RuntimeException> T toRuntimeException(Throwable throwable,
Class<T> type)
type
based on throwable.
If throwable is already a runtime exception of
the desired type, it will simply be returned. Otherwise a new
runtime exception of the desired type is created, throwable
is set as the cause, and the created runtime exception is returned.
T - The type of throwable.throwable - The throwable; cannot be null.type - The specific runtime exception type as a class token;
cannot be null.
NullPointerException - If either parameter is null.
RuntimeException - If the current context to does have
access to create a runtime exception of the desired type;
or if the desired type does not have a default constructor,
or the construction fails.
public static final <T extends RuntimeException> T toRuntimeException(Throwable throwable,
Class<T> type,
boolean unwind)
type
based on throwable.
If throwable is already a runtime exception of the desired type,
it will simply be returned. If not and if unwind is true, a
runtime exception of the desired type is tried unwound
from the cause chain acquired from throwable and if found
returned. Otherwise a new runtime exception of the desired type is created,
throwable is set as the cause, and the created runtime
exception is returned.
T - The type of throwable.throwable - The throwable; cannot be null.type - The specific runtime exception type as a class token;
cannot be null.unwind - True to try and unwind a runtime exception of the desired
type from cause chain, false to create such a new runtime exception
if needed (a new instance will also be created if no such runtime
exception can be found in the cause chain).
NullPointerException - If either parameter is null.
RuntimeException - If the current context to does have
access to create a runtime exception of the desired type;
or if the desired type does not have a default constructor,
or the construction fails.public static final CharSequence toStackTrace(Throwable throwable)
throwable into
the returned char sequence.
Instead of writing to, for example, System.err,
the same output is simply written to the returned char
sequence, including newlines.
throwable - The throwable; cannot be null.
throwable; never null.
NullPointerException - If throwable is null.
public static final <T extends Throwable> T toThrowableType(Throwable throwable,
Class<T> type)
type
based on throwable.
If throwable is already an instance of
the desired type, it will simply be returned. Otherwise a new
throwable of the desired type is created, throwable
is set as the cause, and the created throwable is returned.
This method can be used as a simple idiom for re-throwing the correct type of exception if the exception cannot be handled, without having to use several different catch-blocks to avoid hiding the actual exception type.
Consider:
public foo() throws FooException {
try {
..
} catch (FooException fe) {
throw fe;
} catch (Exception e) {
throw new FooException(e);
}
}
Using this method instead:
public foo() throws FooException {
try {
..
} catch (Exception e) {
throw toThrowableType(e, FooException.class);
}
}
T - The type of throwable.throwable - The throwable; cannot be null.type - The specific type as a class token; cannot be null.
NullPointerException - If either parameter is null.
RuntimeException - If the current context does not have
access to create a throwable exception of the desired type;
or if the desired type does not have a no-arg constructor,
or the construction fails.toThrowableType(Throwable, Class, boolean)
public static final <T extends Throwable> T toThrowableType(Throwable throwable,
Class<T> type,
boolean unwind)
type
based on throwable.
If throwable is already an instance of the desired type,
it will simply be returned. If not and if unwind
is true, a throwable of the desired type is tried unwound
from the cause chain acquired from throwable and if found
returned. Otherwise a new throwable of the desired type is created,
throwable is set as the cause, and the created throwable
is returned.
This method can be used as a simple idiom for re-throwing the correct type of exception if the exception cannot be handled, without having to use several different catch-blocks to avoid hiding the actual exception type.
Consider:
public foo() throws FooException {
try {
..
} catch (FooException fe) {
throw fe;
} catch (Exception e) {
throw new FooException(e);
}
}
Using this method instead:
public foo() throws FooException {
try {
..
} catch (Exception e) {
throw toThrowableType(e, FooException.class, true); // true = try and unwind
}
}
T - The type of throwable.throwable - The throwable; cannot be null.type - The specific type as a class token; cannot be null.unwind - True to try and unwind a throwable of type T
from cause chain, false to create a new throwable
if needed (a new instance will also be created if
no such type can be found in the cause chain).
NullPointerException - If throwable or type are null.
RuntimeException - If a throwable must be created and the current context
does not have access to create a throwable exception of the desired type;
or if the desired type does not have a no-arg constructor,
or the construction fails.toThrowableType(Throwable, Class)
public static final <T extends Throwable> T unwind(Throwable throwable,
Class<T> type)
type in the
cause chain acquired from throwable, if any.
The returned throwable may be throwable it self.
T - The type of throwable to find in the cause stack.throwable - The throwable to supply the cause chain; cannot be null.type - The type as a class token; cannot be null.
type, or null
if no such throwable is found.
NullPointerException - If either argument is null.
|
Gunni Rode / rode.dk | ||||||||
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