Package org.assertj.core.util

Class Throwables

java.lang.Object

org.assertj.core.util.Throwables

public final class Throwables
extends Object

Utility methods related to Throwables.

Author:

Alex Ruiz, Daniel Zlotin

Field Summary

Fields

Modifier and Type	Field	Description
private static Function<Throwable,String>	ERROR_DESCRIPTION_EXTRACTOR
private static String	JAVA_LANG_REFLECT_CONSTRUCTOR
private static String	ORG_ASSERTJ
private static String	ORG_ASSERTJ_CORE_ERROR_CONSTRUCTOR_INVOKER

Constructor Summary

Constructors

Modifier	Constructor	Description
private	Throwables()

Method Summary

Modifier and Type	Method	Description
static void	appendStackTraceInCurrentThreadToThrowable(Throwable t, String methodToStartFrom)	Appends the stack trace of the current thread to the one in the given Throwable.
static List<String>	describeErrors(List<? extends Throwable> errors)
static Throwable	getRootCause(Throwable throwable)	Get the root cause (ie the last non null cause) from a Throwable.
static String	getStackTrace(Throwable throwable)	Get the stack trace from a Throwable as a String.
static void	removeAssertJRelatedElementsFromStackTrace(Throwable throwable)	Removes the AssertJ-related elements from the Throwable stack trace that have little value for end user.
private static List<StackTraceElement>	stackTraceInCurrentThread()
private static List<StackTraceElement>	stackTraceInCurrentThread(String methodToStartFrom)

Methods inherited from class java.lang.Object

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

Field Detail

ORG_ASSERTJ_CORE_ERROR_CONSTRUCTOR_INVOKER

private static final String ORG_ASSERTJ_CORE_ERROR_CONSTRUCTOR_INVOKER

See Also:

Constant Field Values

JAVA_LANG_REFLECT_CONSTRUCTOR

private static final String JAVA_LANG_REFLECT_CONSTRUCTOR

See Also:

Constant Field Values

ORG_ASSERTJ

private static final String ORG_ASSERTJ

See Also:

Constant Field Values

ERROR_DESCRIPTION_EXTRACTOR

private static final Function<Throwable,String> ERROR_DESCRIPTION_EXTRACTOR

Constructor Detail

Throwables

private Throwables()

Method Detail

describeErrors

public static List<String> describeErrors(List<? extends Throwable> errors)

appendStackTraceInCurrentThreadToThrowable

public static void appendStackTraceInCurrentThreadToThrowable(Throwable t,
                                                              String methodToStartFrom)

Appends the stack trace of the current thread to the one in the given Throwable.

Parameters:

t - the given Throwable.

methodToStartFrom - the name of the method used as the starting point of the current thread's stack trace.

stackTraceInCurrentThread

private static List<StackTraceElement> stackTraceInCurrentThread(String methodToStartFrom)

stackTraceInCurrentThread

private static List<StackTraceElement> stackTraceInCurrentThread()

removeAssertJRelatedElementsFromStackTrace

public static void removeAssertJRelatedElementsFromStackTrace(Throwable throwable)

Removes the AssertJ-related elements from the Throwable stack trace that have little value for end user. Therefore, instead of seeing this:

 org.junit.ComparisonFailure: expected:<'[Ronaldo]'> but was:<'[Messi]'>
   at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
   at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
   at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
   at java.lang.reflect.Constructor.newInstance(Constructor.java:501)
   at org.assertj.core.error.ConstructorInvoker.newInstance(ConstructorInvoker.java:34)
   at org.assertj.core.error.ShouldBeEqual.newComparisonFailure(ShouldBeEqual.java:111)
   at org.assertj.core.error.ShouldBeEqual.comparisonFailure(ShouldBeEqual.java:103)
   at org.assertj.core.error.ShouldBeEqual.newAssertionError(ShouldBeEqual.java:81)
   at org.assertj.core.internal.Failures.failure(Failures.java:76)
   at org.assertj.core.internal.Objects.assertEqual(Objects.java:116)
   at org.assertj.core.api.AbstractAssert.isEqualTo(AbstractAssert.java:74)
   at examples.StackTraceFilterExample.main(StackTraceFilterExample.java:13)

We get this:

 org.junit.ComparisonFailure: expected:<'[Ronaldo]'> but was:<'[Messi]'>
   at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
   at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
   at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
   at examples.StackTraceFilterExample.main(StackTraceFilterExample.java:20)

Parameters:

throwable - the Throwable to filter stack trace.

getRootCause

public static Throwable getRootCause(Throwable throwable)

Get the root cause (ie the last non null cause) from a Throwable.

Parameters:

throwable - the Throwable to get root cause from.

Returns:

the root cause if any, else null.

getStackTrace

public static String getStackTrace(Throwable throwable)

Get the stack trace from a Throwable as a String.

The result of this method vary by JDK version as this method uses Throwable.printStackTrace(java.io.PrintWriter). On JDK1.3 and earlier, the cause exception will not be shown unless the specified throwable alters printStackTrace.

Parameters:

throwable - the Throwable to get stack trace from.

Returns:

the stack trace as a String.