net.sf.antcontrib.logic
Class TryCatchTask

java.lang.Object
  org.apache.tools.ant.ProjectComponent
      org.apache.tools.ant.Task
          net.sf.antcontrib.logic.TryCatchTask

public class TryCatchTask
extends org.apache.tools.ant.Task

A wrapper that lets you run a set of tasks and optionally run a different set of tasks if the first set fails and yet another set after the first one has finished.

This mirrors Java's try/catch/finally.

The tasks inside of the required <try> element will be run. If one of them should throw a BuildException several things can happen:

• If there is no <catch> block, the exception will be passed through to Ant.
• If the property attribute has been set, a property of the given name will be set to the message of the exception.
• If the reference attribute has been set, a reference of the given id will be created and point to the exception object.
• If there is a <catch> block, the tasks nested into it will be run.

If a <finally> block is present, the task nested into it will be run, no matter whether the first tasks have thrown an exception or not.

Attributes:

Name	Description	Required
property	Name of a property that will receive the message of the exception that has been caught (if any)	No
reference	Id of a reference that will point to the exception object that has been caught (if any)	No

Use the following task to define the <trycatch> task before you use it the first time:

   <taskdef name="trycatch" 
            classname="net.sf.antcontrib.logic.TryCatchTask" />
 

Crude Example

 <trycatch property="foo" reference="bar">
   <try>
     <fail>Tada!</fail>
   </try>

   <catch>
     <echo>In &lt;catch&gt;.</echo>
   </catch>

   <finally>
     <echo>In &lt;finally&gt;.</echo>
   </finally>
 </trycatch>

 <echo>As property: ${foo}</echo>
 <property name="baz" refid="bar" />
 <echo>From reference: ${baz}</echo>
 

results in

   [trycatch] Caught exception: Tada!
       [echo] In <catch>.
       [echo] In <finally>.
       [echo] As property: Tada!
       [echo] From reference: Tada!
 

Author:

Stefan Bodewig, Dan Ritchey

Nested Class Summary

static class

TryCatchTask.CatchBlock

Field Summary

Fields inherited from class org.apache.tools.ant.Task

description, location, target, taskName, taskType, wrapper

Fields inherited from class org.apache.tools.ant.ProjectComponent

project

Constructor Summary

TryCatchTask()

Method Summary

void	addCatch(TryCatchTask.CatchBlock cb)
void	addFinally(org.apache.tools.ant.taskdefs.Sequential seq) Adds a nested <finally> block - at most one is allowed.
void	addTry(org.apache.tools.ant.taskdefs.Sequential seq) Adds a nested <try> block - one is required, more is forbidden.
void	execute() The heart of the task.
void	setProperty(java.lang.String p) Sets the property attribute.
void	setReference(java.lang.String r) Sets the reference attribute.

Methods inherited from class org.apache.tools.ant.Task

getDescription, getLocation, getOwningTarget, getRuntimeConfigurableWrapper, getTaskName, getTaskType, getWrapper, handleErrorFlush, handleErrorOutput, handleFlush, handleInput, handleOutput, init, isInvalid, log, log, maybeConfigure, perform, reconfigure, setDescription, setLocation, setOwningTarget, setRuntimeConfigurableWrapper, setTaskName, setTaskType

Methods inherited from class org.apache.tools.ant.ProjectComponent

getProject, setProject

Methods inherited from class java.lang.Object

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

Constructor Detail

TryCatchTask

public TryCatchTask()

Method Detail

addTry

public void addTry(org.apache.tools.ant.taskdefs.Sequential seq)
            throws org.apache.tools.ant.BuildException

Adds a nested <try> block - one is required, more is forbidden.

Throws:

org.apache.tools.ant.BuildException

addCatch

public void addCatch(TryCatchTask.CatchBlock cb)

addFinally

public void addFinally(org.apache.tools.ant.taskdefs.Sequential seq)
                throws org.apache.tools.ant.BuildException

Adds a nested <finally> block - at most one is allowed.

Throws:

org.apache.tools.ant.BuildException

setProperty

public void setProperty(java.lang.String p)

Sets the property attribute.

setReference

public void setReference(java.lang.String r)

Sets the reference attribute.

execute

public void execute()
             throws org.apache.tools.ant.BuildException

The heart of the task.

Overrides:

execute in class org.apache.tools.ant.Task

Throws:

org.apache.tools.ant.BuildException