org.apache.tools.ant

Class TaskConfigurationChecker

public class TaskConfigurationChecker extends Object

Helper class for the check of the configuration of a given task. This class provides methods for making assumptions about the task configuration. After collecting all violations with assert* and fail methods the checkErrors will throw a BuildException with all collected messages or does nothing if there wasn't any error.

Example:

     public class MyTask extends Task {
         ...
         public void execute() {
             TaskConfigurationChecker checker = TaskConfigurationChecker(this);
             checker.assertConfig(
                 srcdir != null,
                 "Attribute 'srcdir' must be set.
             );
             checker.assertConfig(
                 srcdir.exists(),
                 "Srcdir (" + srcdir + ") must exist."
             );
             if (someComplexCondition()) {
                 fail("Complex condition failed.");
             }
             checker.checkErrors();
         }
     }
 

See Also: Notification Pattern

Constructor Summary
TaskConfigurationChecker(Task task)
Constructor.
Method Summary
voidassertConfig(boolean condition, String errormessage)
Asserts that a condition is true.
voidcheckErrors()
Checks if there are any collected errors and throws a BuildException with all messages if there was one or more.
voidfail(String errormessage)
Registers an error.

Constructor Detail

TaskConfigurationChecker

public TaskConfigurationChecker(Task task)
Constructor.

Parameters: task which task should be checked

Method Detail

assertConfig

public void assertConfig(boolean condition, String errormessage)
Asserts that a condition is true.

Parameters: condition which condition to check errormessage errormessage to throw if a condition failed

checkErrors

public void checkErrors()
Checks if there are any collected errors and throws a BuildException with all messages if there was one or more.

Throws: BuildException if one or more errors were registered

fail

public void fail(String errormessage)
Registers an error.

Parameters: errormessage the message for the registered error