The Java Condition

The Java Condition can be used to check the value of a static field in a java class.

Example accessing a static field:

 <condition type="java" id="myStaticFieldIsTrue">
  <java>
    <class>my.package.MyClass</class>
    <field>myStaticField</field>
  </java>
  <returnvalue type="boolean">true</returnvalue>
</condition>

Example accessing a static method (as from izPack 5.2.0):

 <condition type="java" id="myStaticFieldIsTrue">
  <java>
    <class>my.package.MyClass</class>
    <method>processCondition</method>
  </java>
  <returnvalue type="boolean">true</returnvalue>
</condition>

Nested Elements

The Java condition must have a ava element and a returnvalue element.

java

The java element contains two mandatory elements, class and field. <class> contains the fully qualified name of the class and either a <field> contains the name of the static field or a <method> containing the static method to inspect.

returnvalue

This element defines what is the expected value. Currently, only type="boolean" and "string" (as of izPack 5.2.0) are supported.

Complicated condition checks - example

In order to check for complicated conditions with java you can do the following. Assume that we use the same condition as above.

package my.package
 
public class MyClass {
	public static boolean myStaticField = processCondition();
 
	public static boolean processCondition() {
		boolean conditionTrue = false;	
		//call other classes, conditionals, do processing, etc.
		return conditionTrue;
	}
} 

Note that for logging you will need to use log4j or similar. I use groovy in conjunction with an AntListener to log condition logs to temp. An easier way to accomplish this is to use process panels but if you absolutely must have a condition determined by java methods then this is the best way