Apache ant extension tutorial

Apache Ant We are committed to becoming a flexible and convenient construction tool , Though right Java Support more , Some third-party libraries can also be used to support the construction of other languages , Even some routine maintenance tasks . Whereas Apache Ant Use XML As a configuration language , Be good at description , And cannot deal with overly complex process logic , So there is the famous Ant-Contrib Expansion pack, （ Home page see here ） Where it comes in handy .Ant-Contrib Of course, the use of has increased Apache Ant The programmability of , But from the author's point of view , Contrary to Apache Ant Design intention of , meanwhile XML Even if it has programming ability , The logical expressiveness of traditional programming languages is by no means XML Comparable . in fact , Through its official API Expand Apache Ant Make it complete the user customization function , In the long run , It has better simplicity 、 Robustness, 、 Maintainability and stability , It's just relatively friendly XML, read API The arduous task of concealing expansion Apache Ant Just the advantage of .

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Apache Ant The build file consists of two elements , Namely Task（ Mission ） and DataType（ data type ）. generally , Type represents a collection of resources , Such as Fileset（ File set ）; Tasks are used to perform certain operations . Although there are many differences between tasks and types , But both from Java There are many similarities in class structure . for example ：

package packagePath;
import org.apache.tools.ant.Task;  //  Tasks are inherited from here 
import org.apache.tools.ant.BuildException;

/* *  Use  Java Bean  Specification definition  XML  attribute , Attribute name from  getter/setter  Guess from the name . *  To add child elements , Need to use  addXXX(YYYY e)  Method .XXX  For the child element  XML  Element name  * （ stay  XML  Regardless of case , But in  Java  The naming in should conform to  Java Bean  standard ）; * YYYY  For its practical  Java  Class name . */
public class MyTask extends Task {
    

    private String myStringAttribute;
    private int myIntAttribute;
    private File myFileAttribute;

    private ArrayList<SelfDefinedSubElement> l;

    public MyTask() {
        l = new ArrayList<SelfDefinedSubElement>();
    }

    public String getMyStringAttribute() {
        return myStringAttribute;
    }

    //  The other two  getters ...

    public void setMyStringAttribute(String myStringAttribute) {
        this.myStringAttribute = myStringAttribute;
    }

    //  The other two  setters ...

    public void addSelfDefinedElement(SelfDefinedSubElement e) {
        l.add(e);
    }

    /* *  Start the task here .DataType  There is no such method ; but  DataType  Get references  *  Methods , That is, use attributes in one place  id  Mark the data type and then use it in another place  refid *  Get its reference . Detailed inquiry  Apache Ant API */
    @Override
    public void execute() {
        if (myStringAttribute == null) {
            throw new BuildException("myStringAttribute not set");
        }

        //  Other input checks  ...

        //  What to do  ...
    }  
}

This is a task , One Java file .

#  Defined here  MyTask  stay  XML  Element name in 
nameUsedByMyTaskInBuildfile=packagePath.MyTask
selfDefinedElement= Its fully qualified classpath 

This is the mission statement , One propertes file .

<target name="XXX">
  <!-- some other tasks -->
  <nameUsedByMyTaskInBuildfile myStringAttribute="stringValue" myFileAttribute="C:\Users" myIntAttribute="5">
    <selfDefinedElement someAttributes="" />
  </nameUsedByMyTaskInBuildfile>
  <!-- some other tasks -->
</target>

This is a possible corresponding to the task XML Example .

package anotherPackagePath;
import org.apache.tools.ant.types.DataType;  //  The data type inherits from here 
import org.apache.tools.ant.BuildException;

/* *  The description is the same as the task description  */
public class MyType extends DataType {
    

    private String myStringAttribute;
    private int myIntAttribute;
    private File myFileAttribute;

    private ArrayList<AnotherSelfDefinedSubElement> l;

    public MyTask() {
        l = new ArrayList<AnotherSelfDefinedSubElement>();
    }

    public String getMyStringAttribute() {
        return myStringAttribute;
    }

    //  The other two  getters ...

    public void setMyStringAttribute(String myStringAttribute) {
        this.myStringAttribute = myStringAttribute;
    }

    //  The other two  setters ...

    public void addAnotherSelfDefinedElement(AnotherSelfDefinedSubElement e) {
        l.add(e);
    }
}

This is a data type , One Java file .

nameUsedByMyTypeInBuildfile=anotherPackagePath.MyType
anotherSelfDefinedElement= Its fully qualified classpath 

This is the data type declaration , One propertes file .

<nameUsedByMyTypeInBuildfile myStringAttribute="stringValue" myFileAttribute="C:\Users" myIntAttribute="5" id="my.id">
  <anotherSelfDefinedElement someAttributes="" />
</nameUsedByMyTypeInBuildfile>

This is a possible corresponding to this data type XML Example .

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Related reading ：

Apache Ant API The basic use method

Apache Ant API（ This is a download address ,Apache Ant No official online API）