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ExtendSelector.javaAPI DocApache Ant 1.706824Wed Dec 13 06:16:18 GMT 2006org.apache.tools.ant.types.selectors

ExtendSelector

public class ExtendSelector extends BaseSelector
Selector that selects files by forwarding the request on to other classes.
since
1.5

Fields Summary
private String
classname
private FileSelector
dynselector
private Vector
paramVec
private org.apache.tools.ant.types.Path
classpath
Constructors Summary
public ExtendSelector()
Default constructor.
Methods Summary
public voidaddParam(org.apache.tools.ant.types.Parameter p)
Create new parameters to pass to custom selector.

param
p The new Parameter object

        paramVec.addElement(p);
public final org.apache.tools.ant.types.PathcreateClasspath()
Specify the classpath to use to load the Selector (nested element).

return
a classpath to be configured

        if (isReference()) {
            throw noChildrenAllowed();
        }
        if (this.classpath == null) {
            this.classpath = new Path(getProject());
        }
        return this.classpath.createPath();
public final org.apache.tools.ant.types.PathgetClasspath()
Get the classpath

return
the classpath

        return classpath;
public booleanisSelected(java.io.File basedir, java.lang.String filename, java.io.File file)
Allows the custom selector to choose whether to select a file. This is also where the Parameters are passed to the custom selector, since we know we must have them all by now. And since we must know both classpath and classname, creating the class is deferred to here as well.

param
basedir The the base directory.
param
filename The name of the file to check.
param
file A File object for this filename.
return
whether the file should be selected or not.
exception
BuildException if an error occurs.

        validate();
        if (paramVec.size() > 0 && dynselector instanceof ExtendFileSelector) {
            Parameter[] paramArray = new Parameter[paramVec.size()];
            paramVec.copyInto(paramArray);
            // We know that dynselector must be non-null if no error message
            ((ExtendFileSelector) dynselector).setParameters(paramArray);
        }
        return dynselector.isSelected(basedir, filename, file);
public voidselectorCreate()
Instantiates the identified custom selector class.

        if (classname != null && classname.length() > 0) {
            try {
                Class c = null;
                if (classpath == null) {
                    c = Class.forName(classname);
                } else {
                    AntClassLoader al
                            = getProject().createClassLoader(classpath);
                    c = Class.forName(classname, true, al);
                }
                dynselector = (FileSelector) c.newInstance();
                final Project p = getProject();
                if (p != null) {
                    p.setProjectReference(dynselector);
                }
            } catch (ClassNotFoundException cnfexcept) {
                setError("Selector " + classname
                    + " not initialized, no such class");
            } catch (InstantiationException iexcept) {
                setError("Selector " + classname
                    + " not initialized, could not create class");
            } catch (IllegalAccessException iaexcept) {
                setError("Selector " + classname
                    + " not initialized, class not accessible");
            }
        } else {
            setError("There is no classname specified");
        }
public voidsetClassname(java.lang.String classname)
Sets the classname of the custom selector.

param
classname is the class which implements this selector

        this.classname = classname;
public final voidsetClasspath(org.apache.tools.ant.types.Path classpath)
Set the classpath to load the classname specified using an attribute.

param
classpath the classpath to use

        if (isReference()) {
            throw tooManyAttributes();
        }
        if (this.classpath == null) {
            this.classpath = classpath;
        } else {
            this.classpath.append(classpath);
        }
public voidsetClasspathref(org.apache.tools.ant.types.Reference r)
Set the classpath to use for loading a custom selector by using a reference.

param
r a reference to the classpath

        if (isReference()) {
            throw tooManyAttributes();
        }
        createClasspath().setRefid(r);
public voidverifySettings()
These are errors specific to ExtendSelector only. If there are errors in the custom selector, it should throw a BuildException when isSelected() is called.

        // Creation is done here rather than in isSelected() because some
        // containers may do a validation pass before running isSelected(),
        // but we need to check for the existence of the created class.
        if (dynselector == null) {
            selectorCreate();
        }
        if (classname == null || classname.length() < 1) {
            setError("The classname attribute is required");
        } else if (dynselector == null) {
            setError("Internal Error: The custom selector was not created");
        } else if (!(dynselector instanceof ExtendFileSelector)
                    && (paramVec.size() > 0)) {
            setError("Cannot set parameters on custom selector that does not "
                    + "implement ExtendFileSelector");
        }