https://ant.apache.org/: master POM (The Apache Software Foundation) 
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 *      https://www.apache.org/licenses/LICENSE-2.0
 *
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 *  distributed under the License is distributed on an "AS IS" BASIS,
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package org.apache.tools.ant;

import java.lang.reflect.Method;

import org.apache.tools.ant.dispatch.DispatchUtils;
import org.apache.tools.ant.dispatch.Dispatchable;


Uses introspection to "adapt" an arbitrary Bean which doesn't
itself extend Task, but still contains an execute method and optionally
a setProject method.

/**
 * Uses introspection to "adapt" an arbitrary Bean which doesn't
 * itself extend Task, but still contains an execute method and optionally
 * a setProject method.
 *
 */
public class TaskAdapter extends Task implements TypeAdapter {

    
Object to act as a proxy for. 
/** Object to act as a proxy for. */
    private Object proxy;

    
No-arg constructor for reflection.

/**
     * No-arg constructor for reflection.
     */
    public TaskAdapter() {
    }

    
Constructor for given proxy.
So you could write easier code

myTaskContainer.addTask(new TaskAdapter(myProxy));



Params:
  • proxy – The object which Ant should use as task.
/**
     * Constructor for given proxy.
     * So you could write easier code
     * <pre>
     * myTaskContainer.addTask(new TaskAdapter(myProxy));
     * </pre>
     *
     * @param proxy The object which Ant should use as task.
     */
    public TaskAdapter(Object proxy) {
        this();
        setProxy(proxy);
    }

    
Checks whether or not a class is suitable to be adapted by TaskAdapter.
If the class is of type Dispatchable, the check is not performed because
the method that will be executed will be determined only at runtime of
the actual task and not during parse time.
This only checks conditions which are additionally required for
tasks adapted by TaskAdapter. Thus, this method should be called by
Project.checkTaskClass.
Throws a BuildException and logs as Project.MSG_ERR for
conditions that will cause the task execution to fail.
Logs other suspicious conditions with Project.MSG_WARN.

Params:
  • taskClass – Class to test for suitability.
                 Must not be null.
  • project –   Project to log warnings/errors to.
                 Must not be null.
See Also:
/**
     * Checks whether or not a class is suitable to be adapted by TaskAdapter.
     * If the class is of type Dispatchable, the check is not performed because
     * the method that will be executed will be determined only at runtime of
     * the actual task and not during parse time.
     *
     * This only checks conditions which are additionally required for
     * tasks adapted by TaskAdapter. Thus, this method should be called by
     * Project.checkTaskClass.
     *
     * Throws a BuildException and logs as Project.MSG_ERR for
     * conditions that will cause the task execution to fail.
     * Logs other suspicious conditions with Project.MSG_WARN.
     *
     * @param taskClass Class to test for suitability.
     *                  Must not be <code>null</code>.
     * @param project   Project to log warnings/errors to.
     *                  Must not be <code>null</code>.
     *
     * @see Project#checkTaskClass(Class)
     */
    public static void checkTaskClass(final Class<?> taskClass,
                                      final Project project) {
        if (!Dispatchable.class.isAssignableFrom(taskClass)) {
            // don't have to check for interface, since then
            // taskClass would be abstract too.
            try {
                final Method executeM = taskClass.getMethod("execute");
                // don't have to check for public, since
                // getMethod finds public method only.
                // don't have to check for abstract, since then
                // taskClass would be abstract too.
                if (!Void.TYPE.equals(executeM.getReturnType())) {
                    final String message = "return type of execute() should be "
                        + "void but was \"" + executeM.getReturnType() + "\" in "
                        + taskClass;
                    project.log(message, Project.MSG_WARN);
                }
            } catch (NoSuchMethodException e) {
                final String message = "No public execute() in " + taskClass;
                project.log(message, Project.MSG_ERR);
                throw new BuildException(message);
            } catch (LinkageError e) {
                String message = "Could not load " + taskClass + ": " + e;
                project.log(message, Project.MSG_ERR);
                throw new BuildException(message, e);
            }
        }
    }

    
Check if the proxy class is a valid class to use
with this adapter.
The class must have a public no-arg "execute()" method.

Params:
  • proxyClass – the class to check.
/**
     * Check if the proxy class is a valid class to use
     * with this adapter.
     * The class must have a public no-arg "execute()" method.
     * @param proxyClass the class to check.
     */
    public void checkProxyClass(Class<?> proxyClass) {
        checkTaskClass(proxyClass, getProject());
    }

    
Executes the proxied task.

Throws:
  • BuildException – if the project could not be set
or the method could not be executed.
/**
     * Executes the proxied task.
     *
     * @exception BuildException if the project could not be set
     * or the method could not be executed.
     */
    public void execute() throws BuildException {
        try {
            Method setLocationM =
                proxy.getClass().getMethod("setLocation", Location.class);
            if (setLocationM != null) {
                setLocationM.invoke(proxy, getLocation());
            }
        } catch (NoSuchMethodException e) {
            // ignore this if the class being used as a task does not have
            // a set location method.
        } catch (Exception ex) {
            log("Error setting location in " + proxy.getClass(),
                Project.MSG_ERR);
            throw new BuildException(ex);
        }

        try {
            Method setProjectM =
                proxy.getClass().getMethod("setProject", Project.class);
            if (setProjectM != null) {
                setProjectM.invoke(proxy, getProject());
            }
        } catch (NoSuchMethodException e) {
            // ignore this if the class being used as a task does not have
            // a set project method.
        } catch (Exception ex) {
            log("Error setting project in " + proxy.getClass(),
                Project.MSG_ERR);
            throw new BuildException(ex);
        }

        try {
            DispatchUtils.execute(proxy);
        } catch (BuildException be) {
            throw be;
        } catch (Exception ex) {
            log("Error in " + proxy.getClass(), Project.MSG_VERBOSE);
            throw new BuildException(ex);
        }
    }

    
Sets the target object to proxy for.

Params:
  • o – The target object. Must not be null.
/**
     * Sets the target object to proxy for.
     *
     * @param o The target object. Must not be <code>null</code>.
     */
    public void setProxy(Object o) {
        this.proxy = o;
    }

    
Returns the target object being proxied.

Returns:the target proxy object.
/**
     * Returns the target object being proxied.
     *
     * @return the target proxy object.
     */
    public Object getProxy() {
        return proxy;
    }

}