Ant example source code file (Assertions.java)

This example Ant source code file (Assertions.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Ant tags/keywords

applying, arraylist, arraylist, assertions, assertions, baseassertion, baseassertion, buildexception, enabling, iterator, object, string, string, stringbuffer, util

The Assertions.java source code

/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 */

package org.apache.tools.ant.types;

import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.Project;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.ListIterator;

/**
 * The assertion datatype. This type describes
 * assertion settings for the <java> task and others.
 * One can set the system assertions, and enable/disable those in
 * packages and classes.
 * Assertions can only be enabled or disabled when forking Java.
 *
 * Example: set system assertions and all org.apache packages except
 * for ant, and the class org.apache.tools.ant.Main.
 * <pre>
 * <assertions enableSystemAssertions="true" >
 *   <enable package="org.apache" />
 *   <disable package="org.apache.ant" />
 *   <enable class="org.apache.tools.ant.Main"/>
 * </assertions>
 *</pre>
 * Disable system assertions; enable those in the anonymous package
 * <pre>
 * <assertions enableSystemAssertions="false" >
 *   <enable package="..." />
 * </assertions>
 * </pre>
 * enable assertions in a class called Test
 * <pre>
 * <assertions >
 *   <enable class="Test" />
 * </assertions>
 * </pre>
 * This type is a datatype, so you can declare assertions and use them later
 *
 * <pre>
 * <assertions id="project.assertions" >
 *   <enable project="org.apache.test" />
 * </assertions>
 *
 * <assertions refid="project.assertions" />
 *
 * </pre>
 * @since Ant 1.6
 */
public class Assertions extends DataType implements Cloneable {

    /**
     * enable/disable sys assertions; null means undefined
     */
    private Boolean enableSystemAssertions;

    /**
     * list of type BaseAssertion
     */
    private ArrayList assertionList = new ArrayList();


    /**
     * enable assertions
     * @param assertion an enable assertion nested element
     */
    public void addEnable(EnabledAssertion assertion) {
        checkChildrenAllowed();
        assertionList.add(assertion);
    }

    /**
     * disable assertions
     * @param assertion a disable assertion nested element
     */
    public void addDisable(DisabledAssertion assertion) {
        checkChildrenAllowed();
        assertionList.add(assertion);
    }

    /**
     * enable or disable system assertions.
     * Default is not set (neither -enablesystemassersions or -disablesytemassertions
     * are used on the command line).
     * @param enableSystemAssertions if true enable system assertions
     */
    public void setEnableSystemAssertions(Boolean enableSystemAssertions) {
        checkAttributesAllowed();
        this.enableSystemAssertions = enableSystemAssertions;
    }

    /**
     * Set the value of the refid attribute.
     *
     * <p>Subclasses may need to check whether any other attributes
     * have been set as well or child elements have been created and
     * thus override this method. if they do the must call
     * <code>super.setRefid.

     * @param ref the reference to use
     */
    public void setRefid(Reference ref) {
        if (assertionList.size() > 0 || enableSystemAssertions != null) {
            throw tooManyAttributes();
        }
        super.setRefid(ref);
    }

    /**
     * get whatever we are referencing to. This could be ourself.
     * @return the object that contains the assertion info
     */
    private Assertions getFinalReference() {
        if (getRefid() == null) {
            return this;
        } else {
            Object o = getRefid().getReferencedObject(getProject());
            if (!(o instanceof Assertions)) {
                throw new BuildException("reference is of wrong type");
            }
            return (Assertions) o;
        }
    }

    /**
     * how many assertions are made...will resolve references before returning
     * @return total # of commands to make
     */
    public int size() {
        Assertions clause = getFinalReference();
        return clause.getFinalSize();
    }


    /**
     * what is the final size of this object
     * @return
     */
    private int getFinalSize() {
        return assertionList.size() + (enableSystemAssertions != null ? 1 : 0);
    }

    /**
     * add the assertions to a list in a format suitable
     * for adding to a command line
     * @param commandList the command line to format
     */
    public void applyAssertions(List commandList) {
        getProject().log("Applying assertions", Project.MSG_DEBUG);
        Assertions clause = getFinalReference();
        //do the system assertions
        if (Boolean.TRUE.equals(clause.enableSystemAssertions)) {
            getProject().log("Enabling system assertions", Project.MSG_DEBUG);
            commandList.add("-enablesystemassertions");
        } else if (Boolean.FALSE.equals(clause.enableSystemAssertions)) {
            getProject().log("disabling system assertions", Project.MSG_DEBUG);
            commandList.add("-disablesystemassertions");
        }

        //now any inner assertions
        Iterator it = clause.assertionList.iterator();
        while (it.hasNext()) {
            BaseAssertion assertion = (BaseAssertion) it.next();
            String arg = assertion.toCommand();
            getProject().log("adding assertion " + arg, Project.MSG_DEBUG);
            commandList.add(arg);
        }
    }

    /**
     * apply all the assertions to the command.
     * @param command the command line to format
     */
    public void applyAssertions(CommandlineJava command) {
        Assertions clause = getFinalReference();
        //do the system assertions
        if (Boolean.TRUE.equals(clause.enableSystemAssertions)) {
            addVmArgument(command, "-enablesystemassertions");
        } else if (Boolean.FALSE.equals(clause.enableSystemAssertions)) {
            addVmArgument(command, "-disablesystemassertions");
        }

        //now any inner assertions
        Iterator it = clause.assertionList.iterator();
        while (it.hasNext()) {
            BaseAssertion assertion = (BaseAssertion) it.next();
            String arg = assertion.toCommand();
            addVmArgument(command, arg);
        }
    }

    /**
     * add the assertions to a list in a format suitable
     * for adding to a command line
     * @param commandIterator list of commands
     */
    public void applyAssertions(final ListIterator commandIterator) {
        getProject().log("Applying assertions", Project.MSG_DEBUG);
        Assertions clause = getFinalReference();
        //do the system assertions
        if (Boolean.TRUE.equals(clause.enableSystemAssertions)) {
            getProject().log("Enabling system assertions", Project.MSG_DEBUG);
            commandIterator.add("-enablesystemassertions");
        } else if (Boolean.FALSE.equals(clause.enableSystemAssertions)) {
            getProject().log("disabling system assertions", Project.MSG_DEBUG);
            commandIterator.add("-disablesystemassertions");
        }

        //now any inner assertions
        Iterator it = clause.assertionList.iterator();
        while (it.hasNext()) {
            BaseAssertion assertion = (BaseAssertion) it.next();
            String arg = assertion.toCommand();
            getProject().log("adding assertion " + arg, Project.MSG_DEBUG);
            commandIterator.add(arg);
        }
    }

    /**
     * helper method to add a string JVM argument to a command
     * @param command
     * @param arg
     */
    private static void addVmArgument(CommandlineJava command, String arg) {
        Commandline.Argument argument;
        argument = command.createVmArgument();
        argument.setValue(arg);
    }

    /**
     * clone the objects.
     * This is not a full depth clone; the list of assertions is cloned,
     * but it does not clone the underlying assertions.
     * @return a cli
     * @throws CloneNotSupportedException if the super class does not support cloning
     */
    public Object clone() throws CloneNotSupportedException {
        Assertions that = (Assertions) super.clone();
        that.assertionList = (ArrayList) assertionList.clone();
        return that;
    }

    /**
     * base class for our assertion elements.
     */

    public abstract static class BaseAssertion {
        private String packageName;
        private String className;

        /**
         * name a class
         * @param className a class name
         */
        public void setClass(String className) {
            this.className = className;
        }

        /**
         * name a package
         * @param packageName a package name
         */
        public void setPackage(String packageName) {
            this.packageName = packageName;
        }

        /**
         * what is the class name?
         * @return classname or null
         * @see #setClass
         */
        protected String getClassName() {
            return className;
        }

        /**
         * what is the package name?
         * @return package name or null
         * @see #setPackage
         */
        protected String getPackageName() {
            return packageName;
        }

        /**
         * get the prefix used to begin the command; -ea or -da.
         * @return prefix
         */
        public abstract String getCommandPrefix();

        /**
         * create a full command string from this class
         * @throws BuildException in case of trouble
         * @return The command string
         */
        public String toCommand() {
            //catch invalidness
            if (getPackageName() != null && getClassName() != null) {
                throw new BuildException("Both package and class have been set");
            }
            StringBuffer command = new StringBuffer(getCommandPrefix());
            //see if it is a package or a class
            if (getPackageName() != null) {
                //packages get a ... prefix
                command.append(':');
                command.append(getPackageName());
                if (!command.toString().endsWith("...")) {
                    //append the ... suffix if not there already
                    command.append("...");
                }
            } else if (getClassName() != null) {
                //classes just get the classname
                command.append(':');
                command.append(getClassName());
            }
            return command.toString();
        }
    }


    /**
     * an enabled assertion enables things
     */
    public static class EnabledAssertion extends BaseAssertion {
        /**
         * get the prefix used to begin the command; -ea or -da.
         * @return prefix
         */
        public String getCommandPrefix() {
            return "-ea";
        }

    }

    /**
     * A disabled assertion disables things
     */
    public static class DisabledAssertion extends BaseAssertion {
        /**
         * get the prefix used to begin the command; -ea or -da.
         * @return prefix
         */
        public String getCommandPrefix() {
            return "-da";
        }

    }
}