exportusagetask.java

来自「纯java操作系统jnode,安装简单和操作简单的个人使用的Java操作系统」· Java 代码 · 共 191 行

/*
 * $Id: ExportUsageTask.java,v 1.1 2003/11/25 11:54:02 epr Exp $
 */
package org.jnode.shell.help.ant;

import java.io.File;
import java.io.FileWriter;
import java.lang.reflect.Field;

import org.apache.tools.ant.AntClassLoader;
import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.Project;
import org.apache.tools.ant.types.Path;
import org.dom4j.Document;
import org.dom4j.DocumentHelper;
import org.dom4j.Element;
import org.dom4j.io.XMLWriter;
import org.jnode.build.AbstractPluginsTask;
import org.jnode.plugin.ConfigurationElement;
import org.jnode.plugin.Extension;
import org.jnode.plugin.ExtensionPoint;
import org.jnode.plugin.PluginRegistry;
import org.jnode.shell.alias.AliasManager;
import org.jnode.shell.help.Argument;
import org.jnode.shell.help.Help;
import org.jnode.shell.help.Parameter;
import org.jnode.shell.help.Syntax;

/**
 * Task used to export usage information from a Main class.
 * @author epr
 */
public class ExportUsageTask extends AbstractPluginsTask {

	private File destFile;
	private Path classPath;

	/**
	 * Execute this task
	 * @throws BuildException
	 */
	public void execute() throws BuildException {

		final Document doc = DocumentHelper.createDocument();

		final Element root = doc.addElement("s:shell");
		root.addNamespace("s", "http://jnode.org/xsl/shell");

		final ClassLoader loader = new AntClassLoader(getClass().getClassLoader(), getProject(), classPath, true);

		try {
			final PluginRegistry piRegistry = getPluginRegistry();
			final ExtensionPoint ep = piRegistry.getExtensionPoint(AliasManager.ALIASES_EP_NAME);
			final Extension[] extensions = ep.getExtensions();

			for (int i = 0; i < extensions.length; i++) {
				final Extension ext = extensions[i];
				final ConfigurationElement[] elements = ext.getConfigurationElements();
				for (int j = 0; j < elements.length; j++) {
					String className = elements[j].getAttribute("class");
					try {
						final Class cls = loader.loadClass(className);
						final Field infoField = cls.getField(Help.INFO_FIELD_NAME);
						final Help.Info info = (Help.Info)infoField.get(null);

						new XmlHelp(info).bind(root);

					} catch (ClassCastException ex) {
						ex.printStackTrace();
						throw new BuildException(ex);
					} catch (ClassNotFoundException ex) {
						throw new BuildException(ex);
					} catch (NoSuchFieldException ex) {
						log("No INFO field in class " + className, Project.MSG_INFO);
					} catch (IllegalAccessException ex) {
						throw new BuildException(ex);
					}
				}

			}

			final XMLWriter xmlOut = new XMLWriter(new FileWriter(destFile));
			xmlOut.write(doc);
			xmlOut.flush();
			xmlOut.close();
		} catch (Exception ex) {
			ex.printStackTrace();
			throw new BuildException(ex);
		}
	}

	/**
	 * Gets the destination file
	 */
	public File getDestFile() {
		return destFile;
	}

	/**
	 * Sets the destination file
	 * @param file
	 */
	public void setDestFile(File file) {
		destFile = file;
	}

	public Path createClasspath() {
		return classPath.createPath();
	}

	private class XmlHelp extends Help {
		Element doc = null;
		Element s = null; // syntax element
		Info info;

		XmlHelp(Info info) {
			this.info = info;
		}

		void bind(Element root) {
			doc = root.addElement("s:command");
			doc.addAttribute("name", info.getName());
			help(info);
		}
		/**
		* Shows the complete help for a command.
		*/
		public void help(Info info) {
			final Syntax[] syntaxes = info.getSyntaxes();
			for (int i = 0; i < syntaxes.length; i++)
				help(info.getName(), syntaxes[i]);
		}

		/**
		* Shows the help for a command syntax.
		*/
		public void help(String name, Syntax syntax) {
			usage(name, syntax);

			final Parameter[] params = syntax.getParams();

			for (int i = 0; i < params.length; i++)
				params[i].describe(this);
		}

		/**
		* Shows the usage information of a command.
		*/
		public void usage(Info info) {
			final Syntax[] syntaxes = info.getSyntaxes();
			for (int i = 0; i < syntaxes.length; i++)
				usage(info.getName(), syntaxes[i]);
		}

		/**
		* Shows the usage information of a command.
		*/
		public synchronized void usage(String name, Syntax syntax) {
			s = doc.addElement("s:syntax");

			String line = name;
			final Parameter[] params = syntax.getParams();
			for (int i = 0; i < params.length; i++)
				line += " " + params[i].format();
			s.addElement("s:usage").addText(line);
			s.addElement("s:description").addText(syntax.getDescription());
		}

		public synchronized void describeParameter(Parameter param) {
			final Element p = s.addElement("s:parameter");
			p.addElement("s:name").addText(param.getName());
			p.addElement("s:description").addText(param.getDescription());
		}

		public synchronized void describeArgument(Argument arg) {
			final Element a = s.addElement("s:argument");
			a.addElement("s:name").addText(arg.getName());
			a.addElement("s:description").addText(arg.getDescription());
		}
	}

	/**
	 * @see org.apache.tools.ant.Task#init()
	 */
	public void init() throws BuildException {
		super.init();
		classPath = new Path(getProject());
	}

}