raplaloader.java

来自「Rapla是一个灵活的多用户资源管理系统。它提供的一些功能有：日历GUI」· Java 代码 · 共 125 行

package org.rapla.bootstrap;
import java.io.File;
import java.io.IOException;
import java.lang.reflect.Method;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.ArrayList;
import java.util.StringTokenizer;

/**
  Puts all jar-files from the libdirs into the classpath and start the mainClass.
  Usage:
  <code>
        Syntax:  baseDir libdir1,libdir2,... mainClass arg1 arg2 ...

        Will put all jar-files from the libdirs into the classpath and start the mainClass

          baseDir: replace with the path, from wich you want the lib-dirs to resolve.
          libdir[1-n]: Lib-Directories relativ to the base jars.");
          mainClass: The Java-Class you want to start after loading the jars.
          arg[1-n]:

         Example:  ./lib common,client org.rapla.Main rapla

         loads the jars in lib/common and lib/client and
         starts org.rapla.Main with the argument rapla
  </code>
 */
public class RaplaLoader {
    /** returns all *.jar files in the directories passed in dirList relative to the baseDir */
    public static File[] getJarFiles(String baseDir,String dirList) throws IOException {
        ArrayList completeList = new ArrayList();
        StringTokenizer tokenizer = new StringTokenizer(dirList,",");
        while (tokenizer.hasMoreTokens())
        {
            File jarDir = new File(baseDir,tokenizer.nextToken());
            if (jarDir.exists() && jarDir.isDirectory())
            {
              File[] jarFiles = jarDir.listFiles();
              for (int i = 0; i < jarFiles.length; i++) {
                  if (
                      jarFiles[i].getAbsolutePath().endsWith(".jar")
                    )
                  {
                      completeList.add(jarFiles[i].getCanonicalFile());
                  }
              }
              completeList.add( jarDir.getCanonicalFile() );
            }
            
        }
        return (File[]) completeList.toArray(new File[] {});
    }

   
    private static void printUsage() {
        System.out.println("Syntax:  baseDir libdir1,libdir2,... mainClass arg1 arg2 ...");
        System.out.println();
        System.out.println("Will put all jar-files from the libdirs into the classpath and start the mainClass");
        System.out.println();
        System.out.println("  baseDir: replace with the path, from wich you want the lib-dirs to resolve.");
        System.out.println("  libdir[1-n]: Lib-Directories relativ to the base jars.");
        System.out.println("  mainClass: The Java-Class you want to start after loading the jars.");
        System.out.println("  arg[1-n]: ");
        System.out.println();
        System.out.println(" Example:  ./lib common,client org.rapla.Main rapla ");
        System.out.println("loads the jars in lib/common and lib/client and ");
        System.out.println("  starts org.rapla.Main with the argument rapla");
    }

    public static void main(String[] args) {
        String baseDir;
        String dirList;
        String classname;
        String[] applicationArgs;
       
        if (args.length <3) {
            printUsage();
            System.exit(1);
        }
        baseDir=args[0];
        dirList=args[1];
        classname=args[2];

        applicationArgs = new String[args.length-3];
        for (int i=0;i<applicationArgs.length;i++)
        {
            applicationArgs[i] = args[i+3];
        }
        start( baseDir, dirList, classname, applicationArgs );
    }


    public static void start( String baseDir, String dirList, String classname, String[] applicationArgs )
    {
        try{
            File[] jarFiles = getJarFiles(baseDir,dirList);
            URL[] urls = new URL[jarFiles.length];
            for (int i = 0; i < jarFiles.length; i++) {
                urls[i] = jarFiles[i].toURI().toURL();
//                System.out.println(urls[i]);
            }

            ClassLoader classLoader = new URLClassLoader
                (
                 urls
                ,RaplaLoader.class.getClassLoader()
                );
            Thread.currentThread().setContextClassLoader(classLoader);

            startMain(classLoader,classname,applicationArgs);
        } catch (Exception ex) {
            ex.printStackTrace();
            System.exit(1);
        }
    }

    private static void startMain(ClassLoader classLoader,String classname, String[] args) throws Exception {
        //Class secondClass = classLoader.loadClass("org.apache.avalon.framework.context.Context");
        Class startClass = classLoader.loadClass(classname);
        Method mainMethod = startClass.getMethod("main",new Class[] {args.getClass()});
        mainMethod.invoke(null, new Object[] {args});
    }
}