ioutil.java

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

/*--------------------------------------------------------------------------*
 | Copyright (C) 2006 Christopher Kohlhaas                                  |
 |                                                                          |
 | This program is free software; you can redistribute it and/or modify     |
 | it under the terms of the GNU General Public License as published by the |
 | Free Software Foundation. A copy of the license has been included with   |
 | these distribution in the COPYING file, if not go to www.fsf.org         |
 |                                                                          |
 | As a special exception, you are granted the permissions to link this     |
 | program with every library, which license fulfills the Open Source       |
 | Definition as published by the Open Source Initiative (OSI).             |
 *--------------------------------------------------------------------------*/
package org.rapla.components.util;

import java.io.BufferedInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.io.UnsupportedEncodingException;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLDecoder;
import java.net.URLEncoder;
import java.util.ArrayList;
import java.util.StringTokenizer;

import org.apache.avalon.framework.CascadingException;

/** Some IOHelper methods. */
abstract public class IOUtil {

    /** returns the path of the url without the last path component */
    public static URL getBase(URL url) {
        try {
            String file = url.getPath();
            String separator = "/";
            if (url.getProtocol().equals("file") && file.indexOf(File.separator)>0) {
                separator = File.separator;
            }
            int index = file.lastIndexOf(separator);
            String dir =  (index<0) ? file: file.substring(0,index + 1);
            return new URL(url.getProtocol()
                           ,url.getHost()
                           ,url.getPort()
                           ,dir);
        } catch ( MalformedURLException e) {
            // This should not happen
            e.printStackTrace();
            throw new RuntimeException("Unknown error while getting the base of the url!");
        } // end of try-catch
    }

    /** reads the content form an url into a ByteArray*/
    public static byte[] readBytes(URL url) throws IOException {
        InputStream in = null;
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        try {
            in = url.openStream();
            byte[] buffer = new byte[1024];
            int count = 0;
            do {
                out.write(buffer, 0, count);
                count = in.read(buffer, 0, buffer.length);
            } while (count != -1);
            return out.toByteArray();
        } finally {
            if ( in != null) {
                in.close();
            } // end of if ()
        }
    }



    /** same as {@link URLDecoder#decode}.
     *   But calls the deprecated method under 1.3.
     */
    public static String decode(String s,String enc) throws UnsupportedEncodingException {
        return callEncodeDecode(URLDecoder.class,"decode",s,enc);
    }

    /** same as {@link URLEncoder#encode}.
     * But calls the deprecated method under 1.3.
     */
    public static String encode(String s,String enc) throws UnsupportedEncodingException {
        return callEncodeDecode(URLEncoder.class,"encode",s,enc);
    }

    private static String callEncodeDecode(Class clazz,String methodName,String s,String enc) throws UnsupportedEncodingException {
        Assert.notNull(s);
        Assert.notNull(enc);
        try {
            Method method =
                clazz.getMethod(methodName
                                ,new Class[] {
                                    String.class
                                    ,String.class
                                }
                                           );
            return (String) method.invoke(null,new Object[] {s,enc});
        } catch (NoSuchMethodException ex) {
            try {
                Method method =
                    URLDecoder.class.getMethod(methodName
                                               ,new Class[] {String.class}
                                               );
                return (String) method.invoke(null,new Object[] {s});
            } catch (Exception ex2) {
                ex2.printStackTrace();
                throw new IllegalStateException("Should not happen" + ex2.getMessage());
            }
        } catch (InvocationTargetException ex) {
            throw (UnsupportedEncodingException) ex.getTargetException();
        } catch (IllegalAccessException ex) {
            ex.printStackTrace();
            throw new IllegalStateException("Should not happen" + ex.getMessage());
        }
    }


    /**  returns a BufferedInputStream from the url.
         If the url-protocol is "file" no url connection will
         be opened.
     */
    public static InputStream getInputStream(URL url) throws IOException {
        if (url.getProtocol().equals("file")) {
            String path = decode(url.getPath(),"UTF-8");
            return new BufferedInputStream(new FileInputStream(path));
        } else {
            return new BufferedInputStream(url.openStream());
        } // end of else
    }

    public static File getFileFrom(URL url) throws IOException {
        String path = decode(url.getPath(),"UTF-8");
        return new File( path );
    }


   /** copies a file.
    * @param srcPath the source-path. Thats the path of the file that should be copied.
    * @param destPath the destination-path
      */

     public static void copy( String srcPath, String destPath) throws IOException{
         copy( srcPath, destPath, false);
     }

     /** copies a file.
      * @param srcPath the source-path. Thats the path of the file that should be copied.
      * @param destPath the destination-path
        */
     public static void copy( String srcPath, String destPath,boolean onlyOverwriteIfNewer ) throws IOException{
        copy ( new File( srcPath ) , new File( destPath ), onlyOverwriteIfNewer );
    }

    /** copies a file.
        */
      public static void copy(File srcFile,  File destFile, boolean onlyOverwriteIfNewer) throws IOException {
		  if ( ! srcFile.exists() ) {
			  throw new IOException( srcFile.getPath() + " doesn't exist!!");
		  }
          if ( destFile.exists() && destFile.lastModified() >= srcFile.lastModified() && onlyOverwriteIfNewer)
          {
              return;
          }
		  FileInputStream in = null;
		  FileOutputStream out = null;
		  try {
			  in = new FileInputStream( srcFile );
			  out = new FileOutputStream( destFile);
			  copyStreams ( in, out );
		  } finally {
				if ( in != null )
			       in.close();

				if ( out != null )
			       out.close();
          }
	  }

      /** copies the contents of the input stream to the output stream.
       * @param in
       * @param out
       * @throws IOException
       */
	  public static void copyStreams( InputStream in, OutputStream out ) throws IOException {
		  byte[] buf = new byte[ 32000 ];
		  int n = 0;
		  while ( n != -1 ) {
              out.write( buf, 0, n );
			  n = in.read(buf, 0, buf.length );
		  }
	  }

      /** returns the relative path of file to base.
         * @throws IOException if position of file is not relative  to base
        */
        public static String getRelativePath(File base,File file) throws IOException {
            String filePath = file.getAbsoluteFile().getCanonicalPath();
            String basePath = base.getAbsoluteFile().getCanonicalPath();
            int start = filePath.indexOf(basePath);
            if (start != 0)
                throw new IOException(basePath + " not ancestor of " + filePath);
            return filePath.substring(basePath.length());
        }

        /** returns the relative path of file to base.
         * same as {@link #getRelativePath(File, File)} but replaces windows-plattform-specific
         * file separator <code>\</code> with <code>/</code>
         * @throws IOException if position of file is not relative  to base
         */
        public static String getRelativeURL(File base,File file) throws IOException {
            StringBuffer result= new StringBuffer(getRelativePath(base,file));
            for (int i=0;i<result.length();i++) {
                if (result.charAt(i) == '\\')
                    result.setCharAt(i, '/');
            }
            return result.toString();
        }

        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());
                      }
                  }
                }
            }
            return (File[]) completeList.toArray(new File[] {});
        }

        public static String getStackTraceAsString(Throwable ex) {
            ByteArrayOutputStream bytes = new ByteArrayOutputStream();
            PrintWriter writer = new PrintWriter(bytes,true);
            writer.println("<h2>" + ex.getMessage() +"</h2><br/>");
            ex.printStackTrace(writer);
            while (ex instanceof CascadingException) {
                ex = ((CascadingException) ex).getCause();
                if (ex != null) {
                    writer.println("<br/><h2>Caused by: "+ ex.getMessage() + "</h2><br/>");
                    ex.printStackTrace(writer);
                } else {
                    break;
                }
            }
            return bytes.toString();
        }


}