iotools.java

本文档讲解了OTA的概念

/*
 Copyright (c) 2001-2003 sync4j project
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without
 modification, are permitted provided that the following conditions
 are met:
 
 1. Redistributions of source code must retain the above copyright
    notice, this list of conditions, and the following disclaimer.
 
 2. Redistributions in binary form must reproduce the above copyright
    notice, this list of conditions, and the disclaimer that follows 
    these conditions in the documentation and/or other materials 
    provided with the distribution.

 3. The name "sync4j" must not be used to endorse or promote products
    derived from this software without prior written permission.  
 
 4. Products derived from this software may not be called "sync4j", nor
    may "sync4j" appear in their name, without prior written permission.
 
 In addition, we request (but do not require) that you include in the 
 end-user documentation provided with the redistribution and/or in the 
 software itself an acknowledgement equivalent to the following:

     "This product includes software developed by the
      sync4j project."

 THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 DISCLAIMED.  IN NO EVENT SHALL THE SYNC4J AUTHORS OR THE PROJECT
 CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 SUCH DAMAGE.

 */

package com.ultrapower.tools;

import java.io.*;

/**
 * Container of utility methods for io access
 *
 * @author  Stefano Fornari @ Funambol
 * @version $Id: IOTools.java,v 1.3 2003/12/15 16:58:28 luigiafassina Exp $
 */
public class IOTools {
    
    /** 
     * Reads a file into a byte array given its filename
     *
     * @param file the filename (as java.io.File)
     *
     * @return the content of the file as a byte array
     *
     * @throws java.io.IOException;
     */
    static public byte[] readFileBytes(File file) 
    throws IOException {
        FileInputStream fis = null;
        
        byte[] buf = new byte[(int)file.length()];
        try {
            fis = new FileInputStream(file);
            fis.read(buf);
            fis.close();
        } finally {
            if (fis != null) {
                fis.close();
            }
        }
        
        return buf;
    }
        
    
    /** 
     * Reads a file into a byte array given its filename
     *
     * @param filename the filename (as java.lang.String)
     *
     * @return the content of the file as a byte array
     *
     * @throws java.io.IOException;
     */
    static public byte[] readFileBytes(String filename) 
    throws IOException {
        return readFileBytes(new File(filename));
    }
    
    /** 
     * Reads a file into a String given its filename
     *
     * @param file the filename (as java.io.File)
     *
     * @return the content of the file as a string
     *
     * @throws java.io.IOException;
     */
    static public String readFileString(File file) 
    throws IOException {
        return new String(readFileBytes(file));
    }
    
    /** 
     * Reads a file into a String given its filename
     *
     * @param filename the filename (as java.lang.String)
     *
     * @return the content of the file as a string
     *
     * @throws java.io.IOException;
     */
    static public String readFileString(String filename) 
    throws IOException {
        return readFileString(new File(filename));
    }
    
    /**
     * Writes the given string to the file with the given name
     *
     * @param str the string to write
     * @param file the file name as a java.io.File
     *
     * @throws java.io.IOException
     */
    static public void writeFile(String str, File file) 
    throws IOException {
        writeFile(str.getBytes(), file);
    }
    
    /**
     * Writes the given string to the file with the given name
     *
     * @param str the string to write
     * @param filename the file name as a java.lang.String
     *
     * @throws java.io.IOException
     */
    static public void writeFile(String str, String filename) 
    throws IOException {
        writeFile(str.getBytes(), new File(filename));
    }
    
    /**
     * Writes the given bytes to the file with the given name
     *
     * @param buf the bytes to write
     * @param filename the file name as a java.lang.String
     *
     * @throws java.io.IOException
     */
    static public void writeFile(byte[] buf, String filename) 
    throws IOException {
        writeFile(buf, new File(filename));
    }
    
    /**
     * Writes the given bytes to the file with the given name
     *
     * @param buf the bytes to write
     * @param file the file name as a java.io.File
     *
     * @throws java.io.IOException
     */
    static public void writeFile(byte[] buf, File file) 
    throws IOException {
        FileOutputStream fos = null;
        try {
            fos = new FileOutputStream(file);
            fos.write(buf);
            fos.close();
        } finally {
            if (fos != null) {
                fos.close();
            }
        }
    }
    
    /**
     * Returns a <i>FilenameFilter</i> that accepts only the files of the given
     * type (extension).
     *
     * @param type the type (the file extension) of the files to select. NULL
     *             means all files, the empty string means files without extension
     *             The filtering is case-insensitive
     *
     * @return the filter
     */
    public static FilenameFilter getFileTypeFilter(String type) {
        return new FileTypeFilter(type);
    }
    
    // -------------------------------------------------------------------------
    
    /**
     * This class is a <i>FilenameFilter</i> that accepts only the files of the 
     * specified type (extension). The filtering is case-insensitive,
     */
    public static class FileTypeFilter implements FilenameFilter {
        
        private String type;
        
        /**
         * Creates the filter on the given type. 
         *
         * @param type the type (the file extension) of the files to select. NULL
         *             means all files, the empty string means files without 
         *             extension. The filtering is case-insensitive
         */
        public FileTypeFilter(final String type) {
            this.type = type.toUpperCase();
        }
        
        public boolean accept(File dir, String name) {
            if (type == null) {
                return true;
            }
            
            if (type.length() == 0) {
                return (name.indexOf('.') < 0);
            }
            
            return (name.toUpperCase().endsWith(type));
        }
    }
}