javautils.java

来自「JAVA 所有包」· Java 代码 · 共 124 行

/*
 * Copyright  1999-2004 The Apache Software Foundation.
 *
 *  Licensed 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 com.sun.org.apache.xml.internal.security.utils;



import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;


/**
 * A collection of different, general-purpose methods for JAVA-specific things
 * @author Christian Geuer-Pollmann
 *
 */
public class JavaUtils {

   /** {@link java.util.logging} logging facility */
    static java.util.logging.Logger log = 
        java.util.logging.Logger.getLogger(JavaUtils.class.getName());

   private JavaUtils() {
     // we don't allow instantiation
   }
   /**
    * Method getBytesFromFile
    *
    * @param fileName
    * @return the bytes readed from the file
    *
    * @throws FileNotFoundException
    * @throws IOException
    */
   public static byte[] getBytesFromFile(String fileName)
           throws FileNotFoundException, IOException {

      byte refBytes[] = null;

      {
         FileInputStream fisRef = new FileInputStream(fileName);
         UnsyncByteArrayOutputStream baos = new UnsyncByteArrayOutputStream();
         byte buf[] = new byte[1024];
         int len;

         while ((len = fisRef.read(buf)) > 0) {
            baos.write(buf, 0, len);
         }

         refBytes = baos.toByteArray();
      }

      return refBytes;
   }

   /**
    * Method writeBytesToFilename
    *
    * @param filename
    * @param bytes
    */
   public static void writeBytesToFilename(String filename, byte[] bytes) {

      try {
         if (filename != null && bytes != null) {
            File f = new File(filename);

            FileOutputStream fos = new FileOutputStream(f);

            fos.write(bytes);
            fos.close();
         } else {
            if (log.isLoggable(java.util.logging.Level.FINE))                                     log.log(java.util.logging.Level.FINE, "writeBytesToFilename got null byte[] pointed");
         }
      } catch (Exception ex) {}
   }

   /**
    * This method reads all bytes from the given InputStream till EOF and returns
    * them as a byte array.
    *
    * @param inputStream
    * @return the bytes readed from the stream
    *
    * @throws FileNotFoundException
    * @throws IOException
    */
   public static byte[] getBytesFromStream(InputStream inputStream) throws IOException {

      byte refBytes[] = null;

      {
         UnsyncByteArrayOutputStream baos = new UnsyncByteArrayOutputStream();
         byte buf[] = new byte[1024];
         int len;

         while ((len = inputStream.read(buf)) > 0) {
            baos.write(buf, 0, len);
         }

         refBytes = baos.toByteArray();
      }

      return refBytes;
   }
}