Java example source code file (JavaUtils.java)

This example Java source code file (JavaUtils.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

file, fileinputstream, filenotfoundexception, fileoutputstream, ioexception, javautils, unsyncbytearrayoutputstream

The JavaUtils.java Java example source code

/*
 * reserved comment block
 * DO NOT REMOVE OR ALTER!
 */
/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you 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 org.apache.commons.logging} logging facility */
    private 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 read from the file
     *
     * @throws FileNotFoundException
     * @throws IOException
     */
    public static byte[] getBytesFromFile(String fileName)
        throws FileNotFoundException, IOException {

        byte refBytes[] = null;

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

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

            refBytes = baos.toByteArray();
        } finally {
            if (baos != null) {
                baos.close();
            }
            if (fisRef != null) {
                fisRef.close();
            }
        }

        return refBytes;
    }

    /**
     * Method writeBytesToFilename
     *
     * @param filename
     * @param bytes
     */
    public static void writeBytesToFilename(String filename, byte[] bytes) {
        FileOutputStream fos = null;
        try {
            if (filename != null && bytes != null) {
                File f = new File(filename);

                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 (IOException ex) {
            if (fos != null) {
                try {
                    fos.close();
                } catch (IOException ioe) {
                    if (log.isLoggable(java.util.logging.Level.FINE)) {
                        log.log(java.util.logging.Level.FINE, ioe.getMessage(), ioe);
                    }
                }
            }
        }
    }

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

        byte[] retBytes = null;
        try {
            baos = new UnsyncByteArrayOutputStream();
            byte buf[] = new byte[4 * 1024];
            int len;

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

        return retBytes;
    }
}