com.sharneng.io.IOUtils.java Source code

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Here is the source code for com.sharneng.io.IOUtils.java

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/*
 * Copyright 2002-2013 the original author or authors.
 *
 * 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.sharneng.io;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * IO related static utilities methods are defined in this class.
 * 
 * @author Kenneth Xu
 * 
 */
public final class IOUtils {
    private static final Log log = LogFactory.getLog(IOUtils.class);

    private static final int BUF_SIZE = 512;

    private IOUtils() {
    }

    /**
     * Read everything from <code>in</code> and write to <code>out</code> until reachs the end of the input stream. Both
     * <code>in</code> and <code>out</code> are then quitely closed (see {@link #close(InputStream)} ).
     * 
     * @param in
     *            data copy from
     * @param out
     *            data copy to
     * @throws IOException
     *             IO error occured when coping.
     * @see #copyStream(InputStream, OutputStream, boolean)
     */
    public static void copyStream(InputStream in, OutputStream out) throws IOException {
        copyStream(in, out, true);
    }

    /**
     * Read everything from <code>in</code> and write to <code>out</code> until reachs the end of the input stream. If
     * <code>closeOnFinish</code> is <code>true</code>, it quitely closes both <code>in</code> and <code>out</code> (see
     * {@link #close(InputStream)}) before retun. Otherwise, it leaves both of them open.
     * 
     * @param in
     *            data copy from
     * @param out
     *            data copy to
     * @param closeOnFinish
     *            passing <code>true</code> to close both stream before method return
     * @throws IOException
     *             IO error occured when coping.
     * @see #copyStream(InputStream, OutputStream)
     */
    public static void copyStream(InputStream in, OutputStream out, boolean closeOnFinish) throws IOException {
        byte[] buf = new byte[BUF_SIZE];
        int count;
        try {
            while ((count = in.read(buf)) != -1) {
                out.write(buf, 0, count);
            }
        } finally {
            if (closeOnFinish)
                close(in);
            if (closeOnFinish)
                close(out);
        }
    }

    /**
     * Quietly close a {@linkplain java.io.InputStream}. Exceptions are discarded.
     * 
     * @param in
     *            the input stream to close
     * @see #close(InputStream, boolean)
     */
    public static void close(InputStream in) {
        close(in, false);
    }

    /**
     * Quietly close a {@linkplain java.io.InputStream} without throwing any exception. Exceptions will be logged as
     * error if the <code>logError</code> is <code>true</code>.
     * 
     * @param in
     *            the input stream to close
     * @param logError
     *            true to log exception as error
     * @see #close(InputStream)
     * @see #close(OutputStream, boolean)
     */
    public static void close(InputStream in, boolean logError) {
        if (in != null) {
            try {
                in.close();
            } catch (Throwable t) {
                if (logError)
                    log.error(t.getMessage(), t);
                else
                    log.debug(t.getMessage(), t);
            }
        }
    }

    /**
     * Quietly close a {@linkplain java.io.OutputStream}. Exceptions are discarded.
     * 
     * @param out
     *            the output stream to close
     * @see #close(OutputStream, boolean)
     */
    public static void close(OutputStream out) {
        close(out, false);
    }

    /**
     * Quietly close a {@linkplain java.io.OutputStream} without throwing any exception. Exceptions will be logged as
     * error if the <code>logError</code> is <code>true</code>.
     * 
     * @param out
     *            the output stream to close
     * @param logError
     *            true to log exception as error
     * @see #close(OutputStream)
     * @see #close(InputStream, boolean)
     */
    public static void close(OutputStream out, boolean logError) {
        if (out != null) {
            try {
                out.close();
            } catch (Throwable t) {
                if (logError)
                    log.error(t.getMessage(), t);
                else
                    log.debug(t.getMessage(), t);
            }
        }
    }
}