FileUtil.java

/*
 * Copyright (C) 2015 HouKx <hkx.aidream@gmail.com>
 *
 * 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 androidx.pluginmgr;

import java.io.BufferedOutputStream;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.nio.channels.Channels;
import java.nio.channels.FileChannel;
import java.nio.channels.ReadableByteChannel;

/**
 * 文件操作工具类
 * <p>
 * 使用nio以提高性能
 * 
 * @author HouKangxi
 * 
 */
class FileUtil {

    public static void writeToFile(InputStream dataIns, File target)
            throws IOException {
        final int BUFFER = 1024;
        BufferedOutputStream bos = new BufferedOutputStream(
                new FileOutputStream(target));
        int count;
        byte data[] = new byte[BUFFER];
        while ((count = dataIns.read(data, 0, BUFFER)) != -1) {
            bos.write(data, 0, count);
        }
        bos.close();
    }

    public static void writeToFile(byte[] data, File target) throws IOException {
        FileOutputStream fo = null;
        ReadableByteChannel src = null;
        FileChannel out = null;
        try {
            src = Channels.newChannel(new ByteArrayInputStream(data));
            fo = new FileOutputStream(target);
            out = fo.getChannel();
            out.transferFrom(src, 0, data.length);
        } finally {
            if (fo != null) {
                fo.close();
            }
            if (src != null) {
                src.close();
            }
            if (out != null) {
                out.close();
            }
        }
    }

    /**
     * 
     * 复制文件
     * 
     * @param source
     *            - 源文件
     * 
     * @param target
     *            - 目标文件
     * 
     */
    public static void copyFile(File source, File target) {

        FileInputStream fi = null;
        FileOutputStream fo = null;

        FileChannel in = null;

        FileChannel out = null;

        try {
            fi = new FileInputStream(source);

            fo = new FileOutputStream(target);

            in = fi.getChannel();// 得到对应的文件通道

            out = fo.getChannel();// 得到对应的文件通道

            in.transferTo(0, in.size(), out);// 连接两个通道，并且从in通道读取，然后写入out通道

        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                fi.close();

                in.close();

                fo.close();

                out.close();

            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}