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Comprehensive Java common library (Java7+)

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/*
 * Copyright (C) 2015-2017 S.Violet
 *
 * 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.
 *
 * Project GitHub: https://github.com/shepherdviolet/thistle
 * Email: [email protected]
 */

package sviolet.thistle.util.file;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.channels.FileChannel;

/**
 * 文件复制器快速版
 *
 * @author S.Violet
 */
public class FastFileCopyer {
	
	/**
     * 
	 * 单线程最快的复制文件方法

	 * 目标文件的修改时间与原文件保持基本一致

	 * 目标文件修改时间可能会偏大,偏差<2000ms, 例如:

	 * 原始文件修改时间:****2356

	 * 目标文件修改时间:****4000

     * 
	 * 
	 * @param source 源文件
	 * @param target 目标文件
	 */
    public static void copy(File source,File target) throws IOException {
        FileChannel in = null;
        FileChannel out = null;
        FileInputStream inStream = null;
        FileOutputStream outStream = null;
        try {
            inStream = new FileInputStream(source);
            outStream = new FileOutputStream(target);
            in = inStream.getChannel();
            out = outStream.getChannel();
            long totalSize = in.size();
            long readSize = 0;
            while(totalSize > 0 && readSize < totalSize){
            	readSize += in.transferTo(readSize, totalSize - readSize, out);
            }
        } finally {
            try{in.close();}catch (Exception ignored){}
            try{inStream.close();}catch (Exception ignored){}
            try{outStream.flush();}catch (Exception ignored){}
            try{out.close();}catch (Exception ignored){}
            try{outStream.close();}catch (Exception ignored){}
        }
        //使目标文件修改时间与源文件保持一致
        long lastModified = source.lastModified();
        //解决有时候取出负数, 无法设置时间的问题
        if(lastModified < 0L) {
            lastModified = 0L;
        }
        target.setLastModified(lastModified);
    }
}