IO流操作

FileInputStream和FileOutputStream复制文件

public class streamCopyFile {

    public static void main(String[] args) {
        streamCopyFile("E:/file/1.jpg","E:/file/4.jpg");
    }

    private static void streamCopyFile(String srcFileName, String descFileName) {
        FileInputStream fi = null;
        FileOutputStream fo = null;
        try{
            // 使用字节流进行文件复制
            fi = new FileInputStream(srcFileName);
            fo = new FileOutputStream(descFileName);
//            Integer by = 0;
//            //一次读取一个字节
//            while((by = fi.read()) != -1) {
//                fo.write(by);
//            }
            //创建搬运工具
            byte buffer[] = new byte[1024];
            //创建长度
            int len = 0;
            //循环读取数据
            while((len = fi.read(buffer))!=-1){
                fo.write(buffer,0,len);
            }

        }catch (IOException e){
            e.printStackTrace();
        }finally {
            if(fi!=null){
                try {
                    fi.close();
                }catch (IOException e){
                    throw new RuntimeException("关闭失败");
                }
            }
            if(fo!=null){
                try {
                    fo.close();
                }catch (IOException e){
                    throw new RuntimeException("关闭失败");
                }
            }
        }
     }
}

BufferedInputStream和BufferedOutputStream复制文件

public class BufferedStreamCopyFile {
    public static void main(String[] args) {
        streamCopyFile("E:/file/1.jpg","E:/file/5.jpg");
    }

    private static void streamCopyFile(String srcFileName, String descFileName) {

        BufferedInputStream bis = null;
        BufferedOutputStream bos = null;

        try{

            //缓冲区字节输入流
            bis = new BufferedInputStream(new FileInputStream(srcFileName));
            //缓冲区字节输出流
            bos = new BufferedOutputStream(new FileOutputStream(descFileName));
//            int len = 0;
//            while ((len = bis.read()) != -1) {//读取
//                //写入另一个文件
//                bos.write(len);
//            }
            byte[] buffer = new byte[1024];//构造一个长度为1024的字节数组
            int len = 0;
            while ((len = bis.read(buffer)) != -1) {//读取
                //写入另一个文件
                bos.write(buffer);
            }
            bos.flush();

        }catch (IOException e){
            e.printStackTrace();
        }finally {
            if(bis!=null){
                try {
                    bis.close();
                }catch (IOException e){
                    throw new RuntimeException("关闭失败");
                }
            }
            if(bos!=null){
                try {
                    bos.close();
                }catch (IOException e){
                    throw new RuntimeException("关闭失败");
                }
            }
        }

    }
}

FileWriter和FileReader复制文件

public class WriterReaderCopyFile {

    public static  void copyd() {

        FileWriter fw = null;
        FileReader fd = null;

        try
        {
            fw = new FileWriter("/Users/dongbo/Downloads/a_copy.txt");
            fd = new FileReader("/Users/dongbo/Downloads/a.txt");

            char [] ch = new char[1024];
            int num = 0;

            while((num=fd.read(ch))!=-1) {
                fw.write(ch,0,num);
            }
        } catch(IOException e) {
            System.out.println( e.toString());
        } finally {
            try {
                if(fw!=null)
                    fw.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
            try {
                if(fd!=null)
                    fd.close();
            } catch(IOException e) {
                e.printStackTrace();
            }
        }

    }

}

BufferedReader和BufferedWriter复制文件

public class BufferedWriterReaderCopy {
    public static void main(String[] args) {
        copyFile("E:/file/3.36.txt","E:/file/3.37.txt");
    }

    public static void copyFile(String srcFileName, String descFileName) {

        BufferedReader bf = null;
        BufferedWriter bw = null;
        try {
            //缓冲区字符输入流
            bf = new BufferedReader(new FileReader(srcFileName));
            //缓冲区字符输出流
            bw = new BufferedWriter(new FileWriter(descFileName));
//            int len = 0;
//            char[] buffer = new char[1024];
//            while ((len = bf.read(buffer)) != -1) {//直接按字节读取
//                //写入另一个文件
//                bw.write(buffer);
//            }
            String str;
            while ((str = bf.readLine()) != null) {//直接按字节读取
                //写入另一个文件
                bw.write(str);
                bw.newLine();
                bw.flush();
            }
        }catch (IOException e){
            e.printStackTrace();
        }finally {
            if(bw!=null){
                try {
                    bw.close();
                }catch (IOException e){
                    throw new RuntimeException("关闭失败");
                }
            }
            if(bf!=null){
                try {
                    bf.close();
                }catch (IOException e){
                    throw new RuntimeException("关闭失败");
                }
            }
        }


    }

}

• 字符流的均会出现中文字符乱码的情况
  InputStreamReader isr = new InputStreamReader(new FileInputStream(srcFileName),"GBK");
BufferedReader br = new BufferedReader(new InputStreamReader(new FileInputStream(srcFileName),"GBK"));