IO-Buffered包装类

我们在之前的装饰者设计模式中，我们学到了，包装类BufferedReader和BufferedWriter是用于修饰节点流的。让我们处理节点流能够有更强的功能。

下面演示BufferReader和Writer的基本用法。

package IO流.Buffered;

import java.io.*;


public class BufferedDemo02 {
    public static void main(String[] args) {

        BufferedWriter bw = null;
        BufferedReader br = null;
        try {
            bw = new BufferedWriter(new FileWriter("d:\new1.txt", true));
            br = new BufferedReader(new FileReader("d:\new1.txt"));
            String readstr;
            String writestr = "Hello,JVM";
            bw.newline();
            bw.write(writestr);
            bw.flush();
            while ((readstr = br.readLine())!=null){
                System.out.println(readstr);
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                bw.close();
                br.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}
 

 不难看到，我们在关闭包装流时，只需要对包装流关闭，查看源码我们能发现，close方法中，自动帮我们关闭了节点流。这个in指得就是节点流。

下面使用BufferedReader和Writer进行复制操作。但是注意，不要去操作二进制文件（声音，视频，doc，pdf等）可能会造成文件损坏。如何操作二进制文件呢？使用我们的BufferedInputStream和BufferedOutputStream。

package IO流.Buffered;

import java.io.*;


public class BufferedCopy {
    public static void main(String[] args) {
        String fpath ="d:\new1.txt";
        String tpath ="d:\new3.txt";
        new BufferedCopy().bufferedCopy(fpath,tpath);
    }
    public void bufferedCopy(String frompath ,String topath){
        BufferedReader br = null;
        BufferedWriter bw = null;
        try {
            br = new BufferedReader(new FileReader(frompath));
            bw = new BufferedWriter(new FileWriter(topath));
            String tempStr ;
            while ((tempStr = br.readLine())!=null){
                bw.write(tempStr);
                bw.newline();
                bw.flush();
            }
        }catch (IOException e){
            e.printStackTrace();
        }finally {
            try {
                br.close();
                bw.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }


    }
}

使用BufferedInputStream和BufferedOutputStream操作二进制文件。

package IO流.Buffered;

import java.io.*;


public class BufferedCopy2 {

    public static void main(String[] args) {
        String fpath ="d:\a1.jpg";
        String tpath ="d:\a2.jpg";
        new BufferedCopy2().bufferedCopy(fpath,tpath);
    }
    public void bufferedCopy(String frompath ,String topath){
        BufferedInputStream bis = null;
        BufferedOutputStream bos = null;
        try {
            bis = new BufferedInputStream(new FileInputStream(frompath));
            bos = new BufferedOutputStream(new FileOutputStream(topath));
            int readlen = 0;
            byte[] buff = new byte[1024];
            while ((readlen =  bis.read(buff))!=-1){
                bos.write(buff,0,readlen);

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


    }
}