案例——复制Java文件

需求：把模块目录下的“Com.java”复制到模块目录下的“Copy.java”

package com.itcast;

import java.io.*;

public class CopyJavaDemo01 {
    public static void main(String[] args) throws IOException {
        //根据数据源创建字符流输入对象
        InputStreamReader isr = new InputStreamReader(new FileInputStream("Java进阶\IO流\Com.java"));
       //根据目的地创建字符输出流对象
        OutputStreamWriter osw = new OutputStreamWriter(new FileOutputStream("Java进阶\IO流\Copy.java"));
//  int ss;
//   while((ss=isr.read())!=-1){
//       osw.write(ss);
//   }
//   isr.close();
//   osw.close();
//读写数据，复制文件
        char[] ss = new char[1024];
        int len;
        while ((len=isr.read(ss))!=-1){
                 osw.write(ss,0,len);
        }
        
        osw.write();
        isr.close();


   }

}

升级版本

package com.itcast;

import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;

public class CopyJavaDemo02 {
    public static void main(String[] args) throws IOException {
        FileReader fr = new FileReader("IO流\Com.java");
        FileWriter fw = new FileWriter("IO流\Copy.java");

//        int ss;
//        while((ss=fr.read())!=-1){
//            fw.write(ss);
//        }

        char[] ss = new char[1024];
        int len;
        while((len=fr.read(ss))!=-1){
            fw.write(ss,0,len);
        }
        fw.close();
        fr.close();

    }
}