打印流(PrintWriter ）

PrintWriter
package cn.lijun.demo1;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.PrintWriter;

// 打印流  PrintStream    PrintWriter
//  特点  不负责数据源  只负责数据目的    不会抛IOException     可能会抛出其他异常
public class Demo1PrintWrite {
    public static void main(String[] args) throws Exception {
        fun4();
    }
    //打印流可以开启自动刷新功能   输出的数据必须是流对象  Outputem  Writer
        //  必须调用print 方法
        public static void fun4() throws FileNotFoundException{
            FileOutputStream fos = new FileOutputStream("c:\\ll.txt");
            PrintWriter pr = new PrintWriter(fos,true);
            pr.print("zhang");
            pr.print("zhang");
            pr.print("zhang");
            pr.close();
        }
    //打印流输出目的  是流对象
    public static void fun3() throws FileNotFoundException{
        PrintWriter p= new PrintWriter("c:\\6.txt");
        PrintWriter p1= new PrintWriter(p);
        p1.println("打印流");
        p1.close();

    }

    //打印流 输出目的 String 文件名
    public static void fun2() throws FileNotFoundException{
        PrintWriter p = new PrintWriter("c:\\3.txt");
        p.println(333);
        p.println(333);
        p.close();
    }
    /*向File对象的数据目的写入数据*/
    public static void fun() throws Exception{
        File file =  new File("c:\\2.txt");
        PrintWriter p = new PrintWriter(file);
        p.print(true);
        p.print(100);
        p.close();
    }
}

//打印流复制文件
package cn.lijun.demo1;

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;

public class Demo2PrintReder {
    public static void main(String[] args) throws IOException {
        BufferedReader bf = new BufferedReader(new FileReader("c:\\ll.txt"));
        PrintWriter p= new PrintWriter(new FileWriter("d:\\ll.txt"),true);
        String line= null;
        while((line=bf.readLine())!=null){
            p.print(line);
        }
        p.close();
        bf.close();
    }
}