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(); } }