[Java SE] JAVA.IO 相关--第四篇，写文件

1.以PrintWriter来实现写入

 

import java.io.*;

public class test {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		String path="e://a.txt";
		try {
			FileWriter fw=new FileWriter(path,true);
			PrintWriter pw=new PrintWriter(fw);
			pw.println("世界");
			pw.close();
			//bw.close();
			fw.close();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
 		}
       }
}

 2.以BufferedWriter来实现写入

 

import java.io.*; 

public class test { 
    /** * @param args */ 
   public static void main(String[] args) { 
           String path="e://a.txt"; 
           try { 
                FileWriter fw=new FileWriter(path,true); 
                BufferedWriter bw=new BufferedWriter(fw); 
                bw.newLine(); 
	bw.write("Hello"); 
	bw.newLine(); 
	bw.write("世界"); 
	bw.close();
	 fw.close(); 
         } catch (IOException e) { 
              // TODO Auto-generated catch block 
             e.printStackTrace(); 
          } 
  } 
}
   
//读文件用
//BufferedReader br = new BufferedReader( new FileReader(new File("e://a.txt")));  
 //br.readLine();//一行一行的读 

package test;

import java.io.File;
import java.io.FileOutputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.RandomAccessFile;

public class FileRW {
	public static void main(String[] a)  {
		try {
			FileOutputStream fos = new FileOutputStream (new File("d:\\abc.txt"),true ) ; 
			String str = "ABC \n" ;
			fos.write(str.getBytes()) ;
			fos.close ();
		} catch (IOException e) {
			e.printStackTrace();
		}
		
		try {
			FileWriter fw = new FileWriter("d:\\abc.txt",true);
			PrintWriter pw=new PrintWriter(fw);
			pw.println("append content");
			pw.close () ;
			fw.close () ;
		} catch (IOException e) {
			e.printStackTrace();
		} 
		
		try {
		 RandomAccessFile rf=new RandomAccessFile("d:\\abc.txt","rw"); 
		 rf.seek(rf.length());	//将指针移动到文件末尾 
		 rf.writeBytes("Append a line again!\n"); 
		 rf.close();//关闭文件流 
		}catch (IOException e){
			e.printStackTrace(); 
		}
		
		
	}

}