java 文件读写

package com.wyf.springmvc.common;


import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;


public class FileReadWrite {


/**
* @param args
* @throws IOException 
*/
public static void main(String[] args) throws IOException {
FileReadWrite filetest = new FileReadWrite();
// filetest.createFile();
filetest.readFile();
filetest.readFile2();
}

public void createFile()throws IOException{//写文件
int m [] = {15,65,89,87,51,2,10};
String path = "D:/file";
File f = new File(path);
if(!f.exists()){
f.mkdirs();
}
String fileName = "test.txt";
File file = new File(f,fileName);
if(!file.exists()){
file.createNewFile();
FileWriter fw = new FileWriter(file);
BufferedWriter out = new BufferedWriter(fw);
for(int i = 0; i < m.length; i++){
out.write(m[i]+" ");
}
// out.write("你好！世界");
out.close();
}
}


public void readFile() throws IOException{//FileInputStream 字节输入流读文件
File file = new File("D:/file/test.txt");
FileInputStream in = new FileInputStream(file);

byte[] bs=new byte[1024];
int count = 0;

while((count = in.read(bs)) > 0){
String str=new String(bs,0,count);//反复定义新变量：每一次都 重新定义新变量，接收新读取的数据
System.out.println(str);//反复输出新变量：每一次都 输出重新定义的新变量
}
in.close();
}


public void readFile2() throws IOException{//FileReader 字符输入流读文件
File file = new File("D:/file/test.txt");
FileReader fre = new FileReader(file);
BufferedReader bre = new BufferedReader(fre);

String str = "";
while((str = bre.readLine()) != null){
System.out.println(str);
}
bre.close();
fre.close();
}
}