一文带你读懂Java中的IO流

package cn.xlucas.io;
import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.net.InetAddress;
import java.net.Socket;
public class IoDemo1 {
 public static void main(String[] args) throws IOException {
  //testInput();
  writeFile();
  readFile();
 }
 //将文件的内容读取出来
 public static void readFile() throws IOException{
  //建立文件与程序的输入数据通道
  FileInputStream filein=new FileInputStream("F:\\a.txt");
  //创建输入字节流的转换流并且指定码表进行读取
  InputStreamReader inputin=new InputStreamReader(filein,"utf-8");
  //FileReader filein =new FileReader("F:\\a.txt");//这种会出现乱码的情况 
  int context=0;
  while((context=inputin.read())!=-1){
   System.out.print((char)context);
  }
  //关闭资源
  inputin.close();
  filein.close(); 
 }
 //将内容用utf-8的格式写入文件中
 public static void writeFile() throws IOException{
  //建立了文件与程序的数据 通道
  FileOutputStream fileout=new FileOutputStream("F:\\a.txt");
  //创建一个输出字节流的转换流并且指定码表进行写数据
  OutputStreamWriter output=new OutputStreamWriter(fileout,"utf-8");
  output.write("中国");
  output.close();
  fileout.close();
 }
 public static void testOutput() throws Exception{
  Socket socket = new Socket(InetAddress.getLocalHost(),9090);
  //获取到socket的输出流对象。
  OutputStream outputStream = socket.getOutputStream();
  //把输出字节流转换成输出字符流
  OutputStreamWriter outputStreamWriter = new OutputStreamWriter(outputStream);
  outputStreamWriter.write("不饿!");
 }
 public static void testInput() throws IOException{
  InputStream in=System.in;
  //输入转换流
  InputStreamReader input=new InputStreamReader(in);
  BufferedReader buffer=new BufferedReader(input);//用来做缓冲
  //int context =in.read();// 每次只会读取到一个字节的数据
  System.out.print(buffer.readLine());//读取一行数据
  //关闭字眼
  buffer.close();
  input.close();
 }
}