java基础—IO流——转换流的操作

转换流的使用

转换流：

    InputStreamReader：字节到字符的桥梁，解码。

    OutputStreamWriter：字符到字节的桥梁，编码

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
public class SystemInput 
{
//读取键盘录入的字母，并将所有字母转换成大写字母输出在控制台上
  public static void main(String[] args) 
  {
    // 
    //SystemInDemo1();
    //ReadFileOut();
    ReadFileOut1();
  }
  private static void ReadFileOut1() {
    // 将键盘录入的数据储存到一个文件中去
    BufferedReader br = null;
    br = new BufferedReader(new InputStreamReader(System.in));
    //创建输出文件路径
    BufferedWriter bw = null;
    try {
      bw = new BufferedWriter(new OutputStreamWriter(new FileOutputStream("C:\\Users\\Administrator\\Desktop\\测试文件夹\\SystemInDemos.txt")));
      String len = null;
      while((len = br.readLine())!=null)
      {
        bw.write(len);
        bw.newLine();
        bw.flush();
      }
    } catch (FileNotFoundException  e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    } catch (IOException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    }finally
    {
      try 
      {
        bw.close();
      } catch (IOException e) 
      {
        e.printStackTrace();
      }
      try 
      {
        br.close();
      } catch (IOException e) 
      {
        e.printStackTrace();
      }
    }
    
  }

  private static void ReadFileOut() 
  {
  // 使用转换流将键盘上的数据输出在控制台上
  
    InputStream in = System.in;
    InputStreamReader isr = new InputStreamReader(in);
    
    //字符流
    BufferedReader br = new BufferedReader(isr);
    
    //字节流输出数据
    OutputStream out = System.out;
    
    OutputStreamWriter osw = new OutputStreamWriter(out);
    
    BufferedWriter bw = new BufferedWriter(osw);
    String len = null;
    try {
      while((len = br.readLine())!=null)
      {
        bw.write(len);
        bw.newLine();
        bw.flush();
      }
    } catch (IOException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    }
    
    
}

  private static void SystemInDemo1() {
    // 使用转换流读取一个键盘录入的数据并打印在控制台上
    BufferedReader bis = null;
    BufferedWriter bos = null;

    bis = new BufferedReader(new InputStreamReader(System.in));
    
    bos = new BufferedWriter(new OutputStreamWriter(System.out));
    
    String len = null;
    try {
      while((len=bis.readLine())!=null)
      {
        String s = len.toUpperCase();
        bos.write(s);
        bos.newLine();
        bos.flush();
        
      }
    } catch (IOException e) 
    {
      e.printStackTrace();
    }
    finally
    {
      try 
      {
        bis.close();
      } catch (IOException e) 
      {
        e.printStackTrace();
      }
      try 
      {
        bos.close();
      } catch (IOException e) 
      {
        e.printStackTrace();
      }
    }
    
  }

}