IO流——输入输出流

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1. 首先理解何为输入输出流

1. BufferedReader 从键盘输入到程序

    package cn.itcast.cjj；
   import java.io.BufferedReader;
   import java.io.IOException;
   import java.io.InputStreamReader;
   
   public class InputStreamBufferTest {
   
   public static void main(String[] args) throws IOException {
   BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
   String str = reader.readLine();
   System.out.println(str);
   }
   
   }
   

2. BufferedReader 从键盘输入，BufferedWriter存储到文本中

   package cn.itcast.cjj;
   import java.io.BufferedReader;
   import java.io.BufferedWriter;
   import java.io.FileWriter;
   import java.io.IOException;
   import java.io.InputStreamReader;
   
   public class InputStreamBufferTest {
   
       public static void main(String[] args) throws IOException {
           BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
           String str = reader.readLine();
           System.out.println(str);
           FileWriter file = new FileWriter("C:\\Users\\CJJ\\Desktop\\a.txt");
           BufferedWriter buffWriter = new BufferedWriter(file);
           buffWriter.newLine();
           buffWriter.write(str);
           buffWriter.flush();
           buffWriter.close();
           file.close();
           reader.close();
       }
   
   }
   

3. InputStreamReader从键盘输入

   package cn.itcast.cjj;
   
   import java.io.IOException;
   import java.io.InputStreamReader;
   
   public class InputStreamScannerTest {
   
   public static void main(String[] args) throws IOException {
       InputStreamReader reader = new InputStreamReader(System.in);
       char cbuf[] = new char[24];
       boolean eof = false;
       while (!eof) {
           //输入不足24长度的会用乱码来代替
           int len = reader.read(cbuf,0,24);
               System.out.println(len + " ");
               for(char c : cbuf) {
                   System.out.print(c + " ");
               }
           }
       }
   
   }