Java self-study notes (19): [IO] character stream, the stream buffer

Jifuryu

FileReader

package character;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
public class FileReaderDemo {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        File file = new File("test.txt");
        try {
            FileReader fr = new FileReader(file);
            char[] content;
            content = new char[512];
            fr.read(content); 
            fr.close();
            System.out.println(content);
            
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

}

FIleWriter

package character;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
public class FileWriterDemo {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        File file = new File("test.txt");
        try {
            FileWriter fw = new FileWriter(file);
            String str = "Hello World";
            fw.write(str);
            fw.close();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

}

~ Byte stream and similar operations

FileWriter write buffer is written to the file, so if there is no close (), content is not written, if you do not write close (), the need for flush ().

---

 

Buffer flow

BUfferedReader buffered input stream

package buffered;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;

public class BufferedREaderDemo {

    public static void main(String[] args) {
        File file = new File("test.txt");
        FileReader fr;
        try {
            fr = new FileReader(file);
            BufferedReader br = new BufferedReader(fr);
            String str = br.readLine();
            while(str!=null) {                     //输出所有文本
                System.out.println(str);
                str = br.readLine();
            }
            fr.close();
            br.close();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        
    }

}
}

Commutations InputStreamReader, OutputStreamWriter

package buffered;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class BufferedReaderDemo2 {

    public static void main(String[] args) {
        // 键盘输入
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));   //转换流
        try {
            System.out.println(br.readLine());   //输出
        } catch (IOException e) {
            e.printStackTrace();
        }
        
        //反复输入
        try {
            String str = br.readLine();
            while(str!=null) {
                System.out.println(str);
                str= br.readLine();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

}

 

BufferedWriter buffered output stream

The first output data stored in the buffer

Write:

Package buffered; 

Import java.io.BufferedWriter;
 Import java.io.File;
 Import java.io.FileWriter;
 Import java.io.IOException; 

public  class BufferWriterDemo { 

    public  static  void main (String [] args) {
         // write a poem 
        String [] str = { "I am a little monster, Happy and comfortable," "brutal, people do not eat salt", "a seven or eight belly to bursting," "latrine to shit, think paper forgotten " }; 
        File File = new new File (" test.txt " ); 
        FileWriter FW;
        try {
            fw = new FileWriter (File);
            BufferedWriter bw = new BufferedWriter(fw);
            for(int i=0;i<str.length;i++) {
                bw.write(str[i]);
                bw.write("\n\r");
            }
            bw.close();
            fw.close();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }    
    }
}

All code ~