BufferedReader 读取文件内容，原样输出

shasha 2022年03月22日编程语言 301 0

1.新建目标类：

package com.xuzhiwen.io; 
 
public class TargetFile { 
    public static void main(String[] args) { 
        System.out.println("TargetFile.java"); 
    } 
}

2.测试类：

package com.xuzhiwen.io; 
 
import java.io.BufferedReader; 
import java.io.FileReader; 
 
public class TestBufferedReader { 
    public static void main(String[] args) throws Exception { 
        String filepath = "src/com/xuzhiwen/io/TargetFile.java"; 
        BufferedReader read = new BufferedReader(new FileReader(filepath)); 
        String s; 
        StringBuffer sb = new StringBuffer(); 
        while((s=read.readLine()) != null){ 
            sb.append(s+"\n"); 
        } 
        read.close(); 
        System.out.println(sb); 
    } 
}

3.输出结果为：

4.文件结构树：

5. 将结果用StringReader再读一次：

package com.xuzhiwen.io; 
 
import java.io.BufferedReader; 
import java.io.FileReader; 
import java.io.StringReader; 
 
public class TestBufferedReader { 
    public static void main(String[] args) throws Exception { 
        String filepath = "src/com/xuzhiwen/io/TargetFile.java"; 
        BufferedReader read = new BufferedReader(new FileReader(filepath)); 
        String s; 
        StringBuffer sb = new StringBuffer(); 
        while((s=read.readLine()) != null){ 
            sb.append(s+"\n"); 
        } 
        read.close(); 
        System.out.println(sb); 
         
         
        StringReader sr = new StringReader(sb.toString()); 
        int c; 
        while((c=sr.read()) != -1){ 
            System.out.print((char)c); 
        } 
    } 
}

6. 运行结果如下:

7. 将内容写入文件：

package com.xuzhiwen.io; 
 
import java.io.BufferedReader; 
import java.io.BufferedWriter; 
import java.io.FileReader; 
import java.io.FileWriter; 
import java.io.PrintWriter; 
import java.io.StringReader; 
 
public class TestBufferedReader { 
    public static void main(String[] args) throws Exception { 
        String filepath = "src/com/xuzhiwen/io/TargetFile.java"; 
        BufferedReader read = new BufferedReader(new FileReader(filepath)); 
        String s; 
        StringBuffer sb = new StringBuffer(); 
        while((s=read.readLine()) != null){ 
            sb.append(s+"\n"); 
        } 
        read.close(); 
        System.out.println(sb); 
        System.out.println("=============================================="); 
         
         
        StringReader sr = new StringReader(sb.toString()); 
        int c; 
        while((c=sr.read()) != -1){ 
            System.out.print((char)c); 
        } 
        sr.close(); 
         
        System.out.println("=============================================="); 
         
        String file = "basic.out"; 
        BufferedReader br = new BufferedReader(new StringReader(sb.toString())); 
        PrintWriter pw = new PrintWriter(new BufferedWriter(new FileWriter(file))); 
         
        int lineCount = 1; 
        String ss; 
        while((ss=br.readLine()) != null){ 
            pw.println(lineCount+":  "+ss); 
            lineCount++; 
        } 
        pw.close(); 
    } 
}