BufferedReader读取本地文件
在使用BufferedWriter写入文件时，如果忘记关闭文件（close）同时也没有调用flush(),则被写入的文件中是没有内容的。
在关闭文件的同时系统会自动调用flush()
try { File file=new File("c://aa.txt"); FileInputStream is=new FileInputStream(file); InputStreamReader reader=new InputStreamReader(is,"GBK"); BufferedReader br=new BufferedReader(reader); String line=null; while ((line=br.readLine())!=null) { System.out.println(line); } reader.close(); br.close(); is.close(); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } }
BufferedReader 读取文件内容，原样输出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(); }}
8. 运行结果：
9. 打开： basic.out文件：
以上为个人经验，希望能给大家一个参考，也希望大家多多支持。
带着感恩的心启程，学会爱，爱父母，爱自己，爱朋友，爱他人。
