BufferedReader讀取本地文件
在使用BufferedWriter寫入文件時，如果忘記關(guān)閉文件（close）同時也沒有調(diào)用flush(),則被寫入的文件中是沒有內(nèi)容的。
在關(guān)閉文件的同時系統(tǒng)會自動調(diào)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 讀取文件內(nèi)容，原樣輸出
1.新建目標(biāo)類：
package com.xuzhiwen.io;
public class TargetFile {
public static void main(String[] args) {
System.out.println("TargetFile.java");
}
}
2.測試類：
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+"
");
}
read.close();
System.out.println(sb);
}
}
3.輸出結(jié)果為：
4.文件結(jié)構(gòu)樹：
5. 將結(jié)果用StringReader再讀一次：
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+"
");
}
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. 運(yùn)行結(jié)果如下:
7. 將內(nèi)容寫入文件：
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+"
");
}
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. 運(yùn)行結(jié)果：
9. 打開： basic.out文件：
以上為個人經(jīng)驗(yàn)，希望能給大家一個參考，也希望大家多多支持服務(wù)器之家。
原文鏈接：https://blog.csdn.net/qq_42772927/article/details/91489234
