package test;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
public class test {
public static void main(String[] args) throws IOException {
String status_file = "/home/work/hdfs-manager/round1_result_windows2x_2012-04-20_0000.status";
File fp = new File(status_file);
BufferedReader input = new BufferedReader(new FileReader(status_file));
BufferedWriter output = new BufferedWriter(new FileWriter(status_file));
String line;
while ((line = input.readLine()) != null) {
System.out.println(line);
}
input.close();
//写文件操作
...
}
}
大家好,这几天刚开始写java程序,今天在读写文件的过程中发现了一个奇怪的现象,就是如果只用BufferedReader读文件,那么运行正常;当在程序的后面又想通过BufferedWriter对同一个文件进行写操作的时候,发现文件在被之前会被清空。
即便只运行如下两句代码:
BufferedReader input = new BufferedReader(new FileReader(status_file));
BufferedWriter output = new BufferedWriter(new FileWriter(status_file));
文件仍然会被清空,这是什么原因呢?