Servlet中操作文件详解及实例
因为Servlet本来就是一个.Java文件,因此servlet中操作文件和普通java文件操作文件是一样的。
读取文件主要代码:
FileReader f=new FileReader("f:\\lissdy.txt"); BufferedReader bw=new BufferedReader(f);
读出一行数据
String num=bw.readLine();
注意一定要关闭文件流
bw.close();
写文件的方法与之类似,具体代码为:
读取:
package com.lissdy; import java.io.BufferedReader; import java.io.IOException; import java.io.PrintWriter; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.*; @SuppressWarnings("serial") public class ReadFile extends HttpServlet{ public void doGet(HttpServletRequest req,HttpServletResponse res) { try { res.setContentType("text/html;charset=gbk"); PrintWriter pw=res.getWriter(); FileReader f=new FileReader("d:\\lissdy.txt"); BufferedReader bw=new BufferedReader(f); String num=bw.readLine(); bw.close(); pw.println("从文件中读取的数据是:"+num); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } }
写入:
package com.lissdy; import java.io.IOException; import java.io.PrintWriter; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.*; @SuppressWarnings("serial") public class WriteFile extends HttpServlet{ public void doGet(HttpServletRequest req,HttpServletResponse res) { try { res.setContentType("text/html;charset=gbk"); PrintWriter pw=res.getWriter(); //从内存到磁盘流动为写(输出流) //从磁盘文件到内存流动为读(输入流) FileWriter f=new FileWriter("d:\\lissdy.txt"); BufferedWriter bw=new BufferedWriter(f); bw.write("试一试文件怎么写"); pw.println("向文件写入数据"); bw.close(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } }
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