Servlet中操作文件詳解及實例
因為Servlet本來就是一個.Java文件,因此servlet中操作文件和普通java文件操作文件是一樣的。
讀取文件主要代碼:
FileReader f=new FileReader("f://lissdy.txt");BufferedReader bw=new BufferedReader(f);
讀出一行數據
String num=bw.readLine();
注意一定要關閉文件流
bw.close();
寫文件的方法與之類似,具體代碼為:
讀取:
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("從文件中讀取的數據是:"+num); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } }
寫入:
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(); //從內存到磁盤流動為寫(輸出流) //從磁盤文件到內存流動為讀(輸入流) FileWriter f=new FileWriter("d://lissdy.txt"); BufferedWriter bw=new BufferedWriter(f); bw.write("試一試文件怎么寫"); pw.println("向文件寫入數據"); bw.close(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } }
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