jsp+java类+servlet实现文件读取、写入的功能.doc

本文是根据tomcat平台下实现而做，文件目录为：tom_homewebappsnews下:htmlWEB-INFclasses comFileMan.classFileServlet.classweb.xml首页我们先实现文件读取的类:FileMan.java/FileMan.java 读写文件的一个类package com;import java.io.*;public class FileManprivate String currentRecord = null;/保存文本的变量private BufferedReader file; /BufferedReader对象，用于读取文件数据private String path;/文件完整路径名public FileMan() /ReadFile方法用来读取文件filePath中的数据，并返回这个数据public String ReadFile(String filePath) throws FileNotFoundExceptionpath = filePath;/创建新的BufferedReader对象file = new BufferedReader(new FileReader(path);String returnStr =null;try/读取一行数据并保存到currentRecord变量中currentRecord = file.readLine();catch (IOException e)/错误处理System.out.println(读取数据错误.);if (currentRecord = null)/如果文件为空returnStr = 没有任何记录;else/文件不为空returnStr =currentRecord;/返回读取文件的数据return returnStr;/写入文件public void WriteFile(String filePath,String tempcon) throws FileNotFoundExceptionpath = filePath;try /创建PrintWriter对象，用于写入数据到文件中PrintWriter pw = new PrintWriter(new FileOutputStream(filePath);/用文本格式打印整数Writestrpw.println(tempcon);/清除PrintWriter对象pw.close(); catch(IOException e) /错误处理System.out.println(写入文件错误+e.getMessage();/*下面这一般你可以用来测试java应用程序来读取文件，将前面的/去掉后你可以运行：java FileMan 来测试。*/public static void main(String args)/FileMan fm=new FileMan();/try/fm.WriteFile(test.txt,asf);/catch(FileNotFoundException e)/接着我们先实现servlet:FileServlet .java/* FileServlet.java*/package com;import java.io.*;import .*;import javax.servlet.*;import javax.servlet.http.*;import javax.servlet.jsp.PageContext;/*/public class FileServlet extends HttpServlet ServletContext sc; /* Initializes the servlet. */ public void init(ServletConfig config) throws ServletException super.init(config); sc=config.getServletContext(); /* Destroys the servlet. */ public void destroy() /* Processes requests for both HTTP GET and POST methods. * param request servlet request * param response servlet response */ protected void processRequest(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException response.setContentType(text/html); PrintWriter out = response.getWriter(); /* TODO output your page here out.println(); out.println(); out.println(); out.println(); out.println(); out.println(Hello); out.println(sc.getRealPath(/); FileMan fm=new FileMan();tryfm.WriteFile(sc.getRealPath(/)+/html/test.htm,asf);out.println(fm.ReadFile(sc.getRealPath(/)+/html/test.htm);catch(FileNotFoundException e) out.println(); out.println(); / */ out.close(); /* Handles the HTTP GET method. * param request servlet request * param response servlet response */ protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException processRequest(request, response); /* Handles the HTTP POST method. * param request servlet request * param response servlet response */ protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException processRequest(request, response); /* Returns a short description of the servlet. */ public String getServletInfo() return Short description; 下面开始修改web.xml令filesevelet生效/* Welcome to Tomcat Welcome to Tomcat org.apache.jsp.index_jsp org.apache.jsp.index_jsp org.apache.jsp.index_jsp