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分享servlet中的一个文件读写问题
servlet 文件如下:
import java.text.*;
import java.io.*;
import java.util.*;
import javax.servlet.http.*;
import javax.servlet.*;
public class vote extends HttpServlet
{
public void doGet(HttpServletRequest request,HttpServletResponse res)
throws IOException,ServletException
{
String readstr="";
int j;
int[] num=new int[10];
res.setContentType("text/html");
PrintWriter out=res.getWriter();
out.println("<html>");
out.println("<head>");
out.println("<title>:)</title>");
out.println("</head>");
out.println("<body>");
String checked=request.getParameter("checkbutton");
try
{
readstr="";
j=Integer.parseInt(checked);
FileReader read=new FileReader("vote.txt");
// FileReader in=new FileReader(read);
BufferedReader in = new BufferedReader(read);
for(int i=0;i<10;i++)
{
if(i!=j)
num[i]=Integer.parseInt(in.readLine());
else
num[i]=Integer.parseInt(in.readLine())+1;
}
in.close();
PrintWriter writer=new PrintWriter(new FileWriter("vote.txt"));
for(int i=0;i<10;i++)
writer.println(num[i]);
writer.close();
}
catch(IOException e){
return;
}
out.println("<script>");
out.println("alert(\"谢谢您的合作! \");");
out.println("self.location=\"http://ln/examples/servlets/vote.htm\";");
out.println("</script>");
out.println("</body></html>");
out.close();
}
}
vote.htm文件如下:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<title>无标题文档</title>
</head>
<body>
<div align="center">
<p>问卷调查 </p>
<p align="left"> 请您对本网站作出评价:</p>
<form method="GET" action="http://ln/examples/servlet/vote">
<table width="75%" border="0">
<tr>
<td width="37%"><div align="center">第一选项:</div></td>
<td width="60%"> <input type="radio" name="checkbutton" value="0">
非常满意</td>
<td width="3%"> </td>
</tr>
<tr>
<td><div align="center">第二选项:</div></td>
<td><input type="radio" name="checkbutton" value="1">
一般满意</td>
<td> </td>
</tr>
<tr>
<td><div align="center">第三选项:</div></td>
<td> <input type="radio" name="checkbutton" value="2">
不满意</td>
<td> </td>
</tr>
</table>
<table width="75%" border="0">
<tr>
<td width="20%"><div align="right"> </div></td>
<td width="75%"> </td>
<td width="5%"> </td>
</tr>
<tr>
<td><div align="right">
<input type="submit" name="B1" value="提交">
</div></td>
<td><input type="reset" name="B2" value="取消"></td>
<td> </td>
</tr>
<tr>
<td height="42"> </td>
<td><a href="http://ln/examples/servlet/seevote">查看统计数据</a></td>
<td> </td>
</tr>
</table>
<p> </p>
<p> </p>
<p> </p>
</form>
<p align="left"> </p>
</div>
</body>
</html>
用tomcat examples中srevlet 自带的配置可是不能对建立的vote.txt文件进行访问.....vote.txt文件放在E:\Tomcat 4.1\webapps\examples\WEB-INF\classes下
请高手帮忙看下~~:)
import java.text.*;
import java.io.*;
import java.util.*;
import javax.servlet.http.*;
import javax.servlet.*;
public class vote extends HttpServlet
{
public void doGet(HttpServletRequest request,HttpServletResponse res)
throws IOException,ServletException
{
String readstr="";
int j;
int[] num=new int[10];
res.setContentType("text/html");
PrintWriter out=res.getWriter();
out.println("<html>");
out.println("<head>");
out.println("<title>:)</title>");
out.println("</head>");
out.println("<body>");
String checked=request.getParameter("checkbutton");
try
{
readstr="";
j=Integer.parseInt(checked);
FileReader read=new FileReader("vote.txt");
// FileReader in=new FileReader(read);
BufferedReader in = new BufferedReader(read);
for(int i=0;i<10;i++)
{
if(i!=j)
num[i]=Integer.parseInt(in.readLine());
else
num[i]=Integer.parseInt(in.readLine())+1;
}
in.close();
PrintWriter writer=new PrintWriter(new FileWriter("vote.txt"));
for(int i=0;i<10;i++)
writer.println(num[i]);
writer.close();
}
catch(IOException e){
return;
}
out.println("<script>");
out.println("alert(\"谢谢您的合作! \");");
out.println("self.location=\"http://ln/examples/servlets/vote.htm\";");
out.println("</script>");
out.println("</body></html>");
out.close();
}
}
vote.htm文件如下:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<title>无标题文档</title>
</head>
<body>
<div align="center">
<p>问卷调查 </p>
<p align="left"> 请您对本网站作出评价:</p>
<form method="GET" action="http://ln/examples/servlet/vote">
<table width="75%" border="0">
<tr>
<td width="37%"><div align="center">第一选项:</div></td>
<td width="60%"> <input type="radio" name="checkbutton" value="0">
非常满意</td>
<td width="3%"> </td>
</tr>
<tr>
<td><div align="center">第二选项:</div></td>
<td><input type="radio" name="checkbutton" value="1">
一般满意</td>
<td> </td>
</tr>
<tr>
<td><div align="center">第三选项:</div></td>
<td> <input type="radio" name="checkbutton" value="2">
不满意</td>
<td> </td>
</tr>
</table>
<table width="75%" border="0">
<tr>
<td width="20%"><div align="right"> </div></td>
<td width="75%"> </td>
<td width="5%"> </td>
</tr>
<tr>
<td><div align="right">
<input type="submit" name="B1" value="提交">
</div></td>
<td><input type="reset" name="B2" value="取消"></td>
<td> </td>
</tr>
<tr>
<td height="42"> </td>
<td><a href="http://ln/examples/servlet/seevote">查看统计数据</a></td>
<td> </td>
</tr>
</table>
<p> </p>
<p> </p>
<p> </p>
</form>
<p align="left"> </p>
</div>
</body>
</html>
用tomcat examples中srevlet 自带的配置可是不能对建立的vote.txt文件进行访问.....vote.txt文件放在E:\Tomcat 4.1\webapps\examples\WEB-INF\classes下
请高手帮忙看下~~:)
...全文
请发表友善的回复…
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pigo 2003-10-16
- 打赏
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java.io.FileWriter fw=new java.io.FileWriter(request.getRealPath("/")+"\\counter.txt");
java.io.PrintWriter pw=new java.io.PrintWriter(fw);
pw.print(String.valueOf(Integer.parseInt(countno)+1) );
pw.close();
fw.close();
9731boy 2003-10-16
- 打赏
- 举报
:)
woderoom 2003-10-16
- 打赏
- 举报
for(int i=0;i<10;i++)
{
if(i!=j)
num[i]=Integer.parseInt(in.readLine());
else
num[i]=Integer.parseInt(in.readLine())+1;
}
in.close();
---〉追加
read.close(); //关闭文件，否则直接抛异常了
=============
建议在读文件前增加判断文件是否存在的方法，以增强程序健壮性
if(read.exist())
{
... ...
}
{
if(i!=j)
num[i]=Integer.parseInt(in.readLine());
else
num[i]=Integer.parseInt(in.readLine())+1;
}
in.close();
---〉追加
read.close(); //关闭文件，否则直接抛异常了
=============
建议在读文件前增加判断文件是否存在的方法，以增强程序健壮性
if(read.exist())
{
... ...
}
