编写登录表单处理程序,引人过滤器.统一处理所有请求编码,解决中文乱码问题。 实验步骤: (1) 编写一个用户请求表单页面loginform.html,供用户提供表单向服务器传递请求参数。 (2)编写处理请求参数的Servlet(CheckParamServlet. java),参考代码如下: (3)修改web.xml文件; (4)运行网页,输入用户名和口令,然后单击“提交”按钮,经CheckParamServlet处理后返回结果。 (5)编写一个过滤器EncodingFilter. java,改变请求编码,统一处理请求参数中文编码。 系统中是否启用过滤器可通过web.xml配置文件控制,实验时,注意观察过滤器启用和关闭两种情形的效果(不用过滤器时会产生中文乱码)。 (6)在web. xml文件中配置过滤器,加人编码参数utf-8。
时间: 2023-12-10 07:42:15 浏览: 111
以下是可能的实现,仅供参考。
loginform.html:
```html
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Login Form</title>
</head>
<body>
<form action="CheckParamServlet" method="post">
<label for="username">Username:</label>
<input type="text" id="username" name="username"><br>
<label for="password">Password:</label>
<input type="password" id="password" name="password"><br>
<input type="submit" value="Submit">
</form>
</body>
</html>
```
CheckParamServlet.java:
```java
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class CheckParamServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String username = request.getParameter("username");
String password = request.getParameter("password");
response.setContentType("text/html;charset=UTF-8");
response.getWriter().println("<h1>Username: " + username + "</h1>");
response.getWriter().println("<h1>Password: " + password + "</h1>");
}
}
```
web.xml:
```xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
version="4.0">
<servlet>
<servlet-name>CheckParamServlet</servlet-name>
<servlet-class>CheckParamServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>CheckParamServlet</servlet-name>
<url-pattern>/CheckParamServlet</url-pattern>
</servlet-mapping>
<filter>
<filter-name>EncodingFilter</filter-name>
<filter-class>EncodingFilter</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>UTF-8</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>EncodingFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
</web-app>
```
EncodingFilter.java:
```java
import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
public class EncodingFilter implements Filter {
private String encoding;
public void init(FilterConfig config) throws ServletException {
encoding = config.getInitParameter("encoding");
}
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
throws IOException, ServletException {
request.setCharacterEncoding(encoding);
response.setCharacterEncoding(encoding);
chain.doFilter(request, response);
}
public void destroy() {
}
}
```
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