在eclipse完成一个删除重复词汇的filter案例
时间: 2023-12-10 12:40:42 浏览: 33
好的,下面是一个基于 Eclipse 的删除重复词汇的 Filter 案例:
1. 创建一个名为 "DuplicateWordsFilter" 的 Java 类,并在其中实现 `javax.servlet.Filter` 接口。
```
import java.io.IOException;
import java.util.Arrays;
import java.util.HashSet;
import java.util.Set;
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 DuplicateWordsFilter implements Filter {
private Set<String> stopWords = new HashSet<>(Arrays.asList("a", "an", "the", "and", "or"));
@Override
public void init(FilterConfig filterConfig) throws ServletException {
// 初始化方法
}
@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
throws IOException, ServletException {
// 获取请求参数
String text = request.getParameter("text");
if (text != null && !text.isEmpty()) {
// 删除停用词
String[] words = text.split("\\s+");
StringBuilder sb = new StringBuilder();
for (String word : words) {
if (!stopWords.contains(word.toLowerCase())) {
sb.append(word).append(" ");
}
}
text = sb.toString().trim();
// 删除重复词汇
Set<String> wordSet = new HashSet<>(Arrays.asList(words));
sb = new StringBuilder();
for (String word : wordSet) {
sb.append(word).append(" ");
}
text = sb.toString().trim();
// 将处理后的参数注入请求对象
request.setAttribute("text", text);
}
// 继续执行 Filter 链
chain.doFilter(request, response);
}
@Override
public void destroy() {
// 销毁方法
}
}
```
2. 在 `web.xml` 文件中注册 Filter。
```
<filter>
<filter-name>DuplicateWordsFilter</filter-name>
<filter-class>DuplicateWordsFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>DuplicateWordsFilter</filter-name>
<url-pattern>/process</url-pattern>
</filter-mapping>
```
3. 在 Servlet 中使用 Filter。
```
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
@WebServlet("/process")
public class ProcessServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
// 调用 Filter 处理请求参数
request.getRequestDispatcher("/result.jsp").forward(request, response);
}
}
```
4. 在 JSP 页面中获取处理后的参数并输出。
```
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Result</title>
</head>
<body>
<h1>Result</h1>
<p>Processed text: <%= request.getAttribute("text") %></p>
</body>
</html>
```
以上就是一个基于 Eclipse 的删除重复词汇的 Filter 案例。