獲取請求參數的通用方式
根據參數獲取參數值：
String name = request.getParameter(“name”);
根據參數獲取參數值的數組：
String[] hobbies = request.getParameterValues(“hobby”);
獲取所有請求的參數名稱：
Enumeration parameterNames = request.getParameterNames();
獲取所有參數的map集合
Map<String,String[]> getParameterMap()；
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.Enumeration;
@WebServlet("/RegisterDemo")
public class RegisterDemo extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//通用方法
//根據參數獲取參數值
String name = request.getParameter("name");
//根據參數獲取參數值的數組
String[] hobbies = request.getParameterValues("hobby");
for (String hobby : hobbies) {
System.out.println(hobby);
}
//獲取所有請求的參數名稱
Enumeration<String> parameterNames = request.getParameterNames();
while (parameterNames.hasMoreElements()){
String name1 = parameterNames.nextElement();
System.out.print(name1);
String value = request.getParameter(name1);
System.out.println(value);
//獲取所有參數的map集合
Map<String, String[]> parameterMap = request.getParameterMap();
//遍歷
Set<String> keyset = parameterMap.keySet();
for (String key : keyset) {
//獲取集合中的鍵和值
String[] values = parameterMap.get(key);
System.out.println(key);
for (String value : values) {
System.out.println(value);
}
System.out.println("-------");
}
}
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doPost(request, response);
}
}
相應的html代碼：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>注冊</title>
<form action="/RegisterDemo" method="post">
<input type="text" placeholder="請輸入用戶名" name="username"> <br>
<input type="text" placeholder="請輸入密碼" name="password"> <br>
<input type="checkbox" name="hobby" value="game"> 游戲
<input type="checkbox" name="hobby" value="study"> 學習
<input type="submit" value="注冊">
</form>
</head>
<body>
</body>
</html>