Request获取参数请求通用方式
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2022-07-14 22:33:35
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1.获取请求参数通用方式
目录
1.String getParameter(String name):根据参数名称获取参数值
2.String[] getParameterValues(String name):根据参数名称获取参数值得数组
3.Enumeration getParameterNmaes():获取所有请求得参数名称
4.Map getParameterMap():获取所有参数得map集合,string[]>
regist02.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>注册页面</title>
</head>
<body>
<form action="/RequestDemo06" method="post">
<input type="text" placeholder="请输入用户名" name="username"><br>
<input type="password" placeholder="请输入密码" name="password" ><br>
<input type="submit" value="注册">
</form>
</body>
</html>
1.String getParameter(String name):根据参数名称获取参数值
package servlet.http.request;
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;
@WebServlet( "/RequestDemo06")
public class RequestDemo06 extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//post获取请求参数
//根据参数名称获取参数值
String username = request.getParameter("username");
System.out.println("post");
System.out.println(username);
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//get获取请求参数
//根据参数名称获取参数值
/*String username = request.getParameter("username");
System.out.println("get");
System.out.println(username);*/
this.doPost(request,response);
}
}2.String[] getParameterValues(String name):根据参数名称获取参数值得数组
package servlet.http.request;
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;
@WebServlet( "/RequestDemo06_02")
public class RequestDemo06_02 extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// 2.String[] getParameterValues(String name):根据参数名称获取参数值得数组
String[] hobbies = request.getParameterValues("hobby");
for (String hobby:hobbies) { //foreach
System.out.println(hobby);
}
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
}
}regist03.html复选框测试：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>注册页面</title>
</head>
<body>
<form action="/RequestDemo06_02" method="post">
<input type="text" placeholder="请输入用户名" name="username"><br>
<input type="password" placeholder="请输入密码" name="password" ><br>
<input type="checkbox" name="hobby" value="game">游戏
<input type="checkbox" name="hobby" value="study">学习
<br>
<input type="submit" value="注册">
</form>
</body>
</html>
3.Enumeration<String> getParameterNmaes():获取所有请求得参数名称
package servlet.http.request;
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( "/RequestDemo06_03")
public class RequestDemo06_03 extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// 3.Enumeration<String> getParameterNmaes():获取所有请求得参数名称
Enumeration<String> parameterNames = request.getParameterNames();
while (parameterNames.hasMoreElements()){
String name = parameterNames.nextElement();
System.out.println(name);
String value = request.getParameter(name); //不是数组 对于多选框只能接收一个值
System.out.println(value);
System.out.println("-----------------");
}
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
}
}
4.Map<String,String[]> getParameterMap():获取所有参数得map集合
package servlet.http.request;
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.Map;
import java.util.Set;
@WebServlet( "/RequestDemo06_04")
public class RequestDemo06_04 extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// 4.Map<String,String[]> getParameterMap():获取所有参数得map集合
Map<String, String[]> parameterMap = request.getParameterMap();
//遍历
Set<String> keyset = parameterMap.keySet();
for (String name:keyset) { //迭代
//根据键获取值
String[] values = parameterMap.get(name);
System.out.println(name);
for (String value:values){
System.out.println(value);
}
System.out.println("-----------------------");
}
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
}
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