Spring MVC 表单下拉列表

2025年3月17日 | 阅读 3 分钟

Spring MVC 表单下拉列表包含元素的列表。此标签生成一个 HTML select 元素。它允许将数据绑定到选定的元素。

语法

以下是一些用于选择选项的其他标签。

option 标签

此标签生成一个 HTML option 标签。每个标签都包含一个用户可以选择的值。

语法

options 标签

此标签生成一个 HTML option 标签列表。每个标签都包含用户选择的元素列表。

语法

Spring MVC 表单下拉列表示例

1. 将依赖项添加到 pom.xml 文件。

          <!-- https://mvnrepository.com/artifact/org.springframework/spring-webmvc -->
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-webmvc</artifactId>
    <version>5.1.1.RELEASE</version>
</dependency>

    <!-- https://mvnrepository.com/artifact/javax.servlet/javax.servlet-api -->
<dependency>  
    <groupId>javax.servlet</groupId>  
    <artifactId>servlet-api</artifactId>  
    <version>3.0-alpha-1</version>  
</dependency>

    <!-- https://mvnrepository.com/artifact/javax.servlet/jstl -->
<dependency>
    <groupId>javax.servlet</groupId>
    <artifactId>jstl</artifactId>
    <version>1.2</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.apache.tomcat/tomcat-jasper -->
<dependency>
    <groupId>org.apache.tomcat</groupId>
    <artifactId>tomcat-jasper</artifactId>
    <version>9.0.12</version>
</dependency>

2. 创建 bean 类

Reservation.java

package com.javatpoint;

public class Reservation {

	private String firstName;
	private String lastName;
	private String Gender;
	private String[] Food;
	private String cityFrom;
	private String cityTo;
	public Reservation()
	{		
	}
	public String getFirstName() {
		return firstName;
	}
	public void setFirstName(String firstName) {
		this.firstName = firstName;
	}
	public String getLastName() {
		return lastName;
	}
	public void setLastName(String lastName) {
		this.lastName = lastName;
	}
	public String getGender() {
		return Gender;
	}
	public void setGender(String gender) {
		Gender = gender;
	}
	public String[] getFood() {
		return Food;
	}
	public void setFood(String[] food) {
		Food = food;
	}	
	public String getCityFrom() {
	return cityFrom;
}
public void setCityFrom(String cityFrom) {
	this.cityFrom = cityFrom;
}
public String getCityTo() {
	return cityTo;
}
public void setCityTo(String cityTo) {
	this.cityTo = cityTo;
}	
}

3. 创建控制器类

ReservationController.java

package com.javatpoint;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.RequestMapping;

@RequestMapping("/reservation")
@Controller
public class ReservationController {
	@RequestMapping("/bookingForm")
public String bookingForm(Model model)
{
      //create a reservation object 
	Reservation res=new Reservation();
      //provide reservation object to the model 
	model.addAttribute("reservation", res);
	return "reservation-page";
}
@RequestMapping("/submitForm")
public String submitForm(@ModelAttribute("reservation") Reservation res)
{
	return "confirmation-form";
}
}

4. 在 web.xml 文件中提供控制器的条目

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
  <display-name>SpringMVC</display-name>
   <servlet>  
    <servlet-name>spring</servlet-name>  
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>  
    <load-on-startup>1</load-on-startup>    
</servlet>  
<servlet-mapping>  
    <servlet-name>spring</servlet-name>  
    <url-pattern>/</url-pattern>  
</servlet-mapping>  
</web-app>

5. 在 xml 文件中定义 bean

spring-servlet.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
	xmlns:context="http://www.springframework.org/schema/context"
	xmlns:mvc="http://www.springframework.org/schema/mvc"
	xsi:schemaLocation="
		http://www.springframework.org/schema/beans
    	http://www.springframework.org/schema/beans/spring-beans.xsd
    	http://www.springframework.org/schema/context
    	http://www.springframework.org/schema/context/spring-context.xsd
    	http://www.springframework.org/schema/mvc
        http://www.springframework.org/schema/mvc/spring-mvc.xsd">
	<!-- Provide support for component scanning -->
	<context:component-scan base-package="com.javatpoint" />
	<!--Provide support for conversion, formatting and validation -->
	<mvc:annotation-driven/>
	<!-- Define Spring MVC view resolver -->
     <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/jsp/"></property>
        <property name="suffix" value=".jsp"></property>     
     </bean>
</beans>

6. 创建请求的页面

index.jsp

<!DOCTYPE html>
<html>
<head>
	<title>Railway Registration Form</title>
</head>
<body>
<a href="reservation/bookingForm">Click here for reservation.</a>
</body>
</html>

7. 创建视图组件

reservation-page.jsp

<%@ taglib prefix="form" uri="http://www.springframework.org/tags/form" %>
<!DOCTYPE html>
<html>
<head>
	<title>Reservation Form</title>
</head>
<h3>Railway Reservation Form</h3>
<body>
	<form:form action="submitForm" modelAttribute="reservation">
		First name: <form:input path="firstName" />		
		<br><br>
		Last name: <form:input path="lastName" />
		<br><br>
		Gender: 
		Male<form:radiobutton path="Gender" value="Male"/>
		Female<form:radiobutton path="Gender" value="Female"/>
		<br><br>
		Meals:
		BreakFast<form:checkbox path="Food" value="BreakFast"/>
		Lunch<form:checkbox path="Food" value="Lunch"/>
		Dinner<form:checkbox path="Food" value="Dinner"/>
		<br><br>
		Leaving from: <form:select path="cityFrom">
		<form:option value="Ghaziabad" label="Ghaziabad"/>
		<form:option value="Modinagar" label="Modinagar"/>
		<form:option value="Meerut" label="Meerut"/>
		<form:option value="Amristar" label="Amristar"/>
		</form:select>
		<br><br>
		Going to: <form:select path="cityTo">
		<form:option value="Ghaziabad" label="Ghaziabad"/>
		<form:option value="Modinagar" label="Modinagar"/>
		<form:option value="Meerut" label="Meerut"/>
		<form:option value="Amristar" label="Amristar"/>
		</form:select>
		<br><br>
		<input type="submit" value="Submit" />
	</form:form>
</body>
</html>

confirmation-page.jsp

<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<!DOCTYPE html>
<html>
<body>
<p>Your reservation is confirmed successfully. Please, re-check the details.</p>
First Name : ${reservation.firstName} <br>
Last Name : ${reservation.lastName} <br>
Gender: ${reservation.gender}<br>
Meals: 
<ul>
<c:forEach var="meal" items="${reservation.food}">
<li>${meal}</li>
</c:forEach>
</ul>
Leaving From : ${reservation.cityFrom} <br>
Going To : ${reservation.cityTo}
</body>
</html>

输出