Springmvc 简明教程
Spring MVC - Hibernate Validator Example
以下示例演示了如何在表单中使用 Spring Web MVC 框架进行错误处理和验证。首先，让我们建立一个可用的 Eclipse IDE，并遵循以下步骤，使用 Spring Web 框架开发一个基于动态表单的 Web 应用程序。
The following example shows how to use Error Handling and Validators in forms using the Spring Web MVC framework. To begin with, let us have a working Eclipse IDE in place and adhere to the following steps to develop a Dynamic Form based Web Application using the Spring Web Framework.
Step |
Description |
1 |
Create a project with the name TestWeb under a package com.tutorialspoint as explained in the Spring MVC - Hello World chapter. |
2 |
Create Java classes Student, StudentController and StudentValidator under the com.tutorialspoint package. |
3 |
Create view files addStudent.jsp and result.jsp under the jsp sub-folder. |
4 |
Download Hibernate Validator library Hibernate Validator. Extract hibernate-validator-5.3.4.Final.jar and required dependencies present under the required folder of the downloaded zip file. Put them in your CLASSPATH. |
5 |
Create a properties file messages.properties under the SRC folder. |
6 |
The final step is to create the content of the source and configuration files and export the application as explained below. |
Student.java
package com.tutorialspoint;
import org.hibernate.validator.constraints.NotEmpty;
import org.hibernate.validator.constraints.Range;
public class Student {
@Range(min = 1, max = 150)
private Integer age;
@NotEmpty
private String name;
private Integer id;
public void setAge(Integer age) {
this.age = age;
}
public Integer getAge() {
return age;
}
public void setName(String name) {
this.name = name;
}
public String getName() {
return name;
}
public void setId(Integer id) {
this.id = id;
}
public Integer getId() {
return id;
}
}StudentController.java
package com.tutorialspoint;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.validation.BindingResult;
import org.springframework.validation.annotation.Validated;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.servlet.ModelAndView;
@Controller
public class StudentController {
@RequestMapping(value = "/addStudent", method = RequestMethod.GET)
public ModelAndView student() {
return new ModelAndView("addStudent", "command", new Student());
}
@ModelAttribute("student")
public Student createStudentModel() {
return new Student();
}
@RequestMapping(value = "/addStudent", method = RequestMethod.POST)
public String addStudent(@ModelAttribute("student") @Validated Student student,
BindingResult bindingResult, Model model) {
if (bindingResult.hasErrors()) {
return "addStudent";
}
model.addAttribute("name", student.getName());
model.addAttribute("age", student.getAge());
model.addAttribute("id", student.getId());
return "result";
}
}messages.properties
NotEmpty.student.name = Name is required!
Range.student.age = Age value must be between 1 and 150!在这里，密钥是 <Annotation>.<object-name>.<attribute>。值要显示的消息。
Here, the key is <Annotation>.<object-name>.<attribute>. Value is the message to be displayed.
TestWeb-servlet.xml
<beans xmlns = "http://www.springframework.org/schema/beans"
xmlns:context = "http://www.springframework.org/schema/context"
xmlns:mvc = "http://www.springframework.org/schema/mvc"
xmlns:xsi = "http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation = "
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.0.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd">
<context:component-scan base-package = "com.tutorialspoint" />
<mvc:annotation-driven />
<bean class = "org.springframework.context.support.ResourceBundleMessageSource"
id = "messageSource">
<property name = "basename" value = "messages" />
</bean>
<bean class = "org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name = "prefix" value = "/WEB-INF/jsp/" />
<property name = "suffix" value = ".jsp" />
</bean>
</beans>在这里，对于第一个服务方法 student() ，我们在 ModelAndView 对象中传递了一个空的 Studentobject> ，并命名为“command”，因为 spring 框架期望在 JSP 文件中使用 <form:form> 标记时，有一个名为“command”的对象。所以，当调用 student() 方法时，它返回 addStudent.jsp 视图。
Here, for the first service method student(), we have passed a blank Studentobject> in the ModelAndView object with name "command", because the spring framework expects an object with name "command", if you are using <form:form> tags in your JSP file. So, when the student() method is called, it returns addStudent.jsp view.
第二个服务方法 addStudent() 将在 HelloWeb/addStudent URL上的POST方法中被调用。您将根据提交的信息准备您的模型对象。最后，将从服务方法中返回“result”视图，这将导致渲染result.jsp。如果使用验证器生成了错误，那么将返回相同的“addStudent”视图，Spring将自动在视图中从 BindingResult 注入错误消息。
The second service method addStudent() will be called against a POST method on the HelloWeb/addStudent URL. You will prepare your model object based on the submitted information. Finally, a "result" view will be returned from the service method, which will result in rendering the result.jsp. In case there are errors generated using validator then same view "addStudent" is returned, Spring automatically injects error messages from BindingResult in view.
addStudent.jsp
<%@taglib uri = "http://www.springframework.org/tags/form" prefix = "form"%>
<html>
<head>
<title>Spring MVC Form Handling</title>
</head>
<style>
.error {
color: #ff0000;
}
.errorblock {
color: #000;
background-color: #ffEEEE;
border: 3px solid #ff0000;
padding: 8px;
margin: 16px;
}
</style>
<body>
<h2>Student Information</h2>
<form:form method = "POST" action = "/TestWeb/addStudent" commandName = "student">
<form:errors path = "*" cssClass = "errorblock" element = "div" />
<table>
<tr>
<td><form:label path = "name">Name</form:label></td>
<td><form:input path = "name" /></td>
<td><form:errors path = "name" cssClass = "error" /></td>
</tr>
<tr>
<td><form:label path = "age">Age</form:label></td>
<td><form:input path = "age" /></td>
<td><form:errors path = "age" cssClass = "error" /></td>
</tr>
<tr>
<td><form:label path = "id">id</form:label></td>
<td><form:input path = "id" /></td>
</tr>
<tr>
<td colspan = "2">
<input type = "submit" value = "Submit"/>
</td>
</tr>
</table>
</form:form>
</body>
</html>在这里，我们使用了 path="*" 的 <form:errors /> 标记来呈现错误消息。例如 -
Here, we are using the <form:errors /> tag with path="*" to render error messages. For example −
<form:errors path = "*" cssClass = "errorblock" element = "div" />它将针对所有输入验证呈现错误消息。我们使用了 path = “name” 的 <form:errors /> 标记来呈现 name 字段的错误消息。
It will render error messages for all input validations. We are using <form:errors /> tag with path = "name" to render error message for the name field.
例如 -
For example −
<form:errors path = "name" cssClass = "error" />
<form:errors path = "age" cssClass = "error" />它将针对 name 和 age 字段验证呈现错误消息。
It will render error messages for name and age field validations.
result.jsp
<%@taglib uri = "http://www.springframework.org/tags/form" prefix = "form"%>
<html>
<head>
<title>Spring MVC Form Handling</title>
</head>
<body>
<h2>Submitted Student Information</h2>
<table>
<tr>
<td>Name</td>
<td>${name}</td>
</tr>
<tr>
<td>Age</td>
<td>${age}</td>
</tr>
<tr>
<td>ID</td>
<td>${id}</td>
</tr>
</table>
</body>
</html>一旦创建完源文件和配置文件，导出您的应用程序。右键单击应用程序，使用 Export → WAR File 选项，并将 HelloWeb.war 文件保存到 Tomcat 的 webapps 文件夹中。
Once you are done with creating source and configuration files, export your application. Right click on your application, use Export → WAR File option and save the HelloWeb.war file in Tomcat’s webapps folder.
现在，启动 Tomcat 服务器，确保可以使用标准浏览器访问 webapps 文件夹中的其他网页。尝试一个 URL - http://localhost:8080/TestWeb/addStudent ，如果你输入无效值，我们将看到以下屏幕。
Now, start the Tomcat server and make sure you are able to access other webpages from the webapps folder using a standard browser. Try a URL − http://localhost:8080/TestWeb/addStudent and we will see the following screen, if you have entered invalid values.
