SPRING IN ACTION 第4版笔记-第六章RENDERING WEB VIEWS-002- Spring的JSP标签之form标签(<sf:input><sf:errors><sf:form>)

一、

Spring offers two JSP tag libraries to help define the view of your Spring MVC web views.

One tag library renders HTML form tags that are bound to a model attribute.

The other has a hodgepodge of utility tags that come in handy from time to time.

1.Spring支持的form标签

2.一般用法

 <%@ taglib uri="http://www.springframework.org/tags/form" prefix="sf" %>
 <sf:form method="POST" commandName="spitter">
     First Name:
     <sf:input path="firstName" />
     <br/> Last Name:
     <sf:input path="lastName" />
     <br/> Email:
     <sf:input path="email" />
     <br/> Username:
     <sf:input path="username" />
     <br/> Password:
     <sf:password path="password" />
     <br/>
     <input type="submit" value="Register" />
 </sf:form>

path是和model里的对象的属性对应，commandName是和model的key对应，这里设定了commandName="spitter"，则要保证每个返回到这个view的handler的model都要有值为"spitter"的key,所以showRegistrationForm()要修改，返回一个空对象，否则会报java.lang.IllegalStateException: Neither BindingResult nor plain target object for bean name 'spitter' available as request attribute。

 RequestMapping(value = "/register", method = GET)
 public String showRegistrationForm(Model model) {
     model.addAttribute(new Spitter());
     return "registerForm";
 }

3.Spring form标签还支持html5,如可以指定data、range、email

<sf:input path="email" type="email" />

4.显示错误

 <sf:form method="POST" commandName="spitter">
     First Name:
     <sf:input path="firstName" />
     <sf:errors path="firstName" />
     <br/> ...
 </sf:form>

若验证有错，会解析类似如下：

First Name: <input id="firstName" name="firstName" type="text" value="J"/>
            <span id="firstName.errors">size must be between 2 and 30</span>

5.可以加css

 <sf:form method="POST" commandName="spitter">
     First Name:
     <sf:input path="firstName" />
     <sf:errors path="firstName" cssClass="error" />
     <br/> ...
 </sf:form>

span.error {color: red;}

6.错误集中显示

<sf:form method="POST" commandName="spitter">
    <sf:errors path="*" element="div" cssClass="errors" />
    ...
</sf:form>

div.errors {
    background - color: #ffcccc;
    border: 2 px solid red;
}

7.哪个字段有错就红色显示该字段

 <sf:form method="POST" commandName="spitter">
     <sf:label path="firstName" cssErrorClass="error">First Name</sf:label>:
     <sf:input path="firstName" cssErrorClass="error" />
     <br/> ...
 </sf:form>

8.要实体类中写验证规则

 package spittr;

 import javax.validation.constraints.NotNull;
 import javax.validation.constraints.Size;

 import org.apache.commons.lang3.builder.EqualsBuilder;
 import org.apache.commons.lang3.builder.HashCodeBuilder;
 import org.hibernate.validator.constraints.Email;

 public class Spitter {

   private Long id;

   @NotNull
   @Size(min=5, max=16, message="{username.size}")
   private String username;

   @NotNull
   @Size(min=5, max=25, message="{password.size}")
   private String password;

   @NotNull
   @Size(min=2, max=30, message="{firstName.size}")
   private String firstName;

   @NotNull
   @Size(min=2, max=30, message="{lastName.size}")
   private String lastName;

   @NotNull
   @Email
   private String email;

   @Override
   public boolean equals(Object that) {
     return EqualsBuilder.reflectionEquals(this, that, "firstName", "lastName", "username", "password", "email");
   }

   @Override
   public int hashCode() {
     return HashCodeBuilder.reflectionHashCode(this, "firstName", "lastName", "username", "password", "email");
   }

 }

9.验证信息的资源文件，可定不同的语言版本支持国际化(不知道什么时候加载的

(1)ValidationMessages.properties

 firstName.size=First name must be between {min} and {max} characters long.
 lastName.size=Last name must be between {min} and {max} characters long.
 username.size=Username must be between {min} and {max} characters long.
 password.size=Password must be between {min} and {max} characters long.
 email.valid=The email address must be valid.

(2)ValidationMessages_es.properties 西班牙

 firstName.size=Nombre debe ser entre {min} y {max} caracteres largo.
 lastName.size=El apellido debe ser entre {min} y {max} caracteres largo.
 username.size=Nombre de usuario debe ser entre {min} y {max} caracteres largo.
 password.size=Contraseña debe estar entre {min} y {max} caracteres largo.
 email.valid=La dirección de email no es válida

(3)webconfig.java

 package spittr.web;

 import org.springframework.context.MessageSource;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.ComponentScan;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.context.support.ReloadableResourceBundleMessageSource;
 import org.springframework.web.servlet.ViewResolver;
 import org.springframework.web.servlet.config.annotation.DefaultServletHandlerConfigurer;
 import org.springframework.web.servlet.config.annotation.EnableWebMvc;
 import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
 import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
 import org.springframework.web.servlet.view.InternalResourceViewResolver;

 @Configuration
 @EnableWebMvc
 @ComponentScan("spittr.web")
 public class WebConfig extends WebMvcConfigurerAdapter {

   @Bean
   public ViewResolver viewResolver() {
     InternalResourceViewResolver resolver = new InternalResourceViewResolver();
     resolver.setPrefix("/WEB-INF/views/");
     resolver.setSuffix(".jsp");
     return resolver;
   }

   @Override
   public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
     configurer.enable();
   }

   @Override
   public void addResourceHandlers(ResourceHandlerRegistry registry) {
     // TODO Auto-generated method stub
     super.addResourceHandlers(registry);
   }

   @Bean
   public MessageSource messageSource() {
     ReloadableResourceBundleMessageSource messageSource =
         new ReloadableResourceBundleMessageSource();
     //messageSource.setBasename("file:///Users/habuma/messages");
     //messageSource.setBasename("messages");
     messageSource.setBasename("classpath:messages");
     messageSource.setCacheSeconds(10);
     return messageSource;
   }

 }

10.view

 <%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
 <%@ taglib uri="http://www.springframework.org/tags/form" prefix="sf" %>
 <%@ page session="false" %>
 <html>
   <head>
     <title>Spitter</title>
     <link rel="stylesheet" type="text/css"
           href="<c:url value="/resources/style.css" />" >
   </head>
   <body>
     <h1>Register</h1>

     <sf:form method="POST" commandName="spitter" >
       <sf:errors path="*" element="div" cssClass="errors" />
       <sf:label path="firstName"
           cssErrorClass="error">First Name</sf:label>:
         <sf:input path="firstName" cssErrorClass="error" /><br/>
       <sf:label path="lastName"
           cssErrorClass="error">Last Name</sf:label>:
         <sf:input path="lastName" cssErrorClass="error" /><br/>
       <sf:label path="email"
           cssErrorClass="error">Email</sf:label>:
         <sf:input path="email" cssErrorClass="error" /><br/>
       <sf:label path="username"
           cssErrorClass="error">Username</sf:label>:
         <sf:input path="username" cssErrorClass="error" /><br/>
       <sf:label path="password"
           cssErrorClass="error">Password</sf:label>:
         <sf:password path="password" cssErrorClass="error" /><br/>
       <input type="submit" value="Register" />
     </sf:form>
   </body>
 </html>

11.controller

 package spittr.web;

 import static org.springframework.web.bind.annotation.RequestMethod.*;

 import javax.validation.Valid;

 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Controller;
 import org.springframework.ui.Model;
 import org.springframework.validation.Errors;
 import org.springframework.web.bind.annotation.PathVariable;
 import org.springframework.web.bind.annotation.RequestMapping;

 import spittr.Spitter;
 import spittr.data.SpitterRepository;

 @Controller
 @RequestMapping("/spitter")
 public class SpitterController {

   private SpitterRepository spitterRepository;

   @Autowired
   public SpitterController(SpitterRepository spitterRepository) {
     this.spitterRepository = spitterRepository;
   }

 //  @ModelAttribute
 //  public Spitter spitter() {
 //    return new Spitter();
 //  }

   @RequestMapping(value="/register", method=GET)
   public String showRegistrationForm(Model model) {
     model.addAttribute(new Spitter());
     return "registerForm";
   }

   @RequestMapping(value="/register", method=POST)
   public String processRegistration(
       @Valid Spitter spitter,
       Errors errors) {
     if (errors.hasErrors()) {
       return "registerForm";
     }

     spitterRepository.save(spitter);
     return "redirect:/spitter/" + spitter.getUsername();
   }

   @RequestMapping(value="/{username}", method=GET)
   public String showSpitterProfile(@PathVariable String username, Model model) {
     Spitter spitter = spitterRepository.findByUsername(username);
     model.addAttribute(spitter);
     return "profile";
   }

 }