如何快速构建基于Spring4.0的Rest API（攻略）

你的名字 2022-08-04 04:07 122阅读 0赞

这是关于使用Spring MVC创建Web API的另一个教程。这并不是一个非常精细的教程，而仅仅是一个演习（攻略）。本教程旨在创建一个提供服务器端API的应用，并且使用Mongo作为它的数据库，使用Spring Security作为安全框架。

准备开始——POM

由于我是一个maven脑残粉，所以这个项目还是基于maven的。现在Spring 4.0 RC2已经发布了，所以我决定使用最新的依赖管理工具。本文使用的pom.xml如下：使用这个配置创建Spring MVC应用确实非常简单。这里面比较新鲜的东西就是dependencyManagement 元素。详解猛戳这儿：[http://spring.io/blog/2013/12/03/spring-framework-4-0-rc2-available][http_spring.io_blog_2013_12_03_spring-framework-4-0-rc2-available]

配置

这个应用可以使用JavaConfig完成配置。我把它切分为下面几个部分：

ServicesConfig（服务配置）

无需扫描组件，配置真的非常简单：

@Configuration
    publicclass ServicesConfig {
        @Autowired
        private AccountRepository accountRepository;
     
        @Bean
        public  UserService userService() {
            returnnew UserService(accountRepository);
        }
     
        @Bean
        public PasswordEncoder passwordEncoder() {
            return NoOpPasswordEncoder.getInstance();
        }
    }

PersistenceConfig（持久层配置）

我们想要一个配置了所有可用仓库的MONGODB配置。在这个简单的应用中我们只用了一个仓库，所以配置也非常的简单：

@Configuration
    classPersistenceConfig {
        @Bean
        publicAccountRepository accountRepository() throwsUnknownHostException {
            returnnew MongoAccountRepository(mongoTemplate());
        }
     
        @Bean
        publicMongoDbFactory mongoDbFactory() throwsUnknownHostException {
            returnnew SimpleMongoDbFactory(newMongo(), "r");
        }
     
        @Bean
        publicMongoTemplate mongoTemplate() throwsUnknownHostException {
            MongoTemplate template = newMongoTemplate(mongoDbFactory(), mongoConverter());
            returntemplate;
        }
     
        @Bean
        publicMongoTypeMapper mongoTypeMapper() {
            returnnew DefaultMongoTypeMapper(null);
        }
     
        @Bean
        publicMongoMappingContext mongoMappingContext() {
            returnnew MongoMappingContext();
        }
     
        @Bean
        publicMappingMongoConverter mongoConverter() throwsUnknownHostException {
            MappingMongoConverter converter = newMappingMongoConverter(mongoDbFactory(), mongoMappingContext());
            converter.setTypeMapper(mongoTypeMapper());
            returnconverter;
        }
    }

SecurityConfig（安全配置）

理论上，Spring Security 3.2完全可以使用JavaConfig。但对于我这也仅仅是一个理论，所以这里还是选择xml配置的方式：

<table style="border-collapse:collapse; border-spacing:0px; width:620px; border:0px!important; margin:0px!important; padding:0px!important; font-size:12px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; min-height:auto!important; background:none!important"> 
 <tbody style="border:0px!important; margin:0px!important; padding:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; min-height:auto!important; background:none!important"> 
  <tr style="border:0px!important; margin:0px!important; padding:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; min-height:auto!important; background:none!important"> 
   <td style="border:0px!important; margin:0px!important; padding:0px!important; vertical-align:baseline!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; width:auto!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; min-height:auto!important; color:rgb(175,175,175)!important; background:none!important"> 
    <div style="border-width:0px 3px 0px 0px!important; border-right-style:solid!important; border-right-color:rgb(108,226,108)!important; margin:0px!important; padding:0px 0.5em 0px 1em!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; text-align:right!important; top:auto!important; vertical-align:baseline!important; width:auto!important; min-height:auto!important; white-space:pre!important">
      1 
    </div> 
    <div style="border-width:0px 3px 0px 0px!important; border-right-style:solid!important; border-right-color:rgb(108,226,108)!important; margin:0px!important; padding:0px 0.5em 0px 1em!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; text-align:right!important; top:auto!important; vertical-align:baseline!important; width:auto!important; min-height:auto!important; white-space:pre!important">
      2 
    </div> 
    <div style="border-width:0px 3px 0px 0px!important; border-right-style:solid!important; border-right-color:rgb(108,226,108)!important; margin:0px!important; padding:0px 0.5em 0px 1em!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; text-align:right!important; top:auto!important; vertical-align:baseline!important; width:auto!important; min-height:auto!important; white-space:pre!important">
      3 
    </div> </td> 
   <td style="width:592px; border:0px!important; margin:0px!important; padding:0px!important; vertical-align:baseline!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; min-height:auto!important; background:none!important"> 
    <div style="margin-left:-10px; width:640px; border:0px!important; margin-top:0px!important; margin-right:0px!important; margin-bottom:0px!important; padding:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:relative!important; right:auto!important; top:auto!important; vertical-align:baseline!important; min-height:auto!important; background:none!important"> 
     <div style="border:0px!important; margin:0px!important; padding:0px 1em!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; min-height:auto!important; white-space:pre!important"> 
      <code style="border:0px!important; margin:0px!important; padding:0px!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; min-height:auto!important; color:gray!important; background:none!important">@Configuration</code> 
     </div> 
     <div style="border:0px!important; margin:0px!important; padding:0px 1em!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; min-height:auto!important; white-space:pre!important"> 
      <code style="border:0px!important; margin:0px!important; padding:0px!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; min-height:auto!important; color:gray!important; background:none!important">@ImportResource</code> 
      <code style="border:0px!important; margin:0px!important; padding:0px!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; min-height:auto!important; background:none!important">(</code> 
      <code style="border:0px!important; margin:0px!important; padding:0px!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; min-height:auto!important; color:blue!important; background:none!important">"classpath:spring-security-context.xml"</code> 
      <code style="border:0px!important; margin:0px!important; padding:0px!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; min-height:auto!important; background:none!important">)</code> 
     </div> 
     <div style="border:0px!important; margin:0px!important; padding:0px 1em!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; min-height:auto!important; white-space:pre!important"> 
      <code style="border:0px!important; margin:0px!important; padding:0px!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-weight:bold!important; min-height:auto!important; color:rgb(0,102,153)!important; background:none!important">public</code> 
      <code style="border:0px!important; margin:0px!important; padding:0px!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-weight:bold!important; min-height:auto!important; color:rgb(0,102,153)!important; background:none!important">class</code> 
      <code style="border:0px!important; margin:0px!important; padding:0px!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; min-height:auto!important; background:none!important"> SecurityConfig {}</code> 
     </div> 
    </div> </td> 
  </tr> 
 </tbody> 
</table>

使用这个xml就让API能使用基本的安全机制了。

WebAppInitializer（初始化）

我们不想使用web.xml，所以使用下面的代码配置整个应用：

@Order(2)
    publicclass WebAppInitializer extendsAbstractAnnotationConfigDispatcherServletInitializer {
     
        @Override
        protectedString[] getServletMappings() {
            returnnew String[]{"/"};
        }
     
        @Override
        protectedClass[] getRootConfigClasses() {
            returnnew Class[] {ServicesConfig.class, PersistenceConfig.class, SecurityConfig.class};
        }
     
        @Override
        protectedClass[] getServletConfigClasses() {
            returnnew Class[] {WebMvcConfig.class};
        }
     
        @Override
        protectedFilter[] getServletFilters() {
            CharacterEncodingFilter characterEncodingFilter = newCharacterEncodingFilter();
            characterEncodingFilter.setEncoding("UTF-8");
            characterEncodingFilter.setForceEncoding(true);
            returnnew Filter[] {characterEncodingFilter};
        }
     
        @Override
        protectedvoid customizeRegistration(ServletRegistration.Dynamic registration) {        
            registration.setInitParameter("spring.profiles.active","default");
        }
    }

WebAppSecurityInitializer （安全配置初始化）

相对于Spring3，可以使用下面这种更加新颖的特性来完成配置：

<table style="border-collapse:collapse; border-spacing:0px; width:653px; border:0px!important; margin:0px!important; padding:0px!important; font-size:12px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; min-height:auto!important; background:none!important"> 
 <tbody style="border:0px!important; margin:0px!important; padding:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; min-height:auto!important; background:none!important"> 
  <tr style="border:0px!important; margin:0px!important; padding:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; min-height:auto!important; background:none!important"> 
   <td style="border:0px!important; margin:0px!important; padding:0px!important; vertical-align:baseline!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; width:auto!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; min-height:auto!important; color:rgb(175,175,175)!important; background:none!important"> 
    <div style="border-width:0px 3px 0px 0px!important; border-right-style:solid!important; border-right-color:rgb(108,226,108)!important; margin:0px!important; padding:0px 0.5em 0px 1em!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; text-align:right!important; top:auto!important; vertical-align:baseline!important; width:auto!important; min-height:auto!important; white-space:pre!important">
      1 
    </div> 
    <div style="border-width:0px 3px 0px 0px!important; border-right-style:solid!important; border-right-color:rgb(108,226,108)!important; margin:0px!important; padding:0px 0.5em 0px 1em!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; text-align:right!important; top:auto!important; vertical-align:baseline!important; width:auto!important; min-height:auto!important; white-space:pre!important">
      2 
    </div> </td> 
   <td style="width:625px; border:0px!important; margin:0px!important; padding:0px!important; vertical-align:baseline!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; min-height:auto!important; background:none!important"> 
    <div style="margin-left:-10px; width:640px; border:0px!important; margin-top:0px!important; margin-right:0px!important; margin-bottom:0px!important; padding:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:relative!important; right:auto!important; top:auto!important; vertical-align:baseline!important; min-height:auto!important; background:none!important"> 
     <div style="border:0px!important; margin:0px!important; padding:0px 1em!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; min-height:auto!important; white-space:pre!important"> 
      <code style="border:0px!important; margin:0px!important; padding:0px!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; min-height:auto!important; color:gray!important; background:none!important">@Order</code> 
      <code style="border:0px!important; margin:0px!important; padding:0px!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; min-height:auto!important; background:none!important">(</code> 
      <code style="border:0px!important; margin:0px!important; padding:0px!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; min-height:auto!important; color:rgb(0,153,0)!important; background:none!important">1</code> 
      <code style="border:0px!important; margin:0px!important; padding:0px!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; min-height:auto!important; background:none!important">)</code> 
     </div> 
     <div style="border:0px!important; margin:0px!important; padding:0px 1em!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; min-height:auto!important; white-space:pre!important"> 
      <code style="border:0px!important; margin:0px!important; padding:0px!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-weight:bold!important; min-height:auto!important; color:rgb(0,102,153)!important; background:none!important">public</code> 
      <code style="border:0px!important; margin:0px!important; padding:0px!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-weight:bold!important; min-height:auto!important; color:rgb(0,102,153)!important; background:none!important">class</code> 
      <code style="border:0px!important; margin:0px!important; padding:0px!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; min-height:auto!important; background:none!important"> WebAppSecurityInitializer </code> 
      <code style="border:0px!important; margin:0px!important; padding:0px!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-weight:bold!important; min-height:auto!important; color:rgb(0,102,153)!important; background:none!important">extends</code> 
      <code style="border:0px!important; margin:0px!important; padding:0px!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; min-height:auto!important; background:none!important">AbstractSecurityWebApplicationInitializer {}</code> 
     </div> 
    </div> </td> 
  </tr> 
 </tbody> 
</table>

WebMvcConfig （Mvc配置）

调度控制器配置。这个也非常简单，仅仅包含了构建一个简单API的最重要配置：

@Configuration
    @ComponentScan(basePackages = { "pl.codeleak.r"}, includeFilters = {@Filter(value = Controller.class)})
    publicclass WebMvcConfig extendsWebMvcConfigurationSupport {
     
        privatestatic final String MESSAGE_SOURCE = "/WEB-INF/i18n/messages";
     
        @Override
        publicRequestMappingHandlerMapping requestMappingHandlerMapping() {
            RequestMappingHandlerMapping requestMappingHandlerMapping = super.requestMappingHandlerMapping();
            requestMappingHandlerMapping.setUseSuffixPatternMatch(false);
            requestMappingHandlerMapping.setUseTrailingSlashMatch(false);
            returnrequestMappingHandlerMapping;
        }
     
        @Bean(name = "messageSource")
        publicMessageSource messageSource() {
            ReloadableResourceBundleMessageSource messageSource = newReloadableResourceBundleMessageSource();
            messageSource.setBasename(MESSAGE_SOURCE);
            messageSource.setCacheSeconds(5);
            returnmessageSource;
        }
     
        @Override
        publicValidator getValidator() {
            LocalValidatorFactoryBean validator = newLocalValidatorFactoryBean();
            validator.setValidationMessageSource(messageSource());
            returnvalidator;
        }
     
        @Override
        publicvoid configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
            configurer.enable();
        }
    }

这就是需要的配置，非常简单吧！

IndexController （INDEX控制器）

为了验证这个配置是正确的，我创建了一个IndexController。功能非常简单，只是简单地返回“Hello World”，示例代码如下：\\

@Controller
    @RequestMapping("/")
    publicclass IndexController {
        @RequestMapping
        @ResponseBody
        publicString index() {
            return"This is an API endpoint.";
        }
    }

如果运行一下这个应用，就能够在浏览器中看到返回的“Hello World”文本。

构建API

UserService

为了完成Spring安全框架配置，还需要完成另一个部分：实现之前创建的UserService。

public class UserService implementsUserDetailsService {
        private AccountRepository accountRepository;
     
        public UserService(AccountRepository accountRepository) {
            this.accountRepository = accountRepository;
        }
     
        @Override
        public UserDetails loadUserByUsername(String username) throwsUsernameNotFoundException {
            Account account = accountRepository.findByEmail(username);
            if(account == null) {
                throw new UsernameNotFoundException("user not found");
            }
            return  createUser(account);
        }
     
        public  void signin(Account account) {
            SecurityContextHolder.getContext().setAuthentication(authenticate(account));
        }
     
        private Authentication authenticate(Account account) {
            return new UsernamePasswordAuthenticationToken(createUser(account), null, Collections.singleton(createAuthority(account)));  
        }
     
        private  User createUser(Account account) {
            returnnew User(account.getEmail(), account.getPassword(), Collections.singleton(createAuthority(account)));
        }
     
        private  GrantedAuthority createAuthority(Account account) {
            returnnew SimpleGrantedAuthority(account.getRole());
        }
    }

构建一个API节点需要处理三个方法：获取当前登陆用户、获取所有用户（可能不是太安全）、创建一个新账户。那么我们就按照这个步骤来进行吧。

Account

Account 将会是我们的第一个Mongo文档。同样也是非常简单：

@SuppressWarnings("serial")
    @Document
    public class Account implementsjava.io.Serializable {
     
        @Id
        private String objectId;
     
        @Email
        @Indexed(unique = true)
        private String email;
     
        @JsonIgnore
        @NotBlank
        private String password;
     
        private String role = "ROLE_USER";
     
        private Account() {
     
        }
     
        public Account(String email, String password, String role) {
            this.email = email;
            this.password = password;
            this.role = role;
        }
     
       // getters and setters
    }

Repository

先创建一个接口：

publicinterface AccountRepository {
        Account save(Account account);
     
        List findAll();
     
        Account findByEmail(String email);
    }

接下来创建它的Mongo实现：

public class MongoAccountRepository implements AccountRepository {
     
        private MongoTemplate mongoTemplate;
     
        public MongoAccountRepository(MongoTemplate mongoTemplate) {
            this.mongoTemplate = mongoTemplate;
        }
     
        @Override
        public Account save(Account account) {
            mongoTemplate.save(account);
            return account;
        }
     
        @Override
        public List findAll() {
            return mongoTemplate.findAll(Account.class);
        }
     
        @Override
        public Account findByEmail(String email) {
            return mongoTemplate.findOne(Query.query(Criteria.where("email").is(email)), Account.class);
        }
    }

API控制器

功能快要完成了。我们需要将内容提供给用户，所以需要创建自己的节点：

@Controller
    @RequestMapping("api/account")
    class AccountController {
     
        private AccountRepository accountRepository;
     
        @Autowired
        public AccountController(AccountRepository accountRepository) {
            this.accountRepository = accountRepository;
        }
     
        @RequestMapping(value = "current", method = RequestMethod.GET)
        @ResponseStatus(value = HttpStatus.OK)
        @ResponseBody
        @PreAuthorize(value = "isAuthenticated()")
        public Account current(Principal principal) {
            Assert.notNull(principal);
            return accountRepository.findByEmail(principal.getName());
        }
     
        @RequestMapping(method = RequestMethod.GET)
        @ResponseStatus(value = HttpStatus.OK)
        @ResponseBody
        @PreAuthorize(value = "isAuthenticated()")
        publicAccounts list() {
            List accounts = accountRepository.findAll();
            return new Accounts(accounts);
        }
     
        @RequestMapping(method = RequestMethod.POST)
        @ResponseStatus(value = HttpStatus.CREATED)
        @ResponseBody
        @PreAuthorize(value = "permitAll()")
        public Account create(@ValidAccount account) {
            accountRepository.save(account);
            returnaccount;
        }
     
        private class Accounts extends ArrayList {
            public  Accounts(List accounts) {
                super(accounts);
            }
        }
    }

我希望你能明白：因为需要直接连接数据库，所以没有对密码进行编码。如果你比较在意这些小细节，那么可以稍后修改。目前这种方式是OK的。

完成

最后我考虑到还需要一个错误处理器，这样用户就可以看到JSON格式的错误信息而不是HTML。使用Spring Mvc以及@ControllerAdvice很容易实现这一点：

@ControllerAdvice
    public class ErrorHandler {
     
        @ExceptionHandler(value = Exception.class)
        @ResponseStatus(HttpStatus.BAD_REQUEST)
        @ResponseBody
        public ErrorResponse errorResponse(Exception exception) {
            returnnew ErrorResponse(exception.getMessage());
        }
     
    }
     
    public class ErrorResponse {
        private String message;
        public ErrorResponse(String message) {
            this.message = message;
        }
        public String getMessage() {
            returnmessage;
        }
    }

如果你想了解关于Spring4 中@ControllerAdvice的用法，请点击以下[链接][Link 1]。

测试一下这个app

作为一个单元测试极客，本来应该先创建一个单元测试。但是……这次哥想用用新的工具：Postman（Chrome 插件），所以请往下看我是怎么做的：

获取所有account（非授权）

提交account（无需授权）

获取所有account（已授权）

获取当前account（已授权）

结束语

以上就是所有内容，希望你能像我一样喜欢这种创建项目的方式。创建这个项目以及写这篇文章总共花了我大概三个钟头。其中绝大多数时间是配置安全框架（我希望它在Java中能够更加彻底），以及编写这篇攻略。

原文链接：  [javacodegeeks][]  翻译：  [ImportNew.com ][ImportNew.com] \-  [邬柏][Link 2]  
译文链接：  [http://www.importnew.com/7903.html][http_www.importnew.com_7903.html]

[http_spring.io_blog_2013_12_03_spring-framework-4-0-rc2-available]: http://spring.io/blog/2013/12/03/spring-framework-4-0-rc2-available
[Link 1]: http://blog.codeleak.pl/2013/11/controlleradvice-improvements-in-spring.html%E3%80%82
[javacodegeeks]: http://www.javacodegeeks.com/2013/12/how-to-get-started-quickly-with-spring-4-0-to-build-a-simple-rest-like-api-walkthrough.html
[ImportNew.com]: http://www.importnew.com/
[Link 2]: http://www.importnew.com/author/wubai
[http_www.importnew.com_7903.html]: http://www.importnew.com/7903.html