spring的webflux初探-白红宇

spring的webflux初探

阅读量：4224 次

发布时间：2019-05-26

本文共 8795 字，大约阅读时间需要 29 分钟。

spring的webflux初探

不久前, spring进行了较大的改动, 主要目的是为了增加对响应式编程的支持.

spring 默认是采用了reactor项目作为响应式编程(reactive programming)的支持, 我也以此作为基础来谈.

reactor项目地址:

为什么要reactor

总的来说, reactor也是一个用于编写异步代码的库, 众所周知, 对于同步程序来说, 有IO耗时长之类的开销. 所以人们不断的推崇使用异步的方式来编写一些代码, 而java也提供了编写异步程序的方法给开发者, 那么我们为什么需要reactor. 就我短时间的使用体验来说, reactor使我们编写异步代码变得更加简单快捷, 让某项工作更加简单或让其更有效率, 我觉得就是一个库应该解决的问题, 显然reactor做到了, 在使用了reactor后, 你就再也不用写callback那种又臭又长的面条代码了, 代码的可读性与可维护性大大加强了. 相比于future, reactor又提供了更多功能齐全的操作, 编程复杂的也大大降低

好了, 我们并不是来介绍reactor的, 更多有关reactor的资料以及它与jvm其他异步方式的对比请参考reactor文档:

webflux实例

webflux与webmvc的类比

webmvc	webflux
controller	handler
request mapping	router

* pom.xml


   
       
    
     4.0.0
        
    
     cn.edu.ncu
        
    
     reactive-demo
        
    
     0.0.1-SNAPSHOT
        
    
     jar
        
    
     reactive-demo
        
    
     Demo project for Spring Boot
        
            
     
      org.springframework.boot
             
     
      spring-boot-starter-parent
             
     
      2.0.0.M7
             
      
         
        
            
     
      UTF-8
             
     
      UTF-8
             
     
      1.8
         
        
            
                 
      
       org.springframework.boot
                  
      
       spring-boot-starter
              
             
                 
      
       org.springframework.boot
                  
      
       spring-boot-starter-test
                  
      
       test
              
             
             
                 
      
       org.springframework.boot
                  
      
       spring-boot-starter-webflux
              
             
                 
      
       org.springframework.boot
                  
      
       spring-boot-starter-data-redis
              
             
             
                 
      
       redis.clients
                  
      
       jedis
                  
      
       2.9.0
              
             
             
                 
      
       org.mindrot
                  
      
       jbcrypt
                  
      
       0.4
              
             
             
                 
      
       com.alibaba
                  
      
       fastjson
                  
      
       1.2.44
              
         
        
            
                 
                      
       
        org.springframework.boot
                       
       
        spring-boot-maven-plugin
                   
              
         
        
            
                 
      
       spring-snapshots
                  
      
       Spring Snapshots
                  
      
       https://repo.spring.io/snapshot
                  
                      
       
        true
                   
              
             
                 
      
       spring-milestones
                  
      
       Spring Milestones
                  
      
       https://repo.spring.io/milestone
                  
                      
       
        false
                   
              
         
        
            
                 
      
       spring-snapshots
                  
      
       Spring Snapshots
                  
      
       https://repo.spring.io/snapshot
                  
                      
       
        true
                   
              
             
                 
      
       spring-milestones
                  
      
       Spring Milestones
                  
      
       https://repo.spring.io/milestone
                  
                      
       
        false

编写handler

先写个hello world handler练练手

package cn.edu.ncu.reactivedemo.handlers;@Servicepublic class HelloWorldHandler {
       public Mono
   
     helloWorld(ServerRequest request){        return ServerResponse.ok()                .contentType(MediaType.TEXT_PLAIN)                .body(BodyInserters.fromObject("hello world"));    }}

注册路由

将写好的handler注册到路由上

package cn.edu.ncu.reactivedemo;@Configurationpublic class Router {
       @Autowired private HelloWorldHandler helloWorldHandler;    @Autowired private UserHandler userHandler;    @Bean    public RouterFunction
    routerFunction(){        return RouterFunctions.route(RequestPredicates.GET("/hello"), helloWorldHandler::helloWorld);    }}

启动类

默认采用netty作为reactor的底层启动

package cn.edu.ncu.reactivedemo;@SpringBootApplicationpublic class ReactiveDemoApplication {
       public static void main(String[] args) {        SpringApplication.run(ReactiveDemoApplication.class, args);    }}

访问

返回hello world表示成功

使用数据库

暂时支持reactive编程的数据库只有MongoDB, redis, Cassandra, Couchbase

我们直接采用redis作为测试, 做一个简陋的注册登录的接口就行了

* 配置redis

package cn.edu.ncu.reactivedemo.config;@Configurationpublic class RedisConfig {
       @Autowired    private RedisConnectionFactory factory;    @Bean    public ReactiveRedisTemplate
   
     reactiveRedisTemplate(ReactiveRedisConnectionFactory connectionFactory){        return new ReactiveRedisTemplate
    
     (connectionFactory, RedisSerializationContext.string());    }    @Bean    public ReactiveRedisConnection connection(ReactiveRedisConnectionFactory connectionFactory){        return connectionFactory.getReactiveConnection();    }    public @PreDestroy void flushDb(){        factory.getConnection().flushDb();    }}

测试redis接口

package cn.edu.ncu.reactivedemo;@RunWith(SpringRunner.class)@SpringBootTest(classes = ReactiveDemoApplication.class)public class RedisTests {
       @Autowired    private ReactiveRedisConnection connection;    @Test    public void testRedis(){        connection                .stringCommands().set(ByteBuffer.wrap("h".getBytes()), ByteBuffer.wrap("w".getBytes()))                .subscribe(System.out::println);    }}

编写userHandler

package cn.edu.ncu.reactivedemo.handlers;@Servicepublic class UserHandler {    @Autowired    private ReactiveRedisConnection connection;    public Mono
   
     register(ServerRequest request) {        Mono
     body = request.bodyToMono(Map.class);        return body.flatMap(map -> {            String username = (String) map.get("username");            String password = (String) map.get("password");            String hashedPassword = BCrypt.hashpw(password, BCrypt.gensalt());                return connection.stringCommands()                    .set(ByteBuffer.wrap(username.getBytes()), ByteBuffer.wrap(hashedPassword.getBytes()));        }).flatMap(aBoolean -> {            Map
     
       result = new HashMap<>();            ServerResponse serverResponse = null;            if (aBoolean){                result.put("message", "successful");                return ServerResponse.ok()                        .contentType(MediaType.APPLICATION_JSON_UTF8)                        .body(BodyInserters.fromObject(result));            }else {                result.put("message", "failed");                return ServerResponse.status(HttpStatus.BAD_REQUEST)                        .contentType(MediaType.APPLICATION_JSON_UTF8)                        .body(BodyInserters.fromObject(request));            }        });    }    public Mono
      
        login(ServerRequest request){        Mono
        body = request.bodyToMono(Map.class);        return body.flatMap(map -> {            String username = (String) map.get("username");            String password = (String) map.get("password");            return connection.stringCommands().get(ByteBuffer.wrap(username.getBytes())).flatMap(byteBuffer -> {                byte[] bytes = new byte[byteBuffer.remaining()];                byteBuffer.get(bytes, 0, bytes.length);                String hashedPassword = null;                try {                    hashedPassword = new String(bytes, "UTF-8");                } catch (UnsupportedEncodingException e) {                    e.printStackTrace();                }                Map
        
          result = new HashMap<>(); if (hashedPassword == null || !BCrypt.checkpw(password, hashedPassword)){ result.put("message", "账号或密码错误"); return ServerResponse.status(HttpStatus.UNAUTHORIZED) .contentType(MediaType.APPLICATION_JSON_UTF8) .body(BodyInserters.fromObject(result)); }else { result.put("token", "假token"); return ServerResponse.ok() .contentType(MediaType.APPLICATION_JSON_UTF8) .body(BodyInserters.fromObject(result)); } }); }); }}

添加router

package cn.edu.ncu.reactivedemo;@Configurationpublic class Router {
       @Autowired private HelloWorldHandler helloWorldHandler;    @Autowired private UserHandler userHandler;    @Bean    public RouterFunction
    routerFunction(){        return RouterFunctions.route(RequestPredicates.GET("/hello"), helloWorldHandler::helloWorld)                .andRoute(RequestPredicates.POST("/register"), userHandler::register)                .andRoute(RequestPredicates.POST("/login"), userHandler::login);    }}

接口很粗糙,没有写model层, 也没有数据验证, 测试也直接用http requester进行测试了

参考:

demo地址:

转载地址：http://sigmi.baihongyu.com/

你可能感兴趣的文章