webflux提供响应式API，玩出不一样的花样
先说说什么是响应式
响应式编程或反应式编程（英语：Reactive programming）是一种面向数据流和变化传播的编程范式，直白的说就是：将变化的值通过数据流进行传播。
WebFlux又是什么呢
WebFlux 模块的名称是 spring-webflux，名称中的 Flux 来源于 Reactor 中的类 Flux。Spring webflux 有一个全新的非堵塞的函数式 Reactive Web 框架，可以用来构建异步的、非堵塞的、事件驱动的服务，在伸缩性方面表现非常好。
spring-webflux 模块。该模块包含对响应式 HTTP 和 WebSocket 客户端的支持，以及对 REST，HTML 和 WebSocket 交互等程序的支持。一般来说，Spring MVC 用于同步处理，Spring Webflux 用于异步处理。
Spring Boot Webflux 有两种编程模型实现，一种类似 Spring MVC 注解方式，另一种是基于 Reactor 的响应式方式。
实践走起
我在网找了下发现现在支持的DAL包有：
spring-boot-starter-data-redis-reactive、spring-boot-starter-data-mongodb-reactive
也许还有别的，我本意是想要spring-boot-starter-data-mysql-reactive，然而并木有。那就说下上面2个包的实践把。
spring-boot-starter-data-redis-reactive
用到的包
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-webflux</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-redis-reactive</artifactId>
</dependency>
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-pool2</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-configuration-processor</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>com.github.flying-cattle</groupId>
<artifactId>mybatis-dsc-generator</artifactId>
<version>${mybatis-dsc-generator.version}</version>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>${fastjson.version}</version>
</dependency>YMl配置
server:
port: 8080
spring:
application:
name: webFlux-test
redis:
host: 127.0.0.1
port: 6379
password: pwd2020
timeout: 5000
lettuce:
pool:
max-active: 200
max-idle: 20
min-idle: 5
max-wait: 1000 整合redis-reactive
虽然包是starter，但是还是要有自己的配置才能用不然报错如下：
Description:
Field redisTemplate in com.flying.cattle.wf.service.impl.RedisServiceImpl required a bean of type 'org.springframework.data.redis.core.ReactiveRedisTemplate' that could not be found.
The injection point has the following annotations:
- @org.springframework.beans.factory.annotation.Autowired(required=true)
Action:
Consider defining a bean of type 'org.springframework.data.redis.core.ReactiveRedisTemplate' in your configuration.看了下官方文档需要加上如下：
@Bean
public ReactiveRedisTemplate<String, String> reactiveRedisTemplate(ReactiveRedisConnectionFactory factory) {
ReactiveRedisTemplate<String, String> reactiveRedisTemplate = new ReactiveRedisTemplate<>(factory,RedisSerializationContext.string());
return reactiveRedisTemplate;
}发现了么是ReactiveRedisTemplate<String, String> 感觉就不很友好了，本来我是想声明成ReactiveRedisTemplate<String, Serializable>，搞古了一会儿木有搞定。有那个大佬有好的方案，望指点哈
Service代码：
@Service
public class RedisServiceImpl implements RedisService {
@Autowired
private ReactiveRedisTemplate<String, String> redisTemplate;
@Override
public Mono<String> getById(String key) {
// TODO Auto-generated method stub
ReactiveValueOperations<String, String> operations = redisTemplate.opsForValue();
return operations.get(key);
}
@Override
public Mono<String> addUser(String key,User user) {
// TODO Auto-generated method stub
ReactiveValueOperations<String, String> operations = redisTemplate.opsForValue();
return operations.getAndSet(key, JSON.toJSONString(user));
}
@Override
public Mono<Boolean> deleteById(String key) {
// TODO Auto-generated method stub
ReactiveValueOperations<String, String> operations = redisTemplate.opsForValue();
return operations.delete(key);
}
@Override
public Mono<String> updateById(String key,User user) {
// TODO Auto-generated method stub
ReactiveValueOperations<String, String> operations = redisTemplate.opsForValue();
return operations.getAndSet(key, JSON.toJSONString(user));
}
@Override
public Flux<String> findAll(String key) {
// TODO Auto-generated method stub
ReactiveListOperations<String, String> operations = redisTemplate.opsForList();
return operations.range(key, 0, -1);
}
@Override
public Mono<Long> addlist(String key,List<String> list) {
// TODO Auto-generated method stub
ReactiveListOperations<String, String> operations = redisTemplate.opsForList();
return operations.leftPushAll(key, list);
}
@Override
public Flux<String> findUsers(String key) {
ReactiveValueOperations<String, String> operations = redisTemplate.opsForValue();
return redisTemplate.keys(key).flatMap(keyId ->operations.get(keyId));
}
}Controller代码
@RestController
@RequestMapping("/user")
public class UserController {
public final static String USER_KEY="user";
@Autowired
private RedisService redisService;
@Autowired
private RedisGenerateId redisGenerateId;
@GetMapping("/getId")
public Long getUserId(){
return redisGenerateId.generate(USER_KEY);
}
public String getKey(Long id) {
return USER_KEY+"_"+id;
}
@GetMapping("/getById/{id}")
public Mono<String> getUserById(@PathVariable("id")Long id){
return redisService.getById(getKey(id));
}
@GetMapping("/add")
public Mono<String> add(User user){
user = new User();
user.setAccount("admin1");
user.setPassword("123123");
user.setNickname("admin");
user.setEmail("505237@qq.com");
user.setPhone("13666275002");
user.setSex(true);
String bd="1990-01-01";
DateFormat fmt = new SimpleDateFormat("yyyy-MM-dd");
try {
user.setBirthday(fmt.parse(bd));
} catch (ParseException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
user.setProvince("四川省");
user.setCity("成都市");
user.setCounty("高新区");
user.setAddress("天 府大道XXd段XX号");
user.setState("1");
// 以上是模拟数据
ValidationResult vr=ValidationUtils.validateEntity(user);
if (!vr.isHasErrors()) {
user.setId(getUserId());
System.out.println(JSON.toJSONString(user));
return redisService.addUser(getKey(user.getId()),user);
}else {
return Mono.just(vr.getFirstErrors());
}
}
@GetMapping("/addlist")
public Mono<Long> addlist(){
List<String> list=new ArrayList<String>();
User user = new User();
user.setAccount("admin1");
user.setPassword("123123");
user.setNickname("admin");
user.setEmail("505237@qq.com");
user.setPhone("13666275002");
user.setSex(true);
user.setBirthday(new Date());
user.setProvince("四川省");
user.setCity("成都市");
user.setCounty("高新区");
user.setAddress("天 府大道XXd段XX号");
user.setState("1");
//添加第一条数据
Long id=redisGenerateId.generate("user");
user.setId(id);
list.add(JSON.toJSONString(user));
//添加第二条数据
id=redisGenerateId.generate("user");
user.setId(id);
list.add(JSON.toJSONString(user));
//添加第三条数据
id=redisGenerateId.generate("user");
user.setId(id);
list.add(JSON.toJSONString(user));
return redisService.addlist("list", list);
}
/**
* 这个就是流响应式的接口了，是一个一个的返回数据的，异步返回
* delayElements(Duration.ofSeconds(2))这个是不要的，只是方便看效果
* redis 直接就是一个一个返回，不需要produces，不知道为什么...还木有深究。
*/
@GetMapping(value="/findAll",produces = MediaType.APPLICATION_STREAM_JSON_VALUE)
public Flux<String> findAll(){
return redisService.findAll("list").delayElements(Duration.ofSeconds(2));
}
@GetMapping("/getUsers")
public Flux<String> findUsers() {
// TODO Auto-generated method stub
return redisService.findUsers(USER_KEY+"_"+"*").delayElements(Duration.ofSeconds(2));
}
}一个是差list数据类型，一个是匹配key查询的，都是一个一个返回的，实际开发中去掉.delayElements(Duration.ofSeconds(2))就好
整合mongodb-reactive
需要的包，只需要在redis的基础上下面的jar
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-mongodb-reactive</artifactId>
</dependency>
MongoDB就很人性化了，感觉就很友好。而且是真的starter包，配置好数据库连接，就不需要其他配置了，直接可用
DAO
import org.springframework.data.mongodb.repository.ReactiveMongoRepository;
import com.flying.cattle.wf.entity.User;
public interface UserRepository extends ReactiveMongoRepository<User, Long>{
}SERVICE（接口层我就不贴代码了）
@Service
public class MongoServiceImpl implements MongoService {
@Autowired
private UserRepository userRepository;
@Override
public Mono<User> getById(Long id) {
// TODO Auto-generated method stub
return userRepository.findById(id);
}
@Override
public Mono<User> addUser(User user) {
// TODO Auto-generated method stub
return userRepository.save(user);
}
@Override
public Mono<Boolean> deleteById(Long id) {
// TODO Auto-generated method stub
userRepository.deleteById(id);
return Mono.create(userMonoSink -> userMonoSink.success());
}
@Override
public Mono<User> updateById(User user) {
// TODO Auto-generated method stub
return userRepository.save(user);
}
@Override
public Flux<User> findAllUser() {
// TODO Auto-generated method stub
return userRepository.findAll();
}
}CONTROLLER
@RestController
@RequestMapping("/usermg")
public class UserMongoController {
public final static String USER_KEY="user";
@Autowired
private RedisGenerateId redisGenerateId;
@Autowired
private MongoService mongoService;
@GetMapping("/getId")
public Long getUserId(){
return redisGenerateId.generate(USER_KEY);
}
@GetMapping("/add")
public Mono<User> add(User user) {
user = new User();
user.setAccount("admin1");
user.setPassword("123123");
user.setNickname("admin");
user.setEmail("505237@qq.com");
user.setPhone("13666275002");
user.setSex(true);
String bd = "1990-01-01";
DateFormat fmt = new SimpleDateFormat("yyyy-MM-dd");
try {
user.setBirthday(fmt.parse(bd));
} catch (ParseException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
user.setProvince("四川省");
user.setCity("成都市");
user.setCounty("高新区");
user.setAddress("天 府大道XXd段XX号");
user.setState("1");
// 以上是模拟数据
ValidationResult vr = ValidationUtils.validateEntity(user);
if (!vr.isHasErrors()) {
user.setId(getUserId());
System.out.println(JSON.toJSONString(user));
return mongoService.addUser(user);
} else {
System.err.println(vr.getFirstErrors());
}
return null;
}
/**
* 注意这里produces = MediaType.APPLICATION_STREAM_JSON_VALUE
* 如果不是application/stream+json则调用端无法滚动得到结果，将一直阻塞等待数据流结束或超时。
*/
@GetMapping(value="/findAll",produces = MediaType.APPLICATION_STREAM_JSON_VALUE)
public Flux<User> findAll(){
return mongoService.findAllUser().delayElements(Duration.ofSeconds(1));
}
}代码就这些，大家要体验这个框架，建议还是用MongoDB把，毕竟redis主要是做缓存的。
给大家看下数据结构图
