springboot3+r2dbc響應(yīng)式編程實踐
Spring boot3已經(jīng)M1了,最近群佬們也開始蠢蠢欲動的開始整活Reactive+Spring Boot3,跟著大家的步伐,我也來整一篇工程入門,我們將用java17+Spring Boot3+r2dbc+Reactive棧來講述,歡迎大家來討論。(關(guān)于響應(yīng)式,請大家異步到之前的文章里,有詳細(xì)介紹。)
r2dbc
Reactor還有基于其之上的Spring WebFlux框架。包括vert.x,rxjava等等reactive技術(shù)。我們實際上在應(yīng)用層已經(jīng)有很多優(yōu)秀的響應(yīng)式處理框架。
但是有一個問題就是所有的框架都需要獲取底層的數(shù)據(jù),而基本上關(guān)系型數(shù)據(jù)庫的底層讀寫都還是同步的。
為了解決這個問題,出現(xiàn)了兩個標(biāo)準(zhǔn),一個是oracle提出的 ADBC (Asynchronous Database Access API),另一個就是Pivotal提出的R2DBC (Reactive Relational Database Connectivity)。
R2DBC是基于Reactive Streams標(biāo)準(zhǔn)來設(shè)計的。通過使用R2DBC,你可以使用reactive API來操作數(shù)據(jù)。
同時R2DBC只是一個開放的標(biāo)準(zhǔn),而各個具體的數(shù)據(jù)庫連接實現(xiàn),需要實現(xiàn)這個標(biāo)準(zhǔn)。
今天我們以r2dbc-h2為例,講解一下r2dbc在Spring webFlux中的使用。
工程依賴
以下是 pom.xml清單
<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" ?? ?xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd"> ?? ?<modelVersion>4.0.0</modelVersion> ?? ?<parent> ?? ??? ?<groupId>org.springframework.boot</groupId> ?? ??? ?<artifactId>spring-boot-starter-parent</artifactId> ?? ??? ?<version>3.0.0-M1</version> ?? ??? ?<relativePath/> <!-- lookup parent from repository --> ?? ?</parent> ?? ?<groupId>wang.datahub</groupId> ?? ?<artifactId>springboot3demo</artifactId> ?? ?<version>0.0.1-SNAPSHOT</version> ?? ?<name>springboot3demo</name> ?? ?<description>Demo project for Spring Boot</description> ?? ?<properties> ?? ??? ?<java.version>17</java.version> ?? ?</properties> ?? ?<dependencies> ?? ??? ?<dependency> ?? ??? ??? ?<groupId>org.springframework.boot</groupId> ?? ??? ??? ?<artifactId>spring-boot-starter-data-r2dbc</artifactId> ?? ??? ?</dependency> ?? ??? ?<dependency> ?? ??? ??? ?<groupId>org.springframework.boot</groupId> ?? ??? ??? ?<artifactId>spring-boot-starter-data-redis-reactive</artifactId> ?? ??? ?</dependency> ?? ??? ?<dependency> ?? ??? ??? ?<groupId>org.springframework.boot</groupId> ?? ??? ??? ?<artifactId>spring-boot-starter-data-rest</artifactId> ?? ??? ?</dependency> ?? ??? ?<dependency> ?? ??? ??? ?<groupId>org.springframework.boot</groupId> ?? ??? ??? ?<artifactId>spring-boot-starter-groovy-templates</artifactId> ?? ??? ?</dependency> ?? ??? ?<dependency> ?? ??? ??? ?<groupId>org.springframework.boot</groupId> ?? ??? ??? ?<artifactId>spring-boot-starter-hateoas</artifactId> ?? ??? ?</dependency> ?? ??? ?<dependency> ?? ??? ??? ?<groupId>org.springframework.boot</groupId> ?? ??? ??? ?<artifactId>spring-boot-starter-web</artifactId> ?? ??? ?</dependency> ?? ??? ?<dependency> ?? ??? ??? ?<groupId>org.springframework.boot</groupId> ?? ??? ??? ?<artifactId>spring-boot-starter-webflux</artifactId> ?? ??? ?</dependency> ?? ??? ?<dependency> ?? ??? ??? ?<groupId>org.springframework.boot</groupId> ?? ??? ??? ?<artifactId>spring-boot-configuration-processor</artifactId> ?? ??? ??? ?<optional>true</optional> ?? ??? ?</dependency> ?? ??? ?<dependency> ?? ??? ??? ?<groupId>org.springframework.boot</groupId> ?? ??? ??? ?<artifactId>spring-boot-devtools</artifactId> ?? ??? ?</dependency> ?? ??? ?<dependency> ?? ??? ??? ?<groupId>io.r2dbc</groupId> ?? ??? ??? ?<artifactId>r2dbc-h2</artifactId> ?? ??? ?</dependency> ?? ??? ?<dependency> ?? ??? ??? ?<groupId>com.h2database</groupId> ?? ??? ??? ?<artifactId>h2</artifactId> ?? ??? ?</dependency> ?? ??? ?<dependency> ?? ??? ??? ?<groupId>mysql</groupId> ?? ??? ??? ?<artifactId>mysql-connector-java</artifactId> ?? ??? ??? ?<scope>runtime</scope> ?? ??? ?</dependency> ?? ??? ?<dependency> ?? ??? ??? ?<groupId>org.springframework.boot</groupId> ?? ??? ??? ?<artifactId>spring-boot-starter-test</artifactId> ?? ??? ??? ?<scope>test</scope> ?? ??? ?</dependency> ?? ??? ?<dependency> ?? ??? ??? ?<groupId>io.projectreactor</groupId> ?? ??? ??? ?<artifactId>reactor-test</artifactId> ?? ??? ??? ?<scope>test</scope> ?? ??? ?</dependency> ?? ??? ?<dependency> ?? ??? ??? ?<groupId>io.projectreactor</groupId> ?? ??? ??? ?<artifactId>reactor-test</artifactId> <!--?? ??? ??? ?<version>3.4.14</version>--> <!--?? ??? ??? ?<scope>compile</scope>--> ?? ??? ?</dependency> ?? ?</dependencies> ?? ?<build> ?? ??? ?<plugins> ?? ??? ??? ?<plugin> ?? ??? ??? ??? ?<groupId>org.springframework.boot</groupId> ?? ??? ??? ??? ?<artifactId>spring-boot-maven-plugin</artifactId> ?? ??? ??? ?</plugin> ?? ??? ?</plugins> ?? ?</build> ?? ?<repositories> ?? ??? ?<repository> ?? ??? ??? ?<id>spring-milestones</id> ?? ??? ??? ?<name>Spring Milestones</name> ?? ??? ??? ?<url>https://repo.spring.io/milestone</url> ?? ??? ??? ?<snapshots> ?? ??? ??? ??? ?<enabled>false</enabled> ?? ??? ??? ?</snapshots> ?? ??? ?</repository> ?? ??? ?<repository> ?? ??? ??? ?<id>spring-snapshots</id> ?? ??? ??? ?<name>Spring Snapshots</name> ?? ??? ??? ?<url>https://repo.spring.io/snapshot</url> ?? ??? ??? ?<releases> ?? ??? ??? ??? ?<enabled>false</enabled> ?? ??? ??? ?</releases> ?? ??? ?</repository> ?? ?</repositories> ?? ?<pluginRepositories> ?? ??? ?<pluginRepository> ?? ??? ??? ?<id>spring-milestones</id> ?? ??? ??? ?<name>Spring Milestones</name> ?? ??? ??? ?<url>https://repo.spring.io/milestone</url> ?? ??? ??? ?<snapshots> ?? ??? ??? ??? ?<enabled>false</enabled> ?? ??? ??? ?</snapshots> ?? ??? ?</pluginRepository> ?? ??? ?<pluginRepository> ?? ??? ??? ?<id>spring-snapshots</id> ?? ??? ??? ?<name>Spring Snapshots</name> ?? ??? ??? ?<url>https://repo.spring.io/snapshot</url> ?? ??? ??? ?<releases> ?? ??? ??? ??? ?<enabled>false</enabled> ?? ??? ??? ?</releases> ?? ??? ?</pluginRepository> ?? ?</pluginRepositories> </project>
配置文件
這里我們只配置了r2dbc鏈接信息
配置類
用于配置默認(rèn)鏈接,創(chuàng)建初始化數(shù)據(jù)
package wang.datahub.springboot3demo.config;
import io.netty.util.internal.StringUtil;
import io.r2dbc.spi.ConnectionFactories;
import io.r2dbc.spi.ConnectionFactory;
import io.r2dbc.spi.ConnectionFactoryOptions;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import reactor.core.publisher.Flux;
import static io.r2dbc.spi.ConnectionFactoryOptions.*;
@Configuration
@ConfigurationProperties(prefix = "r2dbc")
public class DBConfig {
private String url;
private String user;
private String password;
public String getUrl() {
return url;
}
public void setUrl(String url) {
this.url = url;
}
public String getUser() {
return user;
}
public void setUser(String user) {
this.user = user;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
@Bean
public ConnectionFactory connectionFactory() {
System.out.println("url ==> "+url);
ConnectionFactoryOptions baseOptions = ConnectionFactoryOptions.parse(url);
ConnectionFactoryOptions.Builder ob = ConnectionFactoryOptions.builder().from(baseOptions);
if (!StringUtil.isNullOrEmpty(user)) {
ob = ob.option(USER, user);
}
if (!StringUtil.isNullOrEmpty(password)) {
ob = ob.option(PASSWORD, password);
}
return ConnectionFactories.get(ob.build());
}
@Bean
public CommandLineRunner initDatabase(ConnectionFactory cf) {
return (args) ->
Flux.from(cf.create())
.flatMap(c ->
Flux.from(c.createBatch()
.add("drop table if exists Users")
.add("create table Users(" +
"id IDENTITY(1,1)," +
"firstname varchar(80) not null," +
"lastname varchar(80) not null)")
.add("insert into Users(firstname,lastname)" +
"values('Jacky','Li')")
.add("insert into Users(firstname,lastname)" +
"values('Doudou','Li')")
.add("insert into Users(firstname,lastname)" +
"values('Maimai','Li')")
.execute())
.doFinally((st) -> c.close())
)
.log()
.blockLast();
}
}
bean
創(chuàng)建用戶bean
package wang.datahub.springboot3demo.bean;
import org.springframework.data.annotation.Id;
public class Users {
@Id
private Long id;
private String firstname;
private String lastname;
public Users(){
}
public Users(Long id, String firstname, String lastname) {
this.id = id;
this.firstname = firstname;
this.lastname = lastname;
}
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getFirstname() {
return firstname;
}
public void setFirstname(String firstname) {
this.firstname = firstname;
}
public String getLastname() {
return lastname;
}
public void setLastname(String lastname) {
this.lastname = lastname;
}
@Override
public String toString() {
return "User{" +
"id=" + id +
", firstname='" + firstname + '\'' +
", lastname='" + lastname + '\'' +
'}';
}
}
DAO
dao代碼清單如下,包含查詢列表、按id查詢,以及創(chuàng)建用戶等操作
package wang.datahub.springboot3demo.dao;
import io.r2dbc.spi.Connection;
import io.r2dbc.spi.ConnectionFactory;
import org.springframework.data.r2dbc.core.R2dbcEntityTemplate;
import org.springframework.data.relational.core.query.Query;
import org.springframework.stereotype.Component;
import reactor.core.publisher.Flux;
import reactor.core.publisher.Mono;
import wang.datahub.springboot3demo.bean.Users;
import static org.springframework.data.r2dbc.query.Criteria.where;
import static org.springframework.data.relational.core.query.Query.query;
@Component
public class UsersDao {
? ? private ConnectionFactory connectionFactory;
? ? private R2dbcEntityTemplate template;
? ? public UsersDao(ConnectionFactory connectionFactory) {
? ? ? ? this.connectionFactory = connectionFactory;
? ? ? ? this.template = new R2dbcEntityTemplate(connectionFactory);
? ? }
? ? public Mono<Users> findById(long id) {
? ? ? ? return this.template.selectOne(query(where("id").is(id)),Users.class);
// ? ? ? ?return Mono.from(connectionFactory.create())
// ? ? ? ? ? ? ? ?.flatMap(c -> Mono.from(c.createStatement("select id,firstname,lastname from Users where id = $1")
// ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?.bind("$1", id)
// ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?.execute())
// ? ? ? ? ? ? ? ? ? ? ? ?.doFinally((st) -> close(c)))
// ? ? ? ? ? ? ? ?.map(result -> result.map((row, meta) ->
// ? ? ? ? ? ? ? ? ? ? ? ?new Users(row.get("id", Long.class),
// ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?row.get("firstname", String.class),
// ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?row.get("lastname", String.class))))
// ? ? ? ? ? ? ? ?.flatMap( p -> Mono.from(p));
? ? }
? ? public Flux<Users> findAll() {
? ? ? ? return this.template.select(Users.class).all();
// ? ? ? ?return Mono.from(connectionFactory.create())
// ? ? ? ? ? ? ? ?.flatMap((c) -> Mono.from(c.createStatement("select id,firstname,lastname from users")
// ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?.execute())
// ? ? ? ? ? ? ? ? ? ? ? ?.doFinally((st) -> close(c)))
// ? ? ? ? ? ? ? ?.flatMapMany(result -> Flux.from(result.map((row, meta) -> {
// ? ? ? ? ? ? ? ? ? ?Users acc = new Users();
// ? ? ? ? ? ? ? ? ? ?acc.setId(row.get("id", Long.class));
// ? ? ? ? ? ? ? ? ? ?acc.setFirstname(row.get("firstname", String.class));
// ? ? ? ? ? ? ? ? ? ?acc.setLastname(row.get("lastname", String.class));
// ? ? ? ? ? ? ? ? ? ?return acc;
// ? ? ? ? ? ? ? ?})));
? ? }
? ? public Mono<Users> createAccount(Users account) {
? ? ? ? return Mono.from(connectionFactory.create())
? ? ? ? ? ? ? ? .flatMap(c -> Mono.from(c.beginTransaction())
? ? ? ? ? ? ? ? ? ? ? ? .then(Mono.from(c.createStatement("insert into Users(firstname,lastname) values($1,$2)")
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? .bind("$1", account.getFirstname())
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? .bind("$2", account.getLastname())
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? .returnGeneratedValues("id")
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? .execute()))
? ? ? ? ? ? ? ? ? ? ? ? .map(result -> result.map((row, meta) ->
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? new Users(row.get("id", Long.class),
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? account.getFirstname(),
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? account.getLastname())))
? ? ? ? ? ? ? ? ? ? ? ? .flatMap(pub -> Mono.from(pub))
? ? ? ? ? ? ? ? ? ? ? ? .delayUntil(r -> c.commitTransaction())
? ? ? ? ? ? ? ? ? ? ? ? .doFinally((st) -> c.close()));
? ? }
? ? private <T> Mono<T> close(Connection connection) {
? ? ? ? return Mono.from(connection.close())
? ? ? ? ? ? ? ? .then(Mono.empty());
? ? }
}controller
controller代碼清單如下,包含了查詢列表、按id查詢,以及創(chuàng)建用戶等操作
package wang.datahub.springboot3demo.controller;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.*;
import reactor.core.publisher.Flux;
import reactor.core.publisher.Mono;
import wang.datahub.springboot3demo.bean.Users;
import wang.datahub.springboot3demo.dao.UsersDao;
@RestController
public class UsersController {
@Autowired
private final UsersDao usersDao;
public UsersController(UsersDao usersDao) {
this.usersDao = usersDao;
}
@GetMapping("/users/{id}")
public Mono<ResponseEntity<Users>> getUsers(@PathVariable("id") Long id) {
return usersDao.findById(id)
.map(acc -> new ResponseEntity<>(acc, HttpStatus.OK))
.switchIfEmpty(Mono.just(new ResponseEntity<>(null, HttpStatus.NOT_FOUND)));
}
@GetMapping("/users")
public Flux<Users> getAllAccounts() {
return usersDao.findAll();
}
@PostMapping("/createUser")
public Mono<ResponseEntity<Users>> createUser(@RequestBody Users user) {
return usersDao.createAccount(user)
.map(acc -> new ResponseEntity<>(acc, HttpStatus.CREATED))
.log();
}
}
啟動類清單:
package wang.datahub.springboot3demo;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import wang.datahub.springboot3demo.config.DBConfig;
@SpringBootApplication
@EnableConfigurationProperties(DBConfig.class)
public class WebFluxR2dbcApp {
? ? public static void main(String[] args) {
? ? ? ? SpringApplication.run(WebFluxR2dbcApp.class, args);
? ? }
}好了,致此我們整個 Demo 就實現(xiàn)完成了
參考鏈接:
https://zhuanlan.zhihu.com/p/299069835
到此這篇關(guān)于springboot3+r2dbc響應(yīng)式編程實踐的文章就介紹到這了,更多相關(guān)springboot3 r2dbc響應(yīng)式編程內(nèi)容請搜索腳本之家以前的文章或繼續(xù)瀏覽下面的相關(guān)文章希望大家以后多多支持腳本之家!
相關(guān)文章
Spring?MVC基于注解的使用之JSON數(shù)據(jù)處理的方法
這篇文章主要介紹了Spring?MVC基于注解的使用JSON數(shù)據(jù)處理,json是一種輕量級的數(shù)據(jù)交換格式,是一種理想的數(shù)據(jù)交互語言,它易于閱讀和編寫,同時也易于機器解析和生成,本文通過實例代碼給大家介紹的非常詳細(xì),需要的朋友可以參考下2022-05-05
淺析Android系統(tǒng)中HTTPS通信的實現(xiàn)
這篇文章主要介紹了淺析Android系統(tǒng)中HTTPS通信的實現(xiàn),實現(xiàn)握手的源碼為Java語言編寫,需要的朋友可以參考下2015-07-07
自定義@RequestBody注解如何獲取JSON數(shù)據(jù)
這篇文章主要介紹了自定義@RequestBody注解如何獲取JSON數(shù)據(jù)問題,具有很好的參考價值,希望對大家有所幫助。如有錯誤或未考慮完全的地方,望不吝賜教2023-04-04
SpringCloud項目的log4j2漏洞解決方案詳解流程
很多小伙伴因為Log4j2的驚爆0Day漏洞一時束手無策,這里提供最終解決方案可以進(jìn)行一個版本號的升級,感興趣的朋友來看看吧2022-04-04

