使用反应式数据库客户端扩展 Spring WebFlux 应用程序时出现问题：冲突的 Maven 依赖项？
Problem extending Spring WebFlux application with reactive DB client: conflicting Maven dependencies?
我有一个基于此代码制作的小型 Spring WebFlux 应用程序：
https://github.com/chang-chao/spring-webflux-reactive-jdbc-sample
据我所知，这是纯反应式编程和通常的阻塞关系数据库之间的某种混合。
现在我的任务是将反应式数据库客户端添加到我的应用程序。我盯着这个指南：
https://spring.io/guides/gs/accessing-data-r2dbc/
但是一旦我将以下依赖项添加到我的 pom.xml:
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-r2dbc</artifactId>
<version>2.3.4.RELEASE</version>
</dependency>
<dependency>
<groupId>io.r2dbc</groupId>
<artifactId>r2dbc-h2</artifactId>
<version>0.8.4.RELEASE</version>
<scope>runtime</scope>
</dependency>
我的 WORKING 应用程序启动失败，提示找不到自动装配的存储库 bean。一旦我删除了上面的两个依赖项，这个错误就消失了。
工作应用的 pom.xml 初始完整：
<?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>2.3.4.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.freelance</groupId>
<artifactId>studentlist</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>student-list</name>
<description>Spring WebFlux application for managing students</description>
<properties>
<java.version>11</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-webflux</artifactId>
<version>2.3.4.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
<version>2.3.4.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<version>2.3.4.RELEASE</version>
<scope>test</scope>
<exclusions>
<exclusion>
<groupId>org.junit.vintage</groupId>
<artifactId>junit-vintage-engine</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>io.projectreactor</groupId>
<artifactId>reactor-test</artifactId>
<version>3.3.10.RELEASE</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>com.h2database</groupId>
<artifactId>h2</artifactId>
<version>1.4.200</version>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
我想有些依赖项相互冲突。有没有办法将这些依赖项与我的所有其他依赖项一起实际使用，以便我能够遵循该指南？
不知道这个问题是否需要app的Java代码，如果需要，需要哪几段。现在我只添加 application.properties:
spring.h2.console.enabled=true
spring.h2.console.path=/h2_console
spring.datasource.url=jdbc:h2:~/studentlist
spring.datasource.platform=h2
spring.datasource.initialization-mode=always
spring.datasource.username=sa
spring.datasource.password=
spring.datasource.driverClassName=org.h2.Driver
spring.jpa.generate-ddl=true
spring.jpa.database-platform=org.hibernate.dialect.H2Dialect
spring.jpa.hibernate.ddl-auto = update
spring.jpa.show-sql=true
logging.level.org.springframework=warn
logging.level.org.hibernate.type.descriptor.sql.BasicBinder=trace
logging.level.org.hibernate.SQL=warn
logging.level.io.netty=warn
spring.datasource.maximum-pool-size=100
添加其中之一这两个依赖项，spring-boot-starter-data-r2dbc或r2dbc-h2，没有第二个就足以导致这个错误：
2020-10-20 15:31:26.008 WARN 11580 --- [ main] onfigReactiveWebServerApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'studentController': Unsatisfied dependency expressed through field 'studentService'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'studentService': Unsatisfied dependency expressed through field 'studentRepository'; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'com.freelance.studentlist.repository.StudentRepository' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
2020-10-20 15:31:26.123 ERROR 11580 --- [ main] o.s.b.d.LoggingFailureAnalysisReporter :
***************************
APPLICATION FAILED TO START
***************************
Description:
Field studentRepository in com.freelance.studentlist.service.StudentServiceImpl required a bean of type 'com.freelance.studentlist.repository.StudentRepository' 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 'com.freelance.studentlist.repository.StudentRepository' in your configuration.
Process finished with exit code 1
我删除了 JPA 依赖项，目前我正在尝试只使用 r2dbc。
我想我的 application.properties 将不再有效。你能帮我改一下吗？我使用指南中的代码片段：
public class R2DBCConfiguration extends AbstractR2dbcConfiguration {
@Bean
public H2ConnectionFactory connectionFactory() {
return new H2ConnectionFactory(
H2ConnectionConfiguration.builder()
.url("jdbc:h2:~/studentlist;DB_CLOSE_DELAY=-1;TRACE_LEVEL_FILE=4")
.username("sa")
.build());
}
}
我强烈怀疑这样的url对r2dbc无效。在 r2dbc H2（不是内存中，只是本地数据库）的情况下，jdbc:h2:~/studentlist URL 的有效替代是什么？
我应该如何更改 application.properties 中的这段代码？ URL 特别是！
**spring.datasource.url=jdbc:h2:~/studentlist**
spring.datasource.platform=h2
spring.datasource.initialization-mode=always
spring.datasource.username=sa
spring.datasource.password=
spring.datasource.driverClassName=org.h2.Driver
知道的请帮忙！现在不能google一个合适的例子...
spring.datasource 用于传统的 Jdbc 数据源，要配置 R2dbc 连接，请在 Spring 引导 application.properties 中使用 spring.r2dbc 前缀。
检查 my Spring R2dbc example，如果您是 Spring Data R2dbc 的新手，Readme.md.
中的文档
我有一个基于此代码制作的小型 Spring WebFlux 应用程序：
https://github.com/chang-chao/spring-webflux-reactive-jdbc-sample
据我所知，这是纯反应式编程和通常的阻塞关系数据库之间的某种混合。
现在我的任务是将反应式数据库客户端添加到我的应用程序。我盯着这个指南：
https://spring.io/guides/gs/accessing-data-r2dbc/
但是一旦我将以下依赖项添加到我的 pom.xml:
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-r2dbc</artifactId>
<version>2.3.4.RELEASE</version>
</dependency>
<dependency>
<groupId>io.r2dbc</groupId>
<artifactId>r2dbc-h2</artifactId>
<version>0.8.4.RELEASE</version>
<scope>runtime</scope>
</dependency>
我的 WORKING 应用程序启动失败，提示找不到自动装配的存储库 bean。一旦我删除了上面的两个依赖项，这个错误就消失了。
工作应用的 pom.xml 初始完整：
<?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>2.3.4.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.freelance</groupId>
<artifactId>studentlist</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>student-list</name>
<description>Spring WebFlux application for managing students</description>
<properties>
<java.version>11</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-webflux</artifactId>
<version>2.3.4.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
<version>2.3.4.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<version>2.3.4.RELEASE</version>
<scope>test</scope>
<exclusions>
<exclusion>
<groupId>org.junit.vintage</groupId>
<artifactId>junit-vintage-engine</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>io.projectreactor</groupId>
<artifactId>reactor-test</artifactId>
<version>3.3.10.RELEASE</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>com.h2database</groupId>
<artifactId>h2</artifactId>
<version>1.4.200</version>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
我想有些依赖项相互冲突。有没有办法将这些依赖项与我的所有其他依赖项一起实际使用，以便我能够遵循该指南？
不知道这个问题是否需要app的Java代码，如果需要，需要哪几段。现在我只添加 application.properties:
spring.h2.console.enabled=true
spring.h2.console.path=/h2_console
spring.datasource.url=jdbc:h2:~/studentlist
spring.datasource.platform=h2
spring.datasource.initialization-mode=always
spring.datasource.username=sa
spring.datasource.password=
spring.datasource.driverClassName=org.h2.Driver
spring.jpa.generate-ddl=true
spring.jpa.database-platform=org.hibernate.dialect.H2Dialect
spring.jpa.hibernate.ddl-auto = update
spring.jpa.show-sql=true
logging.level.org.springframework=warn
logging.level.org.hibernate.type.descriptor.sql.BasicBinder=trace
logging.level.org.hibernate.SQL=warn
logging.level.io.netty=warn
spring.datasource.maximum-pool-size=100
添加其中之一这两个依赖项，spring-boot-starter-data-r2dbc或r2dbc-h2，没有第二个就足以导致这个错误：
2020-10-20 15:31:26.008 WARN 11580 --- [ main] onfigReactiveWebServerApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'studentController': Unsatisfied dependency expressed through field 'studentService'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'studentService': Unsatisfied dependency expressed through field 'studentRepository'; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'com.freelance.studentlist.repository.StudentRepository' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
2020-10-20 15:31:26.123 ERROR 11580 --- [ main] o.s.b.d.LoggingFailureAnalysisReporter :
***************************
APPLICATION FAILED TO START
***************************
Description:
Field studentRepository in com.freelance.studentlist.service.StudentServiceImpl required a bean of type 'com.freelance.studentlist.repository.StudentRepository' 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 'com.freelance.studentlist.repository.StudentRepository' in your configuration.
Process finished with exit code 1
我删除了 JPA 依赖项，目前我正在尝试只使用 r2dbc。
我想我的 application.properties 将不再有效。你能帮我改一下吗？我使用指南中的代码片段：
public class R2DBCConfiguration extends AbstractR2dbcConfiguration {
@Bean
public H2ConnectionFactory connectionFactory() {
return new H2ConnectionFactory(
H2ConnectionConfiguration.builder()
.url("jdbc:h2:~/studentlist;DB_CLOSE_DELAY=-1;TRACE_LEVEL_FILE=4")
.username("sa")
.build());
}
}
我强烈怀疑这样的url对r2dbc无效。在 r2dbc H2（不是内存中，只是本地数据库）的情况下，jdbc:h2:~/studentlist URL 的有效替代是什么？
我应该如何更改 application.properties 中的这段代码？ URL 特别是！
**spring.datasource.url=jdbc:h2:~/studentlist**
spring.datasource.platform=h2
spring.datasource.initialization-mode=always
spring.datasource.username=sa
spring.datasource.password=
spring.datasource.driverClassName=org.h2.Driver
知道的请帮忙！现在不能google一个合适的例子...
spring.datasource 用于传统的 Jdbc 数据源，要配置 R2dbc 连接，请在 Spring 引导 application.properties 中使用 spring.r2dbc 前缀。
检查 my Spring R2dbc example，如果您是 Spring Data R2dbc 的新手，Readme.md.
中的文档