将Spring版本从2.0.3更改为2.1.0.M4时出现的问题

Question

当我将Spring版本从2.0.3.RELEASE更改为2.1.0.M4时，我有一个工作代码停止工作

错误是：

Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.

***************************
APPLICATION FAILED TO START
***************************

Description:

The bean 'dataSource', defined in BeanDefinition defined in class path resource [org/springframework/boot/autoconfigure/jdbc/DataSourceConfiguration$Hikari.class], could not be registered. A bean with that name has already been defined in class path resource [org/springframework/boot/autoconfigure/jdbc/DataSourceConfiguration$Hikari.class] and overriding is disabled.

Action:

Consider renaming one of the beans or enabling overriding by setting spring.main.allow-bean-definition-overriding=true

一个类似的问题(Trouble when changing Spring Boot version from 2.0.3.RELEASE to 2.1.0.BUILD-SNAPSHOT)已经被问到了，但没有给出正确的答案。

以下是我的POM.xml

<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>***.***.***</groupId>
        <artifactId>******</artifactId>
        <version>1.0.0</version>
        <relativePath />
        <!-- lookup parent from repository -->
    </parent>
    <artifactId>*****</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>
    <name>${project.artifactId}</name>
    <description>TEST</description>

    <prerequisites>
        <maven>${maven.version}</maven>
    </prerequisites>

    <properties>
        <start-class>c*.*.Application</start-class>
        <junit.jupiter.version>5.2.0</junit.jupiter.version>
    </properties>

    <dependencies>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-webflux</artifactId>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-reactor-netty -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-reactor-netty</artifactId>
            <version>2.0.5.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-config</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.security</groupId>
            <artifactId>spring-security-rsa</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>

        <!-- Sql server driver -->
        <dependency>
            <groupId>com.microsoft.sqlserver</groupId>
            <artifactId>mssql-jdbc</artifactId>
        </dependency>

        <!-- Lombok dependencies -->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <scope>provided</scope>
        </dependency>

        <!-- Commons dependencies -->
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-lang3</artifactId>
        </dependency>
        <dependency>
            <groupId>commons-validator</groupId>
            <artifactId>commons-validator</artifactId>
        </dependency>

        <!-- Logging dependencies -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-sleuth</artifactId>
        </dependency>
        <dependency>
            <groupId>net.logstash.logback</groupId>
            <artifactId>logstash-logback-encoder</artifactId>
        </dependency>

        <!-- Swagger dependencies -->
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger2</artifactId>
        </dependency>
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger-ui</artifactId>
        </dependency>
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-bean-validators</artifactId>
        </dependency>

        <!-- Test dependencies -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>com.vaadin.external.google</groupId>
                    <artifactId>android-json</artifactId>
                </exclusion>
            </exclusions>
        </dependency>

        <!-- Spring REST Docs dependencies -->
        <dependency>
            <groupId>org.springframework.restdocs</groupId>
            <artifactId>spring-restdocs-core</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.restdocs</groupId>
            <artifactId>spring-restdocs-webtestclient</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.restdocs</groupId>
            <artifactId>spring-restdocs-asciidoctor</artifactId>
            <scope>test</scope>
        </dependency>

        <!-- Spring Auto REST Docs dependencies -->
        <dependency>
            <groupId>capital.scalable</groupId>
            <artifactId>spring-auto-restdocs-core</artifactId>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>org.hsqldb</groupId>
            <artifactId>hsqldb</artifactId>
            <scope>test</scope>
        </dependency>

        <!-- JUnit Jupiter API and Engine -->

        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter-api</artifactId>
            <version>${junit.jupiter.version}</version>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter-engine</artifactId>
            <version>${junit.jupiter.version}</version>
            <scope>test</scope>
        </dependency>

        <!-- https://mvnrepository.com/artifact/com.squareup.okhttp3/mockwebserver -->
        <dependency>
            <groupId>com.squareup.okhttp3</groupId>
            <artifactId>mockwebserver</artifactId>
            <version>3.10.0</version>
            <scope>test</scope>
        </dependency>

        <!-- https://mvnrepository.com/artifact/com.google.code.gson/gson -->
        <dependency>
            <groupId>com.google.code.gson</groupId>
            <artifactId>gson</artifactId>
            <version>2.8.5</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/io.projectreactor/reactor-test -->
        <dependency>
            <groupId>io.projectreactor</groupId>
            <artifactId>reactor-test</artifactId>
            <version>3.1.8.RELEASE</version>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>org.mock-server</groupId>
            <artifactId>mockserver-netty</artifactId>
            <version>5.4.1</version>
        </dependency>

    </dependencies>

    <build>
        <resources>
            <resource>
                <filtering>true</filtering>
                <directory>src/main/resources</directory>
                <includes>
                    <include>**/*.xml</include>
                    <include>**/*.properties</include>
                    <include>**/*.yml</include>
                </includes>
                <excludes>
                    <exclude>**/*.jks</exclude>
                </excludes>
            </resource>
            <resource>
                <filtering>false</filtering>
                <directory>src/main/resources</directory>
                <includes>
                    <include>**/*.jks</include>
                </includes>
                <excludes>
                    <exclude>**/*.xml</exclude>
                    <exclude>**/*.properties</exclude>
                    <exclude>**/*.yml</exclude>
                </excludes>
            </resource>
        </resources>
        <plugins>
            <plugin>
                <groupId>com.github.ekryd.sortpom</groupId>
                <artifactId>sortpom-maven-plugin</artifactId>
            </plugin>
            <plugin>
                <groupId>com.github.spotbugs</groupId>
                <artifactId>spotbugs-maven-plugin</artifactId>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-checkstyle-plugin</artifactId>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-enforcer-plugin</artifactId>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-failsafe-plugin</artifactId>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-jar-plugin</artifactId>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-javadoc-plugin</artifactId>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-pmd-plugin</artifactId>
                <configuration>
                    <excludeFromFailureFile>${project.basedir}/exclude-pmd.properties</excludeFromFailureFile>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-resources-plugin</artifactId>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-site-plugin</artifactId>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-source-plugin</artifactId>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-surefire-plugin</artifactId>
            </plugin>
            <plugin>
                <groupId>org.asciidoctor</groupId>
                <artifactId>asciidoctor-maven-plugin</artifactId>
            </plugin>
            <plugin>
                <groupId>org.eclipse.m2e</groupId>
                <artifactId>lifecycle-mapping</artifactId>
            </plugin>
            <plugin>
                <groupId>org.gaul</groupId>
                <artifactId>modernizer-maven-plugin</artifactId>
            </plugin>
            <plugin>
                <groupId>org.jacoco</groupId>
                <artifactId>jacoco-maven-plugin</artifactId>
            </plugin>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
            <plugin>
                <groupId>pl.project13.maven</groupId>
                <artifactId>git-commit-id-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

    <profiles>
        <profile>
            <id>dev</id>
            <activation>
                <activeByDefault>true</activeByDefault>
            </activation>
            <properties>
                <spring.profiles.active>dev</spring.profiles.active>
            </properties>
        </profile>
        <profile>
            <id>qa</id>
            <properties>
                <spring.profiles.active>qa</spring.profiles.active>
            </properties>
        </profile>
        <profile>
            <id>prod</id>
            <properties>
                <spring.profiles.active>prod</spring.profiles.active>
            </properties>
        </profile>
        <profile>
            <id>eclipse</id>
            <dependencyManagement>
                <dependencies>
                    <dependency>
                        <groupId>org.junit.jupiter</groupId>
                        <artifactId>junit-jupiter-engine</artifactId>
                        <version>${junit.jupiter.version}</version>
                        <scope>test</scope>
                    </dependency>
                    <dependency>
                        <groupId>org.junit.platform</groupId>
                        <artifactId>junit-platform-launcher</artifactId>
                        <version>1.1.1</version>
                        <scope>test</scope>
                    </dependency>
                </dependencies>
            </dependencyManagement>
            <dependencies>
                <dependency>
                    <groupId>org.junit.jupiter</groupId>
                    <artifactId>junit-jupiter-engine</artifactId>
                </dependency>
                <dependency>
                    <groupId>org.junit.platform</groupId>
                    <artifactId>junit-platform-launcher</artifactId>
                </dependency>

            </dependencies>
        </profile>
    </profiles>

</project>

我用星号划了几个部分。父BOM在其POM中有一个父元素，如下所示：

<parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.0.M4</version>
        <relativePath /> <!-- lookup parent from repository -->
    </parent>

进展

从Spring2.1.0 M1发行说明(https://github.com/spring-projects/spring-boot/wiki/Spring-Boot-2.1.0-M1-Release-Notes)中，我看到Bean覆盖已经被禁用。

当我在我的application.yml文件中添加允许-bean定义覆盖: true的属性时，错误就消失了，但是接下来我得到了以下错误：

java.lang.ClassNotFoundException: reactor.netty.http.client.HttpClient
        at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
        ... 115 common frames omitted
Wrapped by: java.lang.NoClassDefFoundError: reactor/netty/http/client/HttpClient
        ... 115 common frames omitted
Wrapped by: java.lang.BootstrapMethodError: java.lang.NoClassDefFoundError: reactor/netty/http/client/HttpClient
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) [9 skipped]
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:498)

Answer 1

您的应用程序似乎混合了两个不兼容的Spring版本。

您的主pom.xml似乎正在导入带有2.0.5.RELEASE版本的spring-boot-starter-reactor-netty。

1. 您不应该覆盖Spring库的版本，因为它都是由父POM中的依赖管理来处理的。
2. 你根本不需要反应堆网络起动器，因为它是由网络流量之一带来的。

Answer 2

请不要更改Spring版本，一旦您的项目处于开发之间。启动项目时尝试添加最新版本。一旦开发开始，不要更改版本中的任何内容。我也面临着同样的问题，浪费了4到5个小时，然后又回到了以前的版本，一切都很完美。

删除.project文件并更新maven。