Spring Web Flux与Reactive Mongo db (Spring Boot 2.0.0快照)无法按预期工作

Question

我在start.spring.io上创建了spring boot项目(2.0.0快照)。我选择了反应式网络(Flux)和反应式MongoDB作为依赖项。

这是我的pom.xml文件的样子：

<?xml version="1.0" encoding="UTF-8"?>
...
<groupId>com.example</groupId>
<artifactId>demo</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>

<name>demo</name>
<description>Demo project for Spring Boot</description>

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.0.0.BUILD-SNAPSHOT</version>
    <relativePath/> <!-- lookup parent from repository -->
</parent>

<properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
    <java.version>1.8</java.version>
</properties>

<dependencies>

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-webflux</artifactId>
    </dependency>

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-mongodb-reactive</artifactId>
    </dependency>

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>

</dependencies>

<build>
    <plugins>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
        </plugin>
    </plugins>
</build>

<repositories>
    <repository>
        <id>spring-snapshots</id>
        <name>Spring Snapshots</name>
        <url>https://repo.spring.io/snapshot</url>
        <snapshots>
            <enabled>true</enabled>
        </snapshots>
    </repository>
    <repository>
        <id>spring-milestones</id>
        <name>Spring Milestones</name>
        <url>https://repo.spring.io/milestone</url>
        <snapshots>
            <enabled>false</enabled>
        </snapshots>
    </repository>
</repositories>

<pluginRepositories>
    <pluginRepository>
        <id>spring-snapshots</id>
        <name>Spring Snapshots</name>
        <url>https://repo.spring.io/snapshot</url>
        <snapshots>
            <enabled>true</enabled>
        </snapshots>
    </pluginRepository>
    <pluginRepository>
        <id>spring-milestones</id>
        <name>Spring Milestones</name>
        <url>https://repo.spring.io/milestone</url>
        <snapshots>
            <enabled>false</enabled>
        </snapshots>
    </pluginRepository>
</pluginRepositories>

​

当我运行./mvnw spring-boot:run时，我得到了这个异常：

java.lang.IllegalStateException: java.lang.NullPointerException
at org.springframework.boot.web.reactive.context.ReactiveWebServerApplicationContext.stopAndReleaseReactiveWebServer(ReactiveWebServerApplicationContext.java:152) ~[spring-boot-2.0.0.BUILD-SNAPSHOT.jar:2.0.0.BUILD-SNAPSHOT]
at org.springframework.boot.web.reactive.context.ReactiveWebServerApplicationContext.refresh(ReactiveWebServerApplicationContext.java:52) ~[spring-boot-2.0.0.BUILD-SNAPSHOT.jar:2.0.0.BUILD-SNAPSHOT]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:809) [spring-boot-2.0.0.BUILD-SNAPSHOT.jar:2.0.0.BUILD-SNAPSHOT]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:404) [spring-boot-2.0.0.BUILD-SNAPSHOT.jar:2.0.0.BUILD-SNAPSHOT]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:347) [spring-boot-2.0.0.BUILD-SNAPSHOT.jar:2.0.0.BUILD-SNAPSHOT]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1263) [spring-boot-2.0.0.BUILD-SNAPSHOT.jar:2.0.0.BUILD-SNAPSHOT]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1252) [spring-boot-2.0.0.BUILD-SNAPSHOT.jar:2.0.0.BUILD-SNAPSHOT]
at com.example.DemoApplication.main(DemoApplication.java:10) [classes/:na]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_121]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_121]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_121]
at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_121]
at org.springframework.boot.maven.AbstractRunMojo$LaunchRunner.run(AbstractRunMojo.java:527) [spring-boot-maven-plugin-2.0.0.BUILD-SNAPSHOT.jar:2.0.0.BUILD-SNAPSHOT]
at java.lang.Thread.run(Thread.java:745) [na:1.8.0_121] Caused by: java.lang.NullPointerException: null
at org.springframework.boot.web.embedded.netty.NettyWebServer.stop(NettyWebServer.java:113) ~[spring-boot-2.0.0.BUILD-SNAPSHOT.jar:2.0.0.BUILD-SNAPSHOT]
at org.springframework.boot.web.reactive.context.ReactiveWebServerApplicationContext.stopAndReleaseReactiveWebServer(ReactiveWebServerApplicationContext.java:148) ~[spring-boot-2.0.0.BUILD-SNAPSHOT.jar:2.0.0.BUILD-SNAPSHOT]
... 13 common frames omitted [WARNING] java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springframework.boot.maven.AbstractRunMojo$LaunchRunner.run(AbstractRunMojo.java:527)
at java.lang.Thread.run(Thread.java:745) Caused by: java.lang.IllegalStateException: java.lang.NullPointerException
at org.springframework.boot.web.reactive.context.ReactiveWebServerApplicationContext.stopAndReleaseReactiveWebServer(ReactiveWebServerApplicationContext.java:152)
at org.springframework.boot.web.reactive.context.ReactiveWebServerApplicationContext.refresh(ReactiveWebServerApplicationContext.java:52)
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:809)
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:404)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:347)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1263)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1252)
at com.example.DemoApplication.main(DemoApplication.java:10)
... 6 more Caused by: java.lang.NullPointerException
at org.springframework.boot.web.embedded.netty.NettyWebServer.stop(NettyWebServer.java:113)
at org.springframework.boot.web.reactive.context.ReactiveWebServerApplicationContext.stopAndReleaseReactiveWebServer(ReactiveWebServerApplicationContext.java:148)

请注意，如果我删除spring-boot-starter-data-mongodb-reactive依赖项，应用程序将会运行。

Answer 1

此问题已修复。错误不再发生。使用了快照库(Spring)，并且最近进行了更新。