springCloud项目报错：java.lang.NoClassDefFoundError: org/springframework/boot/bind/RelaxedDataBinder

在新创建spring-cloud项目启动的时候报错：

java.lang.NoClassDefFoundError: org/springframework/boot/bind/RelaxedDataBinder
at org.springframework.cloud.client.HostInfoEnvironmentPostProcessor.getFirstNonLoopbackHostInfo(HostInfoEnvironmentPostProcessor.java:45)
	at org.springframework.cloud.client.HostInfoEnvironmentPostProcessor.postProcessEnvironment(HostInfoEnvironmentPostProcessor.java:34)
	at org.springframework.boot.context.config.ConfigFileApplicationListener.onApplicationEnvironmentPreparedEvent(ConfigFileApplicationListener.java:188)
	at org.springframework.boot.context.config.ConfigFileApplicationListener.onApplicationEvent(ConfigFileApplicationListener.java:176)
	at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:172)
	at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:165)
	at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:139)
	at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:127)
	at org.springframework.boot.context.event.EventPublishingRunListener.environmentPrepared(Even
	……

pom.xml里主要依赖如下：

<parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.2.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
        <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka-server</artifactId>
            <version>1.4.4.RELEASE</version>
        </dependency>

找过很多答案，是说boot版本兼容的问题，boot太新了2.0以上不支持报异常的包，需要把boot版本改低以及更改jdbc链接或数据库连接池。但是：我都没用到链接数据库的依赖。也试着改boot版本改了很多，还有改spring-cloud-starter-eureka-server的版本等，都没用或者会继续报出其他错误。
后来终于查到是，因为

<dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka-server</artifactId>
            <version>1.4.4.RELEASE</version>
        </dependency>

这个依赖spring-cloud-starter-eureka-server被弃用了，在他的maven 官方仓库里货号后面可以看到注释：已被启用，建议使用spring-cloud-starter-netflix-eureka-server。（这里不贴图了）。依赖改成：

<dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
            <version>2.2.0.RELEASE</version>
        </dependency>

问题解决。
版本不兼容问题真的很麻烦，spring系列经常更新，需要多留意。