2018年：
maven突然之间报错了，显示版本冲突，但是其他的机器是好的，
使用命令：mvn compile -P dev -e;
看看测试环境有没有问题，还是有问题。而且，刚开始只是报错：error,连错误原因都不提。
后来把原来的项目删掉，然后执行：mvn compile -P dev -e
开始出现错误的原因了，说是：com.sankuai.qcs 底下的某个包 引用冲突。
后来找到这个包的本地仓库的位置： /Users/yinfuqing/.m2/repository/com/sankuai/qcs
把这个qcs的包整个删掉，这样下次编译的时候，发现本地没有，会先从服务器下载下来，然后在引用。
执行：mvn compile -P dev -e ,编译通过了；
2019年又碰上了，我的方法最终是先把自己做的备份。然后把本地的项目全部删除，在重新下载就好了。
2019 -03-05
又出现了版本冲突，我发现个问题，编译的时候竟然是success的，但是 在运行的时候还是报错，
后来发现是在dependencyManagement里面定义了，但是在外面没有引用：
这是我的：
<dependency>
<groupId>com.meituan.mafka</groupId>
<artifactId>mafka-client_2.</artifactId>
</dependency>
就是这个，东西，因为在inf-bom中定义了所以不用指定版本号，但是并没有显示的引用这个包，所以运行时报错了
<?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.</modelVersion> <groupId>com.sankuai.qcs</groupId>
<artifactId>qcs.regulation.light</artifactId>
<version>0.0.-SNAPSHOT</version>
<packaging>jar</packaging> <name>light</name>
<description>project for Spring Boot</description> <parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0..RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent> <properties>
<project.build.sourceEncoding>UTF-</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-</project.reporting.outputEncoding>
<java.version>1.8</java.version>
<inf-bom.version>1.3.9.1</inf-bom.version>
</properties> <dependencyManagement>
<dependencies>
<dependency>
<groupId>com.sankuai</groupId>
<artifactId>inf-bom</artifactId>
<version>${inf-bom.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency> </dependencies>
</dependencyManagement> <dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
<exclusions>
<exclusion>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-logging</artifactId>
</exclusion>
</exclusions>
</dependency> <!-- starter-log4j2 -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-log4j2</artifactId>
</dependency> <dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency> <dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-lang3</artifactId>
<version>3.3</version>
</dependency> <!-- Json -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.</version>
</dependency> <dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-core</artifactId>
<version>2.9.</version>
</dependency> <dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.9.</version>
</dependency> <dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-annotations</artifactId>
<version>2.9.</version>
</dependency> <dependency>
<groupId>dom4j</groupId>
<artifactId>dom4j</artifactId>
<version>1.6</version>
</dependency> <!-- mafka -->
<dependency>
<groupId>com.sankuai.octo</groupId>
<artifactId>idl-common</artifactId>
</dependency> <dependency>
<groupId>com.sankuai.octo</groupId>
<artifactId>idl-sgagent</artifactId>
</dependency> <dependency>
<groupId>com.sankuai.octo</groupId>
<artifactId>mns-invoker</artifactId>
</dependency> <dependency>
<groupId>com.sankuai.wm</groupId>
<artifactId>retail.mq.client</artifactId>
<version>1.1.-SNAPSHOT</version>
<exclusions>
<exclusion>
<groupId>org.apache.zookeeper</groupId>
<artifactId>zookeeper</artifactId>
</exclusion>
<exclusion>
<groupId>org.apache.zookeeper</groupId>
<artifactId>zookeeper</artifactId>
</exclusion>
<exclusion>
<groupId>com.sankuai.wm</groupId>
<artifactId>retail.mq.mafka</artifactId>
</exclusion>
<exclusion>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
</exclusion>
<exclusion>
<groupId>com.meituan.mafka</groupId>
<artifactId>mafka-client_2.</artifactId>
</exclusion>
<exclusion>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
</exclusion>
</exclusions>
</dependency> <dependency>
<groupId>com.meituan.mafka</groupId>
<artifactId>mafka-client_2.</artifactId>
</dependency>
<dependency>
<groupId>com.meituan.mtrace</groupId>
<artifactId>mtrace</artifactId>
</dependency>
<dependency>
<groupId>com.meituan.mtrace</groupId>
<artifactId>mtrace-http</artifactId>
</dependency> <dependency>
<groupId>com.sankuai.wm</groupId>
<artifactId>retail.mq.mafka</artifactId>
<version>1.1.-SNAPSHOT</version>
<exclusions>
<exclusion>
<groupId>com.meituan.mafka</groupId>
<artifactId>mafka-client_2.</artifactId>
</exclusion>
<exclusion>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
</exclusion>
</exclusions>
</dependency> <!-- log4j --> <dependency>
<groupId>com.meituan.inf</groupId>
<artifactId>xmd-log4j2</artifactId>
</dependency>
<!--如果线上服务已接入scribe-log4j2，请升级到本版本。注意groupId已变更-->
<dependency>
<groupId>com.meituan.log</groupId>
<artifactId>scribe-log4j2</artifactId>
<version>1.3.</version>
<exclusions>
<exclusion>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
</exclusion>
</exclusions>
</dependency> <!--<dependency>-->
<!--<groupId>org.slf4j</groupId>-->
<!--<artifactId>slf4j-log4j12</artifactId>-->
<!--<version>1.7.</version>-->
<!--</dependency>--> </dependencies> <build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build> </project>
其中：
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0..RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
指的是下面的spring 都不用指定版本号了，就按照2.0.3 就可以了；
参考：Spring Boot —— spring-boot-starter-parent
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