springboot集成elasticsearch客戶端問題記錄

1背景說明

服務端ES版本爲5.5.2，springboot版本爲1.5.6。

工程中添加以下依賴

2問題記錄

2.1 NetworkPlugin類找不到

報錯java.lang.ClassNotFoundException: org.elasticsearch.plugins.NetworkPlugin

和java.lang.NoClassDefFoundError: org/elasticsearch/plugins/NetworkPlugin

問題分析：

在biz模塊引入了5.5.2版本的es client jar，能找到對應的類

查看api模塊的war中的es client jar版本確實不是5.5.2，而是springboot默認的2.4.5，此版本確實是沒有NetworkPlugin這個類的。

這裏涉及到maven的Dependency management 的兩個做用，其中第二個方面就解釋了爲何出現jar包版本的問題

1）It is a central place for defining versions of dependencies.

So when an artifact version is defined in the <dependencyManagement> section you can declare the dependency in your pom without defining the version, and the version defined in <dependencyManagement> will be used automatically.

Example 1

Let's say your parent pom defined the following

<dependencyManagement>

  <dependencies>

    <dependency>

      <groupId>com.mememe</groupId>

      <artifactId>mylib</artifactId>

      <version>1.1.12</version>

    </dependency>

  </dependencies>

</dependencyManagement>

Then if you define the following in your pom

<dependencies>

  <dependency>

    <groupId>com.mememe</groupId>

    <artifactId>mylib</artifactId>

  </dependency>

</dependencies>

Your project will automatically use version 1.1.12 as defined in the <dependencyManagement> section of your parent pom.

2）Overriding the versions of transitive dependencies.

If you have an artifact version defined in your <dependencyManagement> and one of your dependencies has a transitive dependency on the same artifact, the version of the artifact defined in your <dependencyManagement> section is used automatically.

Example 2

Let's say this artifact

<dependency>

  <groupId>com.youyou</groupId>

  <artifactId>yourlib</artifactId>

  <version>3.0.0</version>

</dependency>

Has this transitive dependency

<dependency>

  <groupId>com.morestuff</groupId>

  <artifactId>morelib</artifactId>

  <version>2.0.0</version>

</dependency>

Now let's say our parent pom defines this <dependencyManagement> section

<dependencyManagement>

  <dependencies>

    <dependency>

      <groupId>com.morestuff</groupId>

      <artifactId>morelib</artifactId>

      <version>2.5.2</version>

    </dependency>

  </dependencies>

</dependencyManagement>

Then if you define this dependency in your pom

<dependency>

  <groupId>com.youyou</groupId>

  <artifactId>yourlib</artifactId>

  <version>3.0.0</version>

</dependency>

Maven will override yourlib's dependency on morelib version 2.0.0 with morelib version 2.5.2.

參考：

https://stackoverflow.com/questions/49134849/maven-dependencytree-log-version1-compile-version-managed-from-version2

 

解決辦法就是在api模塊的pom文件中再一次添加依賴

2.2 netty版本衝突

報錯

Exception in thread "elasticsearch[_client_][management][T#1]" java.lang.AbstractMethodError:

極光推送的客戶端jar包也引入了netty

去掉便可