Hbase、elasticsearch整合中jar包冲突

问题背景

再数据平台中，项目搭建需要使用es和HBASE搭建数据查询接口，整合的过程中出现jar包冲突的bug :com.google.common.base.Stopwatch.()V from class org.apache.hadoop.hbase.zookeeper.MetaTableLocator

org.apache.hadoop.hbase.DoNotRetryIOException: java.lang.IllegalAccessError: tried to access method com.google.common.base.Stopwatch.<init>()V from class org.apache.hadoop.hbase.zookeeper.MetaTableLocatorat org.apache.hadoop.hbase.client.RpcRetryingCaller.translateException(RpcRetryingCaller.java:239)at org.apache.hadoop.hbase.client.RpcRetryingCaller.callWithRetries(RpcRetryingCaller.java:150)...at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.IllegalAccessError: tried to access method com.google.common.base.Stopwatch.<init>()V from class org.apache.hadoop.hbase.zookeeper.MetaTableLocatorat org.apache.hadoop.hbase.zookeeper.MetaTableLocator.blockUntil...at org.apache.hadoop.hbase.client.RegionServerCallable.prepare(RegionServerCallable.java:75)at org.apache.hadoop.hbase.client.RpcRetryingCaller.callWithRetries(RpcRetryingCaller.java:134)... 45 more

解决办法

经排查，确认是因为 com.google.guava 这个包引起的冲突。es依赖于18及以上版本，而HBASE只支持16及以上版本。而guava这个包从17开始内部发生变化，方法发生改变，所以18并不会向下兼容16版本。在项目运行的过程中，如果同时引入16、18版本，es及hbase的调用过程会发生混乱。那么接下来就好办了，我们可以重新打包，将guava18打入es内部，再在pom文件中显示引用guava16版本的包。这样，es调用包内部打入的guava18，而hbase调用外部的guava16。

重新打包

新建maven工程，在pom文件中进行如下配置：

<?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><!--this maven project is aim to fix the jar comflic in hbase & elasticsearch.in es, required guava 18+ or up. but in hbase you should use guava 16- or blow.cd the project directory and run 'sh ./cleanbuild.sh',you will get a new-self jar.then, adjust your project pom.xml whth:<dependency><groupId>douguo.shaded.elasticsearch</groupId><artifactId>douguo_shaded_elasticsearch</artifactId><version>1.0-SNAPSHOT</version><exclusions><exclusion><groupId>org.elasticsearch</groupId><artifactId>elasticsearch</artifactId></exclusion></exclusions></dependency>finally, your jar comflic will be fixed.@date:2017-11-30@author:zhangjianfei@since:douguo.shaded.elasticsearch-1.0.0--><groupId>douguo.shaded.elasticsearch</groupId><artifactId>douguo_shaded_elasticsearch</artifactId><version>1.0-SNAPSHOT</version><properties><elasticsearch.version>2.4.1</elasticsearch.version></properties><dependencies><dependency><groupId>org.elasticsearch</groupId><artifactId>elasticsearch</artifactId><version>${elasticsearch.version}</version></dependency><dependency><groupId>org.elasticsearch.plugin</groupId><artifactId>shield</artifactId><version>${elasticsearch.version}</version></dependency></dependencies><build><plugins><plugin><groupId>org.apache.maven.plugins</groupId><artifactId>maven-shade-plugin</artifactId><version>2.4.1</version><configuration><createDependencyReducedPom>false</createDependencyReducedPom></configuration><executions><execution><phase>package</phase><goals><goal>shade</goal></goals><configuration><relocations><relocation><pattern>com.google.guava</pattern><shadedPattern>douguo.shaded.elasticsearch.guava</shadedPattern></relocation><relocation><pattern>org.joda</pattern><shadedPattern>douguo.shaded.elasticsearch.joda</shadedPattern></relocation><relocation><pattern>com.google.common</pattern><shadedPattern>douguo.shaded.elasticsearch.common</shadedPattern></relocation><relocation><pattern>com.google.thirdparty</pattern><shadedPattern>douguo.shaded.elasticsearch.thirdparty</shadedPattern></relocation></relocations><transformers><transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer" /></transformers></configuration></execution></executions></plugin></plugins></build><repositories><repository><id>elasticsearch-releases</id><url>http://maven.elasticsearch.org/releases</url><releases><enabled>true</enabled><updatePolicy>daily</updatePolicy></releases><snapshots><enabled>false</enabled></snapshots></repository></repositories></project>

将org.joda等4个可能有冲突的jar包通过maven-shade-plugin插件迁移后重新打个jar包从而使得在引入这个jar包时能够使用该jar包自己的依赖而不是使用外部依赖。这里需要注意的是，需要将com.google.common等4个包全部重新迁移，否则会出现java.lang.IllegalAccessError: tried to access method com.google.common.base的错误

项目打包

mvn clean install

新的依赖包会在.m2 maven仓库中，如果公司搭建了仓库的话，需要上传jar包。如果直接运行jar包的话，记得重新编译项目，并替换lib目录

项目载入新包

只需要在pom文件中配置：

<!-- douguo.shaded.elasticsearch -->
<dependency><groupId>douguo.shaded.elasticsearch</groupId><artifactId>douguo_shaded_elasticsearch</artifactId><version>1.0-SNAPSHOT</version><exclusions><exclusion><groupId>org.elasticsearch</groupId><artifactId>elasticsearch</artifactId></exclusion></exclusions>
</dependency><!-- https://mvnrepository.com/artifact/com.google.guava/guava -->
<!-- this guava is only used in habsein es, 18.0+ is required, but hbase only supported 16.0 or blow.clean as install douguo.shaded.elasticsearch -->
<dependency><groupId>com.google.guava</groupId><artifactId>guava</artifactId><version>16.0</version>
</dependency>

这样，guava18包就在douguo.shaded.elasticsearch下，es会优先调用。而外部配置的guava16就会被HBASE调用。2个版本的jar包互相独立存在！

到此，问题就解决了！

参考文章：

http://blog.csdn.net/sunshine920103/article/details/51659936
https://www.elastic.co/blog/to-shade-or-not-to-shade