目前公司需要对当前的业务进行微服务化改造，经过讨论选择使用用dubbo进行服务治理，并在我的业务功能模块中进行试点，由于之前写过dubbo相关的demo，基础知识就不再重复了，demo地址：
https://github.com/liujifei/dubbo.git
工程的基本搭建参照了另一篇博客，写的十分详尽，推荐一下：
Maven多模块，Dubbo分布式服务框架，SpringMVC，前后端分离项目，基础搭建，搭建过程出现的问题
========================================================================================================================
基本配置完成之后，当使用组播的方式时没有发现问题，服务提供方和调用方都正常，当使用zk集群作为注册中心时，项目启动报错：
java.lang.NoClassDefFoundError: org/apache/curator/shaded/com/google/common/cache/CacheBuilder
处理方法：
在parent的pom.xml中dependencyManagement加入
<dependency> <groupId>org.apache.curator</groupId> <artifactId>curator-framework</artifactId> <version>2.11.0</version> </dependency>子module的pom.xml中加入
<dependency> <groupId>org.apache.curator</groupId> <artifactId>curator-framework</artifactId> </dependency>问题解决。
另附zk集群配置方法：
< dubbo:registry address = "zookeeper://10.20.153.10:2181?backup=10.20.153.11:2181,10.20.153.12:2181" />
或
< dubbo:registry protocol = "zookeeper" address = "10.20.153.10:2181,10.20.153.11:2181,10.20.153.12:2181" />
同中心多组的配置方法：
< dubbo:registry id = "chinaRegistry" protocol = "zookeeper" address = "10.20.153.10:2181" group = "china" />
< dubbo:registry id = "intlRegistry" protocol = "zookeeper" address = "10.20.153.10:2181" group = "intl" />
若遇到其他问题再记录
2018-04-12 11:05:16
====================================================================================
上面的provider搞定了，之后就是consumer。之前的调用方式是简单的sdk调用，服务化之后，需要将原web工程改造为dubbo调用方。
具体改造内容很简单主要包括两个文件：
1、pom.xml
<properties> <!-- dubbo --><dubbo.version>2.6.1</dubbo.version>
</properties> <!-- dubbo相关依赖 --> <dependency> <groupId>com.alibaba</groupId> <artifactId>dubbo</artifactId> <version>${dubbo.version}</version> </dependency> <dependency> <groupId>com.alibaba</groupId> <artifactId>dubbo-rpc-dubbo</artifactId> <version>${dubbo.version}</version> </dependency> <dependency> <groupId>com.alibaba</groupId> <artifactId>dubbo-registry-api</artifactId> <version>${dubbo.version}</version> </dependency> <dependency> <groupId>com.alibaba</groupId> <artifactId>dubbo-registry-zookeeper</artifactId> <version>${dubbo.version}</version> </dependency>另外添加服务提供方api的依赖
2、spring-context.xml
-
beans的namespace添加 xmlns:dubbo="http://code.alibabatech.com/schema/dubbo"；xsi:schemaLocation中添加
http://code.alibabatech.com/schema/dubbo
http://code.alibabatech.com/schema/dubbo/dubbo.xsd -
文件内容中添加
<dubbo:application name="***" />
<dubbo:registry address="***" />
<dubbo:reference id="***" check="false" interface="***"/>
回调：
当provider需要调用consumer中的回调方法时，首先需要在provider的配置文件中修改如下：
<dubbo:service interface="com.***.quality.api.QualityService" ref="qualityService" protocol="dubbo">
<dubbo:method name="excuteJob" >
<dubbo:argument index="1" callback="true" type="com.inspur.quality.api.CallBack"/>
</dubbo:method>
</dubbo:service>
另外需要注意的是，callback作为调用方实现的回调方法，其中不要包含需要dubbo来序列化的对象以及调用其方法，否则会报如下错误：
com.alibaba.dubbo.remoting.RemotingException: Fail to decode request due to: RpcInvocation
如：
1 qualityService.excuteJob(job); 2 // 生产报告 3 qualityService.productReport(new CallBack() { 4 5 @Override 6 public void productReport(String dataBaseName, RuleResult[] result, String jobId, String instanceId) { 7 Long time = System.currentTimeMillis(); 8 for(RuleResult single : result){ 9 StringBuilder sqlB = new StringBuilder(); 10 sqlB.append("insert into "); 11 sqlB.append(RESULT_TABLE); 12 sqlB.append(" (RESULTID,JOBID,INSTANCEID,CHECKID,RESULT) VALUES ( '"); 13 sqlB.append(UUID.randomUUID().toString()); 14 sqlB.append("','"); 15 sqlB.append(jobId); 16 sqlB.append("','"); 17 sqlB.append(instanceId); 18 sqlB.append("','"); 19 sqlB.append(single.getRule().getRuleName()); 20 sqlB.append("','"); 21 sqlB.append(single.getResultNumber()); 22 sqlB.append("')"); 23 24 JdbcUtil.exeSql(dataBaseName, sqlB.toString()); 25 } 26 } 27 }, dataSources[2]);
View Code
需要改成
1qualityService.excuteJob(job, new CallBack() { 2 3 /** 4 * @Field @serialVersionUID : TODO 5 */ 6 private static final long serialVersionUID = -5914504806295102148L; 7 8 @Override 9 public String productReport(String dataBaseName, RuleResult[] result, String jobId, String instanceId) { 10 Long time = System.currentTimeMillis(); 11 StringBuilder sqlB = new StringBuilder(); 12 for(RuleResult single : result){ 13 sqlB.append("insert into "); 14 sqlB.append("QUALITY_RESULT"); 15 sqlB.append(" (RESULTID,JOBID,INSTANCEID,CHECKID,RESULT) VALUES ( '"); 16 sqlB.append(UUID.randomUUID().toString()); 17 sqlB.append("','"); 18 sqlB.append(jobId); 19 sqlB.append("','"); 20 sqlB.append(instanceId); 21 sqlB.append("','"); 22 sqlB.append(single.getRule().getRuleName()); 23 sqlB.append("','"); 24 sqlB.append(single.getResultNumber()); 25 sqlB.append("')"); 26 27 } 28 return sqlB.toString(); 29 } 30 }, dataSources[2]);
View Code
2018-04-18 15:14:13
=====================================================================================
java.lang.NoSuchMethodError: org.apache.curator.utils.ZKPaths.fixForNamespace
问题原因：curator-framework版本为2.11.0与原项目中的包有冲突，改为原项目中的版本2.6.0后，问题解决。
2018-04-23 15:46:31
=====================================================================================
代码的改造进行完之后，调用时发现报错如下：
服务提供方报错：
Caused by: com.alibaba.dubbo.remoting.RemotingException: com.alibaba.com.caucho.hessian.io.HessianProtocolException: 'com.***.quality.rule.MultiCountRule' could not be instantiated
com.alibaba.com.caucho.hessian.io.HessianProtocolException: 'com.***.quality.rule.MultiCountRule' could not be instantiated
Caused by: java.lang.reflect.InvocationTargetException
Caused by: java.lang.NullPointerException
at com.***.quality.rule.MultiCountRule.<init>(MultiCountRule.java:27)
服务调用方报错：
com.alibaba.dubbo.rpc.RpcException: Failed to invoke the method excuteJob in the service com.***.quality.api.QualityService. Tried 3 times of the providers [192.168.138.1:20880] (1/1) from the registry 172.22.5.2:2181 on the consumer 192.168.138.1 using the dubbo version 2.6.1. Last error is: Failed to invoke remote method: excuteJob, provider: dubbo://192.168.138.1:20880/com.***.quality.api.QualityService?anyhost=true&application=crawlManage&check=false&dubbo=2.6.1&excuteJob.1.callback=true&generic=false&interface=com.***.quality.api.QualityService&methods=newExpectCountRule,registDataSource,newNotNullRule,newMultiCountRule,newPatternRule,newUniqueRule,excuteJob,newIntegrityRule,newDataCountRule&pid=115308®ister.ip=192.168.138.1&remote.timestamp=1524468008733&revision=0.0.1-SNAPSHOT&side=consumer×tamp=1524468416127, cause: Fail to decode request due to: RpcInvocation [methodName=excuteJob, parameterTypes=[class com.***.quality.common.QualityCheckJob, interface com.***.quality.api.CallBack, class java.lang.String], arguments=null, attachments={path=com.***.quality.api.QualityService, input=3355, dubbo=2.6.1, version=0.0.0}]
com.alibaba.dubbo.rpc.RpcException: Failed to invoke the method newMultiCountRule in the service com.***.quality.api.QualityService. Tried 3 times of the providers ......
Caused by: com.alibaba.dubbo.remoting.RemotingException: Fail to decode request due to: RpcInvocation [methodName=excuteJob, parameterTypes=[class com.***.quality.common.QualityCheckJob, interface com.***.quality.api.CallBack, class java.lang.String], arguments=null, attachments={path=com.***.quality.api.QualityService, input=3355, dubbo=2.6.1, version=0.0.0}]
问题是由于参数excuteJob中的属性MultiCountRule的类中没有默认构造方法，导致hessian不能正确序列化。
qualityService.productReport(new CallBack() {
/** * @Field @serialVersionUID : TODO */ private static final long serialVersionUID = -5914504806295102148L;
@Override public void productReport(String dataBaseName, RuleResult[] result, String jobId, String instanceId) { Long time = System.currentTimeMillis(); for(RuleResult single : result){ StringBuilder sqlB = new StringBuilder(); sqlB.append("insert into "); sqlB.append("QUALITY_RESULT"); sqlB.append(" (RESULTID,JOBID,INSTANCEID,CHECKID,RESULT) VALUES ( '"); sqlB.append(UUID.randomUUID().toString()); sqlB.append("','"); sqlB.append(jobId); sqlB.append("','"); sqlB.append(instanceId); sqlB.append("','"); sqlB.append(single.getRule().getRuleName()); sqlB.append("','"); sqlB.append(single.getResultNumber()); sqlB.append("')"); JdbcUtil.exeSql(dataBaseName, sqlB.toString()); } } }, dataSources[2]);