Background
Currently, we use Dubbo + Zoo-keeper as the framework for service discovery.
We need different teammates to work on different part of the code, while sharing the same common-library. So we need to investigate the way to manage a project with multiple modules.
To simplify the developing, we also use Spring-boot as the foundation, Maven as the management tool.
Step 1 Create the parent project
- Create the folder-structure for the parent-project. The parent-project just works as a container for the modules
E:\Downloads\documents\STS_projects\justProject>tree . /f
卷 Tools 的文件夹 PATH 列表
卷序列号为 E885-5830
E:\DOWNLOADS\DOCUMENTS\STS_PROJECTS\JUSTPROJECT
│ pom.xml
│
├─common_api
├─consumer
└─provider
- Create the
pom.xmlfor the parent-project, declare it to be a spring-boot project.
4.0.0
com.justproject.example
parentproject
pom
1.0-SNAPSHOT
org.springframework.boot
spring-boot-starter-parent
1.5.7.RELEASE
- Compile the parent-project for a try. Currently the empty project can also be compiled.
E:\Downloads\documents\STS_projects\justProject>mvn clean
[INFO] Scanning for projects...
[INFO]
[INFO] ---------------< com.justproject.example:parentproject >----------------
[INFO] Building parentproject 1.0-SNAPSHOT
[INFO] --------------------------------[ pom ]---------------------------------
[INFO]
[INFO] --- maven-clean-plugin:2.5:clean (default-clean) @ parentproject ---
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 1.058 s
[INFO] Finished at: 2018-08-01T10:16:50+08:00
[INFO] ------------------------------------------------------------------------
E:\Downloads\documents\STS_projects\justProject>mvn compile
[INFO] Scanning for projects...
[INFO]
[INFO] ---------------< com.justproject.example:parentproject >----------------
[INFO] Building parentproject 1.0-SNAPSHOT
[INFO] --------------------------------[ pom ]---------------------------------
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 0.196 s
[INFO] Finished at: 2018-08-01T10:16:58+08:00
[INFO] ------------------------------------------------------------------------
E:\Downloads\documents\STS_projects\justProject>mvn package
[INFO] Scanning for projects...
[INFO]
[INFO] ---------------< com.justproject.example:parentproject >----------------
[INFO] Building parentproject 1.0-SNAPSHOT
[INFO] --------------------------------[ pom ]---------------------------------
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 0.189 s
[INFO] Finished at: 2018-08-01T10:17:49+08:00
[INFO] ------------------------------------------------------------------------
Step 2 Create the provider-project
- Create the folder-structure for the provider-project
E:\Downloads\documents\STS_projects\justProject>cd provider
E:\Downloads\documents\STS_projects\justProject\provider>mkdir src\main\java\app
E:\Downloads\documents\STS_projects\justProject\provider>tree . /f
卷 Tools 的文件夹 PATH 列表
卷序列号为 E885-5830
E:\DOWNLOADS\DOCUMENTS\STS_PROJECTS\JUSTPROJECT\PROVIDER
└─src
└─main
└─java
└─app
- Create the
pom.xmlfor the provider-project.
Content of
provider\pom.xml
4.0.0
com.justproject.example
provider
jar
1.0-SNAPSHOT
com.justproject.example
parentproject
1.0-SNAPSHOT
org.springframework.boot
spring-boot-maven-plugin
- In the
pom.xmlof the parent-project, add this provider-project as a module.
pom.xmlof parent-project
4.0.0
com.justproject.example
parentproject
pom
1.0-SNAPSHOT
org.springframework.boot
spring-boot-starter-parent
1.5.7.RELEASE
provider
- Create a main-entry for the project
Content of
provider\src\main\java\app\Provider.java
package app;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class Provider {
public static void main(String[] args) {
SpringApplication.run(Provider.class, args);
}
}
- Try packaging the provider-project now.
E:\Downloads\documents\STS_projects\justProject\provider>mvn clean package
[INFO] Scanning for projects...
[INFO]
[INFO] ------------------< com.justproject.example:provider >------------------
[INFO] Building provider 1.0-SNAPSHOT
[INFO] --------------------------------[ jar ]---------------------------------
[INFO]
[INFO] --- maven-clean-plugin:2.6.1:clean (default-clean) @ provider ---
[INFO] Deleting E:\Downloads\documents\STS_projects\justProject\provider\target
[INFO]
[INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ provider ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory E:\Downloads\documents\STS_projects\justProject\provider\src\main\resources
[INFO] skip non existing resourceDirectory E:\Downloads\documents\STS_projects\justProject\provider\src\main\resources
[INFO]
[INFO] --- maven-compiler-plugin:3.1:compile (default-compile) @ provider ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 1 source file to E:\Downloads\documents\STS_projects\justProject\provider\target\classes
[INFO] -------------------------------------------------------------
[ERROR] COMPILATION ERROR :
[INFO] -------------------------------------------------------------
[ERROR] /E:/Downloads/documents/STS_projects/justProject/provider/src/main/java/app/Provider.java:[3,32] 程序包org.springframework.boot不存在
[ERROR] /E:/Downloads/documents/STS_projects/justProject/provider/src/main/java/app/Provider.java:[4,46] 程序包org.springframework.boot.autoconfigure不存在
[ERROR] /E:/Downloads/documents/STS_projects/justProject/provider/src/main/java/app/Provider.java:[6,2] 找不到符号
符号: 类 SpringBootApplication
[ERROR] /E:/Downloads/documents/STS_projects/justProject/provider/src/main/java/app/Provider.java:[9,9] 找不到符号
符号: 变量 SpringApplication
位置: 类 app.Provider
[INFO] 4 errors
[INFO] -------------------------------------------------------------
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 3.919 s
[INFO] Finished at: 2018-08-01T11:02:59+08:00
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.1:compile (default-compile) on project provider: Compilation failure: Compilation failure:
[ERROR] /E:/Downloads/documents/STS_projects/justProject/provider/src/main/java/app/Provider.java:[3,32] 程序包org.springframework.boot不存在
[ERROR] /E:/Downloads/documents/STS_projects/justProject/provider/src/main/java/app/Provider.java:[4,46] 程序包org.springframework.boot.autoconfigure不存在
[ERROR] /E:/Downloads/documents/STS_projects/justProject/provider/src/main/java/app/Provider.java:[6,2] 找不到符号
[ERROR] 符号: 类 SpringBootApplication
[ERROR] /E:/Downloads/documents/STS_projects/justProject/provider/src/main/java/app/Provider.java:[9,9] 找不到符号
[ERROR] 符号: 变量 SpringApplication
[ERROR] 位置: 类 app.Provider
[ERROR] -> [Help 1]
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoFailureException
E:\Downloads\documents\STS_projects\justProject\provider>
The build is failed, and the reason is that we didn't declare the dependencies for the provider-project.
- Since we all base on Spring-book, update the
pom.xmlfor the parent-project, to include the common Spring features.
pom.xmlof parent-project
4.0.0
com.justproject.example
parentproject
pom
1.0-SNAPSHOT
org.springframework.boot
spring-boot-starter-parent
1.5.7.RELEASE
org.springframework
spring-context
org.springframework.boot
spring-boot-autoconfigure
provider
- Build the provider-project again, and see
build success
E:\Downloads\documents\STS_projects\justProject\provider>mvn clean package
[INFO] Scanning for projects...
[INFO]
[INFO] ------------------< com.justproject.example:provider >------------------
[INFO] Building provider 1.0-SNAPSHOT
[INFO] --------------------------------[ jar ]---------------------------------
[INFO]
[INFO] --- maven-clean-plugin:2.6.1:clean (default-clean) @ provider ---
[INFO] Deleting E:\Downloads\documents\STS_projects\justProject\provider\target
[INFO]
[INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ provider ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory E:\Downloads\documents\STS_projects\justProject\provider\src\main\resources
[INFO] skip non existing resourceDirectory E:\Downloads\documents\STS_projects\justProject\provider\src\main\resources
[INFO]
[INFO] --- maven-compiler-plugin:3.1:compile (default-compile) @ provider ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 1 source file to E:\Downloads\documents\STS_projects\justProject\provider\target\classes
[INFO]
[INFO] --- maven-resources-plugin:2.6:testResources (default-testResources) @ provider ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory E:\Downloads\documents\STS_projects\justProject\provider\src\test\resources
[INFO]
[INFO] --- maven-compiler-plugin:3.1:testCompile (default-testCompile) @ provider ---
[INFO] No sources to compile
[INFO]
[INFO] --- maven-surefire-plugin:2.18.1:test (default-test) @ provider ---
[INFO] No tests to run.
[INFO]
[INFO] --- maven-jar-plugin:2.6:jar (default-jar) @ provider ---
[INFO] Building jar: E:\Downloads\documents\STS_projects\justProject\provider\target\provider-1.0-SNAPSHOT.jar
[INFO]
[INFO] --- spring-boot-maven-plugin:1.5.7.RELEASE:repackage (default) @ provider ---
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 8.458 s
[INFO] Finished at: 2018-08-01T11:05:58+08:00
[INFO] ------------------------------------------------------------------------
Step 3 Make provider to register to Zoo-Keeper
- Add dependency to dubbo & zoo-keeper for provider-project.
Content of
provider\pom.xml
4.0.0
com.justproject.example
provider
jar
1.0-SNAPSHOT
com.justproject.example
parentproject
1.0-SNAPSHOT
io.dubbo.springboot
spring-boot-starter-dubbo
1.0.0
org.apache.zookeeper
zookeeper
3.4.6
org.slf4j
slf4j-log4j12
log4j
log4j
org.springframework.boot
spring-boot-maven-plugin
- Create a new package
serviceto put interfaces & implementations of exposed services.
E:\Downloads\documents\STS_projects\justProject\provider>mkdir src\main\java\mservice
E:\Downloads\documents\STS_projects\justProject\provider>tree .
卷 Tools 的文件夹 PATH 列表
卷序列号为 E885-5830
E:\DOWNLOADS\DOCUMENTS\STS_PROJECTS\JUSTPROJECT\PROVIDER
├─src
│ └─main
│ ├─java
│ │ ├─app
│ │ └─mservice
└─target
├─classes
│ └─app
├─generated-sources
│ └─annotations
├─maven-archiver
└─maven-status
└─maven-compiler-plugin
└─compile
└─default-compile
- Add a service-interface
Content of
provider\src\main\java\mservice\IDemoService.java
package mservice;
public interface IDemoService{
String sayHello();
}
- Create a class to implement the interface
Content of
provider\src\main\java\mservice\DemoServiceImp.java
package mservice;
public class DemoServiceImp implements IDemoService{
@Override
public String sayHello() {
return "Hello from DemoServiceImp";
}
}
- Use annotation
@Servicefrom dubbo, to mark it as a dubbo-service
Content of
provider\src\main\java\mservice\DemoServiceImp.java
package mservice;
import com.alibaba.dubbo.config.annotation.Service;
@Service
public class DemoServiceImp implements IDemoService{
@Override
public String sayHello() {
return "Hello from DemoServiceImp";
}
}
- Create the
resourcesfolder for provider-project.
E:\Downloads\documents\STS_projects\justProject\provider>mkdir src\main\resources
E:\Downloads\documents\STS_projects\justProject\provider>tree .
卷 Tools 的文件夹 PATH 列表
卷序列号为 E885-5830
E:\DOWNLOADS\DOCUMENTS\STS_PROJECTS\JUSTPROJECT\PROVIDER
├─src
│ └─main
│ ├─java
│ │ ├─app
│ │ └─mservice
│ └─resources
└─target
├─classes
│ └─app
├─generated-sources
│ └─annotations
├─maven-archiver
└─maven-status
└─maven-compiler-plugin
└─compile
└─default-compile
- Create the
application.propertiesfile to save the configuration for provider-project.
Here, we should define to scan the package of the service-implementation, not the package where we define the service-interface!!!
Content of
provider\src\main\resources\application.properties
## Configuration for dubbo
# this is a provider
spring.dubbo.application.name=provider
# register to this zoo-keeper
spring.dubbo.registry.address=zookeeper://xxx.xxx.xxx.xxx:2181
# use dubbo-protocol
spring.dubbo.protocol.name=dubbo
# locally, use this port to communicate with zoo-keeper
spring.dubbo.protocol.port=20880
# scan this package to find the service-interfaces
spring.dubbo.scan=mservice
- Build the project again, to see the effect.
E:\Downloads\documents\STS_projects\justProject\provider>mvn clean package
[INFO] Scanning for projects...
[INFO]
[INFO] ------------------< com.justproject.example:provider >------------------
[INFO] Building provider 1.0-SNAPSHOT
[INFO] --------------------------------[ jar ]---------------------------------
[INFO]
[INFO] --- maven-clean-plugin:2.6.1:clean (default-clean) @ provider ---
[INFO] Deleting E:\Downloads\documents\STS_projects\justProject\provider\target
[INFO]
[INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ provider ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Copying 1 resource
[INFO] Copying 0 resource
[INFO]
[INFO] --- maven-compiler-plugin:3.1:compile (default-compile) @ provider ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 3 source files to E:\Downloads\documents\STS_projects\justProject\provider\target\classes
[INFO]
[INFO] --- maven-resources-plugin:2.6:testResources (default-testResources) @ provider ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory E:\Downloads\documents\STS_projects\justProject\provider\src\test\resources
[INFO]
[INFO] --- maven-compiler-plugin:3.1:testCompile (default-testCompile) @ provider ---
[INFO] No sources to compile
[INFO]
[INFO] --- maven-surefire-plugin:2.18.1:test (default-test) @ provider ---
[INFO] No tests to run.
[INFO]
[INFO] --- maven-jar-plugin:2.6:jar (default-jar) @ provider ---
[INFO] Building jar: E:\Downloads\documents\STS_projects\justProject\provider\target\provider-1.0-SNAPSHOT.jar
[INFO]
[INFO] --- spring-boot-maven-plugin:1.5.7.RELEASE:repackage (default) @ provider ---
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 5.965 s
[INFO] Finished at: 2018-08-01T11:43:42+08:00
[INFO] ------------------------------------------------------------------------
- Run the
jar, from command-line.
E:\Downloads\documents\STS_projects\justProject\provider>java -jar target\provider-1.0-SNAPSHOT.jar
......
......
2018-08-01 11:48:24.641 INFO 19828 --- [ main] app.Provider : Started Provider in 4.749 seconds (JVM running for 5.794)
- Log onto the server where zoo-keeper is running, to check the registered service. Here we can assure that our service has been registered to zoo-keeper.
[xxx@VM_0_8_centos bin]# ./zkCli.sh -server 127.0.0.1:2181
[zk: 127.0.0.1:2181(CONNECTED) 3] ls /
[dubbo, zookeeper]
[zk: 127.0.0.1:2181(CONNECTED) 5] get /dubbo/mservice.IDemoService
null
cZxid = 0x5
ctime = Wed Aug 01 11:48:26 CST 2018
mZxid = 0x5
mtime = Wed Aug 01 11:48:26 CST 2018
pZxid = 0xa
cversion = 2
dataVersion = 0
aclVersion = 0
ephemeralOwner = 0x0
dataLength = 0
numChildren = 2
References
- Blog-post on Dubbo + Spring
- Official document of zoo-keeper command