dubbo+Springboot的实现
一、简介
1、现在dubbo成为了apache的顶级项目，阿里巴巴重新开源了dubbo项目，为了兼容性更强、更完善，添加了dubbo-spring-boot-starter 的依赖库，同时提高了快速开发效率。
2、首先我们创建三个项目dubbo-openapi、dubbox-consumer、dubbox-provider、dubbo-zookeeper。
3、
dubbo-openapi：主要的提供对象属性与方法、其实意思上：抽取dubbox-consumer、dubbox-provider服务中相同的代码。
dubbo-consumer：客户端
dubbo-provider：服务端
dubbo-zookeeper：注册中心
二、搭建项目
1、搭建dubbo-openapi、创建maven的jar项目
pom.xml
4.0.0
com.citydo
dubbo-openapi
0.0.1-SNAPSHOT
jar
dubbo-openapi
http://maven.apache.org
UTF-8
junit
junit
3.8.1
test
User.java
package com.citydo.dubbo_openapi.model;
import java.io.Serializable;
public class User implements Serializable{
private String name;
private Integer age;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Integer getAge() {
return age;
}
public void setAge(Integer age) {
this.age = age;
}
@Override
public String toString() {
return "User[name=" + name + ", age=" + age + "]";
}
public User(String name, Integer age) {
super();
this.name = name;
this.age = age;
}
}
UserService.java
package com.citydo.dubbo_openapi.service;
import com.citydo.dubbo_openapi.model.User;
public interface UserService {
User getUser();
}
2、搭建服务端dubbox-consumer、采用Springboot框架
pom.xml
4.0.0
org.springframework.boot
spring-boot-starter-parent
2.1.3.RELEASE
com.example
dubbox-consumer
0.0.1-SNAPSHOT
dubbox-consumer
jar
Demo project for Spring Boot
UTF-8
UTF-8
1.8
com.citydo
dubbo-openapi
0.0.1-SNAPSHOT
org.springframework.boot
spring-boot-starter-web
org.springframework.boot
spring-boot-starter
com.alibaba.boot
dubbo-spring-boot-starter
0.2.0
org.springframework.boot
spring-boot-starter-test
test
org.springframework.boot
spring-boot-maven-plugin
application.properties
# Spring boot application
spring.application.name = dubbox-consumer
server.port = 9090
management.port = 9091
# Dubbo Config properties
## ApplicationConfig Bean
dubbo.application.id = dubbox-consumer
dubbo.application.name = dubbox-consumer
dubbo.scan.base-packages=com.citydo
## ProtocolConfig Bean
dubbo.protocol.id = dubbo
dubbo.protocol.name = dubbo
dubbo.protocol.port = 12345
3、搭建客户端端dubbox-provider、采用Springboot框架
pom.xml
4.0.0
org.springframework.boot
spring-boot-starter-parent
2.1.3.RELEASE
com.example
dubbox-provider
0.0.1-SNAPSHOT
dubbox-provider
jar
Demo project for Spring Boot
1.8
com.citydo
dubbo-openapi
0.0.1-SNAPSHOT
org.springframework.boot
spring-boot-starter-web
org.springframework.boot
spring-boot-starter
org.springframework.boot
spring-boot-starter-aop
com.alibaba.boot
dubbo-spring-boot-starter
0.2.0
org.springframework.boot
spring-boot-starter-test
test
org.springframework.boot
spring-boot-maven-plugin
application.properties
# Spring boot application
spring.application.name = dubbox-provider
server.port = 7070
management.port = 7071
# Base packages to scan Dubbo Components (e.g., @Service, @Reference)
dubbo.scan.basePackages =com.citydo.impl
# Dubbo Config properties
## ApplicationConfig Bean
dubbo.application.id = dubbox-provider
dubbo.application.name = dubbox-provider
## ProtocolConfig Bean
dubbo.protocol.id = dubbo
dubbo.protocol.name = dubbo
dubbo.protocol.port = 12345
## RegistryConfig Bean
dubbo.registry.id = my-registry
dubbo.registry.address = N/A
UserServiceImpl.java
package com.citydo.impl;
import com.alibaba.dubbo.config.annotation.Service;
import com.citydo.dubbo_openapi.model.User;
import com.citydo.dubbo_openapi.service.UserService;
@Service(
version = "1.0.0",
application = "${dubbo.application.id}",
protocol = "${dubbo.protocol.id}",
registry = "${dubbo.registry.id}"
)
public class UserServiceImpl implements UserService {
@Override
public User getUser() {
// TODO Auto-generated method stub
return new User("张三", 19);
}
}
三、dubbo与中间件的使用
1、zookeeper
https://blog.csdn.net/qq_32447301/article/details/87892621
2、netty
待续
3、admin
待续
四、错误总结
1、
Exception in thread "main" java.lang.UnsupportedClassVersionError: com/citydo/DubboxConsumerApplication : Unsupported major.minor version 52.0
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:800)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:449)
at java.net.URLClassLoader.access$100(URLClassLoader.java:71)
at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:482)
解决办法：
看报错信息，是因为使用的jar包版本不对。这个52.0是什么呢？
J2SE 8 = 52
2、
2019-02-15 09:43:29 ERROR [o.s.w.c.ContextLoader] [] [] [] Context initialization failed
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sqlSessionFactory' defined in URL [beans-dao.xml]: Initialization of bean failed;
nested exception is java.lang.reflect.MalformedParameterizedTypeException
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:480)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory$1.run(AbstractAutowireCapableBeanFactory.java:409)
at java.security.AccessController.doPrivileged(Native Method)
解决办法：换JDK或者jar包依赖冲突
3、
Caused by: java.lang.IllegalArgumentException: No enum constant
解决办法：springboot项目中需要在application.properties或者枚举的数据不能为空
4、解决Tomcat启动时项目重复加载问题
寻找tomcat的目录下的server.xml、修改配置
5、解决has been blocked by CORS policy: Response to preflight request doesn't pass access control
在nginx跨域请求cors配置如下：
location / {
add_header 'Access-Control-Allow-Origin' '*';
add_header "Access-Control-Allow-Credentials" "true";
add_header "Access-Control-Allow-Headers" "x-requested-with,content-type";
proxy_pass http://localhost:8080;
}
4、参考代码：https://github.com/ibywind/dubbo-learn