linux 下安裝zookeeper及配置dubbo

使用zookeeper作爲註冊中心，版本爲3.4.8

一、zookeeper安裝步驟

wget  http://apache.fayea.com/zookeeper/zookeeper-3.4.8/zookeeper-3.4.8.tar.gz
tar -zxvf zookeeper-3.4.8.tar.gz
cd zookeeper-3.4.8
cd conf
mv zoo_sample.cfg zoo.cfg
cd ../bin
./zkServer.sh start

二、開發privider端菜示例

1、在pom.xml中增加以下配置

<dependency>
    <groupId>dangdangdotcom</groupId>
    <artifactId>dubbox</artifactId>
    <version>2.8.4</version>
    <scope>system</scope>
  <systemPath>${project.basedir}/src/main/webapp/WEB-INF/lib/dubbo-2.8.4.jar</systemPath>
</dependency>

<dependency>
    <groupId>org.javassist</groupId>
    <artifactId>javassist</artifactId>
    <version>3.19.0-GA</version>
</dependency>

<dependency>
    <groupId>io.netty</groupId>
    <artifactId>netty</artifactId>
    <version>3.10.5.Final</version>
</dependency>

<dependency>
    <groupId>com.github.sgroschupf</groupId>
    <artifactId>zkclient</artifactId>
    <version>0.1</version>
</dependency>

<dependency>
    <groupId>com.caucho</groupId>
    <artifactId>hessian</artifactId>
    <version>4.0.7</version>
</dependency>

<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-core</artifactId>
    <version>4.1.9.RELEASE</version>
</dependency>

<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-web</artifactId>
    <version>4.1.9.RELEASE</version>
</dependency>

<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-webmvc</artifactId>
    <version>4.1.9.RELEASE</version>
</dependency>

2、dubbo provider的spring配置：

<dubbo:application name="demo-provider" owner="dev1" organization="kk"/>
<dubbo:registry address="zookeeper://127.0.0.1:2181"/>
<bean id="orderService" class="com.kayakwise.dubbo.demo.service.impl.OrderServiceImpl" />
<dubbo:service interface="com.kayakwise.dubbo.demo.service.OrderService" ref="orderService"/>

3、Order類

public class Order implements Serializable {

    private long id;

    private String customerName;

    private String phone;

    private String address;

    public long getId() {
        return id;
    }

    public void setId(long id) {
        this.id = id;
    }

    public String getCustomerName() {
        return customerName;
    }

    public void setCustomerName(String customerName) {
        this.customerName = customerName;
    }

    public String getPhone() {
        return phone;
    }

    public void setPhone(String phone) {
        this.phone = phone;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }
}

4、OrderServicer接口

public interface OrderService {
    Order getOrderById(long id);
}

5、OrderServiceImpl實現類

public class OrderServiceImpl implements OrderService {

    public Order getOrderById(long id) {
        Order order = new Order();
        order.setId(id);
        order.setAddress("淮海路12號");
        order.setCustomerName("劉小強test");
        order.setPhone("18699999999");
        return order;
    }
}

三、 開發consumer端示例


1、pom.xml配置和provider端相同。將provider裏的OrderService接口和Order類打成包，放到consumer工程裏。

dubbo consumer的spring配置：
<dubbo:application name="demo-consumer" owner="dev2" organization="kk"/>
<dubbo:registry address="zookeeper://127.0.0.1:2181"/>
<dubbo:reference id="orderService" interface="com.kayakwise.dubbo.demo.service.OrderService" check="false" />

然後就可以像使用普通spring bean那樣調用orderService了

四、常見問題

1.、超時設置

默認的超時爲1秒，可通過timeout參數進行修改，單位爲毫秒，示例：

<dubbo:reference id="orderService"interface="com.kayakwise.dubbo.demo.service.OrderService" timeout="3000">

 

 

2.、重試設置

默認的重試次數爲2，對於涉及到數據修改的服務，建議設置重試次數爲0，示例：

<dubbo:reference id="bidderService"interface="com.kayakwise.dubbo.demo.service.BidService"  retries="0"/>

 

3.、spring controller注入的dubbo服務的bean，在運行時報空指針異常

在dubbo的spring配置文件中增加dubbo:annotation 配置，package改爲實際的包名。

<dubbo:annotation package="com.kayakwise.dubbo.demo.controller"/>