Question

它是来自mysql服务器的简单select语句，并在控制台上显示输出。不知怎的，结果是在循环中打印，虽然我没有使用任何计时器。

<beans>
<context:component-scan base-package="com.java"/>
<bean destroy-method="close" class="org.apache.commons.dbcp.BasicDataSource" id="dataSource">
<property value="com.mysql.jdbc.Driver" name="driverClassName"/>
<property value="jdbc:mysql://localhost:3306/world" name="url"/>
<property value="root" name="username"/>
<property value="mysql" name="password"/>
</bean>
<!-- configure the Camel SQL component to use the JDBC data source -->
<bean class="org.apache.camel.component.sql.SqlComponent" id="sql">
<property name="dataSource" ref="dataSource"/>
</bean>
<camel:camelContext>
<camel:route>
<camel:from uri="sql:select id from city where countryCode='AFG' and district ='Kabol' "/>
<camel:log message="${body[id]}"/>
<camel:to uri="stream:out"/>
</camel:route>
</camel:camelContext>
</beans>

客户端代码是：

public static void main(String rgs[]) throws InterruptedException{
        PropertyConfigurator.configure("C:/Users/payal.bansal/workspace/CamelOneProject/src/resources/log4j.properties"); 
        //AbstractApplicationContext ctx= new ClassPathXmlApplicationContext("resources/camel-configThree.xml");
        AbstractApplicationContext ctx= new ClassPathXmlApplicationContext("resources/camel-configEight.xml");
         Thread.sleep(5000);
         ctx.close();
    }

Answer 1

默认情况下，from SQL将每500毫秒重复一次SQL调用（其调度）。

http://camel.apache.org/sql-component.html

如果您希望SQL只触发一次，则使用计时器

from timer
to sql

并将计时器配置为仅运行一次。

http://camel.apache.org/timer

输出重复，应该只打印一次

1 个答案: