6.6. camel-sql

SQL 组件允许您使用 JDBC 查询处理数据库。此组件和 JDBC 组件之间的区别在于，如果 SQL 查询是端点的属性，它将消息有效负载用作传递给查询的参数。

CamelContext camelctx = new DefaultCamelContext();
camelctx.addRoutes(new RouteBuilder() {
    @Override
    public void configure() throws Exception {
        from("sql:select name from information_schema.users?dataSource=java:jboss/datasources/ExampleDS")
        .to("direct:end");
    }
});

与 camel-cdi 组件一起使用时，Java EE 注解可以为 Camel 提供数据源。本例使用 @Named 注释，以便 Camel 能够发现所需的数据源。

public class DatasourceProducer {
    @Resource(name = "java:jboss/datasources/ExampleDS")
    DataSource dataSource;

    @Produces
    @Named("wildFlyExampleDS")
    public DataSource getDataSource() {
        return dataSource;
    }
}

现在，可以通过 camel-sql 端点配置上的 dataSource 参数来引用数据源。

@ApplicationScoped
@ContextName("camel-sql-cdi-context")
@Startup
public class CdiRouteBuilder extends RouteBuilder {
    @Override
    public void configure() throws Exception {
        from("sql:select name from information_schema.users?dataSource=wildFlyExampleDS")
        .to("direct:end");
    }
}

使用 camel-spring 时，路由配置类似如下：

<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:jee="http://www.springframework.org/schema/jee"
       xsi:schemaLocation="
       http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
       http://camel.apache.org/schema/spring http://camel.apache.org/schema/spring/camel-spring.xsd
       http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee.xsd">

    <jee:jndi-lookup id="wildFlyExampleDS" jndi-name="java:jboss/datasources/ExampleDS"/>

    <camelContext id="sql-spring-context" xmlns="http://camel.apache.org/schema/spring">
        <route>
            <from uri="sql:select name from information_schema.users?dataSource=#wildFlyExampleDS" />
            <to uri="direct:end" />
        </route>
    </camelContext>

</beans>

<jdbc:embedded-database id="datasource" type="H2">
  <jdbc:script location="db-schema.sql"/>
</jdbc:embedded-database>

<jdbc:initialize-database data-source="datasource">
  <jdbc:script location="classpath:db-init.sql"/>
</jdbc:initialize-database>