Question

我刚开始学习Apache Camel。我理解了路由和组件的基础知识。现在我想尝试连接到Oracle数据库，从一个特定的表读取记录，并使用File组件将这些记录写入文件。要从数据库中读取，我假设我需要使用JDBC组件并提供dataSourceName。

但是，我找不到有关如何使用camel创建dataSource的任何信息。我发现与此主题相关的所有信息都使用Spring DSL示例。我不使用Spring，我只需要使用简单的独立Java应用程序来测试它。

我正在使用JDK7u25和Apache Camel 2.12.1。

有人可以发帖样本从oracle表中读取并写入文件吗？

[编辑]

在网上查看了几个解决方案后，我开始了解以下两种方法：

Camel以standalone运行。这是我的代码：

import javax.sql.DataSource;    
import org.apache.camel.main.Main;
import org.apache.camel.builder.RouteBuilder;
import org.apache.commons.dbcp.BasicDataSource;

public class JDBCExample {

    private Main main;

    public static void main(String[] args) throws Exception {
        JDBCExample example = new JDBCExample();
        example.boot();
    }

    public void boot() throws Exception {
        // create a Main instance
        main = new Main();
        // enable hangup support so you can press ctrl + c to terminate the JVM
        main.enableHangupSupport();

        String url = "jdbc:oracle:thin:@MYSERVER:1521:myDB";
        DataSource dataSource = setupDataSource(url);

        // bind dataSource into the registery
        main.bind("myDataSource", dataSource);

        // add routes
        main.addRouteBuilder(new MyRouteBuilder());

        // run until you terminate the JVM
        System.out.println("Starting Camel. Use ctrl + c to terminate the JVM.\n");
        main.run();
    }

    class MyRouteBuilder extends RouteBuilder {
        public void configure() {
            String dst = "C:/Local Disk E/TestData/Destination";
            from("direct:myTable")
               .setBody(constant("select * from myTable"))
               .to("jdbc:myDataSource")
                .to("file:" + dst);
        }
    }

    private DataSource setupDataSource(String connectURI) {
        BasicDataSource ds = new BasicDataSource();
        ds.setDriverClassName("oracle.jdbc.driver.OracleDriver");
        ds.setUsername("sa");
        ds.setPassword("devon1");
        ds.setUrl(connectURI);
        return ds;
    }
}

使用Claus lbsen提到的方法。这是代码：

import javax.sql.DataSource;
import org.apache.camel.CamelContext;
import org.apache.camel.impl.DefaultCamelContext;
import org.apache.camel.impl.SimpleRegistry;
import org.apache.camel.main.Main;
import org.apache.camel.builder.RouteBuilder;
import org.apache.commons.dbcp.BasicDataSource;

public class JDBCExample {

    private Main main;

    public static void main(String[] args) throws Exception {
        String url = "jdbc:oracle:thin:@MYSERVER:1521:myDB";
        DataSource dataSource = setupDataSource(url);

        SimpleRegistry reg = new SimpleRegistry() ;
        reg.put("myDataSource",dataSource);

        CamelContext context = new DefaultCamelContext(reg);
        context.addRoutes(new JDBCExample().new MyRouteBuilder());
        context.start();
        Thread.sleep(5000);
        context.stop();
    }

    class MyRouteBuilder extends RouteBuilder {
        public void configure() {
            String dst = "C:/Local Disk E/TestData/Destination";
            from("direct:myTable")
               .setBody(constant("select * from myTable"))
               .to("jdbc:myDataSource")
                .to("file:" + dst);
        }
    }

    private static DataSource setupDataSource(String connectURI) {
        BasicDataSource ds = new BasicDataSource();
        ds.setDriverClassName("oracle.jdbc.driver.OracleDriver");
        ds.setUsername("sa");
        ds.setPassword("devon1");
        ds.setUrl(connectURI);
        return ds;
    }
}

但在这两种情况下，我都会遇到异常：

Caused by: org.apache.camel.ResolveEndpointFailedException: Failed to resolve endpoint: jdbc://myDataSource due to: No component found with scheme: jdbc
    at org.apache.camel.impl.DefaultCamelContext.getEndpoint(DefaultCamelContext.java:534)
    at org.apache.camel.util.CamelContextHelper.getMandatoryEndpoint(CamelContextHelper.java:63)
    at org.apache.camel.model.RouteDefinition.resolveEndpoint(RouteDefinition.java:192)
    at org.apache.camel.impl.DefaultRouteContext.resolveEndpoint(DefaultRouteContext.java:106)
    at org.apache.camel.impl.DefaultRouteContext.resolveEndpoint(DefaultRouteContext.java:112)
    at org.apache.camel.model.SendDefinition.resolveEndpoint(SendDefinition.java:61)
    at org.apache.camel.model.SendDefinition.createProcessor(SendDefinition.java:55)
    at org.apache.camel.model.ProcessorDefinition.makeProcessor(ProcessorDefinition.java:500)
    at org.apache.camel.model.ProcessorDefinition.addRoutes(ProcessorDefinition.java:213)
    at org.apache.camel.model.RouteDefinition.addRoutes(RouteDefinition.java:909)
    ... 12 more
[Thread-0] INFO org.apache.camel.main.MainSupport$HangupInterceptor - Received hang up - stopping the main instance.

Answer 1

有一个SQL示例，演示如何设置DataSource

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

是的，使用Spring XML的例子。但是，如何设置DataSource也可以在Java代码中完成。然后，您需要在Camel注册表中注册DataSource。

例如，您可以使用JndiRegistry或SimpleRegistry。后者更容易。

这是一些伪代码，显示了创建注册表，将bean添加到此注册表，然后将注册表提供给DefaultCamelContext的构造函数的原则。

SimpleRegistry registry = new SimpleRegistry();

// code to create data source here
DateSource ds = ...

registry.put("myDataSource", ds);

CamelContext camel = new DefaultCamelContext(registry);

Answer 2

太傻了！我没有在CLASSPATH中包含camel-jdbc-2.12.1.jar。现在上面的例子工作。

Answer 3

Spring之所以提到它只是因为它是使用DB的非常有用的范例（主要是因为templates introduced by Spring Framework。）当然你可以连接标准JDBC连接并自己实现DAO - 没有错了。

如何使用camel创建数据源？

3 个答案: