java - 如何从 Spring Controller 启动 CommandLineRunner

Question

我在启动的顶级包中有一个主要的 Spring Boot 应用程序，在子包中有不同的 Controller :

即

ca.example.batch.MainBatchApplication
ca.example.batch.job1.Job1Controller (/batch/startJob1)
ca.example.batch.job2.Job2Controller (/batch/startJob2)

我可以通过访问 URL 来启动 Spring Batch:http://localhost:8080/batch/startJob1或http://localhost:8080/batch/startJob2 .

但是，在另一个包中我有:

ca.example.batch.job3.Job3Controller
ca.example.batch.job3.Job3Application

...这不是 Spring Batch，而是 Spring CommandLineRunner。我想知道是否有一种方法可以启动 MainBatchApplication 而无需自动启动 CommandLineRunner，而是通过 Controller 运行它，即 http://localhost:8080/batch/startJob3 .

我正在查看的 Controller 代码是:

package ca.example.batch.job3;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

@Controller
public class Job3Controller {

    @RequestMapping("/batch/startJob3")
    public String handle() throws Exception {

        Job3Application app = new Job3Application();

        Logger logger = LoggerFactory.getLogger(this.getClass());

        logger.info("app: " + app);

        String args = "";
        app.run(args);

        return "COMPLETE";
    }
}

Job3Application 是:

package ca.example.batch.job3;

import static java.lang.System.exit;
import java.util.List;
import javax.sql.DataSource;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.Banner;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.WebApplicationType;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.context.annotation.Import;
import ca.example.batch.common.CommonLibraryReference;
import ca.example.batch.common.domain.WasHost;
import ca.example.batch.common.svc.WasHostService;

@SpringBootApplication
@Import(CommonLibraryReference.class)
public class Job3Application implements CommandLineRunner {

    private final Logger logger = LoggerFactory.getLogger(Job3Application.class);

    @Autowired
    public DataSource dataSource;

    @Autowired
    public WasHostService wasHostService;

    public Job3Application() {
    }

    public static void main(String[] args) throws Exception {
        new SpringApplicationBuilder(Job3Application.class)
        .web(WebApplicationType.NONE)
        .bannerMode(Banner.Mode.OFF)
        .run(args);
    }

    @Override
    public void run(String... strings) throws Exception {
        logger.info("Loading data...");

        logger.info("wasHostService: " + wasHostService);
        List<WasHost> hostList = wasHostService.findAll();
        if (!hostList.isEmpty()) {
            for (WasHost host : hostList) {
                logger.info("hostname: " + host.getHostname());
            }
        } else {
            logger.info("No hosts found in database. Aborting data collection.");
            exit(0);
        }
    }
}

我在日志中收到的错误是:

""2018-07-07 12:56:09 [http-nio-9191-exec-1] INFO  o.a.c.c.C.[Tomcat].[localhost].[/] - Initializing Spring FrameworkServlet 'dispatcherServlet'
""2018-07-07 12:56:09 [http-nio-9191-exec-1] INFO  c.e.b.job3.Job3Controller - app: ca.example.batch.job3.Job3Application@472d7ac
""2018-07-07 12:56:09 [http-nio-9191-exec-1] INFO  c.e.b.job3.Job3Application - Loading data...
""2018-07-07 12:56:09 [http-nio-9191-exec-1] INFO  c.e.b.job3.Job3Application - wasHostService: null
""2018-07-07 12:56:09 [http-nio-9191-exec-1] ERROR o.a.c.c.C.[.[.[.[dispatcherServlet] - Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is java.lang.NullPointerException] with root cause
"java.lang.NullPointerException: null
    at ca.example.batch.job3.Job3Application.run(Job3Application.java:47)
    at ca.example.batch.job3.Job3Controller.handle(Job3Controller.java:21)

...当我启动 Controller 请求时。

如果这不是正确的方法，请提出建议。

基本上，我想做的是从 Controller 内启动 main() ，但使用 MainBatchApplication 运行时来运行它(如果这有意义吗？)。当程序完成时，它将返回代码发送回 Controller 并显示在浏览器中。

谢谢你，乔伊

Answer 1

ca.example.batch.MainBatchApplication 是您启动的主应用程序。因此它会扫描ca.example.batch包中的所有组件。这意味着它应该检测到ca.example.batch.job3.Job3Application，因此您应该能够在Job3Controller

中 @Autowire它>

这应该有效:

@Controller
public class Job3Controller {
  private final Job3Application job3Application;      

  public Job3Controller (Job3Application job3Application){
     this.job3Application = job3Application;
  }

  @RequestMapping("/batch/startJob3")
  public String handle() throws Exception {
    String[] args = ...
    this.job3Application.run(args);
    return "COMPLETE";
  }

  ....
}