xxl-job执行器启动源码分析

淡淡的烟草味﹌ 2022-12-25 00:57 112阅读 0赞

xxl-job版本：2.3.0-SNAPSHOT

# 1.XxlJobSpringExecutor.afterSingletonsInstantiated()方法执行 #

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2Zzandpbg_size_16_color_FFFFFF_t_70]  
afterSingletonsInstantiated方法其触发时机为postProcessAfterInitialization之后，postProcessAfterInitialization方法什么时候执行不在细说，是spring的基础知识了。

# 2.initJobHandlerMethodRepository执行 #

private void initJobHandlerMethodRepository(ApplicationContext applicationContext) {

此方法的最后一行调用注册handler逻辑

registJobHandler(name, new MethodJobHandler(bean, executeMethod, initMethod, destroyMethod));

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2Zzandpbg_size_16_color_FFFFFF_t_70 1]

特别注意，这个方法的执行在一个for循环中：

for (Map.Entry<Method, XxlJob> methodXxlJobEntry : annotatedMethods.entrySet()) { 
                    Method executeMethod = methodXxlJobEntry.getKey();
                    XxlJob xxlJob = methodXxlJobEntry.getValue();
                    if (xxlJob == null) { 
                        continue;
                    }
    
                    String name = xxlJob.value();
                    if (name.trim().length() == 0) { 
                        throw new RuntimeException("xxl-job method-jobhandler name invalid, for[" + bean.getClass() + "#" + executeMethod.getName() + "] .");
                    }
                    if (loadJobHandler(name) != null) { 
                        throw new RuntimeException("xxl-job jobhandler[" + name + "] naming conflicts.");
                    }
    
                    // execute method
                    /*if (!(method.getParameterTypes().length == 1 && method.getParameterTypes()[0].isAssignableFrom(String.class))) { throw new RuntimeException("xxl-job method-jobhandler param-classtype invalid, for[" + bean.getClass() + "#" + method.getName() + "] , " + "The correct method format like \" public ReturnT<String> execute(String param) \" ."); } if (!method.getReturnType().isAssignableFrom(ReturnT.class)) { throw new RuntimeException("xxl-job method-jobhandler return-classtype invalid, for[" + bean.getClass() + "#" + method.getName() + "] , " + "The correct method format like \" public ReturnT<String> execute(String param) \" ."); }*/
    
                    executeMethod.setAccessible(true);
    
                    // init and destory
                    Method initMethod = null;
                    Method destroyMethod = null;
    
                    if (xxlJob.init().trim().length() > 0) { 
                        try { 
                            initMethod = bean.getClass().getDeclaredMethod(xxlJob.init());
                            initMethod.setAccessible(true);
                        } catch (NoSuchMethodException e) { 
                            throw new RuntimeException("xxl-job method-jobhandler initMethod invalid, for[" + bean.getClass() + "#" + executeMethod.getName() + "] .");
                        }
                    }
                    if (xxlJob.destroy().trim().length() > 0) { 
                        try { 
                            destroyMethod = bean.getClass().getDeclaredMethod(xxlJob.destroy());
                            destroyMethod.setAccessible(true);
                        } catch (NoSuchMethodException e) { 
                            throw new RuntimeException("xxl-job method-jobhandler destroyMethod invalid, for[" + bean.getClass() + "#" + executeMethod.getName() + "] .");
                        }
                    }
    
                    // registry jobhandler
                    registJobHandler(name, new MethodJobHandler(bean, executeMethod, initMethod, destroyMethod));
                }

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2Zzandpbg_size_16_color_FFFFFF_t_70 2]

syahello是我写的一个测试的handler：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2Zzandpbg_size_16_color_FFFFFF_t_70 3]  
特别注意家里@XxlJob注解。

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2Zzandpbg_size_16_color_FFFFFF_t_70 4]  
那么注册到哪里呢？

# 3. registJobHandler(String name, IJobHandler jobHandler)调用 #

public static IJobHandler registJobHandler(String name, IJobHandler jobHandler){ 
            logger.info(">>>>>>>>>>> xxl-job register jobhandler success, name:{}, jobHandler:{}", name, jobHandler);
            return jobHandlerRepository.put(name, jobHandler);
        }

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2Zzandpbg_size_16_color_FFFFFF_t_70 5]  
注册进jobHandlerRepository中：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2Zzandpbg_size_16_color_FFFFFF_t_70 6]  
放进去后让谁用呢？肯定是调用它的调度器用了。因为@XxlJob的都是执行器。  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2Zzandpbg_size_16_color_FFFFFF_t_70 7]  
可以看到currentMap的结构了。是不是心里很有底了。

# 4. 那么久剩最后一个问题,为什么被@XxlJob注解的会被扫描到呢？ #

1.  获得被注解的方法  
    ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2Zzandpbg_size_16_color_FFFFFF_t_70 8]  
    ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2Zzandpbg_size_16_color_FFFFFF_t_70 9]
2.  手里拿到了这些被注解的方法，操作还不是易如反掌。

# 5.总结 #

1.  获得被@XxlJob注解的方法的执行器
2.  注册这些扫描到的执行器到一个currentMap中待调度器调度用。
3.  这是新的版本代码，旧版本差不多了。

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