还未构造实例就开始设置属性的错误

java.lang.IllegalStateException: Failed to load ApplicationContext

    at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:124)
    at org.springframework.test.context.support.DefaultTestContext.getApplicationContext(DefaultTestContext.java:83)
    at org.springframework.test.context.web.ServletTestExecutionListener.setUpRequestContextIfNecessary(ServletTestExecutionListener.java:189)
    at org.springframework.test.context.web.ServletTestExecutionListener.prepareTestInstance(ServletTestExecutionListener.java:131)
    at org.springframework.test.context.TestContextManager.prepareTestInstance(TestContextManager.java:230)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.createTest(SpringJUnit4ClassRunner.java:228)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner$1.runReflectiveCall(SpringJUnit4ClassRunner.java:287)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.methodBlock(SpringJUnit4ClassRunner.java:289)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:247)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:94)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
    at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
    at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:191)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
    at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
    at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
    at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
    at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)
Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'purchaseInputOrderController': Unsatisfied dependency expressed through field 'purchaseInputOrderService'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'purchaseInputOrderServiceImpl': Unsatisfied dependency expressed through field 'handlerFactory'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'purchaseInputOrderHandlerFactory' defined in file [E:\IdeaProjects\eshop\target\classes\com\wz\eshop\wms\service\impl\PurchaseInputOrderHandlerFactory.class]: Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.wz.eshop.wms.service.impl.PurchaseInputOrderHandlerFactory]: Constructor threw exception; nested exception is java.lang.NullPointerException
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:588)
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:88)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:366)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1264)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:553)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:761)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:867)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:543)
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:693)
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:360)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:303)

@Component
public class PurchaseInputOrderHandlerFactory {


    /**
     * 更新采购入库单状态handler
     */
    @Autowired
    private UpdatePurchaseInputOrderStatusHandler updatePurchaseInputOrderStatusHandler;
    /**
     * 通知采购中心handler
     */
    @Autowired
    private InformPurchaseCenterHandler informPurchaseCenterHandler;
    /**
     * 更新本地库存handler
     */
    @Autowired
    private UpdateStockHandler updateStockHandler;
    /**
     * 通知调度中心handler
     */
    @Autowired
    private InformScheduleCenterHandler informScheduleCenterHandler;
    /**
     * 通知财务中心handler
     */
    @Autowired
    private InformFinanceCenterHandler informFinanceCenterHandler;
    
    /**
     * 构造函数：组装责任链条
     */
    public PurchaseInputOrderHandlerFactory() {
        updatePurchaseInputOrderStatusHandler.setSuccessor(informPurchaseCenterHandler);
        informPurchaseCenterHandler.setSuccessor(updateStockHandler);
        updateStockHandler.setSuccessor(informScheduleCenterHandler); 
        informScheduleCenterHandler.setSuccessor(informFinanceCenterHandler); 
    }
    
    /**
     * 创建采购入库单handler链条
     * @param purchaseInputOrder 采购入库单
     * @return handler链条
     * @throws Exception
     */
    public PurchaseInputOrderHandler getHandlerChain() throws Exception {
        return updatePurchaseInputOrderStatusHandler;
    }
    
}

此时PurchaseInputOrderHandlerFactory()还未构造好，就设置属性，会报构造函数空指针错误。

修改如下：

@Component
public class PurchaseInputOrderHandlerFactory {
    /**
     * 是否构建好了handler链条
     */
    private Boolean buildedHandlerChain = false;

    /**
     * 更新采购入库单状态handler
     */
    @Autowired
    private UpdatePurchaseInputOrderStatusHandler updatePurchaseInputOrderStatusHandler;
    /**
     * 通知采购中心handler
     */
    @Autowired
    private InformPurchaseCenterHandler informPurchaseCenterHandler;
    /**
     * 更新本地库存handler
     */
    @Autowired
    private UpdateStockHandler updateStockHandler;
    /**
     * 通知调度中心handler
     */
    @Autowired
    private InformScheduleCenterHandler informScheduleCenterHandler;
    /**
     * 通知财务中心handler
     */
    @Autowired
    private InformFinanceCenterHandler informFinanceCenterHandler;


    /**
     * 创建采购入库单handler链条
     * @return handler链条
     * @throws Exception
     */
    public PurchaseInputOrderHandler getHandlerChain() throws Exception {
        if(!buildedHandlerChain) {
            buildHandlerChain();
        }
        return updatePurchaseInputOrderStatusHandler;
    }

    /**
     * 构造handler链条
     * @throws Exception
     */
    private void buildHandlerChain() throws Exception {
        updatePurchaseInputOrderStatusHandler.setSuccessor(informPurchaseCenterHandler);
        informPurchaseCenterHandler.setSuccessor(updateStockHandler);
        updateStockHandler.setSuccessor(informScheduleCenterHandler);
        informScheduleCenterHandler.setSuccessor(informFinanceCenterHandler);
    }
    
}