Java:Spring Boot 类构造函数有太多 DI？

Question

假设我有一个 Spring Boot 类:

public class SomeClass {

    private ApplicationContext applicationContext;
    private MessagingService messagingService;
    private ClientReportFactoryImpl clientReportFactory;
    private TerminalReportFactoryImpl terminalReportFactory;
    private XMLView xmlView;
    private PrepareXMLService prepareXMLService;

我在该类中有一个构造函数:

@Autowired
    public SomeClass (ApplicationContext applicationContext, MessagingService messagingService, ClientReportFactoryImpl clientReportFactory,
                                                                TerminalReportFactoryImpl terminalReportFactory,
                                                                XMLView xmlView,
                                                                PrepareXMLService prepareXMLService) {
        Assert.notNull(applicationContext, "ApplicationContext must not be null!");
        this.applicationContext = applicationContext;
        Assert.notNull(messagingService, "MessagingService must no be null!");
        this.messagingService = messagingService;
        Assert.notNull(clientReportFactory, "ClientReportFactory must not be null!");
        this.clientReportFactory = clientReportFactory;
        Assert.notNull(terminalReportFactory, "TerminalReportFactory must not be null!");
        this.terminalReportFactory = terminalReportFactory;
        Assert.notNull(xmlView, "XMLView must not be null!");
        this.xmlView = xmlView;
        Assert.notNull("PrepareXMLService must not be null");
        this.prepareXMLService = prepareXMLService;
    }

在类构造函数中使用这么多依赖项是否被认为是不好的做法？我是否应该重构我的类，以便构造函数中只有 1-2 个 DI？

Answer 1

您不应该直接在 Application 类中调用所有服务，how to structure your code 有一个很好的指南(这一章和后续章节)所以它可能看起来像这样:

com
+- example
 +- myproject
     +- Application.java
     |
     +- domain
     |   +- Customer.java
     |   +- CustomerRepository.java
     |
     +- service
     |   +- CustomerService.java
     |
     +- web
         +- CustomerController.java

基本上，您的服务是 annotated with attributes就像 @Service (显然)，这样它们就会被 Application 中的 @ComponentScan 拾取。