Java Spring Boot Autowired null
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Spring Boot Autowired null
提问by dexBerlin
I have several classes in a Spring Boot project, some work with @Autowired, some do not. Here my code follows:
我在 Spring Boot 项目中有几个类，有些与 @Autowired 一起工作，有些则没有。这里我的代码如下：
Application.java (@Autowired works):
Application.java（@Autowired 有效）：
package com.example.myproject;
@ComponentScan(basePackages = {"com.example.myproject"})
@Configuration
@EnableAutoConfiguration
@EnableJpaRepositories(basePackages = "com.example.myproject.repository")
@PropertySource({"classpath:db.properties", "classpath:soap.properties"})
public class Application {
@Autowired
private Environment environment;
public static void main(String[] args) {
SpringApplication.run(Application.class);
}
@Bean
public SOAPConfiguration soapConfiguration() {
SOAPConfiguration SOAPConfiguration = new SOAPConfiguration();
SOAPConfiguration.setUsername(environment.getProperty("SOAP.username"));
SOAPConfiguration.setPassword(environment.getProperty("SOAP.password"));
SOAPConfiguration.setUrl(environment.getProperty("SOAP.root"));
return SOAPConfiguration;
}
HomeController (@Autowired works):
HomeController（@Autowired 有效）：
package com.example.myproject.controller;
@Controller
class HomeController {
@Resource
MyRepository myRepository;
MyService (@Autowired does not work):
MyService（@Autowired 不起作用）：
package com.example.myproject.service;
@Service
public class MyServiceImpl implements MyService {
@Autowired
public SOAPConfiguration soapConfiguration; // is null
private void init() {
log = LogFactory.getLog(MyServiceImpl.class);
log.info("starting init, soapConfiguration: " + soapConfiguration);
url = soapConfiguration.getUrl(); // booom -> NullPointerException
I do not get the SOAPConfiguration but my application breaks with a null pointer exception when I try to access it.
我没有得到 SOAPConfiguration，但是当我尝试访问它时，我的应用程序因空指针异常而中断。
I have already read many Threads here and googled around, but did not find a solution yet. I tried to deliver all necessary information, please let me know if anything misses.
我已经在这里阅读了许多线程并用谷歌搜索，但还没有找到解决方案。我试图提供所有必要的信息，如果有任何遗漏，请告诉我。
采纳答案by sinujohn
I guess you call init()before the autowiring takes place. Annotate init()with @PostConstruct to make it call automatically after all the spring autowiring.
我猜你init()在自动装配之前打电话。init()使用@PostConstruct 进行注释，使其在所有 spring 自动装配后自动调用。
EDIT: after seeing your comment, I guess you are creating it using new MyServiceImpl(). This takes away the control of the MyServiceImpl from Spring and gives it to you. Autowiring won't work in those case
编辑：看到您的评论后，我猜您是使用new MyServiceImpl(). 这从 Spring 中夺走了 MyServiceImpl 的控制权，并将其交给您。在这种情况下自动装配不起作用
回答by furkan3ayraktar
Did you created a bean for the class SOAPConfiguration in any of your configuration classes? If you want to autowire a class in your project, you need to create a bean for it. For example,
您是否在任何配置类中为类 SOAPConfiguration 创建了一个 bean？如果你想在你的项目中自动装配一个类，你需要为它创建一个 bean。例如，
@Configuration
public class SomeConfiguration{
@Bean
public SOAPConfiguration createSOAPConfiguration(){
return new SOAPConfiguration();
}
}
public class SomeOtherClass{
@Autowired
private SOAPConfiguration soapConfiguration;
}
