Java Web 服务中的 Spring Autowired 无法正常工作
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Spring Autowired in Web Service not working
提问by user3207820
I must be missing something simple, but I'm having trouble getting an Autowired property to be assigned to a bean. All similar answers posted here seem to revolve around one of three solutions:
我一定遗漏了一些简单的东西，但是我无法将 Autowired 属性分配给 bean。此处发布的所有类似答案似乎都围绕以下三种解决方案之一：
- extend SpringBeanAutowiringSupport
- use <context:component-scan base-package="..." /> in applicationContext.xml
- use <context:annotation-config /> in applicationContext.xml
- 扩展 SpringBeanAutowiringSupport
- 在 applicationContext.xml 中使用 <context:component-scan base-package="..." />
- 在 applicationContext.xml 中使用 <context:annotation-config />
I tried to make a minimalist bean to represent my DAO and inject it into a Web Service.
我尝试制作一个极简的 bean 来表示我的 DAO 并将其注入到 Web 服务中。
DAO interface:
DAO接口：
package wb;
public interface FooDAO {
public String doNothing();
}
DAO implementation:
DAO 实现：
package wb;
import org.springframework.stereotype.Component;
@Component
public class FooDAOImpl implements FooDAO {
public FooDAOImpl() {
System.out.println("FooDAOImpl: Instantiated " + this);
}
@Override
public String doNothing() {
System.out.println("FooDAOImpl: doNothing() called");
return "Did nothing!";
}
}
Web Service with injection:
带注入的 Web 服务：
package ws;
import javax.jws.WebService;
import javax.jws.WebMethod;
import javax.jws.WebResult;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.context.support.SpringBeanAutowiringSupport;
import wb.FooDAO;
@WebService(serviceName = "WS")
public class WS extends SpringBeanAutowiringSupport {
@Autowired(required = true)
private FooDAO fooDAO;
@WebMethod(exclude = true)
public void setFooDAO(FooDAO fooDAO) {
this.fooDAO = fooDAO;
System.out.println("WS: fooDAO set = " + fooDAO);
}
public WS() {
System.out.println("WS: WS bean instantiated!");
}
@WebMethod(operationName = "doNothing")
@WebResult(name = "whatDidIDo")
public String doNothing() {
System.out.println("WS: doNothing() says DAO = " + fooDAO);
return fooDAO == null ? "Could not do nothing!" : fooDAO.doNothing();
}
}
applicationContext.xml content within the beans tags:
bean 标签中的 applicationContext.xml 内容：
<context:annotation-config />
<context:component-scan base-package="ws"/>
<bean id="fooDAO" class="wb.FooDAOImpl" />
This was all created in the latest NetBeans, in a project created with Spring and Hibernate frameworks. When I deploy to JBoss, and the app starts up, I get the expected Bean instantiation:
这都是在最新的 NetBeans 中创建的，在一个使用 Spring 和 Hibernate 框架创建的项目中。当我部署到 JBoss 并且应用程序启动时，我得到了预期的 Bean 实例化：
11:01:46,767 INFO [stdout] (MSC service thread 1-6) WS: WS bean instantiated!
11:01:47,571 INFO [stdout] (MSC service thread 1-15) FooDAOImpl: Instantiated wb.FooDAOImpl@11176682
Once I call the web service, the log also reports:
一旦我调用 Web 服务，日志也会报告：
11:03:07,097 INFO [stdout] (http--127.0.0.1-8080-1) WS: doNothing() says DAO = null
What am I missing?
我错过了什么？
采纳答案by Kevin Bowersox
SpringBeanAutowiringSupportmust be a bean. You need to annotate that class with @Serviceor another annotation such as @Componentthat indicates a class should be a bean when component scanning occurs. These will be picked up by Springand made into beans.
SpringBeanAutowiringSupport必须是豆子。您需要使用@Service或其他注释对该类进行注释，例如在@Component发生组件扫描时指示类应该是 bean。这些将被捡起Spring并制成豆子。
Remember that in order to be a participant in autowiring, such as having another bean injected, the class must be a bean itself and managed by Spring's IOC container.
请记住，为了成为自动装配的参与者，例如注入另一个 bean，该类必须是一个 bean 本身并由 Spring 的 IOC 容器管理。
回答by Alireza Fattahi
The springshould start before webservices.
该spring前应启动webservices。
The the webservices-rt*.jaris a plugable jar which starts automaticly to find the end points.
本该webservices-rt*.jar是一个可插拔的罐子它开始全自动找到终点。
In some cases it may happen that the webservices starts before spring. So the injectscan not be done. Make sure that the start up has correct order.
在某些情况下，webservice 可能会在 spring 之前启动。所以injects是做不到的。确保启动顺序正确。
