Spring 获取 ServletContext 并将其作为 Bean 提供

Question

I want to get the ServletContext in a Java Spring Webproject and use it to get the absolute path of my web-application project. I'm still a beginner in JavaEE and Spring, so maybe I've got some concepts wrong. In the java class, in which I want to use the ServletContext, I got only an empty object when using @Autowired ServletContext context; But in my RestConfiguartion class, which extends the WebMvcConfigurerAdapter class, I got the ServletContext and I'm able to use it in a Java Bean, with the return type of ServletContext. But I have no idea, how I can use the Bean in another class to get the ServletContext, is this possible?

@Configuration
@EnableWebMvc
@Import({ ServiceConfiguration.class, SecurityConfiguration.class })
@ComponentScan(basePackages = { "de.rest", "de.security" })
public class RestConfiguration extends WebMvcConfigurerAdapter {

  @Autowired
  ServletContext context;    

  @Bean
  public ServletContext getServletContext() {
    System.out.println("*** Context path: *** " + context.getRealPath("/"));
    return context;
  }}

Answer 1

你可以写

@Autowired
ServletContext context;

在其他 bean 中也注释了 classes。您将获得相同的上下文。因此，您无需指定：

@Bean
  public ServletContext getServletContext() {
    System.out.println("*** Context path: *** " + context.getRealPath("/"));
    return context;
  }}

例如（目录中的任何 class，在您的注释 @ComponentScan 中指定）：

@Bean
class X {
    @Autowired
    ServletContext context;

    ...
}

Answer 2

感谢您的帮助，我已经解决了这个问题，方法是将我的目标 class 的包添加到 @ComponentScan，声明我的目标 class @Component 并插入我之前使用的 Bean。这些是生成的代码片段：

...
@ComponentScan(basePackages = { "de.rest", "de.security", "de.targetPackage" })
public class RestConfiguration extends WebMvcConfigurerAdapter {
...



@Component
public class targetClass {

  private static String absoluteServletContextPath;

  @Autowired
  ServletContext context;

  @Bean
  public ServletContext getServletContext() {
    absoluteServletContextPath = context.getRealPath("/");
    System.out.println(absoluteServletContextPath);
    return context;
  }

  @Override
  public void myMethod {

        absoluteServletContextPath = absoluteServletContextPath.replaceAll("webapp\\", "")
          .replaceAll("\\", "/");}}

Spring 获取 ServletContext 并将其作为 Bean 提供

Spring get ServletContext and provide it as a Bean

java

spring

servlets

spring-mvc

javabeans