如何在Spring中使用请求范围？

Question

package test.service;

@Path("/test")
public class TestResource {

    @Inject
    private Query query;

    @GET
    public String test() {
        return "found: " + query.toString();
    }
}

package test.utils;

public class QueryFactory implements Factory<Query> {

    @Inject
    private UriInfo uriInfo;

    @Override
    public Query provide() {
        Query query = new Query();
        Iterator<String> it = uriInfo.getQueryParameters().keySet().iterator();

        if(it.hasNext()) {
            String key = it.next();
            List<String> valueList = uriInfo.getQueryParameters().get(key);
            String value;
            if(valueList.isEmpty())
                value = "no value";
            else
                value = valueList.get(0);

            query.setKey(key);
            query.setValue(value);
        } else {
            query.setKey("no query");
        }
        return query;
    }

    @Override
    public void dispose(Query query) {
    }
}

package test.config

@Configuration
@ComponentScan("test")
public class SpringConfiguration {

    @Autowired
    QueryFactory queryFactory;

    @Bean
    public Query query() throws Exception {
        return queryFactory.getObject();
    }
}

<listener>
    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>

<listener>
    <listener-class>org.springframework.web.context.request.RequestContextListener</listener-class>
</listener>

<context-param>
    <param-name>contextClass</param-name>
    <param-value>org.springframework.web.context.support.AnnotationConfigWebApplicationContext</param-value>
</context-param>

<context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>test.config.SpringConfiguration</param-value>
</context-param>

更改TestResource

package test.service;

@Path("/test")
@Component
public class TestResource {

    @Autowired
    private Query query;

    @GET
    public String test() {
        return "found: " + query.toString();
    }
}

并向QueryFactory添加注释

@Component
@Scope("request")
public class QueryFactory implements FactoryBean<Query>

我理解使用请求范围需要RequestContextListener。然而，当我运行它时，我得到一个异常，它告诉我

`java.lang.IllegalStateException: No thread-bound request found:` 

我看不出哪里出了问题。你能给我指出这个配置应该如何正确地完成吗？

Answer 1

问题是您告诉Spring QueryFactory有一个请求范围

@Component
@Scope("request")
public class QueryFactory

因此，这个objec只存在于web请求的中间。但您试图在web请求之外使用它。

@Autowired
QueryFactory queryFactory;

您可以在异常中看到它