java.lang.NoSuchFieldError:INSTANCE

Question

当我尝试通过StormSubmitter提交我的拓扑时,我得到了 -

Caused by: java.lang.NoSuchFieldError: INSTANCE  
at org.apache.http.impl.io.DefaultHttpRequestWriterFactory.<init>(DefaultHttpRequestWriterFactory.java:52)

我正在使用Spring.

我没有在Spout/Bolt构造函数中初始化HttpClient.相反,它是在一个类的构造函数中初始化的,该类是从Spring的上下文中获取prepare()的

代码结构如下 -

SomeBolt.java

@Component
public class SomeBolt extends BaseRichBolt {
    private OutputCollector _collector;
    private SomeClient someClient;

    @Override
    public void prepare(Map conf, TopologyContext context, OutputCollector collector) {
        _collector = collector;
        someClient = AppContext.getBean(SomeClient.class);
    }
}

SomeClient.java

@Component
public class SomeClient {
    private final CloseableHttpClient httpClient;

    public SomeClient() {
        this.httpClient = (httpClient == null ? HttpClients.createDefault() : httpClient);
    }
}

AppContext.java

@Component
public class AppContext implements ApplicationContextAware {

    private static ApplicationContext applicationContext;

    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        AppContext.applicationContext = applicationContext;
    }

    public static <T> T getBean(Class<T> c) {
        return applicationContext.getBean(c);
    }
}

Answer 1

这可能是一个依赖问题.

这是一个非常不清楚的错误消息,但我发现类似的东西: Hibernate NoSuchFieldError INSTANCE但只有Struts 1？

Answer 2

我遇到类似这样的问题,在我的类路径中有两个jar包含相同的类,httpcore-4.3和apache-httpcomponents-httpcore,我已经从类路径中删除了apache-httpcomponents-httpcore解决了这个问题.