我在@Named @ViewScoped带有 JBoss-7.1.1-Final 的 Bean 中使用 RestEasy 客户端框架，通过自定义从 REST 服务中检索数据HttpRequestInterceptor：
RegisterBuiltin.register(ResteasyProviderFactory.getInstance());
DefaultHttpClient httpClient = new DefaultHttpClient();
httpClient.addRequestInterceptor(new PreemptiveAuthInterceptor("test","test"), 0);
ClientExecutor clientExecutor = new ApacheHttpClient4Executor(httpClient); //<---
//The error occurs above, the code below is only for completeness
MyRest rest = ProxyFactory.create(MyRest.class,
"http://localhost:8080/rest",clientExecutor);
这在独立的客户端应用程序中运行良好（当我删除 时也可以ClientExecutor，但我需要它来验证 REST 服务）。该 bean 位于 aWAR内的一个模块中EAR，resteasy 的依赖层次结构解析为以下内容：
httpclientorhttpcore中没有WARor EAR。在 Bean 内部，我得到以下异常：
java.lang.NoClassDefFoundError: org/apache/http/HttpRequestInterceptor
似乎很容易（尽管我想知道 resteasy 包装）并且我添加org.apache.httpcomponents:httpclient了编译范围：
不，我得到他以下例外：
java.lang.LinkageError: loader constraint violation: when resolving method
"org.jboss.resteasy.client.core.executors.ApacheHttpClient4Executor.<init>
(Lorg/apache/http/client/HttpClient;)V"
the class loader (instance of org/jboss/modules/ModuleClassLoader)
of the current class, my/TestBean, and
the class loader (instance of org/jboss/modules/ModuleClassLoader)
for resolved class,
org/jboss/resteasy/client/core/executors/ApacheHttpClient4Executor,
have different Class objects for the type org/apache/http/client/HttpClient
used in the signature my.TestBean.init(TestBean.java:65)
更新要重现这一点，您不需要 REST 接口，在实例化 时会发生错误ApacheHttpClient4Executor，但您可能需要自定义PreemptiveAuthInterceptor：
public class PreemptiveAuthInterceptor implements HttpRequestInterceptor
{
private String username;
private String password;
public PreemptiveAuthInterceptor(String username, String password)
{
this.username=username;
this.password=password;
}
@Override
public void process(org.apache.http.HttpRequest request, HttpContext context) throws HttpException, IOException
{
AuthState authState = (AuthState) context.getAttribute(ClientContext.TARGET_AUTH_STATE);
authState.setAuthScope(org.apache.http.auth.AuthScope.ANY);
authState.setCredentials(new UsernamePasswordCredentials(username,password));
authState.setAuthScheme(new BasicScheme());
}
}