httpcomponents未按文档所述工作

Question

使用我在这里找到的代码：http://hc.apache.org/httpcomponents-client-ga/quickstart.html，我创建了一个快速的HTTP客户端应用程序。下面是一个代码片段：

DefaultHttpClient httpclient = new DefaultHttpClient();
HttpGet httpGet = new HttpGet(url);
log.info("Logging in");
HttpResponse response;
try {
  response = httpclient.execute(httpGet);
}
catch (ClientProtocolException cpe) {
  String msg = "Error logging in with:" + rootUrl;
  log.error(msg, cpe);
  throw new BusinessRuleException(msg, cpe);
}
catch (IOException ioe) {
  String msg = "Error logging in with:" + rootUrl;
  log.error(msg, ioe);
  throw new BusinessRuleException(msg, ioe);
}

try {
  System.out.println(response.getStatusLine());
  HttpEntity entity = response.getEntity();
  // do something useful with the response body
  // and ensure it is fully consumed
  EntityUtils.consume(entity);
}
catch (IOException ioe) {
  String msg = "Error retrieving login response:" + rootUrl;
  log.error(msg, ioe);
  throw new BusinessRuleException(msg, ioe);
}
finally {
  httpGet.releaseConnection();
}

我得到了这个例外：

java.lang.NoSuchMethodError: org.apache.http.client.methods.HttpGet.releaseConnection()V
    at com.xerox.tclg.juror.schedule.RestScheduleRunner.runDailyCheckout(RestScheduleRunner.java:93)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at org.springframework.util.MethodInvoker.invoke(MethodInvoker.java:276)
    at org.springframework.scheduling.quartz.MethodInvokingJobDetailFactoryBean$MethodInvokingJob.executeInternal(MethodInvokingJobDetailFactoryBean.java:260)

我发现一些文档说releaseConnection()不是必需的，所以我删除了finally块。然后我得到了这个异常：

java.lang.NoSuchMethodError: org.apache.http.util.EntityUtils.consume(Lorg/apache/http/HttpEntity;)V
    at com.xerox.tclg.juror.schedule.RestScheduleRunner.runDailyCheckout(RestScheduleRunner.java:85)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at org.springframework.util.MethodInvoker.invoke(MethodInvoker.java:276)
    at org.springframework.scheduling.quartz.MethodInvokingJobDetailFactoryBean$MethodInvokingJob.executeInternal(MethodInvokingJobDetailFactoryBean.java:260)

有没有人看过这个？

Answer 1

在这种情况下，java.lang.NoSuchMethodError很可能意味着您获得了其中一个Http组件JAR文件的错误版本。

如果你能找出"RestScheduleRunner.java:85“到底发生了什么，它可能会帮助你诊断这个问题。