访问百度推广API报java.net.UnknownHostException异常
在windows上运行是正常的，在linux上运行就报以下异常

Exception in thread "main" javax.xml.ws.WebServiceException: org.apache.cxf.service.factory.ServiceConstructionException: Failed to create service.
  at org.apache.cxf.jaxws.ServiceImpl.<init>(ServiceImpl.java:152)
  at org.apache.cxf.jaxws.spi.ProviderImpl.createServiceDelegate(ProviderImpl.java:63)
  at javax.xml.ws.Service.<init>(Service.java:57)
  at com.baidu.api.client.core.CoreService.<init>(Unknown Source)
  at com.baidu.api.client.core.ServiceFactory.getInternalService(Unknown Source)
  at com.baidu.api.client.core.VersionService.getService(Unknown Source)
  at com.baidu.api.client.core.VersionService.getService(Unknown Source)
  at com.baidu.api.client.examples.CampaignReportServiceExamples.<init>(Unknown Source)
  at com.baidu.api.client.examples.CampaignReportServiceExamples.getReport(Unknown Source)
  at com.zhenai.client.ReportUtils.main(Unknown Source)
Caused by: org.apache.cxf.service.factory.ServiceConstructionException: Failed to create service.
  at org.apache.cxf.wsdl11.WSDLServiceFactory.<init>(WSDLServiceFactory.java:93)
  at org.apache.cxf.jaxws.ServiceImpl.initializePorts(ServiceImpl.java:207)
  at org.apache.cxf.jaxws.ServiceImpl.<init>(ServiceImpl.java:150)
  ... 9 more
Caused by: javax.wsdl.WSDLException: WSDLException: faultCode=PARSER_ERROR: Problem parsing 'https://api.baidu.com/sem/sms/v2/ReportService?wsdl'.: java.net.UnknownHostException: api.baidu.com
  at com.ibm.wsdl.xml.WSDLReaderImpl.getDocument(Unknown Source)
  at com.ibm.wsdl.xml.WSDLReaderImpl.readWSDL(Unknown Source)
  at com.ibm.wsdl.xml.WSDLReaderImpl.readWSDL(Unknown Source)
  at org.apache.cxf.wsdl11.WSDLManagerImpl.loadDefinition(WSDLManagerImpl.java:232)
  at org.apache.cxf.wsdl11.WSDLManagerImpl.getDefinition(WSDLManagerImpl.java:179)
  at org.apache.cxf.wsdl11.WSDLServiceFactory.<init>(WSDLServiceFactory.java:91)
  ... 11 more
Caused by: java.net.UnknownHostException: api.baidu.com
  at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:177)
  at java.net.Socket.connect(Socket.java:519)
  at java.net.Socket.connect(Socket.java:469)
  at sun.net.NetworkClient.doConnect(NetworkClient.java:157)
  at sun.net.www.http.HttpClient.openServer(HttpClient.java:388)
  at sun.net.www.http.HttpClient.openServer(HttpClient.java:515)
  at sun.net.www.protocol.https.HttpsClient.<init>(HttpsClient.java:271)
  at sun.net.www.protocol.https.HttpsClient.New(HttpsClient.java:328)
  at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.getNewHttpClient(AbstractDelegateHttpsURLConnection.java:176)
  at sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:733)
  at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(AbstractDelegateHttpsURLConnection.java:162)
  at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:981)
  at sun.net.www.protocol.https.HttpsURLConnectionImpl.getInputStream(HttpsURLConnectionImpl.java:234)
  at com.sun.org.apache.xerces.internal.impl.XMLEntityManager.setupCurrentEntity(XMLEntityManager.java:677)
  at com.sun.o