Java 使用paypal api时无法建立SOAP连接

我正在尝试使用paypal soap客户端，并参考执行setExpressCheckout方法

所以这里我只使用paypal-base.jar和paypal-stubs.jar soap客户机（从wsdl生成）的

我已尝试执行此方法，但出现异常，原因是

com.paypal.sdk.exceptions.FatalException:无法建立SOAP连接

原因：java.lang.NullPointerException 位于com.paypal.sdk.core.APICallerBase.getEndpointUrl（APICallerBase.java:296）

完整堆栈跟踪是：

com.paypal.sdk.exceptions.FatalException: Unable to establish SOAP connection
        at com.paypal.sdk.core.soap.SOAPAPICaller.setupConnection(SOAPAPICaller.java:292)
        at com.paypal.sdk.services.CallerServices.setAPIProfile(CallerServices.java:112)
        at com.imedicor.liferay.organizations.util.PaypalService.setExpressCheckout(PaypalService.java:92)
        at com.imedicor.liferay.organizations.util.PaypalService.testing(PaypalService.java:43)
        at org.apache.jsp.organization_005fdetails_jsp._jspService(organization_005fdetails_jsp.java:500)
        at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
        at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:432)
        at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
        at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:72)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:116)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilter.doFilter(InvokerFilter.java:73)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
        at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:684)
        at org.apache.catalina.core.ApplicationDispatcher.doInclude(ApplicationDispatcher.java:593)
        at org.apache.catalina.core.ApplicationDispatcher.include(ApplicationDispatcher.java:530)
        at com.liferay.portlet.PortletRequestDispatcherImpl.dispatch(PortletRequestDispatcherImpl.java:323)
        at com.liferay.portlet.PortletRequestDispatcherImpl.include(PortletRequestDispatcherImpl.java:134)
        at com.imedicor.liferay.organizations.portlet.OrganizationPortlet.doView(OrganizationPortlet.java:83)
        at com.liferay.portal.kernel.portlet.LiferayPortlet.doDispatch(LiferayPortlet.java:218)
        at com.liferay.util.bridges.mvc.MVCPortlet.doDispatch(MVCPortlet.java:319)
        at javax.portlet.GenericPortlet.render(GenericPortlet.java:233)
        at com.liferay.portlet.FilterChainImpl.doFilter(FilterChainImpl.java:100)
        at com.liferay.portal.kernel.portlet.PortletFilterUtil.doFilter(PortletFilterUtil.java:64)
        at com.liferay.portal.kernel.servlet.PortletServlet.service(PortletServlet.java:111)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:72)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilter.doFilter(InvokerFilter.java:73)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
        at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:684)
        at org.apache.catalina.core.ApplicationDispatcher.doInclude(ApplicationDispatcher.java:593)
        at org.apache.catalina.core.ApplicationDispatcher.include(ApplicationDispatcher.java:530)
        at com.liferay.portlet.InvokerPortletImpl.invoke(InvokerPortletImpl.java:534)
        at com.liferay.portlet.InvokerPortletImpl.invokeRender(InvokerPortletImpl.java:607)
        at com.liferay.portlet.InvokerPortletImpl.render(InvokerPortletImpl.java:359)
        at org.apache.jsp.html.portal.render_005fportlet_jsp._jspService(render_005fportlet_jsp.java:1207)
        at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
        at com.liferay.portal.servlet.DirectRequestDispatcher.include(DirectRequestDispatcher.java:97)
        at com.liferay.portal.servlet.PACLRequestDispatcherWrapper.doDispatch(PACLRequestDispatcherWrapper.java:90)
        at com.liferay.portal.servlet.PACLRequestDispatcherWrapper.include(PACLRequestDispatcherWrapper.java:54)
        at com.liferay.portal.util.PortalImpl.renderPortlet(PortalImpl.java:5158)
        at com.liferay.portal.util.PortalUtil.renderPortlet(PortalUtil.java:1569)
        at com.liferay.portlet.layoutconfiguration.util.RuntimePortletImpl.processPortlet(RuntimePortletImpl.java:165)
        at com.liferay.portlet.layoutconfiguration.util.RuntimePortletImpl.processPortlet(RuntimePortletImpl.java:203)
        at com.liferay.portlet.layoutconfiguration.util.RuntimePortletImpl.processPortlet(RuntimePortletImpl.java:190)
        at com.liferay.portlet.layoutconfiguration.util.RuntimePortletUtil.processPortlet(RuntimePortletUtil.java:87)
        at com.liferay.portlet.layoutconfiguration.util.velocity.TemplateProcessor.processMax(TemplateProcessor.java:165)
        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.apache.velocity.util.introspection.UberspectImpl$VelMethodImpl.doInvoke(UberspectImpl.java:389)
        at org.apache.velocity.util.introspection.UberspectImpl$VelMethodImpl.invoke(UberspectImpl.java:378)
        at org.apache.velocity.runtime.parser.node.ASTMethod.execute(ASTMethod.java:270)
        at org.apache.velocity.runtime.parser.node.ASTReference.execute(ASTReference.java:262)
        at org.apache.velocity.runtime.parser.node.ASTReference.render(ASTReference.java:342)
        at org.apache.velocity.runtime.parser.node.SimpleNode.render(SimpleNode.java:336)
        at org.apache.velocity.Template.merge(Template.java:328)
        at org.apache.velocity.Template.merge(Template.java:235)
        at org.apache.velocity.app.VelocityEngine.mergeTemplate(VelocityEngine.java:381)
        at com.liferay.portal.velocity.VelocityEngineImpl.mergeTemplate(VelocityEngineImpl.java:264)
        at com.liferay.portal.kernel.velocity.VelocityEngineUtil.mergeTemplate(VelocityEngineUtil.java:73)
        at com.liferay.portlet.layoutconfiguration.util.RuntimePortletImpl.doProcessTemplate(RuntimePortletImpl.java:499)
        at com.liferay.portlet.layoutconfiguration.util.RuntimePortletImpl.doDispatch(RuntimePortletImpl.java:394)
        at com.liferay.portlet.layoutconfiguration.util.RuntimePortletImpl.processTemplate(RuntimePortletImpl.java:228)
        at com.liferay.portlet.layoutconfiguration.util.RuntimePortletUtil.processTemplate(RuntimePortletUtil.java:125)
        at org.apache.jsp.html.portal.layout.view.control_005fpanel_jsp._jspService(control_005fpanel_jsp.java:676)
        at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
        at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:432)
        at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
        at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:72)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:116)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilter.doFilter(InvokerFilter.java:73)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
        at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:684)
        at org.apache.catalina.core.ApplicationDispatcher.doInclude(ApplicationDispatcher.java:593)
        at org.apache.catalina.core.ApplicationDispatcher.include(ApplicationDispatcher.java:530)
        at com.liferay.portal.action.LayoutAction.includeLayoutContent(LayoutAction.java:468)
        at com.liferay.portal.action.LayoutAction.processLayout(LayoutAction.java:735)
        at com.liferay.portal.action.LayoutAction.execute(LayoutAction.java:249)
        at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:431)
        at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:236)
        at com.liferay.portal.struts.PortalRequestProcessor.process(PortalRequestProcessor.java:187)
        at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196)
        at org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:414)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
        at com.liferay.portal.servlet.MainServlet.callParentService(MainServlet.java:560)
        at com.liferay.portal.servlet.MainServlet.service(MainServlet.java:537)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:72)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:116)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:116)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:116)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:116)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:116)
        at com.liferay.portal.kernel.servlet.BaseFilter.processFilter(BaseFilter.java:163)
        at com.liferay.portal.servlet.filters.secure.SecureFilter.processFilter(SecureFilter.java:294)
        at com.liferay.portal.kernel.servlet.BaseFilter.doFilter(BaseFilter.java:57)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.processDoFilter(InvokerFilterChain.java:206)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:108)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilter.doFilter(InvokerFilter.java:73)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
        at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:684)
        at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:471)
        at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:402)
        at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:329)
        at com.liferay.portal.servlet.FriendlyURLServlet.service(FriendlyURLServlet.java:138)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:72)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:116)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:116)
        at com.liferay.portal.kernel.servlet.BaseFilter.processFilter(BaseFilter.java:163)
        at com.liferay.portal.servlet.filters.strip.StripFilter.processFilter(StripFilter.java:335)
        at com.liferay.portal.kernel.servlet.BaseFilter.doFilter(BaseFilter.java:57)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.processDoFilter(InvokerFilterChain.java:206)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:108)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:116)
        at com.liferay.portal.kernel.servlet.BaseFilter.processFilter(BaseFilter.java:163)
        at com.liferay.portal.servlet.filters.gzip.GZipFilter.processFilter(GZipFilter.java:123)
        at com.liferay.portal.kernel.servlet.BaseFilter.doFilter(BaseFilter.java:57)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.processDoFilter(InvokerFilterChain.java:206)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:108)
        at com.liferay.portal.kernel.servlet.BaseFilter.processFilter(BaseFilter.java:163)
        at com.liferay.portal.servlet.filters.secure.SecureFilter.processFilter(SecureFilter.java:294)
        at com.liferay.portal.kernel.servlet.BaseFilter.doFilter(BaseFilter.java:57)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.processDoFilter(InvokerFilterChain.java:206)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:108)
        at com.liferay.portal.kernel.servlet.BaseFilter.processFilter(BaseFilter.java:163)
        at com.liferay.portal.servlet.filters.i18n.I18nFilter.processFilter(I18nFilter.java:241)
        at com.liferay.portal.kernel.servlet.BaseFilter.doFilter(BaseFilter.java:57)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.processDoFilter(InvokerFilterChain.java:206)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:108)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:116)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:116)
        at com.liferay.portal.kernel.servlet.BaseFilter.processFilter(BaseFilter.java:163)
        at com.liferay.portal.servlet.filters.etag.ETagFilter.processFilter(ETagFilter.java:56)
        at com.liferay.portal.kernel.servlet.BaseFilter.doFilter(BaseFilter.java:57)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.processDoFilter(InvokerFilterChain.java:206)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:108)
        at com.liferay.portal.kernel.servlet.BaseFilter.processFilter(BaseFilter.java:163)
        at com.liferay.portal.servlet.filters.autologin.AutoLoginFilter.processFilter(AutoLoginFilter.java:246)
        at com.liferay.portal.kernel.servlet.BaseFilter.doFilter(BaseFilter.java:57)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.processDoFilter(InvokerFilterChain.java:206)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:108)
        at com.liferay.portal.kernel.servlet.BaseFilter.processFilter(BaseFilter.java:163)
        at com.liferay.portal.servlet.filters.sso.ntlm.NtlmPostFilter.processFilter(NtlmPostFilter.java:83)
        at com.liferay.portal.kernel.servlet.BaseFilter.doFilter(BaseFilter.java:57)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.processDoFilter(InvokerFilterChain.java:206)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:108)
        at com.liferay.portal.kernel.servlet.BaseFilter.processFilter(BaseFilter.java:163)
        at com.liferay.portal.sharepoint.SharepointFilter.processFilter(SharepointFilter.java:80)
        at com.liferay.portal.kernel.servlet.BaseFilter.doFilter(BaseFilter.java:57)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.processDoFilter(InvokerFilterChain.java:206)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:108)
        at com.liferay.portal.kernel.servlet.BaseFilter.processFilter(BaseFilter.java:163)
        at com.liferay.portal.servlet.filters.virtualhost.VirtualHostFilter.processFilter(VirtualHostFilter.java:216)
        at com.liferay.portal.kernel.servlet.BaseFilter.doFilter(BaseFilter.java:57)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.processDoFilter(InvokerFilterChain.java:206)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:108)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.processDirectCallFilter(InvokerFilterChain.java:187)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:95)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:116)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:116)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:116)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:116)
        at org.tuckey.web.filters.urlrewrite.UrlRewriteFilter.doFilter(UrlRewriteFilter.java:738)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.processDoFilter(InvokerFilterChain.java:206)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:108)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.processDirectCallFilter(InvokerFilterChain.java:167)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:95)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:116)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.processDirectCallFilter(InvokerFilterChain.java:167)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:95)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:116)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.processDirectCallFilter(InvokerFilterChain.java:187)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:95)
        at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilter.doFilter(InvokerFilter.java:73)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:225)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:169)
        at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
        at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:927)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
        at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:999)
        at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:565)
        at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:309)
        at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
        at java.lang.Thread.run(Thread.java:619)
Caused by: java.lang.NullPointerException
        at com.paypal.sdk.core.APICallerBase.getEndpointUrl(APICallerBase.java:296)
        at com.paypal.sdk.core.soap.SOAPAPICaller.setupConnection(SOAPAPICaller.java:193)

所以我得到这个异常是因为没有设置端点url

在这种情况下，如何设置端点url

在上述方法的开头，我还尝试按照以下方式为端点添加配置

Map<String, String> sdkConfig = new HashMap<String, String>();
        sdkConfig.put("mode", "sandbox");
        sdkConfig.put("acct1.UserName", "sdk-three_api1.sdk.com");
        sdkConfig.put("acct1.Password", "QFZCWN5HZM8VBG7Q");
        sdkConfig.put("acct1.Signature","AVGidzoSQiGWu.lGj3z15HLczXaaAcK6imHawrjefqgclVwBe8imgCHZ");
        PayPalAPIInterfaceServiceService service = new PayPalAPIInterfaceServiceService(sdkConfig);

Map sdkConfig=newhashmap（）；
sdkConfig.put（“模式”、“沙盒”）；
sdkConfig.put（“acct1.UserName”，“sdk-three_api1.sdk.com”）；
sdkConfig.put（“账户密码”、“QFZCWN5HZM8VBG7Q”）；
sdkConfig.put（“acct1.Signature”、“AVGidzoSQiGWu.lgj3z15hlczxaaaack6imhawrjeffqgclvwbe8imgchz”）；
PayPalAPIInterfaceServiceService=新的PayPalAPIInterfaceServiceService（sdkConfig）；

但我还是得到了同样的例外

请在这方面指导我

---

谢谢，

您需要设置端点url

    service.EndPoint=https://api-3t.paypal.com/2.0

此外，您可能还需要一些设置：

    service.Binding=SOAP
    service.EndPoint=https://api-3t.paypal.com/2.0
    service.RedirectURL=https://www.paypal.com/webscr&cmd=
    service.DevCentralURL=https://developer.paypal.com
    service.IPNEndpoint=https://www.paypal.com/cgi-bin/webscr

   service.Binding=SOAP
   service.EndPoint=https://api-3t.sandbox.paypal.com/2.0
   service.RedirectURL=https://www.sandbox.paypal.com/webscr&cmd=
   service.DevCentralURL=https://developer.paypal.com
   service.IPNEndpoint=https://www.sandbox.paypal.com/cgi-bin/webscr

如果使用沙箱，请使用以下设置：

    service.Binding=SOAP
    service.EndPoint=https://api-3t.paypal.com/2.0
    service.RedirectURL=https://www.paypal.com/webscr&cmd=
    service.DevCentralURL=https://developer.paypal.com
    service.IPNEndpoint=https://www.paypal.com/cgi-bin/webscr

   service.Binding=SOAP
   service.EndPoint=https://api-3t.sandbox.paypal.com/2.0
   service.RedirectURL=https://www.sandbox.paypal.com/webscr&cmd=
   service.DevCentralURL=https://developer.paypal.com
   service.IPNEndpoint=https://www.sandbox.paypal.com/cgi-bin/webscr

---

好的，所以我没有设法找出

CallerService

抛出所提到的异常的原因，因为即使在对所提到的

paypal_base.jar

进行反编译之后，代码还是相当繁琐，很难找出幕后发生了什么。看起来它已经过时了，因为除了几个地方之外，我在网上的任何地方都找不到对这个罐子的引用

但我真的建议您坚持使用PayPal提供的原始文档。我自己试过了，我发现：

按照上述文章中的链接，然后单击

Classic API

类别下的

Merchant

链接（如果你在网上搜索，你会发现PayPal Merchant API应该用于ExpressCheckout请求）。单击上面的

Java

按钮，使用

Maven

（首选）或只使用页面底部的下载链接下载SDK

将下载的JAR添加到您的项目中，并删除其他PayPal JAR，因为下载的

Merchant API

JAR应该包含所有必要的类

现在一切都取决于猜测：）因此，在上面的代码片段中，您已经形成了

SetExpressCheckoutRequestType

的实例，并且您需要

一些调用代码

，它接受

SetExpressCheckoutRequestType

的实例并返回

SetExpressCheckoutResponseType

的实例

我在Eclipse中使用了功能

Search->References->Workspace

，以查找

SetExpressCheckoutRequestType

在

merchantapi

jar中的使用位置。此搜索显示（除其他位置外）有一个名为

SetExpressCheckoutReq

的类，它的方法是

setSetExpressCheckoutRequest（SetExpressCheckoutRequestType）

然后我再次使用搜索功能搜索

SetExpressCheckoutReq

类的用法，发现有class

PayPalAPIInterfaceServiceService

方法

setExpressCheckout（SetExpressCheckoutReq SetExpressCheckoutReq）

返回所需

SetExpressCheckoutResponseType

在

setExpressCheckout（SetExpressCheckoutReq SetExpressCheckoutReq）

method的旁边，有一个方法也采用

ICredential

参数，并具有以下签名：

setExpressCheckout（SetExpressCheckoutReq SetExpressCheckoutReq，ICredential凭证）

再次使用Eclipse，我查找了实现

ICredential

接口的类，发现有一个名为

SignatureCredential

的类，构造函数有3个参数：用户名、密码、签名。在我看来，这是一条路要走

因此，非常接近-代码片段现在应该如下所示：

final SetExpressCheckoutRequestType ppRequest = ...; // here you create your request as in code snippet above

final Properties serviceConfigurationProperties = ...; // bookmark #1
final PayPalAPIInterfaceServiceService service = new PayPalAPIInterfaceServiceService(serviceConfigurationProperties);

final SetExpressCheckoutReq request = new SetExpressCheckoutReq();
request.setSetExpressCheckoutRequest(ppRequest);

final ICredentials credentials = new SignatureCredentials(username, password, signature);
final SetExpressCheckoutResponseType response = service.setExpressCheckout(request, credentials);

Bookmark#1

：应该传递带有服务配置的

Properties

实例。为了找出应该指定哪些属性，你应该搜索它，并尝试坚持使用原始PayPal文档，而不是第三方博客：）如果你查看

PayPalAPIInterfaceServiceService

类的Javadocs，他/她会发现有提到“sdk\u config.properties”的文件。在谷歌搜索之后，我找到了该文件的几个示例：

请注意，这不是一个完整的解决方案——它相当像我以前使用PayPal SOAP API时使用的一组提示。这个API经常变化，文档不简洁，所以我建议下载

merchantapi

jar和源代码，每当出现问题时，也要查看代码，这通常会澄清很多问题。请同时遵守PayPal的原始文档：

此外，如果您没有使用Java的Web服务客户端的经验，我建议您尝试使用网上教程实现一些简单的客户端，这可能会澄清很多问题

再次为没有发布完整而简洁的代码片段感到抱歉-从现在起我已经有2年没有与PayPal合作了，当时我花了一周的时间来了解所有细节，并将其设置并运行。请发布问题-我会在有时间时尝试回答

希望这有助于

编辑

关于

response.getAck（）。我通过试验请求中发送的参数解决了这个问题-
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