Java 在android中基于代理的环境中使用SOAP web服务

我在一个基于代理的环境中工作，在这个环境中，我无法通过emulator使用SOAP web服务。有人知道如何在基于代理的环境中使用SOAPWeb服务吗

我创建了这个类：

import java.io.IOException;
import java.net.Proxy;
import org.kobjects.base64.Base64;
import org.ksoap2.transport.HttpTransportSE;
import org.ksoap2.transport.ServiceConnection;
//class to handle authentication in a proxy based environment

public class HttpTransportBasicAuth extends HttpTransportSE {
//username and password for accessing a proxy based network
        private String username;
        private String password;
  public HttpTransportBasicAuth(String url, String username, String password) {
    super(url);
    this.username = username;
    this.password = password;
  }

  @Override
  public ServiceConnection getServiceConnection() throws IOException {
    ServiceConnection serviceConnection = super.getServiceConnection();
    addBasicAuthentication(serviceConnection);
    return serviceConnection;
  }

  protected void addBasicAuthentication(ServiceConnection serviceConnection) 
      throws IOException {

    if (username != null && password != null) {
      StringBuffer buffer = new StringBuffer(username);
      buffer.append(':').append(password);
      byte[] bytes = buffer.toString().getBytes();
      buffer.setLength(0);
      buffer.append("Basic ");
      Base64.encode(bytes, 0, bytes.length, buffer);
      serviceConnection.setRequestProperty
        ("Authorization", buffer.toString());
    }
  }

}

然后我创建了它的对象，如：

HttpTransportBasicAuth androidHttpTransportSE=新的HttpTransportBasicAuth（url）； androidHttpTransportSE.call（url）

但是它返回空指针异常，我无法找到在基于代理的网络中访问webservice的解决方案。请帮助

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提前感谢

您如何使用基于soap的Web服务？您能显示您的代码片段吗？SoapObject请求=新的SoapObject（名称空间、方法\名称）；addProperty（“设备id”，“0:0:0:0:0”）；SoapSerializationEnvelope=新的SoapSerializationEnvelope（SoapEnvelope.VER11）；envelope.dotNet=true；envelope.setOutputSoapObject（请求）；System.out.println（“信封==>”+信封.bodyOut.toString（））；androidHttpTransport.debug=true；调用（SOAP_操作，信封）；SoapObject obj=（SoapObject）envelope.bodyIn；System.out.println（obj.toString（））；您是否可以使用HttpTransport而不是androidHttpTransport。请参阅，androidHttpTransport是HttpTransportSE的对象