简单工厂加上反射

public static?xxx getInstance()
??? {
??????? Class decoderClass = null;
??????? if (null == instance)
??????? {
??????????? try
??????????? {
??????????????? decoderClass = Class
??????????????????? .forName(HttpAgentData.HttpSOAPDecoderClass);
??????????? }
??????????? catch (ClassNotFoundException e)
??????????? {
?????????????????? ex.printStackTrace();
??????????? }
??????????? Constructor constructor = decoderClass.getConstructors()[0];
??????????? try
??????????? {
??????????????? instance = (SOAPDecoder)constructor.newInstance(null);
??????????? }
??????????? catch (Exception e)
??????????? {
??????????????? e.printStackTrace();
??????????? }
??????? }
??????? return instance;
??? }