improve:ProviderMethodModel add parameterClasses (#3693)

dubbo-rpc/dubbo-rpc-api/src/main/java/org/apache/dubbo/rpc/model/ProviderMethodModel.java

@@ -17,20 +17,24 @@
 package org.apache.dubbo.rpc.model;
 
 import java.lang.reflect.Method;
+import java.lang.reflect.Type;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
 
 public class ProviderMethodModel {
     private final Method method;
     private final String methodName;
+    private final Class<?>[] parameterClasses;
     private final String[] methodArgTypes;
-
+    private final Type[] genericParameterTypes;
     private final ConcurrentMap<String, Object> attributeMap = new ConcurrentHashMap<>();
 
     public ProviderMethodModel(Method method) {
         this.method = method;
         this.methodName = method.getName();
+        this.parameterClasses = method.getParameterTypes();
         this.methodArgTypes = getArgTypes(method);
+        this.genericParameterTypes = method.getGenericParameterTypes();
     }
 
     public Method getMethod() {
@@ -61,4 +65,12 @@ private static String[] getArgTypes(Method method) {
         }
         return methodArgTypes;
     }
+
+    public Class<?>[] getParameterClasses() {
+        return parameterClasses;
+    }
+
+    public Type[] getGenericParameterTypes() {
+        return genericParameterTypes;
+    }
 }

dubbo-rpc/dubbo-rpc-api/src/main/java/org/apache/dubbo/rpc/model/ProviderModel.java

@@ -74,6 +74,11 @@ public ProviderMethodModel getMethodModel(String methodName, String[] argTypes)
         return null;
     }
 
+    public List<ProviderMethodModel> getMethodModelList(String methodName) {
+        return methods.get(methodName);
+    }
+
+
     private void initMethod(Class<?> serviceInterfaceClass) {
         Method[] methodsToExport = null;
         methodsToExport = serviceInterfaceClass.getMethods();