public Type BuildType(Type serviceType)
{
if (!NeedBuildType(serviceType))
{
return(null);
}
Type interfaceType = serviceType;
FeignClientAttribute feignClientAttribute = interfaceType.GetCustomAttribute <FeignClientAttribute>();
IMethodBuilder methodBuilder;
Type parentType;
if (feignClientAttribute.Fallback != null)
{
methodBuilder = _fallbackMethodBuilder;
parentType = typeof(FallbackFeignClientHttpProxy <,>);
parentType = parentType.MakeGenericType(interfaceType, feignClientAttribute.Fallback);
}
else if (feignClientAttribute.FallbackFactory != null)
{
methodBuilder = _fallbackMethodBuilder;
parentType = typeof(FallbackFactoryFeignClientHttpProxy <,>);
parentType = parentType.MakeGenericType(interfaceType, feignClientAttribute.FallbackFactory);
}
else
{
methodBuilder = _methodBuilder;
parentType = typeof(FeignClientHttpProxy <>);
parentType = parentType.MakeGenericType(interfaceType);
}
parentType = GetParentType(parentType);
TypeBuilder typeBuilder = CreateTypeBuilder(GetTypeFullName(interfaceType), parentType);
BuildConstructor(typeBuilder, parentType);
BuildServiceIdProperty(typeBuilder, interfaceType);
BuildBaseUriProperty(typeBuilder, interfaceType);
BuildUrlProperty(typeBuilder, interfaceType);
typeBuilder.AddInterfaceImplementation(interfaceType);
foreach (var method in interfaceType.GetMethods())
{
methodBuilder.BuildMethod(typeBuilder, interfaceType, method, feignClientAttribute);
}
var typeInfo = typeBuilder.CreateTypeInfo();
Type type = typeInfo.AsType();
return(type);
}
public FeignClientTypeInfo Build(Type serviceType)
{
//校验一下是否可以生成代理类型
if (!NeedBuildType(serviceType))
{
return(null);
}
//获取一下描述特性
FeignClientAttribute feignClientAttribute = serviceType.GetCustomAttributeIncludingBaseInterfaces <FeignClientAttribute>();
IMethodBuilder methodBuilder;
Type parentType;
if (feignClientAttribute.Fallback != null)
{
//此服务支持服务降级
methodBuilder = _fallbackMethodBuilder;
parentType = typeof(FallbackFeignClientHttpProxy <,>);
parentType = parentType.MakeGenericType(serviceType, feignClientAttribute.Fallback);
}
else if (feignClientAttribute.FallbackFactory != null)
{
//此服务支持服务降级(降级服务由factory提供)
methodBuilder = _fallbackMethodBuilder;
parentType = typeof(FallbackFactoryFeignClientHttpProxy <,>);
parentType = parentType.MakeGenericType(serviceType, feignClientAttribute.FallbackFactory);
}
else
{
//默认的服务
methodBuilder = _methodBuilder;
parentType = typeof(FeignClientHttpProxy <>);
parentType = parentType.MakeGenericType(serviceType);
}
parentType = GetParentType(parentType);
FeignClientTypeInfo feignClientTypeInfo = new FeignClientTypeInfo(serviceType)
{
ParentType = parentType
};
//创建类型
TypeAttributes typeAttributes = TypeAttributes.Public |
TypeAttributes.Class |
TypeAttributes.AutoClass |
TypeAttributes.AnsiClass |
TypeAttributes.BeforeFieldInit |
TypeAttributes.AutoLayout;
TypeBuilder typeBuilder = _dynamicAssembly.DefineType(GetTypeFullName(serviceType), typeAttributes, parentType, new Type[] { serviceType });
//写入构造函数
typeBuilder.BuildFirstConstructor(parentType);
//写入serviceId
typeBuilder.DefineReadOnlyProperty(serviceType, "ServiceId", feignClientAttribute.Name);
//写入baseUri
typeBuilder.DefineReadOnlyProperty(serviceType, "BaseUri", serviceType.GetCustomAttribute <RequestMappingAttribute>()?.Value);
// 写入url
if (feignClientAttribute.Url != null)
{
typeBuilder.DefineReadOnlyProperty(serviceType, "Url", feignClientAttribute.Url);
}
foreach (var method in serviceType.GetMethodsIncludingBaseInterfaces())
{
//生成方法
var buildMethod = methodBuilder.BuildMethod(typeBuilder, serviceType, method, feignClientAttribute);
feignClientTypeInfo.Methods.Add(buildMethod);
}
foreach (var property in serviceType.GetPropertiesIncludingBaseInterfaces())
{
//写入自动属性
//typeBuilder.DefineAutoProperty(serviceType, property);
typeBuilder.DefineExplicitAutoProperty(serviceType, property);
}
var typeInfo = typeBuilder.CreateTypeInfo();
Type type = typeInfo.AsType();
feignClientTypeInfo.BuildType = type;
return(feignClientTypeInfo);
}
void BuildMethod(TypeBuilder typeBuilder, Type serviceType, MethodInfo method, FeignClientAttribute feignClientAttribute, RequestMappingBaseAttribute requestMapping)
{
MethodBuilder methodBuilder = CreateMethodBuilder(typeBuilder, method);
ILGenerator iLGenerator = methodBuilder.GetILGenerator();
if (requestMapping == null)
{
iLGenerator.Emit(OpCodes.Newobj, typeof(NotSupportedException).GetConstructor(Type.EmptyTypes));
iLGenerator.Emit(OpCodes.Throw);
return;
}
string uri = requestMapping.Value ?? "";
LocalBuilder local_Uri = iLGenerator.DeclareLocal(typeof(string)); // uri
LocalBuilder local_OldValue = iLGenerator.DeclareLocal(typeof(string)); // temp
iLGenerator.Emit(OpCodes.Ldstr, uri);
iLGenerator.Emit(OpCodes.Stloc, local_Uri);
List <EmitRequestContent> emitRequestContents = EmitParameter(iLGenerator, method, local_Uri, local_OldValue);
EmitCallMethod(typeBuilder, methodBuilder, iLGenerator, serviceType, method, requestMapping, local_Uri, emitRequestContents);
}
public void BuildMethod(TypeBuilder typeBuilder, Type serviceType, MethodInfo method, FeignClientAttribute feignClientAttribute)
{
BuildMethod(typeBuilder, serviceType, method, feignClientAttribute, GetRequestMappingAttribute(method));
}
FeignClientMethodInfo BuildMethod(TypeBuilder typeBuilder, Type serviceType, MethodInfo method, FeignClientAttribute feignClientAttribute, RequestMappingBaseAttribute requestMapping)
{
FeignClientMethodInfo feignClientMethodInfo = new FeignClientMethodInfo
{
MethodId = GetMethodId(method),
MethodMetadata = method
};
//创建方法
MethodBuilder methodBuilder = CreateMethodBuilder(typeBuilder, method);
ILGenerator iLGenerator = methodBuilder.GetILGenerator();
if (requestMapping == null)
{
//如果找不到mapping,抛出 NotSupportedException 异常
iLGenerator.Emit(OpCodes.Newobj, typeof(NotSupportedException).GetConstructor(Type.EmptyTypes));
iLGenerator.Emit(OpCodes.Throw);
return(new FeignClientMethodInfo
{
MethodId = GetMethodId(method),
MethodMetadata = method
});
}
string uri = requestMapping.Value ?? "";
LocalBuilder local_Uri = iLGenerator.DeclareLocal(typeof(string)); // 定义uri
iLGenerator.Emit(OpCodes.Ldstr, uri);
iLGenerator.Emit(OpCodes.Stloc, local_Uri);
List <EmitRequestContent> emitRequestContents = EmitParameter(typeBuilder, requestMapping, iLGenerator, method, local_Uri);
EmitCallMethod(typeBuilder, methodBuilder, iLGenerator, serviceType, feignClientMethodInfo, requestMapping, local_Uri, emitRequestContents);
methodBuilder.CopyCustomAttributes(method);
return(feignClientMethodInfo);
}
