| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package pkg |
| |
| import ( |
| "context" |
| "strings" |
| "sync" |
| ) |
| |
| import ( |
| "github.com/apache/dubbo-go/common/extension" |
| "github.com/apache/dubbo-go/filter" |
| "github.com/apache/dubbo-go/protocol" |
| "github.com/dubbogo/gost/log" |
| ) |
| |
| func init() { |
| /** |
| * MyCustomFilter would be the name that used in your configuration file. |
| * it can be used as reference filter and provider filter. |
| * For example, using this filter in server, and the configure file looks like: |
| * |
| * filter: "MyCustomFilter", |
| * registries: |
| * "demoZk": |
| * protocol: "zookeeper" |
| * timeout : "3s" |
| * address: "127.0.0.1:2181" |
| * Another important things is that you should make sure this statement executed. It usually means that |
| * this file should be imported. |
| */ |
| extension.SetFilter("MyCustomFilter", GetMyCustomFilter) |
| |
| // or using the singleton |
| // filter.SetFilter("MyCustomFilter", GetMyCustomFilterSingleton) |
| } |
| |
| type myCustomFilter struct{} |
| |
| func (mf myCustomFilter) Invoke(ctx context.Context, invoker protocol.Invoker, invocation protocol.Invocation) protocol.Result { |
| // the logic put here... |
| // you can get many params in url. And the invocation provides more information about |
| url := invoker.GetUrl() |
| serviceKey := url.ServiceKey() |
| gxlog.CInfo("Here is the my custom filter. The service is invoked: %s", serviceKey) |
| return invoker.Invoke(ctx, invocation) |
| } |
| |
| func (mf myCustomFilter) OnResponse(ctx context.Context, result protocol.Result, invoker protocol.Invoker, invocation protocol.Invocation) protocol.Result { |
| // you can do something here with result |
| gxlog.CInfo("Got result!") |
| if user, ok := result.Result().(*User); ok { |
| user.Name = strings.ToUpper(user.Name) |
| user.Age = user.Age + 10 |
| } |
| return result |
| } |
| |
| func GetMyCustomFilter() filter.Filter { |
| return &myCustomFilter{} |
| } |
| |
| var ( |
| myFilterOnce sync.Once |
| myFilter *myCustomFilter |
| ) |
| |
| /** |
| * In most cases, the filter would be designed as singleton. |
| */ |
| func GetMyCustomFilterSingleton() filter.Filter { |
| myFilterOnce.Do(func() { |
| myFilter = &myCustomFilter{} |
| }) |
| return myFilter |
| } |