## Mix Bean
DI、IoC 容器，参考 spring bean 设计
DI, IoC container, reference spring bean
> 该库还有 php 版本：https://github.com/mix-php/bean
## Overview
一个创建对象以及处理对象依赖关系的库，该库可以实现统一管理依赖，全局对象管理，动态配置刷新等。
## Installation
- 安装
```
go get -u github.com/mix-go/bean
```
## Usage
- `ConstructorArgs` 构造器注入
```golang
var definitions = []bean.Definition{
{
Name: "foo",
Reflect: bean.NewReflect(NewHttpClient),
ConstructorArgs: bean.ConstructorArgs{
time.Duration(time.Second * 3),
},
},
}
// 必须返回指针类型
func NewHttpClient(timeout time.Duration) *http.Client {
return &http.Client{
Timeout: timeout,
}
}
context := bean.NewApplicationContext(definitions)
foo := context.Get("foo").(*http.Client) // 返回的都是指针类型
fmt.Println(fmt.Sprintf("%+v", foo))
```
- `Fields` 字段注入
```golang
var definitions = []bean.Definition{
{
Name: "foo",
Reflect: bean.NewReflect(http.Client{}),
Fields: bean.Fields{
"Timeout": time.Duration(time.Second * 3),
},
},
}
context := bean.NewApplicationContext(definitions)
foo := context.Get("foo").(*http.Client) // 返回的都是指针类型
fmt.Println(fmt.Sprintf("%+v", foo))
```
- `ConstructorArgs + Fields` 混合使用
```golang
var definitions = []bean.Definition{
{
Name: "foo",
Reflect: bean.NewReflect(NewHttpClient),
ConstructorArgs: bean.ConstructorArgs{
time.Duration(time.Second * 3),
},
Fields: bean.Fields{
"Timeout": time.Duration(time.Second * 2),
},
},
}
// 必须返回指针类型
func NewHttpClient(timeout time.Duration) *http.Client {
return &http.Client{
Timeout: timeout,
}
}
context := bean.NewApplicationContext(definitions)
foo := context.Get("foo").(*http.Client) // 返回的都是指针类型
fmt.Println(fmt.Sprintf("%+v", foo))
```
- `NewReference` 引用
引用其他依赖注入
```golang
type Foo struct {
Client *http.Client // 引用注入的都是指针类型
}
var definitions = []bean.Definition{
{
Name: "foo",
Reflect: bean.NewReflect(Foo{}),
},
Fields: bean.Fields{
"Client": NewReference("bar"),
},
},
{
Name: "bar",
Reflect: bean.NewReflect(http.Client{}),
Fields: bean.Fields{
"Timeout": time.Duration(time.Second * 3),
},
},
}
context := bean.NewApplicationContext(definitions)
foo := context.Get("foo").(*Foo) // 返回的都是指针类型
cli := foo.Client
fmt.Println(fmt.Sprintf("%+v", cli))
```
- `Scope: SINGLETON` 单例
定义组件为全局单例
```golang
var definitions = []bean.Definition{
{
Name: "foo",
Scope: bean.SINGLETON, // 这里定义了单例模式
Reflect: bean.NewReflect(http.Client{}),
Fields: bean.Fields{
"Timeout": time.Duration(time.Second * 3),
},
},
}
context := bean.NewApplicationContext(definitions)
foo := context.Get("foo").(*http.Client) // 返回的都是指针类型
fmt.Println(fmt.Sprintf("%+v", foo))
```
- `InitMethod` 初始化方法
对象创建完成并且 `ConstructorArgs + Fields` 两种注入全部完成后执行该方法，用来初始化处理。
```golang
type Foo struct {
Bar string
}
func (c *Foo) Init() {
c.Bar = "bar ..."
fmt.Println("init")
}
var definitions = []bean.Definition{
{
Name: "foo",
InitMethod: "Init", // 这里定义了初始化方法
Reflect: bean.NewReflect(Foo{}),
Fields: bean.Fields{
"Bar": "bar",
},
},
}
context := bean.NewApplicationContext(definitions)
foo := context.Get("foo").(*Foo) // 返回的都是指针类型
fmt.Println(fmt.Sprintf("%+v", foo))
```
- `Refresh` 动态刷新配置
这个通常用于通过微服务配置中心实现动态刷新微服务配置的功能。
```golang
type Foo struct {
Bar string
}
var definitions = []bean.Definition{
{
Name: "foo",
Reflect: bean.NewReflect(Foo{}),
Fields: bean.Fields{
"Bar": "bar",
},
},
}
context := bean.NewApplicationContext(definitions)
// 第一次获取
foo := context.Get("foo").(*Foo)
fmt.Println(fmt.Sprintf("%+v", foo))
// 修改配置
bd := context.GetBeanDefinition("foo")
bd.Fields["Bar"] = "bar2"
bd.Refresh()
// 第二次获取就是新的配置
foo := context.Get("foo").(*Foo)
fmt.Println(fmt.Sprintf("%+v", foo))
```
## License
Apache License Version 2.0, http://www.apache.org/licenses/
