Moshi的基本使用

谁借莪１个温暖的怀抱￠ 2023-07-09 02:07 2阅读 0赞

moshi是square出品的面向Java和Kotlin的JSON解析库，尤其适合基于Kotlin的Android开发。[https://github.com/square/moshi][https_github.com_square_moshi]

# gradle 引入 #

--------------------

compile 'com.squareup.moshi:moshi-kotlin:$latest_version'

# POJO定义 #

--------------------

## data class ##

data class User(val name:String,val detail:UserDetail)
    data class UserDetail(val age:Int, val job:String)

## creator ##

fun  createUser():User{ 
        return User("Jack",UserDetail(25,"Sales"));
    }
    
    fun createMultiUser(): List<User> { 
    
        return listOf<User>(User("Jack",UserDetail(25,"Sales")),
                User("Pony",UserDetail(30,"Marketing")),
                User("Robin",UserDetail(31,"Engineer")))
    }

# JSON解析 #

--------------------

## CLASS→JSON ##

val user = createUser()
    
    // CLASS -> JSON
    val moshi = Moshi.Builder().build()
    val adapter = moshi.adapter(User::class.java)
    val decodeJson = adapter.toJson(user)
    
    println("CLASS→JSON：${ decodeJson}")

通过Pojo类信息创建`adapter`，然后通过其`toJson`传入实际对象进行转换

output：
    --------
    CLASS→JSON：{"detail":{"age":25,"job":"Sales"},"name":"Jack"}

## JSON→CLASS ##

// JSON→CLASS
     val json = "{\"detail\":{\"age\":30,\"job\":\"Sales\"},\"name\":\"Ben\"}"
    
        val fromJson = adapter.fromJson(json)
        println("JSON→CLASS：${ fromJson}")

通过`adapter`的`fromJson`将JSON你转换为CLASS

output:
    --------
    JSON→CLASS：User(name=Ben, detail=UserDetail(age=30, job=Sales))

# LIST的JSON解析 #

--------------------

## LIST→JSON ##

val type = Types.newParameterizedType(List::class.java,User::class.java)
    val listAdapter:JsonAdapter<List<User>> = moshi.adapter(type)
    val multiUserJson = listAdapter.toJson(createMultiUser())
    
    println("LIST→JSON:${ multiUserJson}")

创建adapter时需要List中泛型信息，所以先通过`Types.newParameterizedType`创建参数化化类型的type，然后基于type创建adapter，最后再通过toJson进行转换

output:
    ---------
    LIST→JSON:[{"detail":{"age":25,"job":"Sales"},"name":"Jack"},{"detail":{"age":30,"job":"Marketing"},"name":"Pony"},{"detail":{"age":31,"job":"Engineer"},"name":"Robin"}]

## JSON→LIST ##

val file = File("src/main/resources/list_data.json")
        val fileContents = file.absoluteFile.bufferedReader().use {  it.readText() }
    
        val listObject = listAdapter.fromJson(fileContents);
        println("JSON→LIST:${ listObject}")

list\_data.json中的内容如下：

[
      { 
        "name": "Jack",
        "detail": { 
          "age": 25,
          "job": "Sales"
        }
      },
      { 
        "name": "Pony",
        "detail": { 
          "age": 31,
          "job": "Marketing"
        }
      },
      { 
        "name": "Robin",
        "detail": { 
          "age": 30,
          "job": "Engineer"
        }
      }
    ]

output:
    ---------
    JSON→LIST:[User(name=Jack, detail=UserDetail(age=25, job=Sales)), User(name=Pony, detail=UserDetail(age=31, job=Marketing)), User(name=Robin, detail=UserDetail(age=30, job=Engineer))]

[https_github.com_square_moshi]: https://github.com/square/moshi