Kotlin使用Gson解析本地json数据

1.本地res文件夹下新建一个raw文件夹，json文件放进去。

1）java加载方式：

public class StreamUtils {
	
	public static String get(Context context, int id) {
		InputStream stream = context.getResources().openRawResource(id);
		return read(stream);
	}
	
	public static String read(InputStream stream) {
		return read(stream, "utf-8");
	}
	
	public static String read(InputStream is, String encode) {
        if (is != null) {
            try {
                BufferedReader reader = new BufferedReader(new InputStreamReader(is, encode));
                StringBuilder sb = new StringBuilder();
                String line = null;
                while ((line = reader.readLine()) != null) {
                    sb.append(line + "\n");
                }
                is.close();
                return sb.toString();
            } catch (UnsupportedEncodingException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return "";
    }
}

String data = StreamUtils.get(APP.getInstance(), R.raw.update);

2）Kotlin加载方式

class JsonReadUtils private constructor() {

    private object StreamUtilsInstance {
        val jsonReadUtils = JsonReadUtils()
    }

    companion object {
        fun getInstance(): JsonReadUtils {
            return StreamUtilsInstance.jsonReadUtils
        }
    }

    fun get(context: Context, id: Int): String {
        val stream = context.resources.openRawResource(id)
        return read(stream)
    }

    fun read(stream: InputStream): String {
        return read(stream, "utf-8")
    }

    fun read(inputStream: InputStream, encode: String): String {
        if (inputStream != null) {
            try {
                val reader = BufferedReader(InputStreamReader(inputStream, encode))
                var line = reader.readLine()
                var result = ""
                while (line != null) {
                    result += line
                    line = reader.readLine()
                }
                inputStream.close()
                return result
            } catch (e: UnsupportedEncodingException) {
                e.printStackTrace()
            } catch (e: IOException) {
                e.printStackTrace()
            }

        }
        return ""
    }
    
}

val data = JsonReadUtils.getInstance().get(context, R.raw.update)

2.Gson解析

1）解析Object对象：

val data = JsonReadUtils.getInstance().get(AppConfig.application!!, R.raw.update)
val bean: Bean = Gson().fromJson(data, Bean::class.java)

2）解析Array数组

方式一：

val data = JsonReadUtils.getInstance().get(AppConfig.application!!, R.raw.update)
val type = object : TypeToken<List<Bean>>(){}.type
val listBe: List<Bean> = Gson().fromJson(data, type)

方式二：

inline fun <reified T> genericType() = object: TypeToken<T>() {}.type
val turnsType = genericType<List<Turns>>()

如果解析的数组带有key值

class Test(val deviceInfo: DeviceInfo) {

}

序号	api	作用
1	toJson(Object)	序列化
2	fromJson(String, Class)	反序列化
3	JsonParser().parse(String)	解析字段

Kotlin中的Gson使用