Moshi 之HashMap

就是这个错 moshi让你写自定义Adapter呢，

报错摘要：

No JsonAdapter for class java.util.HashMap, you should probably use Map instead of HashMap (Moshi only supports the collection interfaces by default) or else register a custom JsonAdapter.
 

解决方法

自定义 HashMap Adapter代码如下

class HashMapJsonAdapter<K, V>(moshi: Moshi, keyType: Type?, valueType: Type?) :

    JsonAdapter<HashMap<K?, V?>?>() {
private val keyAdapter: JsonAdapter<K>
private val valueAdapter: JsonAdapter<V>

@Throws(IOException::class)
override fun toJson(writer: JsonWriter, value: HashMap<K?, V?>?) {

        writer.beginObject()
for (entry: Map.Entry<K?, V?> in value!!.entries) {
if (entry.key == null) {
throw JsonDataException("Map key is null at " + writer.path)

            }

            writer.promoteValueToName()

            keyAdapter.toJson(writer, entry.key)

            valueAdapter.toJson(writer, entry.value)

        }

        writer.endObject()

    }

@Throws(IOException::class)
override fun fromJson(reader: JsonReader): HashMap<K?, V?> {
val result = HashMap<K?, V?>()

        reader.beginObject()
while (reader.hasNext()) {

            reader.promoteNameToValue()
val name = keyAdapter.fromJson(reader)
val value = valueAdapter.fromJson(reader)
val replaced = result.put(name, value)
if (replaced != null) {
throw JsonDataException(
"Map key '"

                            + name

                            + "' has multiple values at path "

                            + reader.path

                            + ": "

                            + replaced

                            + " and "

                            + value

                )

            }

        }

        reader.endObject()
return result

    }

override fun toString(): String {
return "JsonAdapter($keyAdapter=$valueAdapter)"

    }

companion object {
val FACTORY: Factory =

            Factory { type, annotations, moshi ->
val rawType = Types.getRawType(type)
if (annotations.isNotEmpty()) return@Factory null
if (rawType != java.util.HashMap::class.java) return@Factory null
val keyAndValue = if (type === java.util.Properties::class.java) arrayOf<Type>(

                    String::class.java,

                    String::class.java

                ) else {

                    arrayOf<Type>(Any::class.java, Any::class.java)

                }

                HashMapJsonAdapter<Any?, Any>(

                    moshi,

                    keyAndValue[0],

                    keyAndValue[1]

                ).nullSafe()

            }

    }

init {

        keyAdapter = moshi.adapter(keyType)

        valueAdapter = moshi.adapter(valueType)

    }

}
 

其实完全就是在抄Moshi的MapJsonAdapter 然后略微修改一下FACTORY。

如何使用

Moshi.Builder()

    .add(HashMapJsonAdapter.FACTORY)

    .build()
 

完美解决