Retrofit 找不到ScalarsConverterFactory

刚开始学Retrofit的时候，就不去用复杂的Converter了。想先用下基本款String的Converter：ScalarsConverterFactory。于是敲下一下代码：

	Retrofit retrofit = new Retrofit.Builder()
		    .baseUrl(MyConstant.baseUrl)
		    .addConverterFactory(ScalarsConverterFactory.create())
		    .build();

结果发现找不到ScalarsConverterFactory这个类，明明已经引入了retrofit的包。回去看官方文档，发现有这么一段话：

Converters can be added to support other types. Six sibling modules adapt popular serialization libraries for your convenience.

Gson: com.squareup.retrofit2:converter-gson
Jackson: com.squareup.retrofit2:converter-jackson
Moshi: com.squareup.retrofit2:converter-moshi
Protobuf: com.squareup.retrofit2:converter-protobuf
Wire: com.squareup.retrofit2:converter-wire
Simple XML: com.squareup.retrofit2:converter-simplexml
Scalars (primitives, boxed, and String): com.squareup.retrofit2:converter-scalars

好家伙，原来Converter居然是独立包引入的，还有这种操作。去Maven repository搜一下converter-scalars，把依赖加上。

		<!-- Converter的依赖 -->
		<dependency>
		    <groupId>com.squareup.retrofit2</groupId>
		    <artifactId>converter-scalars</artifactId>
		    <version>2.3.0</version>
		</dependency>

问题解决。