创建以下两个类，手动对String类型的字段进行处理
//NullStringToEmptyAdapterFactory.java
public class NullStringToEmptyAdapterFactory implements TypeAdapterFactory {
public TypeAdapter create(Gson gson, TypeToken type) {
Class rawType = (Class) type.getRawType();
if (rawType != String.class) {
return null;
}
return (TypeAdapter) new StringNullAdapter();
}
}
//StringNullAdapter.java
public class StringNullAdapter extends TypeAdapter {
@Override
public String read(JsonReader reader) throws IOException {
if (reader.peek() == JsonToken.NULL) {
reader.nextNull();
return "";
}
return reader.nextString();
}
@Override
public void write(JsonWriter writer, String value) throws IOException {
if (value == null) {
writer.value("");
return;
}
writer.value(value);
}
}
使用方法：
/**
*这里生成Gson时注册自定义处理String NULL值的TypeAdapter
*/
Gson gson = new GsonBuilder()
.registerTypeAdapterFactory(new NullStringToEmptyAdapterFactory())
.setDateFormat("yyyy-MM-dd'T'HH:mm:ss")
.create();
这样就实现了解析null值String，引用没有判断报空指针的问题
