Spark的DSL常用操作
有一份数据：
user.json
{"username":"zhangsan","age":3}
{"username":"lisi","age":7}
{"username":"wangwu","age":2}
现在需要用dsl求年龄的平均值
结果；
有一份数据：
user.json
{"username":"zhangsan","age":3}
{"username":"lisi","age":7}
{"username":"wangwu","age":2}
现在需要用dsl求年龄的平均值
结果；