Scala中使用fastJson 解析json字符串

添加依赖

 
        
            com.alibaba
            fastjson
            1.2.36
        

2.解析json字符

2.1可以通过JSON中的parseObject方法，把json字符转转换为一个JSONObject对象

 val jsonOBJ :JSONObject  = JSON.parseObject(json串)

2.2然后可调用JSONObject中的方法，根据key获取值

//获取这种类型的 {"dataId":123,"dataType":"redis"}可以使用getString
val getStr : String = jsonOBJ.getString("dataId")

2.3对于JSON中的套JSON字符串的可以使用

{
	"dataId":123,
	"dataType":"mysql",
	"resultData":[
				  {"binlog":"mysql_binlog.000","column":[{"name":"single","type":"int(5)"},{"name":"single3","type":"int(5)"} ]},
				  {"binlog1":"redis_binlog.000","column":[{"name":"single3","type":"int(5)"},{"name":"single3","type":"int(5)"} ]},
			     ]
}

//解析稍微复杂类型的可以使用，上面实际上是一条json，为了更好的看清结构所以换了个行

val  result : JSONArray=   jsonOBJ.getJSONArray("resultData")
//获取result中的 的数组的对应的第一个JSONObject
val nObject: JSONObject = result.getJSONObject(0)
//或取里面的value值
val str = nObject.getString("binlog")
//里面的column对应的还是一个数组类型的当然还可以使用getJSONArray
val column  : JSONArray   = nObject.getJSONArray("column")
//可以通过上面的getString 方法获取每一个字段

2.4如果想要遍历JSONArray中的所有数据，想不使用getJSONObject方法，但是想要这里面的遍历的所有的JSONObject可以使用

      import scala.collection.JavaConversions._  
      //可以把Java中的集合转成Scala中的集合
      //先把JSONArray转换成迭代器Iterator[AnyRef]类型，再转换为List
      转换为List时需要导入 上面的包
      
      val list: List[AnyRef] = result.iterator().toList
      
      val listOBJ: List[JSONObject] = list.map(m=> 
      JSON.parseObject(m.toString)
      /*或者使用m.asInstanceOf[JSONObject]*/
      )
      然后可以使用for循环或者foreach尽心循环

3.实例

json字符串：

{"dataId":123,"dataType":"redis","resultData":
[{"binlog":"mysql_binlog.000","column":[{"columnname":"single_cloum0","columntype":"varchar(10)","index":0,"modified":false,"pk":false,"sqlType":0,"value":"7"},
{"columnname":"single_cloum1","columntype":"varchar(10)","index":1,"modified":false,"pk":false,"sqlType":0,"value":"7"},
{"columnname":"single_cloum2","columntype":"int(5)","index":2,"modified":false,"pk":false,"sqlType":0,"value":"7"},
{"columnname":"single_cloum3","columntype":"int(5)","index":3,"modified":false,"pk":false,"sqlType":0,"value":"7"}],
"db":"demo","eventType":"insert","pkValue":"7","sql":"woshisql","table":"student","time":80146942099474},
{"binlog":"mysql_binlog.001","column":[{"columnname":"single_cloum0","columntype":"varchar(10)","index":0,"modified":false,"pk":false,"sqlType":0,"value":"9"},
{"columnname":"single_cloum1","columntype":"varchar(10)","index":1,"modified":false,"pk":false,"sqlType":0,"value":"9"},
{"columnname":"single_cloum2","columntype":"int(5)","index":2,"modified":false,"pk":false,"sqlType":0,"value":"9"},
{"columnname":"single_cloum3","columntype":"int(5)","index":3,"modified":false,"pk":false,"sqlType":0,"value":"9"}],
"db":"demo","eventType":"insert","pkValue":"9","sql":"woshisql","table":"student","time":80146943574276},]}

解析这一条Json字符串：

import com.alibaba.fastjson.{JSON, JSONArray, JSONObject}

import scala.collection.immutable
import scala.io.Source

object JsonDemo02 {
  def main(args: Array[String]): Unit = {

    val lines: Iterator[String] = Source.fromFile("D:\\json2.txt").getLines()
    val list: List[String] = lines.toList
    val jSONObjects: immutable.Seq[JSONObject] = list.map(x => {  //取出每一条数据，把数据转换成JSONObject类型
      println(x)
      JSON.parseObject(x)
    })
    jSONObjects.foreach(t=>{
      val str: String = t.getString("resultData")  //取出resultData的数据，
      val oNArray: JSONArray = t.getJSONArray("resultData")
      //result对应的数据是一个 数组中 存的是 [{json字符串},{json字符串}]

      // /想要遍历JSONArray中的数据可以使用
      import scala.collection.JavaConversions._  //可以把Java中的集合转成Scala中的集合
      val list: List[AnyRef] = oNArray.iterator().toList
      val listOBJ: List[JSONObject] = list.map(m=> JSON.parseObject(m.toString)/*或者使用m.asInstanceOf[JSONObject]*/)

      val str1 = oNArray.getString(0)
      //也可以通过getJSONObject(下标)  获取相应的JSONObject
      val nObject: JSONObject = oNArray.getJSONObject(1)
      //获取column
      val value = nObject.getString("column")
      val array = nObject.getJSONArray("column")
      println(str1)
      println(value)
      println(array.getString(0))
      val on1 = array.getJSONObject(0)
      val str3 = on1.getString("modified")
      println(str3)
    })
  }
}