For environmental preparation, please refer to: https://blog.51cto.com/mapengfei/2546985
Read data from the collection
Create a new package, com.mafei.apitest, create a new scala Object class,
package com.mafei.apitest
import org.apache.flink.api.scala.createTypeInformation
import org.apache.flink.streaming.api.scala.StreamExecutionEnvironment
//获取传感器数据
case class SensorReading(id: String,timestamp: Long, temperature: Double)
object SourceTest {
def main(args: Array[String]): Unit = {
//创建执行环境
val env = StreamExecutionEnvironment.getExecutionEnvironment
// 1、从集合中读取数据
val dataList = List(
SensorReading("sensor1",1603766281,41),
SensorReading("sensor2",1603766282,42),
SensorReading("sensor3",1603766283,43),
SensorReading("sensor4",1603766284,44)
)
val stream1 = env.fromCollection(dataList)
stream1.print()
//执行
env.execute(" source test")
}
}
代码目录图:
运行效果
SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
SLF4J: Defaulting to no-operation (NOP) logger implementation
SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.
2> SensorReading(sensor3,1603766283,43.0)
4> SensorReading(sensor1,1603766281,41.0)
3> SensorReading(sensor4,1603766284,44.0)
1> SensorReading(sensor2,1603766282,42.0)
Read data from file
Like the first step, create a new package, com.mafei.apitest, create a new scala Object class,
package com.mafei.apitest
import org.apache.flink.api.scala.createTypeInformation
import org.apache.flink.streaming.api.scala.StreamExecutionEnvironment
//获取传感器数据
case class SensorReading(id: String,timestamp: Long, temperature: Double)
object SourceTest {
def main(args: Array[String]): Unit = {
//创建执行环境
val env = StreamExecutionEnvironment.getExecutionEnvironment
//从文件中读取数据
val stream2= env.readTextFile("/opt/java2020_study/maven/flink1/src/main/resources/sensor.txt")
stream2.print()
//执行
env.execute(" source test")
}
}
Create a new sensor.txt in the resources directory and write the following content
sensor1,1603766281,41
sensor2,1603766282,42
sensor3,1603766283,43
sensor4,1603766284,44
Code structure diagram:
Code running effect:
1> sensor1,1603766281,41
1> sensor2,1603766282,42
2> sensor3,1603766283,43
3> sensor4,1603766284,44