add readme

Author: zhangblue

README.md

@@ -0,0 +1,72 @@
+# Flink Demo
+
+## 1. Word Count
+### 1.1 批处理
+```scala
+package com.zhangblue.wc
+
+import org.apache.flink.api.scala._
+
+//批处理word count
+object WordCount {
+
+  def main(args: Array[String]): Unit = {
+    //创建一个批处理的执行环境
+    val env = ExecutionEnvironment.getExecutionEnvironment
+   //从文件中读取数据
+    val inputPath = "D:\\software\\workspace\\FlinkTutorial\\src\\main\\resources\\hello.txt"
+    val inputDataSet = env.readTextFile(inputPath)
+
+    //分词之后做count
+   val wordCountDataSet = inputDataSet.flatMap(_.split(" "))
+     .map((_,1))
+     .groupBy(0)
+     .sum(1)
+
+    //打印输出
+    wordCountDataSet.print()
+  }
+}
+```
+
+### 1.2 流式处理
+```scala
+package com.zhangblue.wc
+
+import org.apache.flink.api.java.utils.ParameterTool
+import org.apache.flink.streaming.api.scala._
+
+/**
+ * 流式处理word count
+ */
+object StreamWordCount {
+
+  def main(args: Array[String]): Unit = {
+
+    //通过参数进行传递. 参数传递方式：--host localhost --port 7777
+    val parameter = ParameterTool.fromArgs(args)
+    val host:String  = parameter.get("host")
+    val port:Int = parameter.getInt("port")
+
+
+    //创建一个流处理的执行环境
+    val env = StreamExecutionEnvironment.getExecutionEnvironment
+
+    //接收socket数据流
+    val testDataStream = env.socketTextStream(host,port)
+
+    //逐一读取数据
+   val wordCountDataStream = testDataStream.flatMap(_.split(" "))
+     .filter(_.nonEmpty)
+     .map((_,1))
+     .keyBy(0)
+     .sum(1)
+
+    //打印输出
+    wordCountDataStream.print()
+
+    //执行任务
+    env.execute("Stream WordCount Example")
+  }
+}
+```