add flatMap()

ryanlr · ryanlr · commit 5d1986286992 · 2014-11-10T15:05:18.000-05:00
diff --git a/src/com/programcreek/java8/stream/Java8FlatMap.java b/src/com/programcreek/java8/stream/Java8FlatMap.java
@@ -0,0 +1,88 @@
+package com.programcreek.java8.stream;
+
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.stream.Stream;
+
+
+public class Java8FlatMap {
+
+	public static void main(String[] args) {
+		ArrayList<Order> orders = new ArrayList<Order>();
+		Stream<Item> itemStream = orders.stream().flatMap(order -> order.getItems().stream());
+		
+	}
+	
+	public static Stream<Character> convertToCharStream(String s){
+		ArrayList<Character> list = new ArrayList<Character>();
+		for(char c: s.toCharArray()){
+			list.add(c);
+		}
+		return list.stream();
+	}
+	
+	public static void test() throws IOException{
+		Path path = Paths.get(null);
+		Stream<String> lines = Files.lines(path, StandardCharsets.UTF_8);
+	    Stream<String> words = lines.flatMap(line -> Stream.of(line.split(" +")));
+	}
+}
+
+class Order{
+	String orderId;
+	ArrayList<Item> items = new ArrayList<Item>();
+	
+	public Order(String orderId, ArrayList<Item> orderItems) {
+		super();
+		this.orderId = orderId;
+		this.items = orderItems;
+	} 
+	
+	public String getOrderId() {
+		return orderId;
+	}
+	
+	public void setOrderId(String orderId) {
+		this.orderId = orderId;
+	}
+	
+	public ArrayList<Item> getItems() {
+		return items;
+	}
+	
+	public void setItems(ArrayList<Item> orderItems) {
+		this.items = orderItems;
+	}
+}
+
+class Item{
+	String itemId;
+	String itemName;
+	
+	public Item(String itemId, String itemName) {
+		super();
+		this.itemId = itemId;
+		this.itemName = itemName;
+	}
+	
+	public String getItemId() {
+		return itemId;
+	}
+	
+	public void setItemId(String itemId) {
+		this.itemId = itemId;
+	}
+	
+	public String getItemName() {
+		return itemName;
+	}
+	
+	public void setItemName(String itemName) {
+		this.itemName = itemName;
+	}
+}
diff --git a/src/com/programcreek/java8/stream/Java8WhatIsStream.java b/src/com/programcreek/java8/stream/Java8WhatIsStream.java
@@ -1,5 +1,8 @@
 package com.programcreek.java8.stream;
 
+import java.util.ArrayList;
+import java.util.List;
+
 public class Java8WhatIsStream {
 
 	public static void main(String[] args) {
@@ -9,8 +12,20 @@ public static void main(String[] args) {
 		// operations. The following example illustrates an aggregate operation
 		// using Stream and IntStream:
 
-		//int sum = widgets.stream().filter(w -> w.getColor() == RED)
-		//		.mapToInt(w -> w.getWeight()).sum();
+		// int sum = widgets.stream().filter(w -> w.getColor() == RED)
+		// .mapToInt(w -> w.getWeight()).sum();
+
+		List<String> list = new ArrayList<String>();
+		list.add("java");
+		list.add("php");
+		list.add("python");
+
+		list.stream()
+				.filter(s -> s.length() > 2)
+				.map(String::toUpperCase)
+				.sorted()
+				.forEach(System.out::println);
+
 	}
 
 }
