java8
diff --git a/‎src/main/java/lambdasinaction/chap2/FilteringApples.java‎
Lines changed: 148 additions & 132 deletions b/‎src/main/java/lambdasinaction/chap2/FilteringApples.java‎
Lines changed: 148 additions & 132 deletions
diff --git a/‎src/main/java/lambdasinaction/chap2/MeaningOfThis.java‎
Lines changed: 20 additions & 20 deletions b/‎src/main/java/lambdasinaction/chap2/MeaningOfThis.java‎
Lines changed: 20 additions & 20 deletions
diff --git a/‎src/main/java/lambdasinaction/chap3/ExecuteAround.java‎
Lines changed: 16 additions & 18 deletions b/‎src/main/java/lambdasinaction/chap3/ExecuteAround.java‎
Lines changed: 16 additions & 18 deletions
@@ -1,136 +1,152 @@
 package lambdasinaction.chap2;
 
+// function interface make simple
+
 import java.util.*;
 
-public class FilteringApples{
-
-	public static void main(String ... args){
-
-		List<Apple> inventory = Arrays.asList(new Apple(80,"green"), new Apple(155, "green"), new Apple(120, "red"));	
-
-		// [Apple{color='green', weight=80}, Apple{color='green', weight=155}]
-		List<Apple> greenApples = filterApplesByColor(inventory, "green");
-		System.out.println(greenApples);
-
-		// [Apple{color='red', weight=120}]
-		List<Apple> redApples = filterApplesByColor(inventory, "red");
-		System.out.println(redApples);
-
-		// [Apple{color='green', weight=80}, Apple{color='green', weight=155}]
-		List<Apple> greenApples2 = filter(inventory, new AppleColorPredicate());
-		System.out.println(greenApples2);
-
-		// [Apple{color='green', weight=155}]
-		List<Apple> heavyApples = filter(inventory, new AppleWeightPredicate());
-		System.out.println(heavyApples);
-
-		// []
-		List<Apple> redAndHeavyApples = filter(inventory, new AppleRedAndHeavyPredicate());
-		System.out.println(redAndHeavyApples);
-
-		// [Apple{color='red', weight=120}]
-		List<Apple> redApples2 = filter(inventory, new ApplePredicate() {
-			public boolean test(Apple a){
-				return a.getColor().equals("red"); 
-			}
-		});
-		System.out.println(redApples2);
-
-	}
-
-	public static List<Apple> filterGreenApples(List<Apple> inventory){
-		List<Apple> result = new ArrayList<>();
-		for(Apple apple: inventory){
-			if("green".equals(apple.getColor())){
-				result.add(apple);
-			}
-		}
-		return result;
-	}
-
-	public static List<Apple> filterApplesByColor(List<Apple> inventory, String color){
-		List<Apple> result = new ArrayList<>();
-		for(Apple apple: inventory){
-			if(apple.getColor().equals(color)){
-				result.add(apple);
-			}
-		}
-		return result;
-	}
-
-	public static List<Apple> filterApplesByWeight(List<Apple> inventory, int weight){
-		List<Apple> result = new ArrayList<>();
-		for(Apple apple: inventory){
-			if(apple.getWeight() > weight){
-				result.add(apple);
-			}
-		}
-		return result;
-	}
-
-
-	public static List<Apple> filter(List<Apple> inventory, ApplePredicate p){
-		List<Apple> result = new ArrayList<>();
-		for(Apple apple : inventory){
-			if(p.test(apple)){
-				result.add(apple);
-			}
-		}
-		return result;
-	}       
-
-	public static class Apple {
-		private int weight = 0;
-		private String color = "";
-
-		public Apple(int weight, String color){
-			this.weight = weight;
-			this.color = color;
-		}
-
-		public Integer getWeight() {
-			return weight;
-		}
-
-		public void setWeight(Integer weight) {
-			this.weight = weight;
-		}
-
-		public String getColor() {
-			return color;
-		}
-
-		public void setColor(String color) {
-			this.color = color;
-		}
-
-		public String toString() {
-			return "Apple{" +
-					"color='" + color + '\'' +
-					", weight=" + weight +
-					'}';
-		}
-	}
-
-	interface ApplePredicate{
-		public boolean test(Apple a);
-	}
-
-	static class AppleWeightPredicate implements ApplePredicate{
-		public boolean test(Apple apple){
-			return apple.getWeight() > 150; 
-		}
-	}
-	static class AppleColorPredicate implements ApplePredicate{
-		public boolean test(Apple apple){
-			return "green".equals(apple.getColor());
-		}
-	}
-
-	static class AppleRedAndHeavyPredicate implements ApplePredicate{
-		public boolean test(Apple apple){
-			return "red".equals(apple.getColor()) 
-					&& apple.getWeight() > 150; 
-		}
-	}
-}
+public class FilteringApples {
+
+    public static void main(String... args) {
+
+        List<Apple> inventory = Arrays.asList(
+                new Apple(80, "green"),
+                new Apple(155, "green"),
+                new Apple(120, "red"));
+
+        List<Apple> greenApples = filterApplesByColor(inventory, "green");
+        System.out.println(greenApples);
+
+        List<Apple> redApples = filterApplesByColor(inventory, "red");
+        System.out.println(redApples);
+
+        List<Apple> greenApples2 = filter(inventory, new AppleColorPredicate());
+        System.out.println(greenApples2);
+
+        List<Apple> heavyApples = filter(inventory, new AppleWeightPredicate());
+        System.out.println(heavyApples);
+
+        List<Apple> redAndHeavyApples = filter(inventory, new AppleRedAndHeavyPredicate());
+        System.out.println(redAndHeavyApples);
+
+        // inner class
+        List<Apple> redApples2 = filter(inventory, new ApplePredicate() {
+            public boolean test(Apple a) {
+                return a.getColor().equals("red");
+            }
+        });
+
+        // if interface only have one method
+        // not inner class, but pass lambda express
+        List<Apple> redApples3 = filter(inventory, (a) -> a.getColor().equals("red"));
+
+        System.out.println(redApples3);
+    }
+
+    // traditional way
+    public static List<Apple> filterGreenApples(List<Apple> inventory) {
+        List<Apple> result = new ArrayList<>();
+        for (Apple apple : inventory) {
+            if ("green".equals(apple.getColor())) {
+                result.add(apple);
+            }
+        }
+        return result;
+    }
+
+    // traditional way
+    public static List<Apple> filterApplesByColor(List<Apple> inventory, String color) {
+        List<Apple> result = new ArrayList<>();
+        for (Apple apple : inventory) {
+            if (apple.getColor().equals(color)) {
+                result.add(apple);
+            }
+        }
+        return result;
+    }
+
+    // traditional way
+    public static List<Apple> filterApplesByWeight(List<Apple> inventory, int weight) {
+        List<Apple> result = new ArrayList<>();
+        for (Apple apple : inventory) {
+            if (apple.getWeight() > weight) {
+                result.add(apple);
+            }
+        }
+        return result;
+    }
+
+
+    // function interface ApplePredicate as method parameter
+    public static List<Apple> filter(List<Apple> inventory, ApplePredicate p) {
+        List<Apple> result = new ArrayList<>();
+        for (Apple apple : inventory) {
+            if (p.test(apple)) {
+                result.add(apple);
+            }
+        }
+        return result;
+    }
+
+    public static class Apple {
+        private int weight;
+        private String color;
+
+        public Apple(int weight, String color) {
+            this.weight = weight;
+            this.color = color;
+        }
+
+        public Integer getWeight() {
+            return weight;
+        }
+
+        public void setWeight(Integer weight) {
+            this.weight = weight;
+        }
+
+        public String getColor() {
+            return color;
+        }
+
+        public void setColor(String color) {
+            this.color = color;
+        }
+
+        public String toString() {
+            return "Apple{" + "color='" + color + '\'' + ", weight=" + weight + '}';
+        }
+    }
+
+    // customize function interface ApplePredicate
+    interface ApplePredicate {
+        public boolean test(Apple a);
+    }
+
+    //
+    static class AppleWeightPredicate implements ApplePredicate {
+        public boolean test(Apple apple) {
+            return apple.getWeight() > 150;
+        }
+    }
+
+    static class AppleColorPredicate implements ApplePredicate {
+        public boolean test(Apple apple) {
+            return "green".equals(apple.getColor());
+        }
+    }
+
+    static class AppleRedAndHeavyPredicate implements ApplePredicate {
+        public boolean test(Apple apple) {
+            return "red".equals(apple.getColor())
+                    && apple.getWeight() > 150;
+        }
+    }
+}
+/* output:
+[Apple{color='green', weight=80}, Apple{color='green', weight=155}]
+[Apple{color='red', weight=120}]
+[Apple{color='green', weight=80}, Apple{color='green', weight=155}]
+[Apple{color='green', weight=155}]
+[]
+[Apple{color='red', weight=120}]
+ */
@@ -1,23 +1,23 @@
 package lambdasinaction.chap2;
 
-public class MeaningOfThis
-{
-	public final int value = 4;
-	public void doIt()
-	{
-		int value = 6;
-		Runnable r = new Runnable(){
-			public final int value = 5;
-			public void run(){
-				int value = 10;
-				System.out.println(this.value);
-			}
-		};
-		r.run(); 
-	}
-	public static void main(String...args)
-	{       
-		MeaningOfThis m = new MeaningOfThis();
-		m.doIt(); // ???   
-	}
+public class MeaningOfThis {
+    public final int value = 4;
+
+    public void doIt() {
+        int value = 6;
+        Runnable r = new Runnable() {
+            public final int value = 5;
+
+            public void run() {
+                int value = 10;
+                System.out.println(this.value);
+            }
+        };
+        r.run();
+    }
+
+    public static void main(String... args) {
+        MeaningOfThis m = new MeaningOfThis();
+        m.doIt(); // ???
+    }
 }
@@ -1,41 +1,39 @@
 package lambdasinaction.chap3;
 
 import java.io.*;
+
 public class ExecuteAround {
 
-	public static void main(String ...args) throws IOException{
+    public static void main(String... args) throws IOException {
 
         // method we want to refactor to make more flexible
         String result = processFileLimited();
         System.out.println(result);
 
         System.out.println("---");
 
-		String oneLine = processFile((BufferedReader b) -> b.readLine());
-		System.out.println(oneLine);
+        String oneLine = processFile((BufferedReader b) -> b.readLine());
+        System.out.println(oneLine);
 
-		String twoLines = processFile((BufferedReader b) -> b.readLine() + b.readLine());
-		System.out.println(twoLines);
+        String twoLines = processFile((BufferedReader b) -> b.readLine() + b.readLine());
+        System.out.println(twoLines);
 
-	}
+    }
 
     public static String processFileLimited() throws IOException {
-        try (BufferedReader br =
-                     new BufferedReader(new FileReader("lambdasinaction/chap3/data.txt"))) {
+        try (BufferedReader br = new BufferedReader(new FileReader("lambdasinaction/chap3/data.txt"))) {
             return br.readLine();
         }
     }
 
 
-	public static String processFile(BufferedReaderProcessor p) throws IOException {
-		try(BufferedReader br = new BufferedReader(new FileReader("lambdasinaction/chap3/data.txt"))){
-			return p.process(br);
-		}
-
-	}
-
-	public interface BufferedReaderProcessor{
-		public String process(BufferedReader b) throws IOException;
+    public static String processFile(BufferedReaderProcessor p) throws IOException {
+        try (BufferedReader br = new BufferedReader(new FileReader("lambdasinaction/chap3/data.txt"))) {
+            return p.process(br);
+        }
+    }
 
-	}
+    public interface BufferedReaderProcessor {
+        String process(BufferedReader b) throws IOException;
+    }
 }