Examples of Method Reference and Constructor Reference

core-java-8/src/test/java/com/baeldung/doublecolumn/TestComputerUtils.java

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+package com.baeldung.doublecolumn;
+
+import com.baeldung.doublecolumn.function.TriFunction;
+import org.junit.After;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.util.*;
+import java.util.function.BiFunction;
+
+import static com.baeldung.doublecolumn.ComputerUtils.*;
+
+public class TestComputerUtils {
+
+
+    @Before
+    public void setup (){
+    }
+
+    @After
+    public void tearDown(){
+    }
+
+    @Test
+    public void testFilter(){
+
+        Computer c1=new Computer(2015,"white");
+        Computer c2=new Computer(2009,"black");
+        Computer c3=new Computer(2014,"black");
+
+        BiFunction<Integer,String,Computer> c4Function=Computer::new;
+        Computer c4=c4Function.apply(2013,"white");
+        BiFunction<Integer,String,Computer> c5Function=Computer::new;
+        Computer c5=c5Function.apply(2010,"black");
+        BiFunction<Integer,String,Computer> c6Function=Computer::new;
+        Computer c6=c6Function.apply(2008,"black");
+
+        List<Computer> inventory = Arrays.asList(c1,c2,c3,c4,c5,c6);
+
+        List<Computer> blackComputer = filter(inventory, blackPredicate);
+        Assert.assertEquals("The black Computers are: ",blackComputer.size(),4);
+
+        List<Computer> after2010Computer = filter(inventory, after2010Predicate);
+        Assert.assertEquals("The Computer bought after 2010 are: ",after2010Computer.size(),3);
+
+        List<Computer> before2011Computer = filter(inventory, c -> c.getAge() < 2011);
+        Assert.assertEquals("The Computer bought before 2011 are: ",before2011Computer.size(),3);
+
+        inventory.sort(Comparator.comparing(Computer::getAge));
+
+        Assert.assertEquals("Oldest Computer in inventory", c6,inventory.get(0) );
+
+    }
+
+    @Test
+    public void testRepair() {
+
+        Computer c1 = new Computer(2015, "white", 35);
+        Computer c2 = new Computer(2009, "black", 65);
+        TriFunction<Integer, String, Integer, Computer> c6Function = Computer::new;
+        Computer c3 = c6Function.apply(2008, "black", 90);
+
+        List<Computer> inventory = Arrays.asList(c1, c2, c3);
+        inventory.forEach(ComputerUtils::repair);
+
+        Assert.assertEquals("Computer repaired", new Integer(100), c1.getHealty());
+    }
+
+}