Code for Optional stream filtering document (#696)

* Add new module for mocks comparison. * Add sources for testing. * Changes on testCase. * Enter some tests for mockito. * More tests for Mockito. * Even more tests. * Add the rest of the mocking libraries. * Javadoc on test. * Test bare bones for EasyMock. * Fist kind of test and setup. * Add tests using EasyMock with a change on LoginService. * Create LoginControllerTest.java * Test setup * [JMockit] No method called test. * [JMockit] Two methods called test. * [JMockit] One method called test. * [JMockit] Exception mock test * [JMockit] Mocked object to pass around test. * [JMockit] Custom matcher test. * [JMockit] Partial mocking test. * [JMockit] Fix with IDE. * Not stubs. Mocks. MOCKS!!! * Remove unnecesary import. * Use correct encoding. Was having problems with buildings. * Remove failing module. * Create new module mocks and move mock-comparisons there. * Add jmockit module. * Add model class. * Add collaborator class. * Add performer class. * Add performer test. * Fix * Add interface for tests. * Test for any. * Test for with. * Test for null. * Test for times. * Test for arg that. * Test for result and returns. * Test for delegate. * Add verifications to any tests. * Add verifications to with test. * Add verification examples to methods using null. * Add verifications to methods using times. * Formatting. * Compress tests and fix one test. * Adding new article to readme. * [BAEL-178] Add collaborator for advanced article. * [BAEL-178] Add link to readme. * [BAEL-178] Add test for mockUp. * [BAEL-178] Add test for invoke method. * [BAEL-178] Add constructors and tests for mockup for constructors. * [BAEL-178] Add private fields and more test for deencapsulation. * [BAEL-178] Add inner class and test for instantiating inner classes. * [BAEL-178] Multimocks. * [BAEL-178] Add test for expectation reusing. * [BAEL-178] Move test class to tests folders. * Add postgresql dependency. * Add test and config with properties. * [BAEL-114] Add new project for JPA with JNDI. * [BAEL-114] Config without xml. * [BAEL-114] Bring part of Foo, FooServie and FooDao. * [BAEL-114] Show all foos. * [BAEL-114] Readme. * [BAEL-114] Undo changes on main jpa project. * [BAEL-114] Remove unnecesary dependencies. * [BAEL-114] Add tomcat config. * [BAEL-114] Fixes. * Add tests for Optional streams. * Add Java 9 version of the test. * Rename and move to new core-java-9 module.
2016-09-23 14:25:09 +02:00 · 2016-09-23 14:25:09 +02:00 · 043a6bddc8
commit 043a6bddc8
parent eaa04c6c7f
1 changed files with 63 additions and 0 deletions
--- a/core-java-9/src/test/java/com/baeldung/java9/Java9OptionalsStreamTest.java
+++ b/core-java-9/src/test/java/com/baeldung/java9/Java9OptionalsStreamTest.java
@ -0,0 +1,63 @@
+package com.baeldung.java8;
+
+import static org.junit.Assert.assertEquals;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.Optional;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+import org.junit.Before;
+import org.junit.Test;
+
+public class Java9OptionalsStreamTest {
+
+    private List<Optional<String>> listOfOptionals;
+
+    @Before
+    public void populateStream() {
+        listOfOptionals = Arrays.asList(Optional.empty(), Optional.of("foo"), Optional.empty(), Optional.of("bar"));
+    }
+    
+    @Test
+    public void filterOutPresentOptionalsWithFilter() {
+        assertEquals(4, listOfOptionals.size());
+        //@format:off
+        List<String> filteredList = listOfOptionals.stream()
+                .filter(Optional::isPresent)
+                .map(Optional::get)
+                .collect(Collectors.toList());
+        //@format:on
+        assertEquals(2, filteredList.size());
+        assertEquals("foo", filteredList.get(0));
+        assertEquals("bar", filteredList.get(1));
+    }
+    
+    @Test
+    public void filterOutPresentOptionalsWithFlatMap() {
+        assertEquals(4, listOfOptionals.size());
+        //@format:off
+        List<String> filteredList = listOfOptionals.stream()
+                .flatMap(o -> o.isPresent() ? Stream.of(o.get()) : Stream.empty())
+                .collect(Collectors.toList());
+        //@format:on
+        assertEquals(2, filteredList.size());
+        assertEquals("foo", filteredList.get(0));
+        assertEquals("bar", filteredList.get(1));
+    }
+
+    @Test
+    public void filterOutPresentOptionalsWithJava9() {
+        assertEquals(4, listOfOptionals.size());
+        //@format:off
+        List<String> filteredList = listOfOptionals.stream()
+                .flatMap(Optional::stream)
+                .collect(Collectors.toList());
+        //@format:on
+        assertEquals(2, filteredList.size());
+        assertEquals("foo", filteredList.get(0));
+        assertEquals("bar", filteredList.get(1));
+    }
+
+}