Stream API: last Stream element example refactor (#1943)

* Refactor

* Delete ApplicationContextTestBeanInjectionTypes.java

* Delete BeanInjectionJavaConfigIntegrationTest.java

* Delete BeanInjectionXMLConfigIntegrationTest.java

core-java/src/main/java/com/baeldung/stream/StreamApi.java

@@ -5,17 +5,17 @@ import java.util.stream.Stream;
 
 public class StreamApi {
 
-    public String getLastElementUsingReduce(List<String> valueList) {
+    public static String getLastElementUsingReduce(List<String> valueList) {
         Stream<String> stream = valueList.stream();
         return stream.reduce((first, second) -> second).orElse(null);
     }
     
-    public Integer getInfiniteStreamLastElementUsingReduce() {
+    public static Integer getInfiniteStreamLastElementUsingReduce() {
         Stream<Integer> stream = Stream.iterate(0, i -> i + 1);
         return stream.limit(20).reduce((first, second) -> second).orElse(null);
     }
     
-    public String getLastElementUsingSkip(List<String> valueList) {
+    public static String getLastElementUsingSkip(List<String> valueList) {
         long count = valueList.stream().count();
         Stream<String> stream = valueList.stream();
         return stream.skip(count - 1).findFirst().orElse(null);

core-java/src/test/java/com/baeldung/stream/StreamApiTest.java

@@ -1,41 +1,40 @@
 package com.baeldung.stream;
 
-import static org.junit.Assert.assertEquals;
+import org.junit.Test;
 
 import java.util.ArrayList;
 import java.util.List;
 
-import org.junit.Test;
+import static org.junit.Assert.assertEquals;
 
 public class StreamApiTest {
-    private StreamApi streamApi = new StreamApi();
 
     @Test
     public void givenList_whenGetLastElementUsingReduce_thenReturnLastElement() {
-        List<String> valueList = new ArrayList<String>();
+        List<String> valueList = new ArrayList<>();
         valueList.add("Joe");
         valueList.add("John");
         valueList.add("Sean");
 
-        String last = streamApi.getLastElementUsingReduce(valueList);
+        String last = StreamApi.getLastElementUsingReduce(valueList);
 
         assertEquals("Sean", last);
     }
     
     @Test
     public void givenInfiniteStream_whenGetInfiniteStreamLastElementUsingReduce_thenReturnLastElement() {
-        Integer last = streamApi.getInfiniteStreamLastElementUsingReduce();
+        int last = StreamApi.getInfiniteStreamLastElementUsingReduce();
-        assertEquals(new Integer(19), last);
+        assertEquals(19, last);
     }
     
     @Test
     public void givenListAndCount_whenGetLastElementUsingSkip_thenReturnLastElement() {
-        List<String> valueList = new ArrayList<String>();
+        List<String> valueList = new ArrayList<>();
         valueList.add("Joe");
         valueList.add("John");
         valueList.add("Sean");
 
-        String last = streamApi.getLastElementUsingSkip(valueList);
+        String last = StreamApi.getLastElementUsingSkip(valueList);
 
         assertEquals("Sean", last);
     }

spring-core/src/main/java/com/baeldung/beaninjection/AnotherSampleDAOBean.java

@@ -1,17 +0,0 @@
-package com.baeldung.beaninjection;
-
-public class AnotherSampleDAOBean implements IAnotherSampleDAO {
-
-    private String propertyY;
-
-    public AnotherSampleDAOBean(String propertyY) {
-        this.propertyY = propertyY;
-    }
-
-    // standard setters and getters
-
-    public String getPropertyY() {
-        return propertyY;
-    }
-
-}

spring-core/src/main/java/com/baeldung/beaninjection/ExampleDAOBean.java

@@ -1,39 +0,0 @@
-package com.baeldung.beaninjection;
-
-import java.util.List;
-
-public class ExampleDAOBean implements IExampleDAO {
-
-    private String propertyX;
-
-    public ExampleDAOBean(String propertyX) {
-        this.propertyX = propertyX;
-    }
-
-    public String getPropertyX() {
-        return propertyX;
-    }
-
-    public void setPropertyX(String propertyX) {
-        this.propertyX = propertyX;
-    }
-
-    @Override
-    public List<SampleDomainObject> getDomainList() {
-        // TODO Auto-generated method stub
-        return null;
-    }
-
-    @Override
-    public SampleDomainObject createNewDomain(SampleDomainObject inputDomain) {
-        // TODO Auto-generated method stub
-        return null;
-    }
-
-    @Override
-    public SampleDomainObject getSomeDomain() {
-        // TODO Auto-generated method stub
-        return new SampleDomainObject();
-    }
-
-}

spring-core/src/main/java/com/baeldung/beaninjection/ExampleServiceBean.java

@@ -1,47 +0,0 @@
-package com.baeldung.beaninjection;
-
-import java.util.List;
-
-public class ExampleServiceBean implements IExampleService {
-
-    private IExampleDAO exampleDAO;
-    private IAnotherSampleDAO anotherSampleDAO;
-
-    public ExampleServiceBean(IExampleDAO exampleDAO) {
-        this.exampleDAO = exampleDAO;
-    }
-
-    public void setAnotherSampleDAO(IAnotherSampleDAO anotherSampleDAO) {
-        this.anotherSampleDAO = anotherSampleDAO;
-    }
-
-    // standard setters and getters
-
-    public IAnotherSampleDAO getAnotherSampleDAO() {
-        return anotherSampleDAO;
-    }
-
-    public void setExampleDAO(ExampleDAOBean exampleDAO) {
-        this.exampleDAO = exampleDAO;
-    }
-
-    public IExampleDAO getExampleDAO() {
-        return exampleDAO;
-    }
-
-    private String propertyX;
-
-    public String getPropertyX() {
-        return propertyX;
-    }
-
-    public void setPropertyX(String propertyX) {
-        this.propertyX = propertyX;
-    }
-
-    public List<SampleDomainObject> serviceMethodX() {
-        /*get domain list from DAO .. business logic on domain objects..return*/
-        return exampleDAO.getDomainList();
-    }
-
-}

spring-core/src/main/java/com/baeldung/beaninjection/FileReader.java

@@ -1,19 +0,0 @@
-package com.baeldung.beaninjection;
-
-import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.stereotype.Component;
-
-@Component
-public class FileReader {
-
-    @Autowired
-    private Location location;
-
-    public Location getLocation() {
-        return location;
-    }
-
-    public void setLocation(Location location) {
-        this.location = location;
-    }
-}

spring-core/src/main/java/com/baeldung/beaninjection/FtpReader.java

@@ -1,28 +0,0 @@
-package com.baeldung.beaninjection;
-
-public class FtpReader {
-    private String ftpHost = null;
-    private Integer ftpPort = null;
-
-    // Constructor with arguments
-    public FtpReader(String host, Integer port) {
-        this.ftpHost = host;
-        this.ftpPort = port;
-    }
-
-    public String getFtpHost() {
-        return ftpHost;
-    }
-
-    public void setFtpHost(String ftpHost) {
-        this.ftpHost = ftpHost;
-    }
-
-    public Integer getFtpPort() {
-        return ftpPort;
-    }
-
-    public void setFtpPort(Integer ftpPort) {
-        this.ftpPort = ftpPort;
-    }
-}

spring-core/src/main/java/com/baeldung/beaninjection/IAnotherSampleDAO.java

@@ -1,5 +0,0 @@
-package com.baeldung.beaninjection;
-
-public interface IAnotherSampleDAO {
-
-}

spring-core/src/main/java/com/baeldung/beaninjection/IExampleDAO.java

@@ -1,12 +0,0 @@
-package com.baeldung.beaninjection;
-
-import java.util.List;
-
-public interface IExampleDAO {
-
-    List<SampleDomainObject> getDomainList();
-
-    SampleDomainObject createNewDomain(SampleDomainObject domainObject);
-
-    SampleDomainObject getSomeDomain();
-}

spring-core/src/main/java/com/baeldung/beaninjection/IExampleService.java

@@ -1,9 +0,0 @@
-package com.baeldung.beaninjection;
-
-import java.util.List;
-
-public interface IExampleService {
-
-    List<SampleDomainObject> serviceMethodX();
-
-}

spring-core/src/main/java/com/baeldung/beaninjection/Location.java

@@ -1,17 +0,0 @@
-package com.baeldung.beaninjection;
-
-import org.springframework.stereotype.Component;
-
-@Component
-public class Location {
-    private String filePath;
-
-    public String getFilePath() {
-        return filePath;
-    }
-
-    public void setFilePath(String filePath) {
-        this.filePath = filePath;
-    }
-
-}

spring-core/src/main/java/com/baeldung/beaninjection/ReaderApplicationConfig.java

@@ -1,15 +0,0 @@
-package com.baeldung.beaninjection;
-
-import org.springframework.context.annotation.Bean;
-import org.springframework.context.annotation.ComponentScan;
-import org.springframework.context.annotation.Configuration;
-
-@Configuration
-@ComponentScan(basePackages = { "com.baeldung.beaninjection" })
-public class ReaderApplicationConfig {
-
-    @Bean
-    public FtpReader exampleDAO() {
-        return new FtpReader("localhost", 21);
-    }
-}

spring-core/src/main/java/com/baeldung/beaninjection/ReaderManager.java

@@ -1,33 +0,0 @@
-package com.baeldung.beaninjection;
-
-import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.stereotype.Component;
-
-@Component
-public class ReaderManager {
-    private FileReader fileReader;
-    private FtpReader ftpReader;
-
-    @Autowired
-    public ReaderManager(FtpReader ftpReader) {
-        this.ftpReader = ftpReader;
-    }
-
-    @Autowired
-    public void setFileReader(FileReader fileReader) {
-        this.fileReader = fileReader;
-    }
-
-    public FileReader getFileReader() {
-        return fileReader;
-    }
-
-    public void setFtpReader(FtpReader ftpReader) {
-        this.ftpReader = ftpReader;
-    }
-
-    public FtpReader getFtpReader() {
-        return ftpReader;
-    }
-
-}

spring-core/src/main/java/com/baeldung/beaninjection/ReaderService.java

@@ -1,14 +0,0 @@
-package com.baeldung.beaninjection;
-
-public class ReaderService {
-    private FtpReader ftpReader;
-
-    public void setFtpReader(FtpReader reader) {
-        this.ftpReader = reader;
-    }
-
-    public FtpReader getFtpReader() {
-        return ftpReader;
-    }
-
-}

spring-core/src/main/java/com/baeldung/beaninjection/SampleDomainObject.java

@@ -1,31 +0,0 @@
-package com.baeldung.beaninjection;
-
-import java.io.Serializable;
-
-public class SampleDomainObject implements Serializable {
-
-    /**
-     * 
-     */
-    private static final long serialVersionUID = 449859763481296747L;
-
-    private String domainPropX;
-    private String domainPropY;
-
-    public String getDomainPropX() {
-        return domainPropX;
-    }
-
-    public void setDomainPropX(String domainPropX) {
-        this.domainPropX = domainPropX;
-    }
-
-    public String getDomainPropY() {
-        return domainPropY;
-    }
-
-    public void setDomainPropY(String domainPropY) {
-        this.domainPropY = domainPropY;
-    }
-
-}

spring-core/src/main/java/com/baeldung/configuration/ApplicationContextTestBeanInjectionTypes.java

@@ -1,36 +0,0 @@
-package com.baeldung.configuration;
-
-import org.springframework.context.annotation.Bean;
-import org.springframework.context.annotation.ComponentScan;
-import org.springframework.context.annotation.Configuration;
-
-import com.baeldung.beaninjection.AnotherSampleDAOBean;
-import com.baeldung.beaninjection.ExampleDAOBean;
-import com.baeldung.beaninjection.ExampleServiceBean;
-import com.baeldung.beaninjection.IAnotherSampleDAO;
-import com.baeldung.beaninjection.IExampleDAO;
-import com.baeldung.beaninjection.IExampleService;
-
-@Configuration
-@ComponentScan(basePackages = { "com.baeldung.beaninjection" })
-public class ApplicationContextTestBeanInjectionTypes {
-
-    @Bean
-    public IExampleDAO exampleDAO() {
-        return new ExampleDAOBean("Mandatory DAO Property X");
-    }
-
-    @Bean
-    public IExampleService exampleServiceBean() {
-        ExampleServiceBean serviceBean = new ExampleServiceBean(exampleDAO());
-        serviceBean.setAnotherSampleDAO(anotherSampleDAO());
-        serviceBean.setPropertyX("Some Service Property X");
-        return serviceBean;
-    }
-
-    @Bean
-    public IAnotherSampleDAO anotherSampleDAO() {
-        return new AnotherSampleDAOBean("Mandatory DAO Property Y");
-    }
-
-}

spring-core/src/test/java/com/baeldung/beaninjection/FileReaderTest.java

@@ -1,24 +0,0 @@
-package com.baeldung.beaninjection;
-
-import static org.junit.Assert.assertNotNull;
-
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.context.ApplicationContext;
-import org.springframework.test.context.ContextConfiguration;
-import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
-
-@RunWith(SpringJUnit4ClassRunner.class)
-@ContextConfiguration(classes = ReaderApplicationConfig.class)
-public class FileReaderTest {
-
-    @Autowired
-    private ApplicationContext context;
-
-    @Test
-    public void testAutowiredAnnotation_WhenField_ThenInjected() {
-        FileReader service = context.getBean(FileReader.class);
-        assertNotNull(service.getLocation());
-    }
-}

spring-core/src/test/java/com/baeldung/beaninjection/FtpReaderTest.java

@@ -1,25 +0,0 @@
-package com.baeldung.beaninjection;
-
-import static org.junit.Assert.assertNotNull;
-
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.context.ApplicationContext;
-import org.springframework.test.context.ContextConfiguration;
-import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
-
-@RunWith(SpringJUnit4ClassRunner.class)
-@ContextConfiguration(locations = "classpath:injectiontypes.xml")
-public class FtpReaderTest {
-
-    @Autowired
-    private ApplicationContext context;
-
-    @Test
-    public void testXMLBeanConfig_WhenConstructorArguments_ThenInjected() {
-        FtpReader service = context.getBean(FtpReader.class);
-        assertNotNull(service.getFtpHost());
-        assertNotNull(service.getFtpPort());
-    }
-}

spring-core/src/test/java/com/baeldung/beaninjection/ReaderManagerTest.java

@@ -1,25 +0,0 @@
-package com.baeldung.beaninjection;
-
-import static org.junit.Assert.assertNotNull;
-
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.context.ApplicationContext;
-import org.springframework.test.context.ContextConfiguration;
-import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
-
-@RunWith(SpringJUnit4ClassRunner.class)
-@ContextConfiguration(classes = ReaderApplicationConfig.class)
-public class ReaderManagerTest {
-
-    @Autowired
-    private ApplicationContext context;
-
-    @Test
-    public void testAutowiredAnnotation_WhenConstructorAndSetter_ThenInjected() {
-        ReaderManager service = context.getBean(ReaderManager.class);
-        assertNotNull(service.getFtpReader());
-        assertNotNull(service.getFileReader());
-    }
-}

spring-core/src/test/java/com/baeldung/beaninjection/ReaderServiceTest.java

@@ -1,24 +0,0 @@
-package com.baeldung.beaninjection;
-
-import static org.junit.Assert.assertNotNull;
-
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.context.ApplicationContext;
-import org.springframework.test.context.ContextConfiguration;
-import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
-
-@RunWith(SpringJUnit4ClassRunner.class)
-@ContextConfiguration(locations = "classpath:injectiontypes.xml")
-public class ReaderServiceTest {
-
-    @Autowired
-    private ApplicationContext context;
-
-    @Test
-    public void testXMLBeanConfig_WhenSetter_ThenInjected() {
-        ReaderService service = context.getBean(ReaderService.class);
-        assertNotNull(service.getFtpReader());
-    }
-}

spring-core/src/test/java/com/baeldung/test/beaninjection/BeanInjectionJavaConfigIntegrationTest.java

@@ -1,50 +0,0 @@
-package com.baeldung.test.beaninjection;
-
-import static org.junit.Assert.assertNotNull;
-import static org.junit.Assert.assertTrue;
-
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.springframework.beans.BeansException;
-import org.springframework.context.ApplicationContext;
-import org.springframework.context.ApplicationContextAware;
-import org.springframework.test.context.ContextConfiguration;
-import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
-
-import com.baeldung.beaninjection.AnotherSampleDAOBean;
-import com.baeldung.beaninjection.ExampleDAOBean;
-import com.baeldung.beaninjection.ExampleServiceBean;
-import com.baeldung.configuration.ApplicationContextTestBeanInjectionTypes;
-
-@RunWith(SpringJUnit4ClassRunner.class)
-@ContextConfiguration(classes = ApplicationContextTestBeanInjectionTypes.class)
-public class BeanInjectionJavaConfigIntegrationTest implements ApplicationContextAware {
-
-    private ApplicationContext beanInjectedContext;
-
-    @Test
-    public void testDAOInjectionByJava() {
-        ExampleServiceBean serviceBean = beanInjectedContext.getBean(ExampleServiceBean.class);
-        assertNotNull("Failed: Constructor Injection,Bean Reference Injection,Java Config, ExampleServiceBean", serviceBean.getExampleDAO());
-        assertNotNull("Failed: Constructor Injection,Bean Reference Injection,Java Config, ExampleServiceBean", serviceBean.getAnotherSampleDAO());
-        assertTrue("Failed: Constructor Injection,String Property , Java Config", serviceBean.getPropertyX()
-            .equals("Some Service Property X"));
-    }
-
-    @Test
-    public void testPropertyInjectioninDAOByJava() {
-        ExampleDAOBean daoBean = beanInjectedContext.getBean(ExampleDAOBean.class);
-        assertTrue("Failed: Constructor Injection,String Property , Java Config", daoBean.getPropertyX()
-            .equals("Mandatory DAO Property X"));
-
-        AnotherSampleDAOBean anotherDAOBean = beanInjectedContext.getBean(AnotherSampleDAOBean.class);
-        assertTrue("Failed: Constructor Injection,String Property , XML Config", anotherDAOBean.getPropertyY()
-            .equals("Mandatory DAO Property Y"));
-    }
-
-    @Override
-    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
-        // TODO Auto-generated method stub
-        this.beanInjectedContext = applicationContext;
-    }
-}

spring-core/src/test/java/com/baeldung/test/beaninjection/BeanInjectionXMLConfigIntegrationTest.java

@@ -1,49 +0,0 @@
-package com.baeldung.test.beaninjection;
-
-import static org.junit.Assert.assertNotNull;
-import static org.junit.Assert.assertTrue;
-
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.springframework.beans.BeansException;
-import org.springframework.context.ApplicationContext;
-import org.springframework.context.ApplicationContextAware;
-import org.springframework.test.context.ContextConfiguration;
-import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
-
-import com.baeldung.beaninjection.AnotherSampleDAOBean;
-import com.baeldung.beaninjection.ExampleDAOBean;
-import com.baeldung.beaninjection.ExampleServiceBean;
-
-@RunWith(SpringJUnit4ClassRunner.class)
-@ContextConfiguration(locations = "classpath:beaninjectiontypes-context.xml")
-public class BeanInjectionXMLConfigIntegrationTest implements ApplicationContextAware {
-
-    private ApplicationContext beanInjectedContext;
-
-    @Test
-    public void testDAOInjectionByXML() {
-        ExampleServiceBean serviceBean = beanInjectedContext.getBean(ExampleServiceBean.class);
-        assertNotNull("Failed: Constructor Injection,Bean Reference Injection,XML Config, ExampleServiceBean", serviceBean.getExampleDAO());
-        assertNotNull("Failed: Constructor Injection,Bean Reference Injection,XML Config, ExampleServiceBean", serviceBean.getAnotherSampleDAO());
-        assertTrue("Failed: Constructor Injection,String Property , XML Config", serviceBean.getPropertyX()
-            .equals("Some Service Property X"));
-    }
-
-    @Test
-    public void testPropertyInjectioninDAOByXML() {
-        ExampleDAOBean daoBean = beanInjectedContext.getBean(ExampleDAOBean.class);
-        assertTrue("Failed: Constructor Injection,String Property , XML Config", daoBean.getPropertyX()
-            .equals("Mandatory DAO Property X"));
-
-        AnotherSampleDAOBean anotherDAOBean = beanInjectedContext.getBean(AnotherSampleDAOBean.class);
-        assertTrue("Failed: Constructor Injection,String Property , XML Config", anotherDAOBean.getPropertyY()
-            .equals("Mandatory DAO Property Y"));
-    }
-
-    @Override
-    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
-        // TODO Auto-generated method stub
-        this.beanInjectedContext = applicationContext;
-    }
-}