BAEL-5776 - Mock a URL Connection in Java (#14184)

* BAEL-4706 - Spring Boot with Spring Batch

* BAEL-3948 - Fix test(s) in spring-batch which leaves repository.sqlite
changed

* BAEL-4736 - Convert JSONArray to List of Object using camel-jackson

* BAEL-4756 - Mockito MockSettings

* BAEL-4756 - Mockito MockSettings - fix spelling

* BAEL-2674 - Upgrade the Okhttp article

* BAEL-4204 - Adding Interceptors in OkHTTP

* BAEL-4836 - Mocking Static Methods with Mockito

* BAEL-4205 - A Guide to Events in OkHTTP

* BAEL-5408 - Update Camel version in spring-boot-camel module

* BAEL-5234 - Apache Camel Routes Testing in Spring Boot

* BAEL-5234 - Apache Camel Routes Testing in Spring Boot

* BAEL-5237 - Apache Camel Conditional Routing

* BAEL-5236 - Apache Camel Exception Handling

* BAEL-5890 - Jackson's Deserialization with Lombok

* BAEL-5890 - Jackson's Deserialization with Lombok

* BAEL-5890 - Jackson's Deserialization with Lombok

* BAEL-5890 - Jackson's Deserialization with Lombok

* BAEL-5890 - Jackson's Deserialization with Lombok

* BAEL-5776 - Mock a URL Connection in Java

* BAEL-5776 - Mock a URL Connection in Java

---------

Co-authored-by: Jonathan Cook <jcook@sciops.esa.int>
Co-authored-by: jcook02 <jonathan.paul.cook@ext.esa.int>

libraries-http-2/pom.xml

@@ -82,8 +82,32 @@
             <artifactId>converter-gson</artifactId>
             <version>${retrofit.version}</version>
         </dependency>
+        <dependency>
+            <groupId>org.mockito</groupId>
+            <artifactId>mockito-inline</artifactId>
+            <version>${mockito.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency> 
+    		<groupId>org.jmockit</groupId> 
+    		<artifactId>jmockit</artifactId> 
+    		<version>${jmockit.version}</version>
+		</dependency>
     </dependencies>
     
+    <build>
+    	<plugins>
+    		<plugin>
+            	<artifactId>maven-surefire-plugin</artifactId>
+		            <configuration>
+		               <argLine>
+		                  -javaagent:${settings.localRepository}/org/jmockit/jmockit/${jmockit.version}/jmockit-${jmockit.version}.jar
+		               </argLine>
+		            </configuration>
+	         </plugin>
+    	</plugins>
+    </build>     
+
     <properties>
         <okhttp.version>4.9.1</okhttp.version>
         <gson.version>2.8.5</gson.version>
@@ -95,6 +119,7 @@
         <spring.webflux.version>5.1.9.RELEASE</spring.webflux.version>
         <reactive.stream.version>1.0.3</reactive.stream.version>
         <reactor.version>3.2.12.RELEASE</reactor.version>
+        <jmockit.version>1.49</jmockit.version>
     </properties>
 
 </project>

libraries-http-2/src/main/java/com/baeldung/mock/url/UrlFetcher.java

@@ -0,0 +1,23 @@
+package com.baeldung.mock.url;
+
+import java.io.IOException;
+import java.net.HttpURLConnection;
+import java.net.URL;
+
+public class UrlFetcher {
+
+    private URL url;
+
+    public UrlFetcher(URL url) throws IOException {
+        this.url = url;
+    }
+
+    public boolean isUrlAvailable() throws IOException {
+        return getResponseCode() == HttpURLConnection.HTTP_OK;
+    }
+
+    private int getResponseCode() throws IOException {
+        HttpURLConnection con = (HttpURLConnection) this.url.openConnection();
+        return con.getResponseCode();
+    }
+}

libraries-http-2/src/test/java/com/baeldung/mock/url/MockHttpURLConnection.java

@@ -0,0 +1,35 @@
+package com.baeldung.mock.url;
+
+import java.io.IOException;
+import java.net.HttpURLConnection;
+import java.net.URL;
+
+public class MockHttpURLConnection extends HttpURLConnection {
+
+    protected MockHttpURLConnection(URL url) {
+        super(url);
+    }
+
+    @Override
+    public int getResponseCode() {
+        return responseCode;
+    }
+
+    public void setResponseCode(int responseCode) {
+        this.responseCode = responseCode;
+    }
+
+    @Override
+    public void disconnect() {
+    }
+
+    @Override
+    public boolean usingProxy() {
+        return false;
+    }
+
+    @Override
+    public void connect() throws IOException {
+    }
+
+}

libraries-http-2/src/test/java/com/baeldung/mock/url/MockURLStreamHandler.java

@@ -0,0 +1,21 @@
+package com.baeldung.mock.url;
+
+import java.io.IOException;
+import java.net.URL;
+import java.net.URLConnection;
+import java.net.URLStreamHandler;
+
+public class MockURLStreamHandler extends URLStreamHandler {
+
+    private MockHttpURLConnection mockHttpURLConnection;
+
+    public MockURLStreamHandler(MockHttpURLConnection mockHttpURLConnection) {
+        this.mockHttpURLConnection = mockHttpURLConnection;
+    }
+
+    @Override
+    protected URLConnection openConnection(URL url) throws IOException {
+        return this.mockHttpURLConnection;
+    }
+
+}

libraries-http-2/src/test/java/com/baeldung/mock/url/MockURLStreamHandlerFactory.java

@@ -0,0 +1,19 @@
+package com.baeldung.mock.url;
+
+import java.net.URLStreamHandler;
+import java.net.URLStreamHandlerFactory;
+
+public class MockURLStreamHandlerFactory implements URLStreamHandlerFactory {
+
+    private MockHttpURLConnection mockHttpURLConnection;
+
+    public MockURLStreamHandlerFactory(MockHttpURLConnection mockHttpURLConnection) {
+        this.mockHttpURLConnection = mockHttpURLConnection;
+    }
+
+    @Override
+    public URLStreamHandler createURLStreamHandler(String protocol) {
+        return new MockURLStreamHandler(this.mockHttpURLConnection);
+    }
+
+}

libraries-http-2/src/test/java/com/baeldung/mock/url/UrlFetcherJMockitUnitTest.java

@@ -0,0 +1,42 @@
+package com.baeldung.mock.url;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.net.HttpURLConnection;
+import java.net.URL;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+
+import mockit.Expectations;
+import mockit.Mocked;
+import mockit.integration.junit5.JMockitExtension;
+
+
+@ExtendWith(JMockitExtension.class)
+class UrlFetcherJMockitUnitTest {
+
+    @Test
+    void givenMockedUrl_whenRequestSent_thenIsUrlAvailableTrue(@Mocked URL anyURL, @Mocked HttpURLConnection mockConn) throws Exception {
+        new Expectations() {{
+                mockConn.getResponseCode();
+                result = HttpURLConnection.HTTP_OK;
+        }};
+
+        UrlFetcher fetcher = new UrlFetcher(new URL("https://www.baeldung.com/"));
+        assertTrue(fetcher.isUrlAvailable(), "Url should be available: ");
+    }
+    
+    @Test
+    void givenMockedUrl_whenRequestSent_thenIsUrlAvailableFalse(@Mocked URL anyURL, @Mocked HttpURLConnection mockConn) throws Exception {
+        new Expectations() {{
+                mockConn.getResponseCode();
+                result = HttpURLConnection.HTTP_INTERNAL_ERROR;
+        }};
+
+        UrlFetcher fetcher = new UrlFetcher(new URL("https://www.baeldung.com/"));
+        assertFalse(fetcher.isUrlAvailable(), "Url should NOT be available: ");
+    }
+
+}

libraries-http-2/src/test/java/com/baeldung/mock/url/UrlFetcherMockitoUnitTest.java

@@ -0,0 +1,39 @@
+package com.baeldung.mock.url;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+import java.net.HttpURLConnection;
+import java.net.URL;
+
+import org.junit.jupiter.api.Test;
+
+class UrlFetcherMockitoUnitTest {
+    
+    @Test
+    void givenMockedUrl_whenRequestSent_thenIsUrlAvailableTrue() throws Exception {
+        HttpURLConnection mockHttpURLConnection = mock(HttpURLConnection.class);
+        when(mockHttpURLConnection.getResponseCode()).thenReturn(HttpURLConnection.HTTP_OK);
+        
+        URL mockURL = mock(URL.class);
+        when(mockURL.openConnection()).thenReturn(mockHttpURLConnection);
+
+        UrlFetcher fetcher = new UrlFetcher(mockURL);
+        assertTrue(fetcher.isUrlAvailable(), "Url should be available: ");
+    }
+
+    @Test
+     void givenMockedUrl_whenRequestSent_thenIsUrlAvailableFalse() throws Exception {
+        HttpURLConnection mockHttpURLConnection = mock(HttpURLConnection.class);
+        when(mockHttpURLConnection.getResponseCode()).thenReturn(HttpURLConnection.HTTP_NOT_FOUND);
+        
+        URL mockURL = mock(URL.class);
+        when(mockURL.openConnection()).thenReturn(mockHttpURLConnection);
+        
+        UrlFetcher fetcher = new UrlFetcher(mockURL);
+        assertFalse(fetcher.isUrlAvailable(), "Url should NOT be available: ");
+    }
+
+}

libraries-http-2/src/test/java/com/baeldung/mock/url/UrlFetcherUnitTest.java

@@ -0,0 +1,40 @@
+package com.baeldung.mock.url;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.net.HttpURLConnection;
+import java.net.URL;
+
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+
+class UrlFetcherUnitTest {
+
+    private static MockHttpURLConnection mockHttpURLConnection;
+
+    @BeforeAll
+    public static void setUp() {
+        mockHttpURLConnection = new MockHttpURLConnection(null);
+        URL.setURLStreamHandlerFactory(new MockURLStreamHandlerFactory(mockHttpURLConnection));
+    }
+
+    @Test
+    void givenMockedUrl_whenRequestSent_thenIsUrlAvailableTrue() throws Exception {
+        mockHttpURLConnection.setResponseCode(HttpURLConnection.HTTP_OK);
+        URL url = new URL("https://www.baeldung.com/");
+
+        UrlFetcher fetcher = new UrlFetcher(url);
+        assertTrue(fetcher.isUrlAvailable(), "Url should be available: ");
+    }
+
+    @Test
+    void givenMockedUrl_whenRequestSent_thenIsUrlAvailableFalse() throws Exception {
+        mockHttpURLConnection.setResponseCode(HttpURLConnection.HTTP_FORBIDDEN);
+        URL url = new URL("https://www.baeldung.com/");
+
+        UrlFetcher fetcher = new UrlFetcher(url);
+        assertFalse(fetcher.isUrlAvailable(), "Url should NOT be available: ");
+    }
+
+}