<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>mtitek.junit.samples</groupId> <artifactId>mtitek-junit-samples</artifactId> <packaging>jar</packaging> <version>1.0.0-SNAPSHOT</version> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <maven.compiler.source>19</maven.compiler.source> <!-- maven-compiler-plugin property --> <maven.compiler.target>19</maven.compiler.target> <!-- maven-compiler-plugin property --> </properties> <dependencies> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.13.2</version> <scope>test</scope> </dependency> <dependency> <groupId>org.mockito</groupId> <artifactId>mockito-core</artifactId> <version>5.0.0</version> <scope>test</scope> </dependency> <dependency> <groupId>com.github.tomakehurst</groupId> <artifactId>wiremock</artifactId> <version>2.27.2</version> <scope>test</scope> </dependency> <dependency> <groupId>org.apache.httpcomponents</groupId> <artifactId>httpcore</artifactId> <version>4.4.16</version> <scope>test</scope> </dependency> <dependency> <groupId>org.apache.httpcomponents</groupId> <artifactId>httpclient</artifactId> <version>4.5.14</version> <scope>test</scope> </dependency> <dependency> <groupId>commons-io</groupId> <artifactId>commons-io</artifactId> <version>2.11.0</version> <scope>test</scope> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> <version>3.10.1</version> </plugin> </plugins> </build> </project>

src/main/java/mtitek/junit/samples/MyAbc.java:
package mtitek.junit.samples; public class MyAbc { public Integer offset = 1; public Integer add(final Integer v1, final Integer v2) { return v1 + v2; } public Integer div(final Integer v1, final Integer v2) { return v1 / v2; } public void initOffset(final Integer v1) { this.offset = v1; } }
src/test/java/mtitek/junit/samples/MockitoTest.java:
package mtitek.junit.samples; import org.junit.Assert; import org.junit.Test; import org.mockito.ArgumentMatchers; import org.mockito.Mockito; public class MockitoTest { @Test public void testMockito() { final MyAbc myAbc = Mockito.mock(MyAbc.class); // when Mockito.when(myAbc.add(ArgumentMatchers.anyInt(), ArgumentMatchers.any(Integer.class))).thenReturn(1); Assert.assertEquals(myAbc.add(1, 2), Integer.valueOf(1)); // verify Mockito.verify(myAbc, Mockito.times(1)).add(1, 2); Mockito.verify(myAbc, Mockito.never()).add(1, 3); // thenAnswer Mockito.when(myAbc.div(ArgumentMatchers.eq(8), ArgumentMatchers.eq(4))) .thenAnswer(invocationOnMock -> invocationOnMock.getArgument(0, Integer.class) / invocationOnMock.getArgument(1, Integer.class)); Assert.assertEquals(myAbc.div(8, 4), Integer.valueOf(2)); // doAnswer Mockito.doAnswer(invocationOnMock -> myAbc.offset = 0).when(myAbc).initOffset(4); myAbc.initOffset(4); Assert.assertEquals(myAbc.offset, Integer.valueOf(0)); // thenThrow Mockito.when(myAbc.div(ArgumentMatchers.eq(2), ArgumentMatchers.eq(0))).thenThrow(new ArithmeticException()); try { myAbc.div(2, 0); Assert.fail(); } catch (ArithmeticException e) { // expected exception } // doThrow Mockito.doThrow(new IllegalStateException()).when(myAbc).initOffset(3); try { myAbc.initOffset(3); Assert.fail(); } catch (IllegalStateException e) { // expected exception } } }

src/test/resources/abc.txt:
Hello 'abc.txt' content!!!
src/test/java/mtitek/junit/samples/TemporaryFolderTest.java:
package mtitek.junit.samples; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.nio.file.Files; import java.nio.file.StandardCopyOption; import org.apache.commons.io.FileUtils; import org.apache.commons.io.IOUtils; import org.junit.Assert; import org.junit.Rule; import org.junit.Test; import org.junit.rules.TemporaryFolder; public class TemporaryFolderTest { @Rule public TemporaryFolder temporaryFolder = new TemporaryFolder(); @Test public void testTemporaryFolder() throws IOException { File createdFolder = temporaryFolder.newFolder("subfolder"); File createdFile = temporaryFolder.newFile("myfile.txt"); System.out.println(createdFolder); System.out.println(createdFile); } // saving/reading data to/from files @Test public void test() throws IOException { final File newFile = temporaryFolder.newFile(); System.out.println("newFile: " + newFile); final String data = "foo"; try (final FileOutputStream fileOutputStream = new FileOutputStream(newFile)) { IOUtils.copy(IOUtils.toInputStream(data, "UTF-8"), fileOutputStream); } try (final InputStream inputStream = new FileInputStream(newFile)) { Assert.assertEquals(data, IOUtils.toString(inputStream, "UTF-8")); } } // copying files @Test public void testFiles() throws IOException { File createdFile = temporaryFolder.newFile("abc-copy.txt"); try (final InputStream input = ClassLoader.getSystemResourceAsStream("abc.txt")) { Files.copy(input, createdFile.toPath(), StandardCopyOption.REPLACE_EXISTING); } Assert.assertEquals("Hello 'abc.txt' content!!!", FileUtils.readFileToString(createdFile, "UTF-8")); final String body = FileUtils.readFileToString(createdFile, "UTF-8"); System.out.println(createdFile.toPath()); System.out.println(body); } }

src/test/java/mtitek/junit/samples/WireMockTest.java:
package mtitek.junit.samples; import java.io.IOException; import org.apache.commons.io.IOUtils; import org.apache.http.HttpEntity; import org.apache.http.HttpStatus; import org.apache.http.client.methods.CloseableHttpResponse; import org.apache.http.client.methods.HttpGet; import org.apache.http.impl.client.CloseableHttpClient; import org.apache.http.impl.client.HttpClients; import org.apache.http.util.EntityUtils; import org.junit.Assert; import org.junit.Rule; import org.junit.Test; import com.github.tomakehurst.wiremock.client.WireMock; import com.github.tomakehurst.wiremock.junit.WireMockRule; public class WireMockTest { @Rule public WireMockRule wireMockRule = new WireMockRule(8880); @Test public void testWireMock() throws IOException { WireMock.stubFor(WireMock.get(WireMock.urlEqualTo("/abc/xyz")) .willReturn(WireMock.aResponse().withStatus(HttpStatus.SC_OK).withBody("Hello WireMock!!!"))); final HttpGet httpGet = new HttpGet("http://localhost:8880/abc/xyz"); try (CloseableHttpClient httpClient = HttpClients.custom().build(); final CloseableHttpResponse httpResponse = httpClient.execute(httpGet)) { WireMock.verify(WireMock.getRequestedFor(WireMock.urlEqualTo("/abc/xyz"))); Assert.assertEquals(HttpStatus.SC_OK, httpResponse.getStatusLine().getStatusCode()); final HttpEntity entity = httpResponse.getEntity(); Assert.assertEquals("Hello WireMock!!!", IOUtils.toString(entity.getContent(), "UTF-8")); // close the content stream. EntityUtils.consumeQuietly(entity); } } }