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How to use ClassLoaders class of org.mockitoutil package

Best Mockito code snippet using org.mockitoutil.ClassLoaders

Source:ClassLoadersTest.java

...8import org.junit.Test;9import org.mockito.Mockito;10import static org.assertj.core.api.Assertions.assertThat;11import static org.junit.Assert.fail;12import static org.mockitoutil.ClassLoaders.currentClassLoader;13import static org.mockitoutil.ClassLoaders.excludingClassLoader;14import static org.mockitoutil.ClassLoaders.isolatedClassLoader;15import static org.mockitoutil.ClassLoaders.jdkClassLoader;16public class ClassLoadersTest {17    public static final String CLASS_NAME_DEPENDING_ON_INTERFACE = "org.mockitoutil.ClassLoadersTest$ClassUsingInterface1";18    public static final String INTERFACE_NAME = "org.mockitoutil.ClassLoadersTest$Interface1";19    @Test(expected = ClassNotFoundException.class)20    public void isolated_class_loader_cannot_load_classes_when_no_given_prefix() throws Exception {21        // given22        ClassLoader cl = isolatedClassLoader().build();23        // when24        cl.loadClass("org.mockito.Mockito");25        // then raises CNFE26    }27    @Test28    public void isolated_class_loader_cannot_load_classes_if_no_code_source_path() throws Exception {29        // given30        ClassLoader cl = isolatedClassLoader()31                .withPrivateCopyOf(CLASS_NAME_DEPENDING_ON_INTERFACE)32                .build();33        // when34        try {35            cl.loadClass(CLASS_NAME_DEPENDING_ON_INTERFACE);36            fail();37        } catch (ClassNotFoundException e) {38            // then39            assertThat(e).hasMessageContaining(CLASS_NAME_DEPENDING_ON_INTERFACE);40        }41    }42    @Test43    public void isolated_class_loader_cannot_load_classes_if_dependent_classes_do_not_match_the_prefixes() throws Exception {44        // given45        ClassLoader cl = isolatedClassLoader()46                .withCurrentCodeSourceUrls()47                .withPrivateCopyOf(CLASS_NAME_DEPENDING_ON_INTERFACE)48                .build();49        // when50        try {51            cl.loadClass(CLASS_NAME_DEPENDING_ON_INTERFACE);52            fail();53        } catch (NoClassDefFoundError e) {54            // then55            assertThat(e).hasMessageContaining("org/mockitoutil/ClassLoadersTest$Interface1");56        }57    }58    @Test59    public void isolated_class_loader_can_load_classes_when_dependent_classes_are_matching_the_prefixes() throws Exception {60        // given61        ClassLoader cl = isolatedClassLoader()62                .withCurrentCodeSourceUrls()63                .withPrivateCopyOf(CLASS_NAME_DEPENDING_ON_INTERFACE)64                .withPrivateCopyOf(INTERFACE_NAME)65                .build();66        // when67        Class<?> aClass = cl.loadClass(CLASS_NAME_DEPENDING_ON_INTERFACE);68        // then69        assertThat(aClass).isNotNull();70        assertThat(aClass.getClassLoader()).isEqualTo(cl);71        assertThat(aClass.getInterfaces()[0].getClassLoader()).isEqualTo(cl);72    }73    @Test74    public void isolated_class_loader_can_load_classes_isolated_classes_in_isolation() throws Exception {75        // given76        ClassLoader cl = isolatedClassLoader()77                .withCurrentCodeSourceUrls()78                .withPrivateCopyOf(ClassLoadersTest.class.getPackage().getName())79                .build();80        // when81        Class<?> aClass = cl.loadClass(AClass.class.getName());82        // then83        assertThat(aClass).isNotNull();84        assertThat(aClass).isNotSameAs(AClass.class);85        assertThat(aClass.getClassLoader()).isEqualTo(cl);86    }87    @Test88    public void isolated_class_loader_cannot_load_classes_if_prefix_excluded() throws Exception {89        // given90        ClassLoader cl = isolatedClassLoader()91                .withCurrentCodeSourceUrls()92                .withPrivateCopyOf(ClassLoadersTest.class.getPackage().getName())93                .without(AClass.class.getName())94                .build();95        // when96        try {97            cl.loadClass(AClass.class.getName());98            fail();99        } catch (ClassNotFoundException e) {100            // then101            assertThat(e).hasMessageContaining("org.mockitoutil")102                         .hasMessageContaining(AClass.class.getName());103        }104    }105    @Test106    public void isolated_class_loader_has_no_parent() throws Exception {107        ClassLoader cl = isolatedClassLoader()108                .withCurrentCodeSourceUrls()109                .withPrivateCopyOf(CLASS_NAME_DEPENDING_ON_INTERFACE)110                .withPrivateCopyOf(INTERFACE_NAME)111                .build();112        assertThat(cl.getParent()).isNull();113    }114    @Test(expected = ClassNotFoundException.class)115    public void excluding_class_loader_cannot_load_classes_when_no_correct_source_url_set() throws Exception {116        // given117        ClassLoader cl = excludingClassLoader()118                .withCodeSourceUrlOf(this.getClass())119                .build();120        // when121        cl.loadClass("org.mockito.Mockito");122        // then class CNFE123    }124    @Test125    public void excluding_class_loader_can_load_classes_when_correct_source_url_set() throws Exception {126        // given127        ClassLoader cl = excludingClassLoader()128                .withCodeSourceUrlOf(Mockito.class)129                .build();130        // when131        cl.loadClass("org.mockito.Mockito");132        // then class successfully loaded133    }134    @Test135    public void excluding_class_loader_cannot_load_class_when_excluded_prefix_match_class_to_load() throws Exception {136        // given137        ClassLoader cl = excludingClassLoader()138                .withCodeSourceUrlOf(Mockito.class)139                .without("org.mockito.BDDMockito")140                .build();141        cl.loadClass("org.mockito.Mockito");142        // when143        try {144            cl.loadClass("org.mockito.BDDMockito");145            fail("should have raise a ClassNotFoundException");146        } catch (ClassNotFoundException e) {147            assertThat(e.getMessage()).contains("org.mockito.BDDMockito");148        }149        // then class successfully loaded150    }151    @Test152    public void can_not_load_a_class_not_previously_registered_in_builder() throws Exception {153        // given154        ClassLoader cl = ClassLoaders155                .inMemoryClassLoader()156                .withClassDefinition("yop.Dude", SimpleClassGenerator.makeMarkerInterface("yop.Dude"))157                .build();158        // when159        try {160            cl.loadClass("not.Defined");161            fail();162        } catch (ClassNotFoundException e) {163            // then164            assertThat(e.getMessage()).contains("not.Defined");165        }166    }167    @Test168    public void can_load_a_class_in_memory_from_bytes() throws Exception {169        // given170        ClassLoader cl = ClassLoaders171                .inMemoryClassLoader()172                .withClassDefinition("yop.Dude", SimpleClassGenerator.makeMarkerInterface("yop.Dude"))173                .build();174        // when175        Class<?> aClass = cl.loadClass("yop.Dude");176        // then177        assertThat(aClass).isNotNull();178        assertThat(aClass.getClassLoader()).isEqualTo(cl);179        assertThat(aClass.getName()).isEqualTo("yop.Dude");180    }181    @Test182    public void cannot_load_a_class_file_not_in_parent() throws Exception {183        // given184        ClassLoader cl = ClassLoaders185                .inMemoryClassLoader()186                .withParent(jdkClassLoader())187                .build();188        cl.loadClass("java.lang.String");189        try {190            // when191            cl.loadClass("org.mockito.Mockito");192            fail("should have not found Mockito class");193        } catch (ClassNotFoundException e) {194            // then195            assertThat(e.getMessage()).contains("org.mockito.Mockito");196        }197    }198    @Test199    public void can_list_all_classes_reachable_in_a_classloader() throws Exception {200        ClassLoader classLoader = ClassLoaders.inMemoryClassLoader()201                                              .withParent(jdkClassLoader())202                                              .withClassDefinition("a.A", SimpleClassGenerator.makeMarkerInterface("a.A"))203                                              .withClassDefinition("a.b.B", SimpleClassGenerator.makeMarkerInterface("a.b.B"))204                                              .withClassDefinition("c.C", SimpleClassGenerator.makeMarkerInterface("c.C"))205//                .withCodeSourceUrlOf(ClassLoaders.class)206                                              .build();207        assertThat(ClassLoaders.in(classLoader).listOwnedClasses()).containsOnly("a.A", "a.b.B", "c.C");208        assertThat(ClassLoaders.in(classLoader).omit("b", "c").listOwnedClasses()).containsOnly("a.A");209    }210    @Test211    public void return_bootstrap_classloader() throws Exception {212        assertThat(jdkClassLoader()).isNotEqualTo(Mockito.class.getClassLoader());213        assertThat(jdkClassLoader()).isNotEqualTo(ClassLoaders.class.getClassLoader());214        assertThat(jdkClassLoader()).isEqualTo(Number.class.getClassLoader());215        assertThat(jdkClassLoader()).isEqualTo(null);216    }217    @Test218    public void return_current_classloader() throws Exception {219        assertThat(currentClassLoader()).isEqualTo(this.getClass().getClassLoader());220    }221    @Test222    public void can_run_in_given_classloader() throws Exception {223        // given224        final ClassLoader cl = isolatedClassLoader()225                .withCurrentCodeSourceUrls()226                .withCodeSourceUrlOf(Assertions.class)227                .withPrivateCopyOf("org.assertj.core")228                .withPrivateCopyOf(ClassLoadersTest.class.getPackage().getName())229                .without(AClass.class.getName())230                .build();231        final AtomicBoolean executed = new AtomicBoolean(false);232        // when233        ClassLoaders.using(cl).execute(new Runnable() {234            @Override235            public void run() {236                assertThat(this.getClass().getClassLoader()).describedAs("runnable is reloaded in given classloader").isEqualTo(cl);237                assertThat(Thread.currentThread().getContextClassLoader()).describedAs("Thread context classloader is using given classloader").isEqualTo(cl);238                try {239                    assertThat(Thread.currentThread()240                                     .getContextClassLoader()241                                     .loadClass("java.lang.String"))242                            .describedAs("can load JDK type")243                            .isNotNull();244                    assertThat(Thread.currentThread()245                                     .getContextClassLoader()246                                     .loadClass("org.mockitoutil.ClassLoadersTest$ClassUsingInterface1"))247                            .describedAs("can load classloader types")248                            .isNotNull();249                } catch (ClassNotFoundException cnfe) {250                    Assertions.fail("should not have raised a CNFE", cnfe);251                }252                executed.set(true);253            }254        });255        // then256        assertThat(executed.get()).isEqualTo(true);257    }258    @Test259    public void cannot_load_runnable_in_given_classloader_if_some_type_cant_be_loaded() throws Exception {260        // given261        final ClassLoader cl = isolatedClassLoader()262                .withCurrentCodeSourceUrls()263                .withPrivateCopyOf(ClassLoadersTest.class.getPackage().getName())264                .without(AClass.class.getName())265                .build();266        // when267        try {268            ClassLoaders.using(cl).execute(new Runnable() {269                @Override270                public void run() {271                    AClass cant_be_found = new AClass();272                }273            });274            Assertions.fail("should have raised a ClassNotFoundException");275        } catch (IllegalStateException ise) {276            // then277            assertThat(ise).hasCauseInstanceOf(NoClassDefFoundError.class)278                           .hasMessageContaining("AClass");279        }280    }281    @SuppressWarnings("unused")282    static class AClass {...

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