KaneAI - World’s First E2E Software Testing Agent.Book a Demo 
How to use Annotation Type Parameterized.BeforeParam class of org.junit.runners package
Best junit code snippet using org.junit.runners.Annotation Type Parameterized.BeforeParam
Source:BlockJUnit4ClassRunnerWithParameters.java 
1package org.junit.runners.parameterized;2import java.lang.annotation.Annotation;3import java.lang.reflect.Field;4import java.util.List;5import org.junit.internal.runners.statements.RunAfters;6import org.junit.internal.runners.statements.RunBefores;7import org.junit.runner.RunWith;8import org.junit.runner.notification.RunNotifier;9import org.junit.runners.BlockJUnit4ClassRunner;10import org.junit.runners.Parameterized;11import org.junit.runners.Parameterized.Parameter;12import org.junit.runners.model.FrameworkField;13import org.junit.runners.model.FrameworkMethod;14import org.junit.runners.model.InitializationError;15import org.junit.runners.model.Statement;16/**17 * A {@link BlockJUnit4ClassRunner} with parameters support. Parameters can be18 * injected via constructor or into annotated fields.19 */20public class BlockJUnit4ClassRunnerWithParameters extends21 BlockJUnit4ClassRunner {22 private enum InjectionType {23 CONSTRUCTOR, FIELD24 }25 private final Object[] parameters;26 private final String name;27 public BlockJUnit4ClassRunnerWithParameters(TestWithParameters test)28 throws InitializationError {29 super(test.getTestClass());30 parameters = test.getParameters().toArray(31 new Object[test.getParameters().size()]);32 name = test.getName();33 }34 @Override35 public Object createTest() throws Exception {36 InjectionType injectionType = getInjectionType();37 switch (injectionType) {38 case CONSTRUCTOR:39 return createTestUsingConstructorInjection();40 case FIELD:41 return createTestUsingFieldInjection();42 default:43 throw new IllegalStateException("The injection type "44 + injectionType + " is not supported.");45 }46 }47 private Object createTestUsingConstructorInjection() throws Exception {48 return getTestClass().getOnlyConstructor().newInstance(parameters);49 }50 private Object createTestUsingFieldInjection() throws Exception {51 List<FrameworkField> annotatedFieldsByParameter = getAnnotatedFieldsByParameter();52 if (annotatedFieldsByParameter.size() != parameters.length) {53 throw new Exception(54 "Wrong number of parameters and @Parameter fields."55 + " @Parameter fields counted: "56 + annotatedFieldsByParameter.size()57 + ", available parameters: " + parameters.length58 + ".");59 }60 Object testClassInstance = getTestClass().getJavaClass().newInstance();61 for (FrameworkField each : annotatedFieldsByParameter) {62 Field field = each.getField();63 Parameter annotation = field.getAnnotation(Parameter.class);64 int index = annotation.value();65 try {66 field.set(testClassInstance, parameters[index]);67 } catch (IllegalAccessException e) {68 IllegalAccessException wrappedException = new IllegalAccessException(69 "Cannot set parameter '" + field.getName()70 + "'. Ensure that the field '" + field.getName()71 + "' is public.");72 wrappedException.initCause(e);73 throw wrappedException;74 } catch (IllegalArgumentException iare) {75 throw new Exception(getTestClass().getName()76 + ": Trying to set " + field.getName()77 + " with the value " + parameters[index]78 + " that is not the right type ("79 + parameters[index].getClass().getSimpleName()80 + " instead of " + field.getType().getSimpleName()81 + ").", iare);82 }83 }84 return testClassInstance;85 }86 @Override87 protected String getName() {88 return name;89 }90 @Override91 protected String testName(FrameworkMethod method) {92 return method.getName() + getName();93 }94 @Override95 protected void validateConstructor(List<Throwable> errors) {96 validateOnlyOneConstructor(errors);97 if (getInjectionType() != InjectionType.CONSTRUCTOR) {98 validateZeroArgConstructor(errors);99 }100 }101 @Override102 protected void validateFields(List<Throwable> errors) {103 super.validateFields(errors);104 if (getInjectionType() == InjectionType.FIELD) {105 List<FrameworkField> annotatedFieldsByParameter = getAnnotatedFieldsByParameter();106 int[] usedIndices = new int[annotatedFieldsByParameter.size()];107 for (FrameworkField each : annotatedFieldsByParameter) {108 int index = each.getField().getAnnotation(Parameter.class)109 .value();110 if (index < 0 || index > annotatedFieldsByParameter.size() - 1) {111 errors.add(new Exception("Invalid @Parameter value: "112 + index + ". @Parameter fields counted: "113 + annotatedFieldsByParameter.size()114 + ". Please use an index between 0 and "115 + (annotatedFieldsByParameter.size() - 1) + "."));116 } else {117 usedIndices[index]++;118 }119 }120 for (int index = 0; index < usedIndices.length; index++) {121 int numberOfUse = usedIndices[index];122 if (numberOfUse == 0) {123 errors.add(new Exception("@Parameter(" + index124 + ") is never used."));125 } else if (numberOfUse > 1) {126 errors.add(new Exception("@Parameter(" + index127 + ") is used more than once (" + numberOfUse + ")."));128 }129 }130 }131 }132 @Override133 protected Statement classBlock(RunNotifier notifier) {134 Statement statement = childrenInvoker(notifier);135 statement = withBeforeParams(statement);136 statement = withAfterParams(statement);137 return statement;138 }139 private Statement withBeforeParams(Statement statement) {140 List<FrameworkMethod> befores = getTestClass()141 .getAnnotatedMethods(Parameterized.BeforeParam.class);142 return befores.isEmpty() ? statement : new RunBeforeParams(statement, befores);143 }144 private class RunBeforeParams extends RunBefores {145 RunBeforeParams(Statement next, List<FrameworkMethod> befores) {146 super(next, befores, null);147 }148 @Override149 protected void invokeMethod(FrameworkMethod method) throws Throwable {150 int paramCount = method.getMethod().getParameterTypes().length;151 method.invokeExplosively(null, paramCount == 0 ? (Object[]) null : parameters);152 }153 }154 private Statement withAfterParams(Statement statement) {155 List<FrameworkMethod> afters = getTestClass()156 .getAnnotatedMethods(Parameterized.AfterParam.class);157 return afters.isEmpty() ? statement : new RunAfterParams(statement, afters);158 }159 private class RunAfterParams extends RunAfters {160 RunAfterParams(Statement next, List<FrameworkMethod> afters) {161 super(next, afters, null);162 }163 @Override164 protected void invokeMethod(FrameworkMethod method) throws Throwable {165 int paramCount = method.getMethod().getParameterTypes().length;166 method.invokeExplosively(null, paramCount == 0 ? (Object[]) null : parameters);167 }168 }169 @Override170 protected Annotation[] getRunnerAnnotations() {171 Annotation[] allAnnotations = super.getRunnerAnnotations();172 Annotation[] annotationsWithoutRunWith = new Annotation[allAnnotations.length - 1];173 int i = 0;174 for (Annotation annotation: allAnnotations) {175 if (!annotation.annotationType().equals(RunWith.class)) {176 annotationsWithoutRunWith[i] = annotation;177 ++i;178 }179 }180 return annotationsWithoutRunWith;181 }182 private List<FrameworkField> getAnnotatedFieldsByParameter() {183 return getTestClass().getAnnotatedFields(Parameter.class);184 }185 private InjectionType getInjectionType() {186 if (fieldsAreAnnotated()) {187 return InjectionType.FIELD;188 } else {189 return InjectionType.CONSTRUCTOR;190 }191 }192 private boolean fieldsAreAnnotated() {193 return !getAnnotatedFieldsByParameter().isEmpty();194 }195}...
Annotation Type Parameterized.BeforeParam
Using AI Code Generation
1import org.junit.runner.RunWith;2import org.junit.runners.Parameterized;3import org.junit.runners.Parameterized.Parameters;4import java.util.Arrays;5import java.util.Collection;6@RunWith(Parameterized.class)7public class BeforeParam {8 public static Collection<Object[]> data() {9 return Arrays.asList(new Object[][] { { "is" }, { "a" }, { "test" } });10 }11 private String fInput;12 public BeforeParam(String input) {13 fInput = input;14 }15}16import static org.junit.Assert.assertEquals;17import org.junit.Test;18import org.junit.runner.RunWith;19import org.junit.runners.Parameterized;20import org.junit.runners.Parameterized.Parameters;21import java.util.Arrays;22import java.util.Collection;23@RunWith(Parameterized.class)24public class AfterParam {25 public static Collection<Object[]> data() {26 return Arrays.asList(new Object[][] { { "is" }, { "a" }, { "test" } });27 }28 private String fInput;29 public AfterParam(String input) {30 fInput = input;31 }32 public void test() {33 assertEquals("a", fInput);34 }35}36import static org.junit.Assert.assertEquals;37import org.junit.Test;38import org.junit.runner.RunWith;39import org.junit.runners.Parameterized;40import org.junit.runners.Parameterized.Parameters;41import java.util.Arrays;42import java.util.Collection;43@RunWith(Parameterized.class)44public class BeforeParam {45 public static Collection<Object[]> data() {46 return Arrays.asList(new Object[][] { { "is" }, { "a" }, { "test" } });47 }48 private String fInput;49 public BeforeParam(String input) {50 fInput = input;51 }52 public void test() {53 assertEquals("a", fInput);54 }55}56import static org.junit.Assert.assertEquals;57import org.junit.Test;58import org.junit.runner.RunWith;59import org.junit.runners.Parameterized;60import org.junit.runners.Parameterized.Parameters;61import java.util.Arrays;62import java.util.Collection;63@RunWith(Parameterized.class)64public class AfterParam {65 public static Collection<Object[]> data() {66 return Arrays.asList(new Object[][] {
Annotation Type Parameterized.BeforeParam
Using AI Code Generation
1import java.util.Arrays;2import java.util.Collection;3import org.junit.Test;4import org.junit.runner.RunWith;5import org.junit.runners.Parameterized;6import org.junit.runners.Parameterized.Parameters;7@RunWith(Parameterized.class)8public class TestParameterized {9 public static Collection<Object[]> data(){10 return Arrays.asList(new Object[][] {11 {1, 2}, {5, 3}, {121, 4}12 });13 }14 private int input;15 private int expected;16 public TestParameterized(int input, int expected) {17 this.input = input;18 this.expected = expected;19 }20 public void test() {21 System.out.println(input + " " + expected);22 }23}24import java.util.Arrays;25import java.util.Collection;26import org.junit.Test;27import org.junit.runner.RunWith;28import org.junit.runners.Parameterized;29import org.junit.runners.Parameterized.Parameters;30@RunWith(Parameterized.class)31public class TestParameterized {32 public static Collection<Object[]> data(){33 return Arrays.asList(new Object[][] {34 {1, 2}, {5, 3}, {121, 4}35 });36 }37 private int input;38 private int expected;39 public TestParameterized(int input, int expected) {40 this.input = input;41 this.expected = expected;42 }43 public void test() {44 System.out.println(input + " " + expected);45 }46}47import java.util.Arrays;48import java.util.Collection;49import org.junit.Test;50import org.junit.runner.RunWith;51import org.junit.runners.Parameterized;52import org.junit.runners.Parameterized.Parameters;53@RunWith(Parameterized.class)54public class TestParameterized {55 public static Collection<Object[]> data(){56 return Arrays.asList(new Object[][] {57 {1, 2}, {5, 3}, {121, 4}58 });59 }60 private int input;61 private int expected;62 public TestParameterized(int input, int expected) {63 this.input = input;
Annotation Type Parameterized.BeforeParam
Using AI Code Generation
1import org.junit.runners.Parameterized;2import java.util.Arrays;3import java.util.Collection;4import org.junit.Before;5import org.junit.Test;6import org.junit.runner.RunWith;7import static org.junit.Assert.*;8@RunWith(Parameterized.class)9public class BeforeParamTest {10 private int number;11 private boolean result;12 public void initialize() {13 System.out.println("BeforeParamTest.initialize()");14 }15 public BeforeParamTest(int number, boolean result) {16 this.number = number;17 this.result = result;18 }19 public static Collection primeNumbers() {20 return Arrays.asList(new Object[][] {21 { 2, true },22 { 6, false },23 { 19, true },24 { 22, false },25 { 23, true }26 });27 }28 public void testPrimeNumberChecker() {29 System.out.println("Parameterized Number is : " + number);30 assertEquals(result, BeforeParamTest.isPrime(number));31 }32 private static boolean isPrime(int number) {33 for(int i=2; i < (number/2); i++) {34 if(number % i == 0) {35 return false;36 }37 }38 return true;39 }40}41BeforeParamTest.initialize()42BeforeParamTest.initialize()43BeforeParamTest.initialize()44BeforeParamTest.initialize()45BeforeParamTest.initialize()46package com.journaldev.junit;47import org.junit.runners.Parameterized;48import java.util.Arrays;49import java.util.Collection;50import org.junit.Before;51import org.junit.Rule;52import org.junit.Test;53import org.junit.runner.RunWith;54import org.junit.rules.ExpectedException;55import static org.junit.Assert.*;56@RunWith(Parameterized.class)57public class BeforeParamRuleTest {58 private int number;59 private boolean result;60 public ExpectedException thrown = ExpectedException.none();
Annotation Type Parameterized.BeforeParam
Using AI Code Generation
1@RunWith(Parameterized.class)2public class TestJunit1 {3 private String name;4 private int age;5 public TestJunit1(String name, int age) {6 this.name = name;7 this.age = age;8 }9 public String getName() {10 return name;11 }12 public int getAge() {13 return age;14 }15 public static Collection<Object[]> data() {16 Object[][] data = new Object[][] { { "John", 20 }, { "Steve", 30 }, { "Bill", 40 } };17 return Arrays.asList(data);18 }19 public void test() {20 System.out.println("Parameterized name is : " + name);21 System.out.println("Parameterized age is : " + age);22 }23}24@RunWith(Parameterized.class)25public class TestJunit1 {26 private String name;27 private int age;28 public TestJunit1(String name, int age) {29 this.name = name;30 this.age = age;31 }32 public String getName() {33 return name;34 }35 public int getAge() {36 return age;37 }38 public static Collection<Object[]> data() {39 Object[][] data = new Object[][] { { "John", 20 }, { "Steve", 30 }, { "Bill", 40 } };40 return Arrays.asList(data);41 }42 public void test() {43 System.out.println("Parameterized name is : " + name);44 System.out.println("Parameterized age is : " + age);45 }46 public void beforeParam() {47 System.out.println("Before
Annotation Type Parameterized.BeforeParam
Using AI Code Generation
1@RunWith(Parameterized.class)2public class ParameterizedTest {3 private int number;4 public ParameterizedTest(int number) {5 this.number = number;6 }7 public static Collection<Object[]> data() {8 Object[][] data = new Object[][] { { 1 }, { 2 }, { 3 }, { 4 }, { 5 } };9 return Arrays.asList(data);10 }11 public void test() {12 assertTrue(number > 0 && number < 6);13 }14}15@RunWith(Parameterized.class)16public class ParameterizedTest {17public ParameterizedTest(int number) {18this.number = number;19public static Collection<Object[]> data() {20Object[][] data = new Object[][] { { 1 }, { 2 }, { 3 }, { 4 }, { 5 } };21return Arrays.asList(data);22assertTrue(number > 0 && number < 6);23I am using JUnit 4.12 and I have imported the following:24import org.junit.Test;25import org
JUnit Tutorial:
LambdaTest also has a detailed JUnit tutorial explaining its features, importance, advanced use cases, best practices, and more to help you get started with running your automation testing scripts.
JUnit Tutorial Chapters:
Here are the detailed JUnit testing chapters to help you get started:
- Importance of Unit testing - Learn why Unit testing is essential during the development phase to identify bugs and errors.
- Top Java Unit testing frameworks - Here are the upcoming JUnit automation testing frameworks that you can use in 2023 to boost your unit testing.
- What is the JUnit framework
- Why is JUnit testing important - Learn the importance and numerous benefits of using the JUnit testing framework.
- Features of JUnit - Learn about the numerous features of JUnit and why developers prefer it.
- JUnit 5 vs. JUnit 4: Differences - Here is a complete comparison between JUnit 5 and JUnit 4 testing frameworks.
- Setting up the JUnit environment - Learn how to set up your JUnit testing environment.
- Getting started with JUnit testing - After successfully setting up your JUnit environment, this chapter will help you get started with JUnit testing in no time.
- Parallel testing with JUnit - Parallel Testing can be used to reduce test execution time and improve test efficiency. Learn how to perform parallel testing with JUnit.
- Annotations in JUnit - When writing automation scripts with JUnit, we can use JUnit annotations to specify the type of methods in our test code. This helps us identify those methods when we run JUnit tests using Selenium WebDriver. Learn in detail what annotations are in JUnit.
- Assertions in JUnit - Assertions are used to validate or test that the result of an action/functionality is the same as expected. Learn in detail what assertions are and how to use them while performing JUnit testing.
- Parameterization in JUnit - Parameterized Test enables you to run the same automated test scripts with different variables. By collecting data on each method's test parameters, you can minimize time spent on writing tests. Learn how to use parameterization in JUnit.
- Nested Tests In JUnit 5 - A nested class is a non-static class contained within another class in a hierarchical structure. It can share the state and setup of the outer class. Learn about nested annotations in JUnit 5 with examples.
- Best practices for JUnit testing - Learn about the best practices, such as always testing key methods and classes, integrating JUnit tests with your build, and more to get the best possible results.
- Advanced Use Cases for JUnit testing - Take a deep dive into the advanced use cases, such as how to run JUnit tests in Jupiter, how to use JUnit 5 Mockito for Unit testing, and more for JUnit testing.
JUnit Certification:
You can also check out our JUnit certification if you wish to take your career in Selenium automation testing with JUnit to the next level.
Run junit automation tests on LambdaTest cloud grid
Perform automation testing on 3000+ real desktop and mobile devices online.
Try LambdaTest Now !!
Get 100 minutes of automation test minutes FREE!!
Was this article helpful?
