@BeforeParam/@AfterParam for Parameterized runner

src/main/java/org/junit/runners/Parameterized.java

@@ -1,5 +1,6 @@
 package org.junit.runners;
 
+import java.lang.annotation.Annotation;
 import java.lang.annotation.ElementType;
 import java.lang.annotation.Inherited;
 import java.lang.annotation.Retention;
@@ -234,13 +235,54 @@ public class Parameterized extends Suite {
         Class<? extends ParametersRunnerFactory> value() default BlockJUnit4ClassRunnerWithParametersFactory.class;
     }
 
+    /**
+     * Annotation for {@code public static void} methods which should be executed before
+     * evaluating tests with a particular parameter.
+     *
+     * @see org.junit.BeforeClass
+     * @see org.junit.Before
+     * @since 4.13
+     */
+    @Retention(RetentionPolicy.RUNTIME)
+    @Target(ElementType.METHOD)
+    public @interface BeforeParam {
+    }
+
+    /**
+     * Annotation for {@code public static void} methods which should be executed after
+     * evaluating tests with a particular parameter.
+     *
+     * @see org.junit.AfterClass
+     * @see org.junit.After
+     * @since 4.13
+     */
+    @Retention(RetentionPolicy.RUNTIME)
+    @Target(ElementType.METHOD)
+    public @interface AfterParam {
+    }
+
     /**
      * Only called reflectively. Do not use programmatically.
      */
     public Parameterized(Class<?> klass) throws Throwable {
         super(klass, RunnersFactory.createRunnersForClass(klass));
     }
 
+    @Override
+    protected void collectInitializationErrors(List<Throwable> errors) {
+        super.collectInitializationErrors(errors);
+        validatePublicStaticVoidMethods(Parameterized.BeforeParam.class, errors);
+        validatePublicStaticVoidMethods(Parameterized.AfterParam.class, errors);
+    }
+
+    private void validatePublicStaticVoidMethods(Class<? extends Annotation> annotation,
+                                                 List<Throwable> errors) {
+        final List<FrameworkMethod> methods = getTestClass().getAnnotatedMethods(annotation);
+        for (FrameworkMethod eachTestMethod : methods) {
+            eachTestMethod.validatePublicVoid(true, errors);
+        }
+    }
+
     private static class RunnersFactory {
         private static final ParametersRunnerFactory DEFAULT_FACTORY = new BlockJUnit4ClassRunnerWithParametersFactory();
 

src/main/java/org/junit/runners/parameterized/BlockJUnit4ClassRunnerWithParameters.java

@@ -2,15 +2,18 @@
 
 import java.lang.annotation.Annotation;
 import java.lang.reflect.Field;
+import java.util.ArrayList;
 import java.util.List;
 
 import org.junit.runner.RunWith;
 import org.junit.runner.notification.RunNotifier;
 import org.junit.runners.BlockJUnit4ClassRunner;
+import org.junit.runners.Parameterized;
 import org.junit.runners.Parameterized.Parameter;
 import org.junit.runners.model.FrameworkField;
 import org.junit.runners.model.FrameworkMethod;
 import org.junit.runners.model.InitializationError;
+import org.junit.runners.model.MultipleFailureException;
 import org.junit.runners.model.Statement;
 
 /**
@@ -134,8 +137,72 @@ protected void validateFields(List<Throwable> errors) {
     }
 
     @Override
-    protected Statement classBlock(RunNotifier notifier) {
-        return childrenInvoker(notifier);
+    protected Statement classBlock(final RunNotifier notifier) {
+        Statement statement = childrenInvoker(notifier);
+        statement = withBeforeParams(statement);
+        statement = withAfterParams(statement);
+        return statement;
+    }
+
+    private Statement withBeforeParams(Statement statement) {
+        final List<FrameworkMethod> befores = getTestClass()
+                .getAnnotatedMethods(Parameterized.BeforeParam.class);
+        return befores.isEmpty() ? statement : new RunBeforeParams(statement, befores);
+    }
+
+    private class RunBeforeParams extends Statement {
+        private final Statement next;
+        private final List<FrameworkMethod> befores;
+
+        RunBeforeParams(Statement next, List<FrameworkMethod> befores) {
+            this.next = next;
+            this.befores = befores;
+        }
+
+        @Override
+        public void evaluate() throws Throwable {
+            for (FrameworkMethod before : befores) {
+                final int paramCount = before.getMethod().getParameterTypes().length;
+                before.invokeExplosively(null, paramCount == 0 ? (Object[]) null : parameters);
+            }
+            next.evaluate();
+        }
+    }
+
+    private Statement withAfterParams(Statement statement) {
+        final List<FrameworkMethod> afters = getTestClass()
+                .getAnnotatedMethods(Parameterized.AfterParam.class);
+        return afters.isEmpty() ? statement : new RunAfterParams(statement, afters);
+    }
+
+    private class RunAfterParams extends Statement {
+        private final Statement next;
+        private final List<FrameworkMethod> afters;
+
+        RunAfterParams(Statement next, List<FrameworkMethod> afters) {
+            this.next = next;
+            this.afters = afters;
+        }
+
+        @Override
+        public void evaluate() throws Throwable {
+            final List<Throwable> errors = new ArrayList<Throwable>();
+            try {
+                next.evaluate();
+            } catch (Throwable e) {
+                errors.add(e);
+            } finally {
+                for (FrameworkMethod each : afters) {
+                    try {
+                        final int paramCount = each.getMethod().getParameterTypes().length;
+                        each.invokeExplosively(null, paramCount == 0 ? (Object[]) null : parameters);
+                    } catch (Throwable e) {
+                        errors.add(e);
+                    }
+                }
+            }
+            MultipleFailureException.assertEmpty(errors);
+        }
     }
 
     @Override

src/test/java/org/junit/tests/running/classes/ParameterizedTestTest.java

@@ -3,8 +3,8 @@
 import static java.util.Arrays.asList;
 import static org.hamcrest.CoreMatchers.allOf;
 import static org.hamcrest.CoreMatchers.containsString;
+import static org.hamcrest.MatcherAssert.assertThat;
 import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertThat;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 import static org.junit.experimental.results.PrintableResult.testResult;
@@ -16,6 +16,7 @@
 
 import org.junit.AfterClass;
 import org.junit.BeforeClass;
+import org.junit.FixMethodOrder;
 import org.junit.Test;
 import org.junit.runner.Description;
 import org.junit.runner.JUnitCore;
@@ -24,6 +25,7 @@
 import org.junit.runner.RunWith;
 import org.junit.runner.Runner;
 import org.junit.runner.notification.Failure;
+import org.junit.runners.MethodSorters;
 import org.junit.runners.Parameterized;
 import org.junit.runners.Parameterized.Parameter;
 import org.junit.runners.Parameterized.Parameters;
@@ -259,6 +261,92 @@ public void beforeAndAfterClassAreRun() {
         assertEquals("before after ", fLog);
     }
 
+    @RunWith(Parameterized.class)
+    @FixMethodOrder(MethodSorters.NAME_ASCENDING)
+    public static class BeforeParamAndAfterParam {
+        @BeforeClass
+        public static void before() {
+            fLog += "beforeClass ";
+        }
+
+        @Parameterized.BeforeParam
+        public static void beforeParam(String x) {
+            fLog += "before(" + x + ") ";
+        }
+
+        @Parameterized.AfterParam
+        public static void afterParam() {
+            fLog += "afterParam ";
+        }
+
+        @AfterClass
+        public static void after() {
+            fLog += "afterClass ";
+        }
+
+        private final String x;
+
+        public BeforeParamAndAfterParam(String x) {
+            this.x = x;
+        }
+
+        @Parameters
+        public static Collection<String> data() {
+            return Arrays.asList("A", "B");
+        }
+
+        @Test
+        public void first() {
+            fLog += "first(" + x + ") ";
+        }
+
+        @Test
+        public void second() {
+            fLog += "second(" + x + ") ";
+        }
+    }
+
+    @Test
+    public void beforeParamAndAfterParamAreRun() {
+        fLog = "";
+        final Result result = JUnitCore.runClasses(BeforeParamAndAfterParam.class);
+        assertEquals(0, result.getFailureCount());
+        assertEquals("beforeClass before(A) first(A) second(A) afterParam "
+                + "before(B) first(B) second(B) afterParam afterClass ", fLog);
+    }
+
+    @RunWith(Parameterized.class)
+    public static class BeforeParamAndAfterParamError {
+        @Parameterized.BeforeParam
+        public void beforeParam(String x) {
+        }
+
+        @Parameterized.AfterParam
+        private static void afterParam() {
+        }
+
+        public BeforeParamAndAfterParamError(String x) {
+        }
+
+        @Parameters
+        public static Collection<String> data() {
+            return Arrays.asList("A", "B");
+        }
+
+        @Test
+        public void test() {
+        }
+    }
+
+    @Test
+    public void beforeParamAndAfterParamValidation() {
+        fLog = "";
+        final Result result = JUnitCore.runClasses(BeforeParamAndAfterParamError.class);
+        assertEquals(1, result.getFailureCount());
+        assertThat(result.getFailures().get(0).getMessage(), containsString("beforeParam() should be static"));
+        assertThat(result.getFailures().get(0).getMessage(), containsString("afterParam() should be public"));
+    }
+
     @RunWith(Parameterized.class)
     static public class EmptyTest {
         @BeforeClass