In JUnit 5, they came up with an annotation that does just that – run a test method n times. Introducing @RepeatedTest(int value). You may read more about it in JUnit 5 User Guide.

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However, we will demonstrates how to perform repeated tests in JUnit 4 for this post. It involves creating a class that implements the TestRule interface, another class that implements Statement interface and a new annotation.

The Annotation class

This annotation will be used along side the @Test annotation.

package com.turreta.junit4.repeatedtest.util;

import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

@Retention(RetentionPolicy.RUNTIME)
@Target({ java.lang.annotation.ElementType.METHOD })
public @interface RepeatTest
{
	int times();
}

package com.turreta.junit4.repeatedtest.util;

import java.lang.annotation.Retention;

import java.lang.annotation.RetentionPolicy;

import java.lang.annotation.Target;

@Retention(RetentionPolicy.RUNTIME)

@Target({ java.lang.annotation.ElementType.METHOD })

public @interface RepeatTest

{

int times();

}

RepeatableTestStatement class

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package com.turreta.junit4.repeatedtest.util;

import org.junit.runners.model.Statement;

public class RepeatableTestStatement extends Statement
{
	private final int times;
	private final Statement statement;

	private RepeatableTestStatement(int times, Statement statement)
	{
		this.times = times;
		this.statement = statement;
	}

	@Override
	public void evaluate() throws Throwable
	{
		for(int i = 0; i < times; i++)
		{
			statement.evaluate();
		}
	}
}

package com.turreta.junit4.repeatedtest.util;

import org.junit.runners.model.Statement;

public class RepeatableTestStatement extends Statement

{

private final int times;

private final Statement statement;

private RepeatableTestStatement(int times, Statement statement)

{

this.times = times;

this.statement = statement;

}

@Override

public void evaluate() throws Throwable

{

for(int i = 0; i < times; i++)

{

statement.evaluate();

}

RepeatedTestRule class

package com.turreta.junit4.repeatedtest.util;

import org.junit.rules.TestRule;
import org.junit.runner.Description;
import org.junit.runners.model.Statement;

public class RepeatedTestRule implements TestRule
{
	@Override
	public Statement apply(Statement statement, Description description)
	{
		Statement result = statement;
		RepeatTest repeat = description.getAnnotation(RepeatTest.class);
		if(repeat != null)
		{
			int times = repeat.times();
			result = new RepeatableTestStatement(times, statement);
		}
		return result;
	}
}

package com.turreta.junit4.repeatedtest.util;

import org.junit.rules.TestRule;

import org.junit.runner.Description;

import org.junit.runners.model.Statement;

public class RepeatedTestRule implements TestRule

{

@Override

public Statement apply(Statement statement, Description description)

{

Statement result = statement;

RepeatTest repeat = description.getAnnotation(RepeatTest.class);

if(repeat != null)

{

int times = repeat.times();

result = new RepeatableTestStatement(times, statement);

}

return result;

}

Put it all together

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package com.turreta.junit4.repeatedtest;

import com.turreta.junit4.repeatedtest.util.RepeatTest;
import com.turreta.junit4.repeatedtest.util.RepeatedTestRule;
import org.junit.Rule;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

@RunWith(SpringRunner.class)
@SpringBootTest
public class ComTurretaJunit4RepeatedtestApplicationTests {

	@Rule
	public RepeatedTestRule repeatRule = new RepeatedTestRule();

	@Test
	@RepeatTest(times = 7)
	public void repeatedTestExample() {
		System.out.println("Test example");
	}
}