@TestInstance(Lifecycle.PER_METHOD)
In JUnit 5, @TestInstance(Lifecycle.PER_METHOD) is the default behavior. When using this lifecycle:
- A new instance of the test class is created for each
@Test method
- Instance variables are not shared between test methods
@BeforeAll and @AfterAll methods must be static
- This provides better isolation between tests
Example - PER_METHOD Default Behavior
package com.logicbig.example;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.TestInstance;
@TestInstance(TestInstance.Lifecycle.PER_METHOD)
public class TestInstancePerMethodTest {
private int counter = 0;
@Test
void testMethod1() {
counter++;
System.out.println("TestMethod1 - Counter: " + counter);
System.out.println("TestMethod1 - Instance: " + this);
}
@Test
void testMethod2() {
counter++;
System.out.println("TestMethod2 - Counter: " + counter);
System.out.println("TestMethod2 - Instance: " + this);
}
@Test
void testMethod3() {
counter++;
System.out.println("TestMethod3 - Counter: " + counter);
System.out.println("TestMethod3 - Instance: " + this);
}
}
mvn test -Dtest=TestInstancePerMethodTest OutputD:\example-projects\junit-5\test-instance\junit-5-test-instance-per-method>mvn test -Dtest=TestInstancePerMethodTest [INFO] Scanning for projects... [INFO] [INFO] -------< com.logicbig.example:junit-5-test-instance-per-method >-------- [INFO] Building junit-5-test-instance-per-method 1.0-SNAPSHOT [INFO] from pom.xml [INFO] --------------------------------[ jar ]--------------------------------- [INFO] [INFO] --- resources:3.3.1:resources (default-resources) @ junit-5-test-instance-per-method --- [WARNING] Using platform encoding (Cp1252 actually) to copy filtered resources, i.e. build is platform dependent! [INFO] skip non existing resourceDirectory D:\example-projects\junit-5\test-instance\junit-5-test-instance-per-method\src\main\resources [INFO] [INFO] --- compiler:3.11.0:compile (default-compile) @ junit-5-test-instance-per-method --- [INFO] No sources to compile [INFO] [INFO] --- resources:3.3.1:testResources (default-testResources) @ junit-5-test-instance-per-method --- [WARNING] Using platform encoding (Cp1252 actually) to copy filtered resources, i.e. build is platform dependent! [INFO] skip non existing resourceDirectory D:\example-projects\junit-5\test-instance\junit-5-test-instance-per-method\src\test\resources [INFO] [INFO] --- compiler:3.11.0:testCompile (default-testCompile) @ junit-5-test-instance-per-method --- [INFO] Nothing to compile - all classes are up to date [INFO] [INFO] --- surefire:3.2.5:test (default-test) @ junit-5-test-instance-per-method --- [INFO] Using auto detected provider org.apache.maven.surefire.junitplatform.JUnitPlatformProvider [INFO] [INFO] ------------------------------------------------------- [INFO] T E S T S [INFO] ------------------------------------------------------- [INFO] Running com.logicbig.example.TestInstancePerMethodTest TestMethod1 - Counter: 1 TestMethod1 - Instance: com.logicbig.example.TestInstancePerMethodTest@20ce78ec TestMethod2 - Counter: 1 TestMethod2 - Instance: com.logicbig.example.TestInstancePerMethodTest@4f18837a TestMethod3 - Counter: 1 TestMethod3 - Instance: com.logicbig.example.TestInstancePerMethodTest@359f7cdf [INFO] Tests run: 3, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.073 s -- in com.logicbig.example.TestInstancePerMethodTest [INFO] [INFO] Results: [INFO] [INFO] Tests run: 3, Failures: 0, Errors: 0, Skipped: 0 [INFO] [INFO] ------------------------------------------------------------------------ [INFO] BUILD SUCCESS [INFO] ------------------------------------------------------------------------ [INFO] Total time: 2.605 s [INFO] Finished at: 2025-12-05T14:03:55+08:00 [INFO] ------------------------------------------------------------------------
Each test method will print counter = 1 because they each get their own instance with counter initialized to 0.
Example ProjectDependencies and Technologies Used: - junit-jupiter-engine 6.0.1 (Module "junit-jupiter-engine" of JUnit)
Version Compatibility: 5.0.0 - 6.0.1 Version compatibilities of junit-jupiter-engine with this example:
- 5.0.0
- 5.0.1
- 5.0.2
- 5.0.3
- 5.1.0
- 5.1.1
- 5.2.0
- 5.3.0
- 5.3.1
- 5.3.2
- 5.4.0
- 5.4.1
- 5.4.2
- 5.5.0
- 5.5.1
- 5.5.2
- 5.6.0
- 5.6.1
- 5.6.2
- 5.6.3
- 5.7.0
- 5.7.1
- 5.7.2
- 5.8.0
- 5.8.1
- 5.8.2
- 5.9.0
- 5.9.1
- 5.9.2
- 5.9.3
- 5.10.0
- 5.10.1
- 5.10.2
- 5.10.3
- 5.10.4
- 5.10.5
- 5.11.0
- 5.11.1
- 5.11.2
- 5.11.3
- 5.11.4
- 5.12.0
- 5.12.1
- 5.12.2
- 5.13.0
- 5.13.1
- 5.13.2
- 5.13.3
- 5.13.4
- 5.14.0
- 5.14.1
- 6.0.0
- 6.0.1
Versions in green have been tested.
- JDK 25
- Maven 3.9.11
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