{"id":26776,"date":"2020-02-15T07:14:09","date_gmt":"2020-02-15T07:14:09","guid":{"rendered":"https:\/\/www.testingdocs.com\/questions\/?p=26776"},"modified":"2025-05-17T07:12:36","modified_gmt":"2025-05-17T07:12:36","slug":"how-to-fix-junit-invalid-test-class-error","status":"publish","type":"post","link":"https:\/\/www.testingdocs.com\/questions\/how-to-fix-junit-invalid-test-class-error\/","title":{"rendered":"How to Fix JUnit Invalid test class Error"},"content":{"rendered":"

How to Fix JUnit Invalid test class Error<\/h1>\n

Exception Trace<\/h2>\n

org.junit.runners.model.InvalidTestClassError: Invalid test class ‘com.testingdocs.tutorials.TestCaseOne’:
\n1. The class com.testingdocs.tutorials.TestCaseOne is not public.
\n2. Test class should have exactly one public constructor
\nat org.junit.runners.ParentRunner.validate(ParentRunner.java:525)
\nat org.junit.runners.ParentRunner.<init>(ParentRunner.java:102)
\nat org.junit.runners.BlockJUnit4ClassRunner.<init>(BlockJUnit4ClassRunner.java:84)
\nat org.junit.runners.JUnit4.<init>(JUnit4.java:23)<\/p>\n

 <\/p>\n

The error message suggests that your JUnit test class has incorrect visibility or constructor issues.<\/p>\n

\"JUnit<\/p>\n

Possible Fixes<\/h2>\n
\n

Ensure the Test Class is Public<\/h3>\n

Your test class must be declared as public<\/code>:<\/p>\n

\npackage com.testingdocs.tutorials;\n\nimport org.junit.Test;\nimport static org.junit.Assert.assertTrue;\n\npublic class TestCaseOne {  \/\/ Ensure the class is public\n\n    @Test\n    public void testExample() {\n        assertTrue(true);\n    }\n}\n            <\/code><\/pre>\n<\/div>\n
\n
Ensure There is Only One Public Constructor<\/h3>\n
JUnit test classes should have only one public constructor<\/strong>. If you have multiple constructors, remove the extra ones.<\/p>\n
Incorrect:<\/strong><\/p>\n
\npublic class TestCaseOne {\n    public TestCaseOne() {}  \/\/ Default constructor (OK)\n    public TestCaseOne(String param) {}  \/\/ Extra constructor (INVALID)\n}\n            <\/code><\/pre>\n
Correct:<\/strong><\/p>\n
\npublic class TestCaseOne {\n    public TestCaseOne() {}  \/\/ OK\n}\n            <\/code><\/pre>\n<\/div>\n
\n
Ensure JUnit is Using the Correct Runner<\/h3>\n
If you are using JUnit 4, add the correct runner annotation:<\/p>\n
\nimport org.junit.runner.RunWith;\nimport org.junit.runners.JUnit4;\n\n@RunWith(JUnit4.class)\npublic class TestCaseOne {\n    @Test\n    public void testExample() {\n        assertTrue(true);\n    }\n}\n            <\/code><\/pre>\n
For JUnit 5 (Jupiter)<\/strong>, no runner annotation is needed:<\/p>\n
\nimport org.junit.jupiter.api.Test;\nimport static org.junit.jupiter.api.Assertions.assertTrue;\n\npublic class TestCaseOne {\n    @Test\n    void testExample() {\n        assertTrue(true);\n    }\n}\n            <\/code><\/pre>\n<\/div>\n
\n
Ensure the Test Class is Not a Nested (Inner) Class<\/h3>\n
If your test class is an inner class, it must be static<\/code>:<\/p>\n
\npublic class OuterClass {\n    public static class TestCaseOne {  \/\/ Must be static\n        @Test\n        public void testExample() {\n            assertTrue(true);\n        }\n    }\n}\n            <\/code><\/pre>\n<\/div>\n
Final Checklist<\/h2>\n
    \n
  • \u2705 Class is public<\/code><\/li>\n
  • \u2705 Only one<\/strong> (or no) constructor<\/li>\n
  • \u2705 No extra constructor parameters<\/li>\n
  • \u2705 Proper @Test<\/code> annotations<\/li>\n
  • \u2705 Using correct JUnit version<\/li>\n<\/ul>\n
    After applying these fixes, try running the test again.<\/p>\n","protected":false},"excerpt":{"rendered":"
    How to Fix JUnit Invalid test class Error Exception Trace org.junit.runners.model.InvalidTestClassError: Invalid test class ‘com.testingdocs.tutorials.TestCaseOne’: 1. The class com.testingdocs.tutorials.TestCaseOne is not public. 2. Test class should have exactly one public constructor at org.junit.runners.ParentRunner.validate(ParentRunner.java:525) at org.junit.runners.ParentRunner.<init>(ParentRunner.java:102) at org.junit.runners.BlockJUnit4ClassRunner.<init>(BlockJUnit4ClassRunner.java:84) at org.junit.runners.JUnit4.<init>(JUnit4.java:23)   The error message suggests that your JUnit test class has incorrect visibility or constructor issues. […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[40],"tags":[],"class_list":["post-26776","post","type-post","status-publish","format-standard","hentry","category-java","has-post-title","has-post-date","has-post-category","has-post-tag","has-post-comment","has-post-author",""],"_links":{"self":[{"href":"https:\/\/www.testingdocs.com\/questions\/wp-json\/wp\/v2\/posts\/26776","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.testingdocs.com\/questions\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.testingdocs.com\/questions\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.testingdocs.com\/questions\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.testingdocs.com\/questions\/wp-json\/wp\/v2\/comments?post=26776"}],"version-history":[{"count":7,"href":"https:\/\/www.testingdocs.com\/questions\/wp-json\/wp\/v2\/posts\/26776\/revisions"}],"predecessor-version":[{"id":27414,"href":"https:\/\/www.testingdocs.com\/questions\/wp-json\/wp\/v2\/posts\/26776\/revisions\/27414"}],"wp:attachment":[{"href":"https:\/\/www.testingdocs.com\/questions\/wp-json\/wp\/v2\/media?parent=26776"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.testingdocs.com\/questions\/wp-json\/wp\/v2\/categories?post=26776"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.testingdocs.com\/questions\/wp-json\/wp\/v2\/tags?post=26776"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}