ShadowingClassLoader.doLoadClass(String) throws a StringIndexOutOfBoundsException during parsing packageName for the class under the default package(no package) [SPR-4443]

[spring-projects-issues]

Pengling Qian opened SPR-4443 and commented

I have created a test class extended AbstractJpaTests under the default package(i.e. no package). The exception is as follows:
java.lang.StringIndexOutOfBoundsException: String index out of range: -1
at java.lang.String.substring(String.java:1938)
at org.springframework.instrument.classloading.ShadowingClassLoader.doLoadClass(ShadowingClassLoader.java:194)
at org.springframework.instrument.classloading.ShadowingClassLoader.loadClass(ShadowingClassLoader.java:131)
at org.springframework.test.jpa.AbstractJpaTests.runBare(AbstractJpaTests.java:235)
at junit.framework.TestResult$1.protect(TestResult.java:110)
at junit.framework.TestResult.runProtected(TestResult.java:128)
at junit.framework.TestResult.run(TestResult.java:113)
at junit.framework.TestCase.run(TestCase.java:124)
at junit.framework.TestSuite.runTest(TestSuite.java:232)
at junit.framework.TestSuite.run(TestSuite.java:227)
at org.junit.internal.runners.JUnit38ClassRunner.run(JUnit38ClassRunner.java:81)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:38)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:460)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:673)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:386)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:196)

I have reviewd the source code, in method doLoadClass(string name)

...
if (cls.getPackage() == null) {
	String packageName = name.substring(0, name.lastIndexOf('.'));
	definePackage(packageName, null, null, null, null, null, null, null);
}
...

The given name is a fully qualified class name, in this case, it is just a simple class name without any package path. So name.lastIndexOf('.') returned -1, and name.substring(0, -1) threw the StringIndexOutOfBoundsException, an unchecked exception.

---

Affects: 2.0.6, 2.0.7, 2.0.8, 2.5 final, 2.5.1

Backported to: 2.0.9

[spring-projects-issues]

Pengling Qian commented

see #7726, this same bug was not fixed, and exists in 2.0.6+.

[spring-projects-issues]

Juergen Hoeller commented

Indeed, we need to check for the default package there. Thanks for spotting this!

Juergen