Java.lang.VerifyError with inner class and lambda

Question

The following code compiles, but raises java.lang.VerifyError . The error occurs even if the run () method fails.

 import java.util.HashMap; import java.util.Map; import java.util.function.Function; public class TestCase { public static void main(String[] args) { new TestCase().run(); } public void run() { class Inner { } Map<String, Inner> map = new HashMap<>(); Function<String, Inner> function = (name) -> { Inner i = map.get(name); if (i == null) { i = new Inner(); map.put(name, i); } return i; }; function.apply("test"); } } 

Error:

 Exception in thread "main" java.lang.VerifyError: Bad type on operand stack Exception Details: Location: TestCase.lambda$0(Ljava/util/Map;Ljava/lang/String;)LTestCase$1Inner; @20: invokespecial Reason: Type 'java/util/Map' (current frame, stack[2]) is not assignable to 'TestCase' Current Frame: bci: @20 flags: { } locals: { 'java/util/Map', 'java/lang/String', 'TestCase$1Inner' } stack: { uninitialized 15, uninitialized 15, 'java/util/Map' } Bytecode: 0000000: 2a2b b900 2d02 00c0 0032 4d2c c700 15bb 0000010: 0032 592a b700 344d 2a2b 2cb9 0037 0300 0000020: 572c b0 Stackmap Table: append_frame(@33,Object[#50]) at java.lang.Class.getDeclaredMethods0(Native Method) at java.lang.Class.privateGetDeclaredMethods(Class.java:2688) at java.lang.Class.getMethod0(Class.java:2937) at java.lang.Class.getMethod(Class.java:1771) at sun.launcher.LauncherHelper.validateMainClass(LauncherHelper.java:544) at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:526) 

However, if I translate the "Inner" class as the inner TestCase class (instead of the declaration in the method), the error will disappear. Or, if I use an anonymous class to define a function, the error disappears. This seems to be a problem with the class declared in the method and using lamba.

Is this a JVM bug? Or am I missing something? I am using Oracle Java 8. The error occurs both on the command line and inside Eclipse 4.4.

EDIT: I upgraded to the latest JDK: java version "1.8.0_11" Java (TM) SE Runtime Environment (build 1.8.0_11-b12) Java HotSpot (TM) 64-bit server VM (build 25.11-b03, mixed mode)

When compiling with javac manually and run it fine. If I run a class compiled by Eclipse, it is not. So now I suspect that the Eclipse compiler has an error.

Answer 1

verify that an error occurs when your compiler generates code that is not verified by the verifier. when the "verifier" discovers that the class file, although well-formed, contains some kind of internal inconsistency or security problem. Therefore, this is clearly a problem with your eclipse compiler, as you suggested. he cannot compile these constructions correctly.