JDK8遇到LambdaConversionException的

示例代码

@Test
public void testJdkSupportGenericType() {
    dummy("");
}
<T extends Serializable & CharSequence> int dummy(T value) {
    return Optional.ofNullable(value).map(CharSequence::length).orElse(0);
}

在OpenJDK-8u172-b11下
将会抛出异常

java.lang.BootstrapMethodError: call site initialization exception

    at java.lang.invoke.CallSite.makeSite(CallSite.java:341)
    at java.lang.invoke.MethodHandleNatives.linkCallSiteImpl(MethodHandleNatives.java:307)
    at java.lang.invoke.MethodHandleNatives.linkCallSite(MethodHandleNatives.java:297)
    at com.example.ExampleTest.dummy(ExampleTest.java:34)
    at com.example.ExampleTest.testJdkSupportGenericType(ExampleTest.java:30)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
    at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
    at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
    at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)
Caused by: java.lang.invoke.LambdaConversionException: Invalid receiver type interface java.io.Serializable; not a subtype of implementation type interface java.lang.CharSequence
    at java.lang.invoke.AbstractValidatingLambdaMetafactory.validateMetafactoryArgs(AbstractValidatingLambdaMetafactory.java:233)
    at java.lang.invoke.LambdaMetafactory.metafactory(LambdaMetafactory.java:303)
    at java.lang.invoke.CallSite.makeSite(CallSite.java:302)
    ... 10 more

解决方法

• 使用s -> s.length() 替代 CharSequence::length
• 将要用到的泛型放到前边
• 升级到修复了这个问题的JDK

相关问题

• https://stackoverflow.com/questions/27031244/lambdaconversionexception-with-generics-jvm-bug