JVM虚拟机笔记一

 

 

 

public class JavaMethodAreaOOM {
    public static void main(String[] args) {
        while (true) {
            Enhancer enhancer = new Enhancer();
            enhancer.setSuperclass(OOMObject.class);
            enhancer.setUseCache(false);
            enhancer.setCallback(new MethodInterceptor() {
                @Override
                public Object intercept(Object o, Method method, Object[] objects, MethodProxy methodProxy) throws Throwable {
                    return methodProxy.invokeSuper(o,objects);
                }
            });
            enhancer.create();
        }
    }

    static class OOMObject{

    }
}

Exception in thread "main" org.springframework.cglib.core.CodeGenerationException: java.lang.reflect.InvocationTargetException-->null
at org.springframework.cglib.core.AbstractClassGenerator.generate(AbstractClassGenerator.java:345)
at org.springframework.cglib.proxy.Enhancer.generate(Enhancer.java:492)
at org.springframework.cglib.core.AbstractClassGenerator$ClassLoaderData.get(AbstractClassGenerator.java:114)
at org.springframework.cglib.core.AbstractClassGenerator.create(AbstractClassGenerator.java:291)
at org.springframework.cglib.proxy.Enhancer.createHelper(Enhancer.java:480)
at org.springframework.cglib.proxy.Enhancer.create(Enhancer.java:305)
at com.fdy.jvmTest.JavaMethodAreaOOM.main(JavaMethodAreaOOM.java:26)
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springframework.cglib.core.ReflectUtils.defineClass(ReflectUtils.java:459)
at org.springframework.cglib.core.AbstractClassGenerator.generate(AbstractClassGenerator.java:336)
... 6 more
Caused by: java.lang.OutOfMemoryError: Metaspace
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:763)
... 11 more
Java HotSpot(TM) 64-Bit Server VM warning: ignoring option PermSize=10m; support was removed in 8.0

 

 

public class JavaMethodAreaOOM {
    public static void main(String[] args) {
        while (true) {
            Enhancer enhancer = new Enhancer();
            enhancer.setSuperclass(OOMObject.class);
            enhancer.setUseCache(false);
            enhancer.setCallback(new MethodInterceptor() {

                public Object intercept(Object o, Method method, Object[] objects, MethodProxy methodProxy) throws Throwable {
                    return methodProxy.invokeSuper(o,objects);
                }
            });
            enhancer.create();
        }
    }

    static class OOMObject{

    }
}

Exception in thread "main"
Exception: java.lang.OutOfMemoryError thrown from the UncaughtExceptionHandler in thread "main"

在jdk8之后没有设置方法区的内存大小, 默认是-1, 就是说受限于本地内存大小

jdk8之后去掉了jvm的永生代

注意导包

jdk6或者jdk7的用这个

    <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>4.0.1.RELEASE</version>
        </dependency>