java平台，服务端初始化失败。
具体代码如下：
import cn.leancloud.core.AVOSService;
AVOSCloud.initialize("MqXhYrXgsHvuFloa2Trv69X9-gzGzoHsz", "XFP6702yBAp9uId8cgfMyAup");
异常信息：
Caused by: java.lang.UnsupportedClassVersionError: okhttp3/Interceptor : Unsupported major.minor version 52.0
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:800)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:449)
at java.net.URLClassLoader.access$100(URLClassLoader.java:71)
at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
at cn.leancloud.core.AVOSCloud.initialize(AVOSCloud.java:67)
at com.youdao.config.InitServlet.afterPropertiesSet(InitServlet.java:32)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1687)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1624)
... 21 more
