java.lang.UnsupportedClassVersionError: com/android/apksigner/ApkSignerTool :

在使用linphone的aar 打包时出现，是因为我生成的 aar文件的jdk 版本的问题吗？打包报错内容如下：

Exception in thread \"main\" java.lang.UnsupportedClassVersionError: com/android/apksigner/ApkSignerTool : Unsupported major.minor version 52.0  
at java.lang.ClassLoader.defineClass1(Native Method)  
at java.lang.ClassLoader.defineClassCond(ClassLoader.java:631)  
at java.lang.ClassLoader.defineClass(ClassLoader.java:615)  
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141)  
at java.net.URLClassLoader.defineClass(URLClassLoader.java:283)  
at java.net.URLClassLoader.access$000(URLClassLoader.java:58)  
at java.net.URLClassLoader$1.run(URLClassLoader.java:197)  
at java.security.AccessController.doPrivileged(Native Method)  
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)  
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)  
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)  
at java.lang.ClassLoader.loadClass(ClassLoader.java:247)  
Could not find the main class: com.android.apksigner.ApkSignerTool. Program will exit.