現象：
objc[27212]: Class JavaLaunchHelper is implemented in both /Library/Java/JavaVirtualMachines/jdk1.8.0_121.jdk/Contents/Home/bin/java and /Library/Java/JavaVirtualMachines/jdk1.8.0_121.jdk/Contents/Home/jre/lib/libinstrument.dylib. One of the two will be used. Which one is undefined.
java.lang.AbstractMethodError: javax.xml.parsers.DocumentBuilderFactory.setFeature(Ljava/lang/String;Z)V
解決:
System.setProperty("javax.xml.parsers.DocumentBuilderFactory","com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderFactoryImpl");