从Python NLTK调用斯坦福NER崩溃

我正在尝试使用斯坦福NER标记命名实体.我的代码非常简单:

 from nltk.tag import StanfordNERTagger
 st = StanfordNERTagger('stanford-ner/classifiers/english.all.3class.distsim.crf.ser.gz', 
                        'stanford-ner/stanford-ner.jar', 
                         encoding='utf-8')
 st.tag('Rami Eid is studying at Stony Brook University in NY'.split())

但是,我无法让它发挥作用.我得到的是一个Java异常说:

 Exception in thread "main" java.lang.UnsupportedClassVersionError: edu/stanford/nlp/ie/crf/CRFClassifier : 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 sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:482)

raise OSError('Java command failed : ' + str(cmd))
OSError: Java command failed : [u'/usr/bin/java', '-mx1000m', '-cp', 'stanford-ner/stanford-ner.jar', 
'edu.stanford.nlp.ie.crf.CRFClassifier', '-loadClassifier', 
'stanford-ner/classifiers/english.all.3class.distsim.crf.ser.gz', '-textFile', '/tmp/tmpq3u0oi', '-outputFormat', 'slashTags', '-tokenizerFactory', 
'edu.stanford.nlp.process.WhitespaceTokenizer', 
'-tokenizerOptions', '"tokenizeNLs=false"']

什么可能导致这次崩溃？先感谢您.

您正在使用旧版本的Java.什么是输出/usr/bin/java -version？它至少应该是Java 8.