Stanford NLP语义分析
环境准备
Eclipse或者IDEA,JDK1.8,Apache Maven(注意,3.5及以后的版本都需要Java8环境才能运行,如果不想在Java8运行的话,请使用以前的版本)。
建立好一个新的Maven工程,在pom文件中加入如下代码:
<properties>
<corenlp.version>3.6.0</corenlp.version>
</properties>
<dependencies>
<dependency>
<groupId>edu.stanford.nlp</groupId>
<artifactId>stanford-corenlp</artifactId>
<version>${corenlp.version}</version>
</dependency>
<dependency>
<groupId>edu.stanford.nlp</groupId>
<artifactId>stanford-corenlp</artifactId>
<version>${corenlp.version}</version>
<classifier>models</classifier>
</dependency>
<dependency>
<groupId>edu.stanford.nlp</groupId>
<artifactId>stanford-corenlp</artifactId>
<version>${corenlp.version}</version>
<classifier>models-chinese</classifier>
</dependency>
</dependencies>
三个依赖包分别是CoreNlp的算法包、英文语料包、中文语料包,由于Maven默认镜像在国外,而Stanford NLP的模型文件很大,因此对网络要求比较高,网速慢的一不小心就time out下载失败了。 解决方法是找一个包含Stanford NLP依赖库的国内镜像,修改Maven的setting,xml中的mirror属性。
英文文本的处理
英文的处理官网也给出了示例代码,我这里只做一下整合,代码如下:
https://stanfordnlp.github.io/CoreNLP/api.html
package edu.zju.cst.krselee.examples.english; import edu.stanford.nlp.dcoref.CorefChain; import edu.stanford.nlp.dcoref.CorefCoreAnnotations; import edu.stanford.nlp.ling.CoreAnnotations; import edu.stanford.nlp.ling.CoreLabel; import edu.stanford.nlp.pipeline.Annotation; import edu.stanford.nlp.pipeline.StanfordCoreNLP; import edu.stanford.nlp.semgraph.SemanticGraph; import edu.stanford.nlp.semgraph.SemanticGraphCoreAnnotations; import edu.stanford.nlp.trees.Tree; import edu.stanford.nlp.trees.TreeCoreAnnotations; import edu.stanford.nlp.util.CoreMap; import java.util.List; import java.util.Map; import java.util.Properties; /** * Created by KrseLee on 2016/11/5. */ public class StanfordEnglishNlpExample { public static void main(String[] args) { StanfordEnglishNlpExample example = new StanfordEnglishNlpExample(); example.runAllAnnotators(); } public void runAllAnnotators(){ // creates a StanfordCoreNLP object, with POS tagging, lemmatization, NER, parsing, and coreference resolution Properties props = new Properties(); props.setProperty("annotators", "tokenize, ssplit, pos, lemma, ner, parse, dcoref"); StanfordCoreNLP pipeline = new StanfordCoreNLP(props); // read some text in the text variable String text = "this is a simple text"; // Add your text here! // create an empty Annotation just with the given text Annotation document = new Annotation(text); // run all Annotators on this text pipeline.annotate(document); parserOutput(document); } public void parserOutput(Annotation document){ // these are all the sentences in this document // a CoreMap is essentially a Map that uses class objects as keys and has values with custom types List<CoreMap> sentences = document.get(CoreAnnotations.SentencesAnnotation.class); for(CoreMap sentence: sentences) { // traversing the words in the current sentence // a CoreLabel is a CoreMap with additional token-specific methods for (CoreLabel token: sentence.get(CoreAnnotations.TokensAnnotation.class)) { // this is the text of the token String word = token.get(CoreAnnotations.TextAnnotation.class); // this is the POS tag of the token String pos = token.get(CoreAnnotations.PartOfSpeechAnnotation.class); // this is the NER label of the token String ne = token.get(CoreAnnotations.NamedEntityTagAnnotation.class); } // this is the parse tree of the current sentence Tree tree = sentence.get(TreeCoreAnnotations.TreeAnnotation.class); System.out.println("语法树:"); System.out.println(tree.toString()); // this is the Stanford dependency graph of the current sentence SemanticGraph dependencies = sentence.get(SemanticGraphCoreAnnotations.CollapsedCCProcessedDependenciesAnnotation.class); System.out.println("依存句法:"); System.out.println(dependencies.toString()); } // This is the coreference link graph // Each chain stores a set of mentions that link to each other, // along with a method for getting the most representative mention // Both sentence and token offsets start at 1! Map<Integer, CorefChain> graph = document.get(CorefCoreAnnotations.CorefChainAnnotation.class); } }
值得注意的是,Stanford NLP采用的是pipeline的方式,给用户一个参数的设置接口,之后的过程全都被封装好了,使用起来非常方便。所有的返回结果都保存在一个<pre>Annotation对象中,根据需要去获取。The Stanford CoreNLP Natural Language Processing Toolkit (http://nlp.stanford.edu/pubs/StanfordCoreNlp2014.pdf)一文中对PileLine方式做了详细的介绍,这里就不多说了,需要提到一点就是参数中,后面的参数往往依赖于前面的参数(直观的讲,就是标注pos依赖于分词tokenize,语法分析paser依赖于标注,等等)。
中文文本的处理
相对于英文来说,中文文本的处理稍微麻烦一点,主要的地方在于一个配置文件。中文语料模型包中有一个默认的配置文件StanfordCoreNLP-chinese.properties,在引入的jar中可以找到。
主要是指定相应pipeline的操作步骤以及对应的语料文件的位置。实际使用中我们可能用不到所有的步骤,或者要使用不同的语料库,因此可以自定义配置文件,再引入代码中。
主要的Java程序代码如下:
package edu.zju.cst.krselee.examples.chinese; import edu.stanford.nlp.dcoref.CorefChain; import edu.stanford.nlp.dcoref.CorefCoreAnnotations; import edu.stanford.nlp.ling.CoreAnnotations; import edu.stanford.nlp.ling.CoreLabel; import edu.stanford.nlp.pipeline.Annotation; import edu.stanford.nlp.pipeline.StanfordCoreNLP; import edu.stanford.nlp.semgraph.SemanticGraph; import edu.stanford.nlp.semgraph.SemanticGraphCoreAnnotations; import edu.stanford.nlp.trees.Tree; import edu.stanford.nlp.trees.TreeCoreAnnotations; import edu.stanford.nlp.util.CoreMap; import edu.stanford.nlp.util.PropertiesUtils; import edu.zju.cst.krselee.examples.english.StanfordEnglishNlpExample; import java.util.List; import java.util.Map; import java.util.Properties; /** * Created by KrseLee on 2016/11/4. */ public class StanfordChineseNlpExample { public static void main(String[] args) { StanfordChineseNlpExample example = new StanfordChineseNlpExample(); example.runChineseAnnotators(); } public void runChineseAnnotators(){ String text = "克林顿说,华盛顿将逐步落实对韩国的经济援助。" + "金大中对克林顿的讲话报以掌声:克林顿总统在会谈中重申,他坚定地支持韩国摆脱经济危机。"; Annotation document = new Annotation(text); StanfordCoreNLP corenlp = new StanfordCoreNLP("StanfordCoreNLP-chinese.properties"); corenlp.annotate(document); parserOutput(document); } public void parserOutput(Annotation document){ // these are all the sentences in this document // a CoreMap is essentially a Map that uses class objects as keys and has values with custom types List<CoreMap> sentences = document.get(CoreAnnotations.SentencesAnnotation.class); for(CoreMap sentence: sentences) { // traversing the words in the current sentence // a CoreLabel is a CoreMap with additional token-specific methods for (CoreLabel token: sentence.get(CoreAnnotations.TokensAnnotation.class)) { // this is the text of the token String word = token.get(CoreAnnotations.TextAnnotation.class); // this is the POS tag of the token String pos = token.get(CoreAnnotations.PartOfSpeechAnnotation.class); // this is the NER label of the token String ne = token.get(CoreAnnotations.NamedEntityTagAnnotation.class); System.out.println(word+"\t"+pos+"\t"+ne); } // this is the parse tree of the current sentence Tree tree = sentence.get(TreeCoreAnnotations.TreeAnnotation.class); System.out.println("语法树:"); System.out.println(tree.toString()); // this is the Stanford dependency graph of the current sentence SemanticGraph dependencies = sentence.get(SemanticGraphCoreAnnotations.CollapsedCCProcessedDependenciesAnnotation.class); System.out.println("依存句法:"); System.out.println(dependencies.toString()); } // This is the coreference link graph // Each chain stores a set of mentions that link to each other, // along with a method for getting the most representative mention // Both sentence and token offsets start at 1! Map<Integer, CorefChain> graph = document.get(CorefCoreAnnotations.CorefChainAnnotation.class); } }

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