Java 在Android中使用OpenNLP的POSTaggerMe时出现NullPointerException

我试图在Android应用程序中使用ApacheOpenNLP。我遇到了一个

NullPointerException

。我正在做的步骤如下

训练一个定制的模型

 private POSModel getCustomPosModel() {

        POSModel model = null;
        InputStream dataIn = null;
        ObjectStream<String> lineStream;
        ObjectStream<POSSample> sampleStream = null;

        try {
            dataIn =aManager.open("customPOS.train");
            lineStream = new PlainTextByLineStream(dataIn, "UTF-8");
            sampleStream = new WordTagSampleStream(lineStream);
            model = POSTaggerME.train("en", sampleStream, opennlp.tools.util.model.ModelType.MAXENT, null, null, 5, 5);
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } 
          return model;
    }

完整的堆栈跟踪如下所示

    public String[] tagTokensForInfo(String[] tokens){

    POSModel model =null;
    String[] posTags = null;
    model = getCustomPosModel();
    POSTaggerME posTagger = null;

    posTagger = new POSTaggerME(model);
    posTags = posTagger.tag(tokens);
    System.out.println("The tags and tokens are shown below");
    for(int i=0;i<posTags.length;i++){
        System.out.println("Token : "+tokens[i]+" ,Tags : "+posTags[i]);
    }
    return posTags;
}

04-01 06:13:24.015: E/AndroidRuntime(906): FATAL EXCEPTION: main
04-01 06:13:24.015: E/AndroidRuntime(906): Process: net.viralpatel.android.speechtotextdemo, PID: 906
04-01 06:13:24.015: E/AndroidRuntime(906): java.lang.NullPointerException
04-01 06:13:24.015: E/AndroidRuntime(906):  at opennlp.tools.util.BeamSearch.bestSequences(BeamSearch.java:118)
04-01 06:13:24.015: E/AndroidRuntime(906):  at opennlp.tools.util.BeamSearch.bestSequence(BeamSearch.java:198)
04-01 06:13:24.015: E/AndroidRuntime(906):  at opennlp.tools.postag.POSTaggerME.tag(POSTaggerME.java:227)
04-01 06:13:24.015: E/AndroidRuntime(906):  at opennlp.tools.postag.POSTaggerME.tag(POSTaggerME.java:223)
04-01 06:13:24.015: E/AndroidRuntime(906):  at com.intuit.opennlp.CustomerTagger.tagTokensForInvoiceInfo(CustomerTagger.java:32)
04-01 06:13:24.015: E/AndroidRuntime(906):  at com.intuit.opennlp.ExtractInvoiceInfo.extract(ExtractInvoiceInfo.java:28)
04-01 06:13:24.015: E/AndroidRuntime(906):  at net.viralpatel.android.speechtotextdemo.MainActivity$1.onClick(MainActivity.java:46)
04-01 06:13:24.015: E/AndroidRuntime(906):  at android.view.View.performClick(View.java:4424)
04-01 06:13:24.015: E/AndroidRuntime(906):  at android.view.View$PerformClick.run(View.java:18383)
04-01 06:13:24.015: E/AndroidRuntime(906):  at android.os.Handler.handleCallback(Handler.java:733)
04-01 06:13:24.015: E/AndroidRuntime(906):  at android.os.Handler.dispatchMessage(Handler.java:95)
04-01 06:13:24.015: E/AndroidRuntime(906):  at android.os.Looper.loop(Looper.java:137)
04-01 06:13:24.015: E/AndroidRuntime(906):  at android.app.ActivityThread.main(ActivityThread.java:4998)
04-01 06:13:24.015: E/AndroidRuntime(906):  at java.lang.reflect.Method.invokeNative(Native Method)
04-01 06:13:24.015: E/AndroidRuntime(906):  at java.lang.reflect.Method.invoke(Method.java:515)
04-01 06:13:24.015: E/AndroidRuntime(906):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:777)
04-01 06:13:24.015: E/AndroidRuntime(906):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:593)
04-01 06:13:24.015: E/AndroidRuntime(906):  at dalvik.system.NativeStart.main(Native Method)

有人遇到过这个错误吗，或者你能帮我解决这个问题吗

---

提前感谢

检查MainActivity.java class.hi sid的第46行，它是程序的入口点，它调用extract（）方法，而extract（）方法又调用我前面提到的tagTokensForInfo（）方法，请您详细说明一下您的建议。Thanks@yash从堆栈跟踪中，我看到

extract（）

方法调用了

tagTokensForInvoiceInfo（）

，而不是您定义的ad

tagTokensForInfo（）

。据我所知，没有提到你在堆栈跟踪中发布的方法，你确定程序流吗？@5agado，是真的，两种方法都是一样的，在这里键入时，我犯了一个错误，实际上是tagTokensForInvoiceInfo（）方法本身。没有歧义。@yash好吧，那么根据官方文档，您应该执行类似于

model=POSTaggerME.train（“en”，sampleStream，TrainingParameters.defaultParams（），null，null）

。在您的例子中，问题恰恰与模型有关（它仍然为空）。此外，我认为您正在使用该方法的不推荐版本。

04-01 06:13:24.015: E/AndroidRuntime(906): FATAL EXCEPTION: main
04-01 06:13:24.015: E/AndroidRuntime(906): Process: net.viralpatel.android.speechtotextdemo, PID: 906
04-01 06:13:24.015: E/AndroidRuntime(906): java.lang.NullPointerException
04-01 06:13:24.015: E/AndroidRuntime(906):  at opennlp.tools.util.BeamSearch.bestSequences(BeamSearch.java:118)
04-01 06:13:24.015: E/AndroidRuntime(906):  at opennlp.tools.util.BeamSearch.bestSequence(BeamSearch.java:198)
04-01 06:13:24.015: E/AndroidRuntime(906):  at opennlp.tools.postag.POSTaggerME.tag(POSTaggerME.java:227)
04-01 06:13:24.015: E/AndroidRuntime(906):  at opennlp.tools.postag.POSTaggerME.tag(POSTaggerME.java:223)
04-01 06:13:24.015: E/AndroidRuntime(906):  at com.intuit.opennlp.CustomerTagger.tagTokensForInvoiceInfo(CustomerTagger.java:32)
04-01 06:13:24.015: E/AndroidRuntime(906):  at com.intuit.opennlp.ExtractInvoiceInfo.extract(ExtractInvoiceInfo.java:28)
04-01 06:13:24.015: E/AndroidRuntime(906):  at net.viralpatel.android.speechtotextdemo.MainActivity$1.onClick(MainActivity.java:46)
04-01 06:13:24.015: E/AndroidRuntime(906):  at android.view.View.performClick(View.java:4424)
04-01 06:13:24.015: E/AndroidRuntime(906):  at android.view.View$PerformClick.run(View.java:18383)
04-01 06:13:24.015: E/AndroidRuntime(906):  at android.os.Handler.handleCallback(Handler.java:733)
04-01 06:13:24.015: E/AndroidRuntime(906):  at android.os.Handler.dispatchMessage(Handler.java:95)
04-01 06:13:24.015: E/AndroidRuntime(906):  at android.os.Looper.loop(Looper.java:137)
04-01 06:13:24.015: E/AndroidRuntime(906):  at android.app.ActivityThread.main(ActivityThread.java:4998)
04-01 06:13:24.015: E/AndroidRuntime(906):  at java.lang.reflect.Method.invokeNative(Native Method)
04-01 06:13:24.015: E/AndroidRuntime(906):  at java.lang.reflect.Method.invoke(Method.java:515)
04-01 06:13:24.015: E/AndroidRuntime(906):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:777)
04-01 06:13:24.015: E/AndroidRuntime(906):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:593)
04-01 06:13:24.015: E/AndroidRuntime(906):  at dalvik.system.NativeStart.main(Native Method)