lucene4.2 java.lang.NullPointerException at org.apache.lucene.analysis.standard.StandardTokenizerIm

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最近在学习Lucene时遇到了问题，先上代码：

public class AnalyzerUtil {    public void displayToken(String str, Analyzer a) {        try {            TokenStream stream = a.tokenStream("content", new StringReader(str));//            PositionIncrementAttribute pia = stream.addAttribute(PositionIncrementAttribute.class);            CharTermAttribute cta = stream.addAttribute(CharTermAttribute.class);//            TypeAttribute ta = stream.addAttribute(TypeAttribute.class);            while(stream.incrementToken()) {                System.out.println(cta);            }            System.out.println("---------------------------------------------");        } catch (IOException e) {            e.printStackTrace();        }    }}

public class AnalyzerTest {    private AnalyzerUtil au = null;    @Before    public void before() {        au = new AnalyzerUtil();    }    @Test    public void AnalyzerTest() {        String str = "this is my book,thank you";        StandardAnalyzer a1 = new StandardAnalyzer(Version.LUCENE_42);        au.displayToken(str, a1);    }}

运行结果：

java.lang.NullPointerExceptionat org.apache.lucene.analysis.standard.StandardTokenizerImpl.zzRefill(StandardTokenizerImpl.java:923)at org.apache.lucene.analysis.standard.StandardTokenizerImpl.getNextToken(StandardTokenizerImpl.java:1133)at org.apache.lucene.analysis.standard.StandardTokenizer.incrementToken(StandardTokenizer.java:180)at org.apache.lucene.analysis.standard.StandardFilter.incrementToken(StandardFilter.java:49)at org.apache.lucene.analysis.core.LowerCaseFilter.incrementToken(LowerCaseFilter.java:54)at org.apache.lucene.analysis.util.FilteringTokenFilter.incrementToken(FilteringTokenFilter.java:50)at com.my.test.analyzer.AnalyzerUtil.displayToken(AnalyzerUtil.java:23)at com.my.test.analyzer.AnalyzerTest.AnalyzerTest(AnalyzerTest.java:24)at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)at org.junit.internal.runners.TestMethodRunner.executeMethodBody(TestMethodRunner.java:99)at org.junit.internal.runners.TestMethodRunner.runUnprotected(TestMethodRunner.java:81)at org.junit.internal.runners.BeforeAndAfterRunner.runProtected(BeforeAndAfterRunner.java:34)at org.junit.internal.runners.TestMethodRunner.runMethod(TestMethodRunner.java:75)at org.junit.internal.runners.TestMethodRunner.run(TestMethodRunner.java:45)at org.junit.internal.runners.TestClassMethodsRunner.invokeTestMethod(TestClassMethodsRunner.java:75)at org.junit.internal.runners.TestClassMethodsRunner.run(TestClassMethodsRunner.java:36)at org.junit.internal.runners.TestClassRunner$1.runUnprotected(TestClassRunner.java:42)at org.junit.internal.runners.BeforeAndAfterRunner.runProtected(BeforeAndAfterRunner.java:34)at org.junit.internal.runners.TestClassRunner.run(TestClassRunner.java:52)at org.junit.runner.JUnitCore.run(JUnitCore.java:130)at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:78)at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:212)at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:68)at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)at com.intellij.rt.execution.application.AppMain.main(AppMain.java:140)

解决办法：

在进行incrementToken之前进行reset。问题随之解决。

运行结果：

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