Lucene-Appengine的SegmentIndexInput readByte方法中的NullPointerException

Question

我從運行Lucene得到以下錯誤跟蹤。 我包括提示錯誤的代碼段。 具體的項目/連接器是Lucene for Appengine

碼

public static void resetAllIndicesUsingDatastore() {
    LOG.info("Inside  resetAllIndicesUsingDatastore ");
    StandardAnalyzer analyzer = new StandardAnalyzer();
    GaeDirectory directory = new GaeDirectory(LuceneWorker.DOGS);// create dog index
    IndexWriterConfig config = GaeLuceneUtil.getIndexWriterConfig(LuceneWorker.LUCENE_VERSION, analyzer);
    IndexWriter writer = null;
    LOG.info("GOING TO TRY ");
    try {
      // delete all elements
      writer = new IndexWriter(directory, config);//LINE 142
      LOG.info("Going to delete all that's there ");
      writer.deleteAll();
      writer.commit();

      // get all dogs from datastore
      List<Dog> dogs = DogDaoImpl.getAll();
      LOG.info("All dogs size is : " + dogs.size());

      for (Dog p : dogs) {
        LuceneIndexDogTaskQueue.indexDog(p.getDogId());
        LOG.info("Dog sent to ask queue for lucene is : " + p.getTitle() + " with id: " + p.getDogId());
      }
      LOG.info("Leaving  resetAllIndicesUsingDatastore with no error ");
    } catch (IOException e) {
      LOG.info("Leaving  resetAllIndicesUsingDatastore with ERROR " + e.getLocalizedMessage() + "   msg:: " + e.getMessage());
      e.printStackTrace();
    } finally {
      if (null != writer) {
        try {
          writer.close();
        } catch (IOException e) {
          e.printStackTrace();
        }
      }
    }

錯誤

com.google.api.server.spi.SystemService invokeServiceMethod: cause={0}
java.lang.NullPointerException
    at com.googlecode.luceneappengine.SegmentIndexInput.readByte(SegmentIndexInput.java:70)
    at org.apache.lucene.store.BufferedChecksumIndexInput.readByte(BufferedChecksumIndexInput.java:41)
    at org.apache.lucene.store.DataInput.readInt(DataInput.java:98)
    at org.apache.lucene.index.SegmentInfos.read(SegmentInfos.java:347)
    at org.apache.lucene.index.SegmentInfos$1.doBody(SegmentInfos.java:458)
    at org.apache.lucene.index.SegmentInfos$FindSegmentsFile.run(SegmentInfos.java:913)
    at org.apache.lucene.index.SegmentInfos$FindSegmentsFile.run(SegmentInfos.java:759)
    at org.apache.lucene.index.SegmentInfos.read(SegmentInfos.java:454)
    at org.apache.lucene.index.IndexWriter.<init>(IndexWriter.java:783)
    at com.company.dogappcloud.taskqueue.lucene.LuceneSearchDog.resetAllIndicesUsingDatastore(LuceneSearchDog.java:142)






//remaining of trace but not as important

at com.company.dogappcloud.dogappApi.findDog(dogappApi.java:968)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:45)
at com.google.api.server.spi.SystemService.invokeServiceMethod(SystemService.java:359)
at com.google.api.server.spi.SystemServiceServlet.execute(SystemServiceServlet.java:160)
at com.google.api.server.spi.SystemServiceServlet.doPost(SystemServiceServlet.java:118)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166)
at com.googlecode.objectify.cache.AsyncCacheFilter.doFilter(AsyncCacheFilter.java:58)
at com.googlecode.objectify.ObjectifyFilter.doFilter(ObjectifyFilter.java:48)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388)
at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at org.mortbay.jetty.Server.handle(Server.java:326)
at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:923)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
at com.google.tracing.TraceContext$TraceContextRunnable.runInContext(TraceContext.java:437)
at com.google.tracing.TraceContext$TraceContextRunnable$1.run(TraceContext.java:444)
at com.google.tracing.CurrentContext.runInContext(CurrentContext.java:230)
at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContextNoUnref(TraceContext.java:308)
at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContext(TraceContext.java:300)
at com.google.tracing.TraceContext$TraceContextRunnable.run(TraceContext.java:441)
at java.lang.Thread.run(Thread.java:745)

這是我的appengine-web.xml文件，我也按照建議使用修改后的RamUsageEstimator

<?xml version="1.0" encoding="utf-8"?>
<appengine-web-app xmlns="http://appengine.google.com/ns/1.0">
    <application>myApplicationId</application>
    <version>1</version>
    <threadsafe>true</threadsafe>

    <system-properties>
        <property name="java.util.logging.config.file" value="WEB-INF/logging.properties"/>
        <property name="java.util.logging.config.file"
                  value="WEB-INF/java-util-logging.properties"/>
        <property name="os.version" value="1.0.GAE whatever"/>
        <property name="os.arch" value="GAE whatever"/>
    </system-properties>

    <class-loader-config>
        <priority-specifier filename="luceneappengine-2.2.0.jar"/>
    </class-loader-config>
</appengine-web-app>

Answer 1

查看SegmentIndexInput hunk的代碼為null。

@Override
    public byte readByte() throws IOException {
70     if(hunkPointer >= hunk.bytes.length) {
                    hunkPointer = 0;

查看GaeDirectory的代碼，null是因為segment沒有創建任何帥哥。 在使用新目錄之前，應調用createOutput(String name)或touchFile(StringName)以便創建至少包含一個touchFile(StringName)段