import org.apache.lucene.codecs.StoredFieldsWriter; //导入依赖的package包/类
/**
 *
 * @return The number of documents in all of the readers
 * @throws CorruptIndexException if the index is corrupt
 * @throws IOException if there is a low-level IO error
 */
private int mergeFields() throws IOException {
  final StoredFieldsWriter fieldsWriter = codec.storedFieldsFormat().fieldsWriter(directory, mergeState.segmentInfo, context);
  
  try {
    return fieldsWriter.merge(mergeState);
  } finally {
    fieldsWriter.close();
  }
}
 

import org.apache.lucene.codecs.StoredFieldsWriter; //导入依赖的package包/类
@Override
public StoredFieldsWriter fieldsWriter(Directory directory, SegmentInfo si, IOContext context) throws IOException {
  if (random.nextInt(100) == 0) {
    throw new IOException("Fake IOException from StoredFieldsFormat.fieldsWriter()");
  }
  return new CrankyStoredFieldsWriter(delegate.fieldsWriter(directory, si, context), random);
}
 

import org.apache.lucene.codecs.StoredFieldsWriter; //导入依赖的package包/类
@Override
public StoredFieldsWriter fieldsWriter(Directory directory, SegmentInfo si,
    IOContext context) throws IOException {
  return new Lucene40StoredFieldsWriter(directory, si.name, context);
}
 

import org.apache.lucene.codecs.StoredFieldsWriter; //导入依赖的package包/类
@Override
public StoredFieldsWriter fieldsWriter(Directory directory, SegmentInfo si,
    IOContext context) throws IOException {
  return new CompressingStoredFieldsWriter(directory, si, segmentSuffix, context,
      formatName, compressionMode, chunkSize);
}
 

import org.apache.lucene.codecs.StoredFieldsWriter; //导入依赖的package包/类
@Override
public StoredFieldsWriter fieldsWriter(Directory directory, SegmentInfo si,
    IOContext context) throws IOException {
  throw new UnsupportedOperationException("this codec can only be used for reading");
}
 

import org.apache.lucene.codecs.StoredFieldsWriter; //导入依赖的package包/类
@Override
public StoredFieldsWriter fieldsWriter(Directory directory, SegmentInfo si, IOContext context) throws IOException {
  throw new UnsupportedOperationException("this codec can only be used for reading");
}
 

import org.apache.lucene.codecs.StoredFieldsWriter; //导入依赖的package包/类
@Override
public StoredFieldsWriter fieldsWriter(Directory directory, SegmentInfo si, IOContext context) throws IOException {
  return new SimpleTextStoredFieldsWriter(directory, si.name, context);
}
 

import org.apache.lucene.codecs.StoredFieldsWriter; //导入依赖的package包/类
@Override
public StoredFieldsWriter fieldsWriter(Directory directory, SegmentInfo si, IOContext context) throws IOException {
  return new AssertingStoredFieldsWriter(in.fieldsWriter(directory, si, context));
}
 

import org.apache.lucene.codecs.StoredFieldsWriter; //导入依赖的package包/类
AssertingStoredFieldsWriter(StoredFieldsWriter in) {
  this.in = in;
  this.docStatus = Status.UNDEFINED;
}
 

import org.apache.lucene.codecs.StoredFieldsWriter; //导入依赖的package包/类
@Override
public StoredFieldsWriter fieldsWriter(Directory directory, SegmentInfo segmentInfo, IOContext context) throws IOException {
  return new PreFlexRWStoredFieldsWriter(directory, segmentInfo.name, context);
}
 

import org.apache.lucene.codecs.StoredFieldsWriter; //导入依赖的package包/类
CrankyStoredFieldsWriter(StoredFieldsWriter delegate, Random random) {
  this.delegate = delegate;
  this.random = random;
}
 

import org.apache.lucene.codecs.StoredFieldsWriter; //导入依赖的package包/类
@Override
public StoredFieldsWriter fieldsWriter(Directory directory, SegmentInfo si, IOContext context) throws IOException {
  return new CompressingStoredFieldsWriter(directory, si, SEGMENT_SUFFIX, context, FORMAT_NAME, _compressionMode,
      _chunkSize);
}