Apache SolrのDataImportHandlerで使用するDataSourceで、7-zipで圧縮されたファイルを読み込むことをできるように拡張したもの。

SevenZFileDataSource.java

package info.pandanote.szdi;

import static org.apache.solr.handler.dataimport.DataImportHandlerException.SEVERE;
import static org.apache.solr.handler.dataimport.DataImportHandlerException.wrapAndThrow;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.io.UnsupportedEncodingException;
import java.lang.invoke.MethodHandles;
import java.nio.charset.StandardCharsets;

import org.apache.solr.handler.dataimport.FileDataSource;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class SevenZFileDataSource extends FileDataSource {
	private static final Logger LOG = LoggerFactory.getLogger(MethodHandles.lookup
			().lookupClass());
	
	@Override
	public Reader getData(String query) {
	     File f = getFile(basePath,query);
	     try {
	       return openStream(f);
	     } catch (Exception e) {
	       wrapAndThrow(SEVERE,e,"Unable to open File : "+f.getAbsolutePath());
	       return null;
	     }
	 }

	static File getFile(String basePath, String query) {
	    try {
	      File file = new File(query);

	      // If it's not an absolute path, try relative from basePath. 
	      if (!file.isAbsolute()) {
	        // Resolve and correct basePath.
	        File basePathFile;
	        if (basePath == null) {
	          basePathFile = new File(".").getAbsoluteFile(); 
	          LOG.warn("FileDataSource.basePath is empty. " +
	              "Resolving to: " + basePathFile.getAbsolutePath());
	        } else {
	          basePathFile = new File(basePath);
	          if (!basePathFile.isAbsolute()) {
	            basePathFile = basePathFile.getAbsoluteFile();
	            LOG.warn("FileDataSource.basePath is not absolute. Resolving to: "
	                + basePathFile.getAbsolutePath());
	          }
	        }

	        file = new File(basePathFile, query).getAbsoluteFile();
	      }

	      if (file.isFile() && file.canRead()) {
	        LOG.debug("Accessing File: " + file.getAbsolutePath());
	        return file;
	      } else {
	        throw new FileNotFoundException("Could not find file: " + query + 
	            " (resolved to: " + file.getAbsolutePath());
	      }
	    } catch (FileNotFoundException e) {
	        throw new RuntimeException(e);
	      }
	}
	
	protected Reader openStream(File file) throws FileNotFoundException,
      UnsupportedEncodingException {
		InputStream is = null;
		if (file.getName().endsWith(".7z")) {
			is = new SevenZFileInputStream(file);
		} else {
			is = new FileInputStream(file);
		}
		if (encoding == null) {
			return new InputStreamReader(is, StandardCharsets.UTF_8);
		} else {
			return new InputStreamReader(is, encoding);
		}
	}
}