EhCache索引查看器

Question

对于 Lucene，我们有一个很好的工具箱，例如 Luke 来查看、诊断、编辑等。我们是否有类似的 EhCache 工具（至少显示）（当我们启用 diskPersistent 时）？

Answer 1

我不知道有任何这样的工具，并且文件格式并未真正指定或定义为 API。基本上，EhCache 将序列化对象写入数据和索引文件。如果直接访问文件，您可以读取并显示它们。为了让您继续前进，这里有一个程序作为起点：

  import java.io.ByteArrayInputStream;
  import java.io.EOFException;
  import java.io.FileInputStream;
  import java.io.ObjectInputStream;
  import java.io.RandomAccessFile;
  import java.lang.reflect.Field;

  import net.sf.ehcache.Element;
  import net.sf.ehcache.store.disk.DiskStorageFactory.DiskMarker;

  public class EhcacheViewer
  {

     public static void main( String[] args ) throws Exception
     {
        final RandomAccessFile data = new RandomAccessFile( "cache/my-cache.data", "r" );
        ObjectInputStream ois = new ObjectInputStream( new FileInputStream( "cache/my-cache.index" ) );
        try
        {
           while( true )
           {
              Object key = ois.readObject();
              DiskMarker marker = (DiskMarker) ois.readObject();
              long pos = getPosition( marker );
              int size = marker.getSize();
              data.seek( pos );
              byte[] value = new byte[size];
              data.readFully( value );
              ObjectInputStream ois2 = new ObjectInputStream( new ByteArrayInputStream( value ) );
              Element element = (Element) ois2.readObject();
              System.out.println( "Element: " + element );
           }
        }
        catch( EOFException e )
        {
           // ...
        }
        ois.close();
        data.close();
     }

     private static long getPosition( DiskMarker marker ) throws Exception
     {
        Field field = marker.getClass().getDeclaredField( "position" );
        field.setAccessible( true );
        return (Long) field.get( marker );
     }

  }