package dao;/** * Berkeley DB interface of DAO * */public interface BerkeleydbDao
    
      {		/**	 * open database	 * */	public void openConnection(String filePath, String databaseName);		/**	 * 关闭数据库	 * */	public void closeConnection();		/**	 * insert	 * */	public void save(String name, T t);		/**	 * delete	 * */	public void delete(String name);		/**	 * update	 * */	public void update(String name, T t);		/**	 * select	 * */	public T get(String name);	}
    

package dao.impl;import java.io.File;import com.sleepycat.bind.EntryBinding;import com.sleepycat.bind.serial.SerialBinding;import com.sleepycat.bind.serial.StoredClassCatalog;import com.sleepycat.collections.StoredMap;import com.sleepycat.je.Database;import com.sleepycat.je.DatabaseConfig;import com.sleepycat.je.Environment;import com.sleepycat.je.EnvironmentConfig;import dao.BerkeleydbDao;/** * 使用StoredMap实现 * */public class BerkeleydbDaoSortedMapImpl
    
      implements BerkeleydbDao
     
       {		Environment env = null;	private Database database = null;	private StoredMap
      
        storedMap = null;	private Class
       
         persistentClass = null;		EntryBinding
        
          keyBinding = null;	SerialBinding
         
           valueBinding = null; public BerkeleydbDaoSortedMapImpl(Class
          
            persistentClass){ this.persistentClass = persistentClass; } @Override public void openConnection(String filePath, String databaseName) { File file = new File(filePath); EnvironmentConfig envConfig = new EnvironmentConfig(); envConfig.setAllowCreate(true); envConfig.setTransactional(true); env = new Environment(file, envConfig); DatabaseConfig databaseConfig = new DatabaseConfig(); databaseConfig.setAllowCreate(true); databaseConfig.setTransactional(true); database = env.openDatabase(null, databaseName, databaseConfig); StoredClassCatalog catalog = new StoredClassCatalog(database); keyBinding = new SerialBinding
           
            (catalog, String.class); valueBinding = new SerialBinding
            
             (catalog, persistentClass); storedMap = new StoredMap
             
              (database, keyBinding, valueBinding, true); } @Override public void closeConnection() { if(database != null){ database.close(); if(env != null){ env.cleanLog(); env.close(); } } } @Override public void delete(String name) { storedMap.remove(name); } @Override public T get(String name) { return storedMap.get(name); } @Override public void save(String name, T t) { storedMap.put(name, t); } @Override public void update(String name, T t) { save(name, t); } }
             
            
           
          
         
        
       
      
     
    

package dao.impl;import java.io.ByteArrayInputStream;import java.io.ByteArrayOutputStream;import java.io.File;import java.io.IOException;import java.io.ObjectInputStream;import java.io.ObjectOutputStream;import com.sleepycat.je.Database;import com.sleepycat.je.DatabaseConfig;import com.sleepycat.je.DatabaseEntry;import com.sleepycat.je.Environment;import com.sleepycat.je.EnvironmentConfig;import com.sleepycat.je.LockMode;import com.sleepycat.je.OperationStatus;import dao.BerkeleydbDao;/** * 通过database对象直接操作 * */public class BerkeleydbDatabaseObjectImpl
    
      implements BerkeleydbDao
     
       {	Environment env = null;	private Database database = null;			@Override	public void openConnection(String filePath, String databaseName) {		File file = new File(filePath);		EnvironmentConfig envConfig = new EnvironmentConfig();		envConfig.setAllowCreate(true);		envConfig.setTransactional(true);		env = new Environment(file, envConfig);		DatabaseConfig databaseConfig = new DatabaseConfig();		databaseConfig.setAllowCreate(true);		databaseConfig.setTransactional(true);		database = env.openDatabase(null, databaseName, databaseConfig);	}		@Override	public void closeConnection() {		if(database != null){			database.close();			if(env != null){				env.cleanLog();				env.close();			}		}	}	@Override	public void delete(String name) {		DatabaseEntry keyEntry = new DatabaseEntry();		keyEntry.setData(name.getBytes());		database.delete(null, keyEntry);	}	@SuppressWarnings("unchecked")	@Override	public T get(String name) {		T t = null;		DatabaseEntry keyEntry = new DatabaseEntry();		DatabaseEntry valueEntry = new DatabaseEntry();		keyEntry.setData(name.getBytes());		if(database.get(null, keyEntry, valueEntry, LockMode.DEFAULT) == OperationStatus.SUCCESS){			ByteArrayInputStream bais = new ByteArrayInputStream(valueEntry.getData());			try {				ObjectInputStream ois = new ObjectInputStream(bais);				t = (T) ois.readObject();			} catch (IOException e) {				e.printStackTrace();			} catch (ClassNotFoundException e) {				e.printStackTrace();			}		}		return t;	}	@Override	public void save(String name, T t) {		DatabaseEntry keyEntry = new DatabaseEntry();		DatabaseEntry valueEntry = new DatabaseEntry();		keyEntry.setData(name.getBytes());		ByteArrayOutputStream baos = new ByteArrayOutputStream();		try {			ObjectOutputStream oos = new ObjectOutputStream(baos);			oos.writeObject(t);		} catch (IOException e) {			e.printStackTrace();		}		valueEntry.setData(baos.toByteArray());		database.put(null, keyEntry, valueEntry);	}	@Override	public void update(String name, T t) {		save(name, t);	}}
     
    

实验证明两种方式存储的数据结构是不一样的，具体是什么样的目前还不清楚，但是如果是第一种方法存储的数据，用第二种是无法读取的，也就是说两者是相互独立的，推荐使用第一种。