bdb数据库java操作手册

     package demos.bdb;
	 
	import java.io.File;
	import com.sleepycat.je.Cursor;
	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 com.sleepycat.je.Transaction;
	import com.sleepycat.je.TransactionConfig;
	 
	/*
	 * 数据库操作类
	 */
	public class BDB {
	 
	    private static Database bdb; // 数据源
	    private static Environment exampleEnv;// 环境对象
	    private static boolean isrunning = false;// 判断是否运行
	 
	    /**
	     * 打开数据库方法
	     */
	    public static void start(String path) {
	        if (isrunning) {
	            return;
	        }
	        /******************** 文件处理 ***********************/
	        File envDir = new File(path);// 操作文件
	        if (!envDir.exists())// 判断文件路径是否存在，不存在则创建
	        {
	            envDir.mkdir();// 创建
	        }
	 
	        /******************** 环境配置 ***********************/
	        EnvironmentConfig envConfig = new EnvironmentConfig();
	        envConfig.setTransactional(false); // 不进行事务处理
	        envConfig.setAllowCreate(true); // 如果不存在则创建一个
	        exampleEnv = new Environment(envDir, envConfig);// 通过路径，设置属性进行创建
	 
	        /******************* 创建适配器对象 ******************/
	        DatabaseConfig dbConfig = new DatabaseConfig();
	        dbConfig.setTransactional(false); // 不进行事务处理
	        dbConfig.setAllowCreate(true);// 如果不存在则创建一个
	        dbConfig.setSortedDuplicates(true);// 数据分类
	 
	        bdb = exampleEnv.openDatabase(null, "simpleDb", dbConfig); // 使用适配器打开数据库
	        isrunning = true; // 设定是否运行
	    }
	 
	    /**
	     * 关闭数据库方法
	     */
	    public static void stop() {
	        if (isrunning) {
	            isrunning = false;
	            bdb.close();
	            exampleEnv.close();
	        }
	    }
	 
	    public static boolean isrunning() {
	        return isrunning;
	    }
	 
	    /**
	     * 数据存储方法 set(Here describes this method function with a few words)
	     *
	     * TODO(Here describes this method to be suitable the condition - to be
	     * possible to elect)
	     *
	     * @param key
	     * @param data
	     *
	     *            void
	     */
	    public static void set(byte[] key, byte[] data) {
	        DatabaseEntry keyEntry = new DatabaseEntry();
	        DatabaseEntry dataEntry = new DatabaseEntry();
	        keyEntry.setData(key); // 存储数据
	        dataEntry.setData(data);
	 
	        OperationStatus status = bdb.put(null, keyEntry, dataEntry);// 持久化数据
	 
	        if (status != OperationStatus.SUCCESS) {
	            throw new RuntimeException("Data insertion got status " + status);
	        }
	    }
	 
	    /*
	     * 执行获取,根据key值获取
	     */
	    public static void selectByKey(String aKey) {
	        DatabaseEntry theKey =null;
	        DatabaseEntry theData = new DatabaseEntry();
	        try {
	             theKey = new DatabaseEntry(aKey.getBytes("utf-8"));
	        } catch (Exception e) {
	            // TODO Auto-generated catch block
	            e.printStackTrace();
	        }
	     
	         
	        if (bdb.get(null,theKey, theData,
	                LockMode.DEFAULT) == OperationStatus.SUCCESS) { //根据key值，进行数据查询
	            // Recreate the data String.
	            byte[] retData = theData.getData();
	            String foundData = new String(retData);
	            System.out.println("For key: '" + aKey + "' found data: '"
	                    + foundData + "'.");
	        }
	         
	    }
	     
	     
	    /**
	     * 查询所有，可遍历数据
	     * selectAll(Here describes this method function with a few words)  
	     *
	     * TODO(Here describes this method to be suitable the condition - to be possible to elect)
	     * 
	     *
	     * void
	     */
	    public static void selectAll() {
	        Cursor cursor = null;
	        cursor=bdb.openCursor(null, null);
	        DatabaseEntry theKey=null;
	        DatabaseEntry theData=null;    
	        theKey = new DatabaseEntry();
	        theData = new DatabaseEntry();
	         
	        while (cursor.getNext(theKey, theData, LockMode.DEFAULT) == OperationStatus.SUCCESS) {
	            System.out.println(new String(theData.getData()));
	        }
	        cursor.close();
	         
	    }
	     
	     
	    /**
	     *  删除方法
	     * delete(Here describes this method function with a few words)  
	     *
	     * TODO(Here describes this method to be suitable the condition - to be possible to elect)
	     *
	     * @param key
	     *
	     * void
	     */
	    public static void delete(String key) {
	        DatabaseEntry keyEntry =null;
	        try {
	            keyEntry = new DatabaseEntry(key.getBytes("utf-8"));
	        } catch (Exception e) {
	            e.printStackTrace();
	        }
	        bdb.delete(null, keyEntry);
	    }
	     
	     
	}