bdb數據庫java操作手冊

     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;

	/*
	 * 數據庫操作類
	 */
	public class BDB {

	    private static Database bdb; // 數據源
	    private static Environment exampleEnv;// 環境對象
	    private static boolean isrunning = false;// 判斷是否運行

	    /**
	     * 打開數據庫方法
	     */
	    public static void start(String path) {
	        if (isrunning) {
	            return;
	        }
	        /******************** 文件處理 ***********************/
	        File envDir = new File(path);// 操作文件
	        if (!envDir.exists())// 判斷文件路徑是否存在，不存在則創建
	        {
	            envDir.mkdir();// 創建
	        }

	        /******************** 環境配置 ***********************/
	        EnvironmentConfig envConfig = new EnvironmentConfig();
	        envConfig.setTransactional(false); // 不進行事務處理
	        envConfig.setAllowCreate(true); // 如果不存在則創建一個
	        exampleEnv = new Environment(envDir, envConfig);// 通過路徑，設置屬性進行創建

	        /******************* 創建適配器對象 ******************/
	        DatabaseConfig dbConfig = new DatabaseConfig();
	        dbConfig.setTransactional(false); // 不進行事務處理
	        dbConfig.setAllowCreate(true);// 如果不存在則創建一個
	        dbConfig.setSortedDuplicates(true);// 數據分類

	        bdb = exampleEnv.openDatabase(null, "simpleDb", dbConfig); // 使用適配器打開數據庫
	        isrunning = true; // 設定是否運行
	    }

	    /**
	     * 關閉數據庫方法
	     */
	    public static void stop() {
	        if (isrunning) {
	            isrunning = false;
	            bdb.close();
	            exampleEnv.close();
	        }
	    }

	    public static boolean isrunning() {
	        return isrunning;
	    }

	    /**
	     * 數據存儲方法 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); // 存儲數據
	        dataEntry.setData(data);

	        OperationStatus status = bdb.put(null, keyEntry, dataEntry);// 持久化數據

	        if (status != OperationStatus.SUCCESS) {
	            throw new RuntimeException("Data insertion got status " + status);
	        }
	    }

	    /*
	     * 執行獲取,根據key值獲取
	     */
	    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) { //根據key值，進行數據查詢
	            // Recreate the data String.
	            byte[] retData = theData.getData();
	            String foundData = new String(retData);
	            System.out.println("For key: '" + aKey + "' found data: '"
	                    + foundData + "'.");
	        }

	    }


	    /**
	     * 查詢所有，可遍歷數據
	     * 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();

	    }


	    /**
	     *  刪除方法
	     * 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);
	    }


	}