bdb数据库java操作手册
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2024-01-22 13:19:28
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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); } }