BerkeleyDB 例子

package test;

import java.io.File;
import java.security.MessageDigest;
import com.sleepycat.je.Database;
import com.sleepycat.je.DatabaseConfig;
import com.sleepycat.je.DatabaseEntry;
import com.sleepycat.je.DatabaseException;
import com.sleepycat.je.Environment;
import com.sleepycat.je.EnvironmentConfig;
import com.sleepycat.je.LockMode;
import com.sleepycat.je.OperationStatus;

public class MyBerkeleyDB {

	private Environment env;
	private Database db;
	
	public MyBerkeleyDB() {
	
	}

	public void setUp(String path, long cacheSize) {
		EnvironmentConfig envConfig = new EnvironmentConfig();
		envConfig.setAllowCreate(true);
		envConfig.setCacheSize(cacheSize);
		try {
			env = new Environment(new File(path),envConfig);
		} catch (DatabaseException e) {
			e.printStackTrace();
		}
	}
	
	public void open(String dbName) {
		DatabaseConfig dbConfig = new DatabaseConfig();
		dbConfig.setAllowCreate(true);
		try {
			db = env.openDatabase(null, dbName, dbConfig);
		} catch (DatabaseException e) {
			e.printStackTrace();
		}
	}
	
	public void close() {
		try {
			if(db != null) {
				db.close();
			}
			if(env != null) {
				env.close();
			}
		} catch (DatabaseException e) {
			e.printStackTrace();
		}
	}
	//get
	public String get(String key) throws Exception {
		DatabaseEntry queryKey = new DatabaseEntry();
		DatabaseEntry value = new DatabaseEntry();
		queryKey.setData(key.getBytes("UTF-8"));
		
		OperationStatus status = db.get(null, queryKey, value,
		LockMode.DEFAULT);
		if (status == OperationStatus.SUCCESS) {
			return new String(value.getData());
		}
		return null;
	}
	//put
	public boolean put(String key, String value) throws Exception {
		byte[] theKey = key.getBytes("UTF-8");
		byte[] theValue = value.getBytes("UTF-8");
		OperationStatus status = db.put(null, new DatabaseEntry(theKey),
		new DatabaseEntry(theValue));
		if(status == OperationStatus.SUCCESS) {
			return true;
		}
		return false;
	}
       //delete
       public boolean delete(String key) throws Exception 
	{
		   byte[] theKey = key.getBytes("UTF-8");
		   OperationStatus status = db.delete(null, new DatabaseEntry(theKey));
		   if(status == OperationStatus.SUCCESS) {
		    return true;
		   }
		   return false;
	}
	//update
	public boolean update(String key, String value) throws Exception 
	{
		   byte[] updateKey = key.getBytes("UTF-8");
		   byte[] updateValue = value.getBytes("UTF-8");

		   OperationStatus status = db.put(null, new DatabaseEntry(updateKey), new DatabaseEntry(updateValue));
		   if (status == OperationStatus.SUCCESS) {
		    return true;
		   }
		   return false;
	}
       //md5
	public static String md5(String string) 
	{
		char hexDigits[] = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd',
		'e', 'f' };
		try {
		byte[] bytes = string.getBytes();
		MessageDigest messageDigest = MessageDigest.getInstance("MD5");
		messageDigest.update(bytes);
		byte[] updateBytes = messageDigest.digest();
		int len = updateBytes.length;
		char myChar[] = new char[len * 2];
		int k = 0;
		for (int i = 0; i < len; i++) {
		byte byte0 = updateBytes[i];
		myChar[k++] = hexDigits[byte0 >>> 4 & 0x0f];
		myChar[k++] = hexDigits[byte0 & 0x0f];
		}
		return new String(myChar);
		} catch (Exception e) {
		return null;
		}
	}

	public static void main(String[] args) {
		MyBerkeleyDB mbdb = new MyBerkeleyDB();
		mbdb.setUp("C:/bdb", 1000000);
		mbdb.open("myDB");
		System.out.println("开始向Berkeley DB中存入数据…");
		try {
			//mbdb.put("xp", "I'm in shanghai");
			//System.out.println(mbdb.get("xp"));
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		for(int i=0; i<10000; i++) {
			try {
				String key = "myKey"+i;
				String value = "myValue"+i;
				System.out.println("[" + key + ":" + value + "]");
				mbdb.put(key , value);
			} catch (Exception e) {
				e.printStackTrace();
			}
		}
		mbdb.close();

	}
}