top sync user session serivice

XinDianBaoSessionService.java

package com.xindianbao.isv;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.concurrent.ExecutionException;

import com.google.common.cache.CacheBuilder;
import com.google.common.cache.CacheLoader;
import com.google.common.cache.LoadingCache;
import com.taobao.top.syncserver.Configuration;
import com.taobao.top.syncserver.service.ISessionService;
import com.taobao.top.syncserver.util.Constant;

/**
 * 这里只是简单的读取 MySQL 的数据，所以就不用什么 ORM 工具了，直接用查询就可以了, 
 * 为了简单，这里不用连接池
 */
public class XinDianBaoSessionService implements ISessionService {

    /** 这里我要读取 mysql 的配置 */
    private static Configuration configure = null;
    
    private static LoadingCache<String, String> sessionCache = 
        CacheBuilder.newBuilder().build(new SessionCacheLoader());;
    private static LoadingCache<Long, String> nickCache = 
        CacheBuilder.newBuilder().build(new NickCacheLoader());;
    private static LoadingCache<String, Long> userIdCache = 
        CacheBuilder.newBuilder().build(new UserIdCacheLoader());;

    public XinDianBaoSessionService(Configuration configure) {
        synchronized (this) {
            if (XinDianBaoSessionService.configure == null) {
                XinDianBaoSessionService.configure = configure;
            }
        }
    }

    @Override
    public String getSessionByNick(String appkey,String nick) {
        String session = null;
        try {
            session = sessionCache.get(nick);
        } catch (ExecutionException e) {
            /* 如果捕获了异常就说明了没有找到 session，返回 null 就可以了 */
        }
        return session;
    }

    @Override
    public String getNickByUserId(Long userid) {
        String nick = null;
        try {
            nick = nickCache.get(userid);
        } catch (ExecutionException e) {
        }
        return nick;
    }

    @Override
    public Long getUserIdByNick(String nick) {
        Long userId = null;
        try {
            userId = userIdCache.get(nick);
        } catch (ExecutionException e) {
        }
        return userId;
    }
    
    private static Connection getConnection() throws SQLException {
        String url = configure.getConfig(Constant.DB_JDBC_URL);
        String user = configure.getConfig(Constant.DB_USER_NAME);
        String password = configure.getConfig(Constant.DB_PASSWORD);
        
        return DriverManager.getConnection(url, user, password);
    }

    private static class SessionCacheLoader extends CacheLoader<String, String> {
        
        private static final String SQL_GET_SESSION_BY_NICK = 
            "select top_session_key from session_key where nick = ?";
                
        @Override
        public String load(String key) throws Exception {
            Connection connection = null;
            PreparedStatement statement = null;
            
            try {
                connection = getConnection();
                statement = connection.prepareStatement(SQL_GET_SESSION_BY_NICK);
                statement.setString(1, key);
                
                ResultSet rs = statement.executeQuery();
                
                if (rs.next()) {
                    return rs.getString(1);
                } else {
                    throw new CacheLoader.InvalidCacheLoadException("no such session");
                }
                
            } catch (SQLException ex) {
                throw new CacheLoader.InvalidCacheLoadException(ex.getMessage());
            } finally {
                try {
                    if (statement != null) {
                        statement.close();
                    }
                    if (connection != null) {
                        connection.close();
                    }

                } catch (SQLException ex) {
                }
            }
        }
        
    }
    
    private static class NickCacheLoader extends CacheLoader<Long, String> {
        
        private static final String SQL_GET_NICK_BY_USERID = 
                "select nick from session_key where user_id = ?";
        
        @Override
        public String load(Long key) throws Exception {
            Connection connection = null;
            PreparedStatement statement = null;
            
            try {
                connection = getConnection();
                statement = connection.prepareStatement(SQL_GET_NICK_BY_USERID);
                statement.setString(1, String.valueOf(key));
                
                ResultSet rs = statement.executeQuery();
                
                if (rs.next()) {
                    return rs.getString(1);
                } else {
                    throw new CacheLoader.InvalidCacheLoadException("no such session");
                }
                
            } catch (SQLException ex) {
                throw new CacheLoader.InvalidCacheLoadException(ex.getMessage());
            } finally {
                try {
                    if (statement != null) {
                        statement.close();
                    }
                    if (connection != null) {
                        connection.close();
                    }

                } catch (SQLException ex) {
                }
            }
        }
        
    }
    
    private static class UserIdCacheLoader extends CacheLoader<String, Long> {
    
        private static final String SQL_GET_USERID_BY_NICK = 
                "select user_id from session_key where nick = ?";
        
        @Override
        public Long load(String key) throws Exception {
            Connection connection = null;
            PreparedStatement statement = null;
            
            try {
                connection = getConnection();
                statement = connection.prepareStatement(SQL_GET_USERID_BY_NICK);
                statement.setString(1, String.valueOf(key));
                
                ResultSet rs = statement.executeQuery();
                
                if (rs.next()) {
                    return Long.valueOf(rs.getString(1));
                } else {
                    throw new CacheLoader.InvalidCacheLoadException("no such session");
                }
                
            } catch (SQLException ex) {
                throw new CacheLoader.InvalidCacheLoadException(ex.getMessage());
            } finally {
                try {
                    if (statement != null) {
                        statement.close();
                    }
                    if (connection != null) {
                        connection.close();
                    }

                } catch (SQLException ex) {
                }
            }
        }
        
    }
}