sequencemgr.java

来自「cwbbs 云网论坛源码」· Java 代码 · 共 224 行

package com.redmoon.forum;

import java.sql.*;
import cn.js.fan.web.Global;
import org.apache.log4j.Logger;
import cn.js.fan.db.Conn;
import cn.js.fan.cache.jcs.RMCache;
import com.cloudwebsoft.framework.util.LogUtil;


public class SequenceMgr implements com.cloudwebsoft.framework.base.ISequence,
        java.io.Serializable {
    String connname;
    private static final String LOAD_ID =
            "SELECT id FROM sq_id WHERE idType=?";
    private static final String UPDATE_ID =
            "UPDATE sq_id SET id=? WHERE idType=? AND id=?";

    public static final int MSG = 0;
    public static final int DOCUMENT = 1;
    public static final int AuctionOrderId = 2;
    public static final int ShopId = 3;
    public static final int SQ_CHATROOM = 4;
    public static final int SQ_FRIEND = 5;
    public static final int SQ_MASTER = 6;
    public static final int SQ_MESSAGE_ATTACH = 7;
    public static final int SQ_USER = 8;
    public static final int DOCUMENT_ATTACH = 9;
    public static final int COMMENT = 10;
    public static final int PHOTO = 11;
    public static final int SQ_FORBID_IP_RANGE = 12;
    public static final int CMS_IMAGES = 13;
    public static final int SQ_IMAGES = 14; 
    public static final int SQ_SHORT_MESSAGE = 15;
    public static final int INFO_ATTACH = 16;
    public static final int PRICE_ID = 17;
    public static final int MARKET_ID = 18;
    public static final int SQ_CHATROOM_EMCEE = 19;
    public static final int CMS_TEMPLATE_ID = 20;
    public static final int THREAD_TYPE_ID = 21;
    public static final int SQ_AD_CONTENT_ID = 22;
    public static final int SQ_AD_BOARD_ID = 23; 
    public static final int DIR_PRIV_ID = 24;
    public static final int BLOG_ID = 25; 
    public static final int CMS_ROBOT_ID = 26; 
    public static final int SQ_SCORE_RECORD = 27;
    public static final int SQ_SCHEDULER = 28;
    public static final int FORUM_ROBOT_ID = 29; 
    public static final int CMS_SUBJECT_LIST_ID = 30; 
    public static final int CMS_IMG_STORE_FILE = 31; 
    public static final int CMS_SOFTWARE_FILE = 32;
    public static final int CMS_AD = 33;
    public static final int PLUGIN_WITKEY_EVALUATION = 34;
    public static final int DESKTOP_ITEM = 35;
    public static final int TOPIC_OP = 36;
    public static final int PLUGIN_PRESENT = 37;
    public static final int SQ_TAG_ID = 38;
    public static final int MESSAGE_REPORT_ID = 39;
    public static final int BLOG_LINK = 40;
    public static final int SQ_LINK = 41;
    public static final int PLUGIN_GROUP = 42;
    public static final int PLUGIN_GROUP_THREAD = 43;
    public static final int PLUGIN_GROUP_PHOTO = 44;
    public static final int PLUGIN_GROUP_ACTIVITY = 45;
    public static final int PLUGIN_AUCTION_CATALOG_PRIV = 46;
    public static final int PLUGIN_AUCTION_WORTH = 47;
    public static final int PLUGIN_AUCTOIN_BID = 48;
    public static final int MESSAGE_RECOMMEND_ID = 49;
    public static final int SMS_SEND_RECORD = 50;
    public static final int GUESTBOOK = 51;
    public static final int DIG = 52;
    public static final int BLOG_MUSIC = 53;
    public static final int BLOG_VIDEO = 54;
    public static final int PLUGIN_FETION_ACTIVITY_MEMBER = 55;

    public static final int SQ_FORUM_MUSIC_USER = 56;

    public static final int PLUGIN_EXAM_QUESTION = 57;
    public static final int PLUGIN_EXAM_QUESTION_OPTION = 58;
    public static final int PLUGIN_EXAM_USER_ANSWER = 59;

    public static final int PLUGIN_BLOG_TEMPLATE = 60;
    public static final int CMS_SITE_AD = 61;
    public static final int CMS_FLASH_STORE_FILE = 62;
    public static final int CMS_SITE_FLASH_IMAGE = 63;
    public static final int CMS_SITE_TEMPLATE = 64;
    public static final int CMS_SITE_SCROLL_IMG = 65;

    private static int INCREMENT = 10;

    static {
        INCREMENT = Global.isCluster() ? 1 : 10;
    }

    public SequenceMgr() {

    }

    public static String getTypeCacheKey(int idType) {
        return "bbs-Sequence-" + idType;
    }

    public static SequenceMgr getSequenceMgr(int idType) {
        
        if (Global.isCluster()) {
            return new SequenceMgr(idType);
        } else {
            SequenceMgr sm = (SequenceMgr) RMCache.getInstance().get(
                    getTypeCacheKey(idType));
            if (sm == null) {
                sm = new SequenceMgr(idType);
                try {
                    RMCache.getInstance().put(getTypeCacheKey(idType), sm);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
            return sm;
        }
    }

    

    public static long nextID() {
        return getSequenceMgr(MSG).nextUniqueID();
    }

    
    public static long nextID(int type) {
        return getSequenceMgr(type).nextUniqueID();
    }

    public long getNextId(int type) {
        return nextID(type);
    }

    private int type;
    private long currentID;
    private long maxID;

    
    public SequenceMgr(int type) {
        connname = Global.defaultDB;
        if (connname.equals(""))
            LogUtil.getLog(getClass()).info("SequenceMgr:DB is empty！");
        this.type = type;
        currentID = 0l;
        maxID = 0l;
    }

    public synchronized long nextUniqueID() {
        
        if (!(currentID < maxID)) {
            getNextBlock(5); 
        }
        

        long id = currentID;
        currentID++;
        return id;
    }

    
    private void getNextBlock(int count) {
        if (count == 0) {
            System.err.println(
                    "Failed at last attempt to obtain an ID, aborting...");
            return;
        }
        boolean success = false;
        Conn conn = new Conn(connname);
        PreparedStatement pstmt = null;
        try {
            
            pstmt = conn.prepareStatement(LOAD_ID);
            pstmt.setInt(1, type);
            ResultSet rs = pstmt.executeQuery();
            if (!rs.next()) {
                throw new SQLException(
                        "Loading the current ID failed. The sq_id table may not be correctly populated.");
            }
            long currentID = rs.getLong(1);
            pstmt.close();
            
            long newID = currentID + INCREMENT;
            pstmt = conn.prepareStatement(UPDATE_ID);
            pstmt.setLong(1, newID);
            pstmt.setInt(2, type);
            pstmt.setLong(3, currentID);

            success = pstmt.executeUpdate() == 1;
            if (success) {
                this.currentID = currentID;
                this.maxID = newID;
            }
        } catch (Exception sqle) {
            sqle.printStackTrace();
        } finally {
            try {
                pstmt.close();
            } catch (Exception e) {
                e.printStackTrace();
            }
            if (conn != null) {
                conn.close();
                conn = null;
            }
        }
        if (!success) {
            LogUtil.getLog(getClass()).warn(
                    "WARNING: failed to obtain next ID block due to " +
                    "thread contention. Trying again...");
            
            
            try {
                Thread.currentThread().sleep(75);
            } catch (InterruptedException ie) {
                LogUtil.getLog(getClass()).error(ie.getMessage());
            }
            getNextBlock(count - 1);
        }
    }
}