com.luoshu.open.id.JdbcIdFactory Maven / Gradle / Ivy

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package com.luoshu.open.id;

import com.luoshu.open.id.exception.IdException;
import lombok.extern.slf4j.Slf4j;

import javax.sql.DataSource;
import java.sql.ResultSet;
import java.sql.SQLException;

/**
 * 基于 jdbc 的 id 工厂
 */
@Slf4j
public class JdbcIdFactory implements IdFactory{

    private final DataSource dataSource;
    /**
     * 是否自动创建表，只支持 mysql
     */
    private final boolean autoCreateTable;

    private final String name;

    public JdbcIdFactory(DataSource dataSource , boolean autoCreateTable) {
        this(IdContext.DEFAULT , dataSource , autoCreateTable);
    }

    public JdbcIdFactory(String name , DataSource dataSource , boolean autoCreateTable) {
        this.dataSource = dataSource;
        this.autoCreateTable = autoCreateTable;
        this.name = name;

        // 根据需要，初始化表
        initTable();
    }

    @Override
    public String getName() {
        return this.name;
    }

    @Override
    public IdGenerate create(String category, JdbcIdConfig config) {
        if(category == null || "".equals(category.trim())){
            throw new IdException("category is empty");
        }
        if(config == null){
            throw new IdException("config is null");
        }
        // category 最大长度
        int maxCategoryLength = 40;
        if(category.length() > maxCategoryLength){
            throw new IdException("category max length " + maxCategoryLength);
        }
        return new JdbcIdGenerate(category , dataSource , config);
    }

    @Override
    public IdGenerate create(String category) {
        return create(category , new JdbcIdConfig());
    }

    /**
     * 根据需求，初始化数据库表
     */
    protected void initTable(){
        if(!autoCreateTable){
            return;
        }

        Boolean existTable = null;
        // 查询数据库是否已存在该表
        String checkSql = "select * from t_id limit 1;";

        try {
            SqlUtil.executeQuery(dataSource , checkSql);
            existTable = true;
        } catch (SQLException e) {
            // 查询失败，代表着需要去初始化创建表
//            log.error(e.getMessage() , e);
            existTable = false;
        }

        if(existTable){
            // 已经存在表，不需要创建
            return;
        }

        String createTableSql = "CREATE TABLE `t_id` (\n" +
                "\t`id` int NOT NULL AUTO_INCREMENT,\n" +
                "\t`category` varchar(50) NOT NULL COMMENT '类别，定义不同的类型，每个类别有一个自己的序列',\n" +
                "\t`num` bigint NOT NULL DEFAULT 1 COMMENT '序列的当前值 ， 当前值可用',\n" +
                "\t`max_num` bigint  COMMENT '序列的最大值，超过将会无法获取',\n" +
                "\t`version` varchar(20) NOT NULL COMMENT '版本号，用于乐观锁',\n" +
                "\t`remark` varchar(128) NOT NULL DEFAULT '' COMMENT '备注信息',\n" +
                "\t`create_time` datetime NOT NULL COMMENT '创建时间',\n" +
                "\t`update_time` datetime NOT NULL COMMENT '修改时间',\n" +
                "\tPRIMARY KEY (`id`),\n" +
                "\tUnique KEY `idx_uni_category`(`category`)\n" +
                ") \n" +
                "COMMENT='分布式id';";

        log.info("luoshu-id init table\n" + createTableSql);

        try {
            SqlUtil.execute(dataSource , createTableSql);
        } catch (Exception e) {
            String errMsg = "luoshu-id init table fail";
            System.err.println(errMsg);
            log.error(errMsg + "," + e.getMessage() , e);

            try {
                Thread.sleep(5000);
            } catch (InterruptedException interruptedException) {
                interruptedException.printStackTrace();
            }
            System.exit(3);
            // 这里不会执行到，为了防止 ide 报黄
            throw new IdException(e);
        }

    }
}