通用的参数配置组件工具

• 通用性：仅依赖一张参数数据表，JDBC支持的数据库均可使用，包括SQLite、MySQL、Oracle、OceanBase等。
• 高性能：本地增加缓存，DB访问越少，性能越高。
• 分布式：受益于集中式的参数数据表，保证了序列全局唯一。

使用步骤

• 个人博客-详细介绍了组件的设计思路：https://ntopic.cn/p/2023062101/

• 个人博客-详细介绍了Maven托管仓库配置方法：https://ntopic.cn/p/2023062201/

设置仓库

本JAR使用了Gitee和GitHub仓库托管，在项目的根pom.xml中，设置仓库地址：

<repositories>
   <repository>
      <id>Gitee-obullxl</id>
      <url>https://gitee.com/obullxl/maven-repository/raw/master/repository</url>
   </repository>
</repositories>

或者：

<repositories>
   <repository>
      <id>GitHub-obullxl</id>
      <url>https://raw.githubusercontent.com/obullxl/maven-repository/master/repository</url>
   </repository>
</repositories>

JAR包引用

仅需要依赖本JAR包，无其他JAR包依赖：

<dependency>
    <groupId>cn.ntopic</groupId>
    <artifactId>ntopic-param</artifactId>
    <version>1.0.1</version>
</dependency>

创建数据表

• 项目根目录有测试的SQLite数据库（NTParam.sqlite），可直接用于测试；其他的数据库，可提前创建数据表。

CREATE TABLE nt_param
(
    id          bigint unsigned NOT NULL auto_increment COMMENT '自增ID',
    category    varchar(64)     NOT NULL COMMENT '分类，如：SYSTEM-系统参数，CONFIG-业务配置等',
    module      varchar(64)     NOT NULL COMMENT '模块，如：USER-用户配置等',
    name        varchar(64)     NOT NULL COMMENT '参数名，如：minAge-最新年龄等',
    content     varchar(4096)            DEFAULT '' COMMENT '参数值，如：18-18岁等',
    create_time timestamp(3)    NOT NULL DEFAULT CURRENT_TIMESTAMP(3) COMMENT '创建时间',
    modify_time timestamp(3)    NOT NULL DEFAULT CURRENT_TIMESTAMP(3) ON UPDATE CURRENT_TIMESTAMP(3) COMMENT '更新时间',
    PRIMARY KEY (id),
    UNIQUE KEY uk_nt_param_m_c_n (category, module, name)
) ENGINE = InnoDB
  DEFAULT CHARSET = utf8mb4 COMMENT ='NTopicX-参数配置数据表'
;

实例化

// 获取数据源，业务代码提供
DruidDataSource ntDataSource = new DruidDataSource();
ntDataSource.setUrl("jdbc:sqlite:./ntopic-param/NTParam.sqlite");
ntDataSource.setDriverClassName("org.sqlite.JDBC");
ntDataSource.setPoolPreparedStatements(false);
ntDataSource.setMaxPoolPreparedStatementPerConnectionSize(-1);
ntDataSource.setTestOnBorrow(true);
ntDataSource.setTestOnReturn(false);
ntDataSource.setTestWhileIdle(true);
ntDataSource.setValidationQuery("SELECT '1' FROM sqlite_master LIMIT 1");

// 实例化参数DAO（特别注意：Bean名称只能为`ntParamDAO`不可变化！）
@Bean("ntParamDAO")
public NTParamDAO ntParamDAO(DataSource ntDataSource) {
    NTParamDAOSQLite ntParamDAO = new NTParamDAOSQLite(ntDataSource);
    
    // 可选：若自定义序列表名，才需要设置（默认为：nt_param）
    ntParamDAO.setTableName("nt_param");
    
    // 可选：尝试创建数据表，若当前用户无建表权限，则需要人工创建；若表已经创建，则忽略建表
    ntParamDAO.createTable();
    
    // 初始化
    ntParamDAO.init();
    
    return ntParamDAO;
}

参数使用

• 第1种方式：查询参数列表
• 第2中方式：指定序列名称（如：USER、ORDER等），每个业务序列独立。

// 获取`DEFAULT`默认序列ID
long newId1 = ntSequence.next();
long newId2 = ntSequence.next();
long newId3 = ntSequence.next();

// 获取`USER`用户ID：
long newUserId1 = ntSequence.next("USER");
long newUserId2 = ntSequence.next("USER");
long newUserId3 = ntSequence.next("USER");

// 获取`ORDER`订单ID：
long newOrderId1 = ntSequence.next("ORDER");
long newOrderId2 = ntSequence.next("ORDER");
long newOrderId3 = ntSequence.next("ORDER");

测试用例

使用本项目根目录SQLite数据库进行测试：

/**
 * Author: obullxl@163.com
 * Copyright (c) 2020-2023 All Rights Reserved.
 */
package cn.ntopic.sequence;

import cn.ntopic.sequence.impl.NTSequenceImpl;
import com.alibaba.druid.pool.DruidDataSource;
import org.junit.Assert;
import org.junit.Test;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.util.*;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.CountDownLatch;

/**
 * 分布式序列服务单元测试
 *
 * @author obullxl 2023年06月22日: 新增
 */
public class NTSequenceTest {

    @Test
    public void test_next() {
        // 1. 创建数据源
        DruidDataSource dataSource = new DruidDataSource();
        dataSource.setUrl("jdbc:sqlite:./sequence-jdbc/SequenceJDBC.sqlite");
        dataSource.setDriverClassName("org.sqlite.JDBC");
        dataSource.setPoolPreparedStatements(false);
        dataSource.setMaxPoolPreparedStatementPerConnectionSize(-1);
        dataSource.setTestOnBorrow(true);
        dataSource.setTestOnReturn(false);
        dataSource.setTestWhileIdle(true);
        dataSource.setValidationQuery("SELECT '1' FROM sqlite_master LIMIT 1");

        final String tableName = "nt_sequence";
        final String testSeqName = "TEST-" + System.currentTimeMillis() + "-" + System.nanoTime();
        try {
            // 2. 清理数据
            this.deleteSequence(dataSource, tableName, testSeqName);

            // 3. 实例化序列服务
            NTSequenceImpl ntSequence = new NTSequenceImpl(dataSource);
            ntSequence.setTableName(tableName);
            ntSequence.createTable();
            ntSequence.setStep(5);
            ntSequence.init();

            // 4. 并发测试
            this.multiThreadTest(ntSequence, testSeqName);

            // 5. 清理测试数据
            this.deleteSequence(dataSource, tableName, testSeqName);
        } finally {
            dataSource.close();
        }
    }

    private void deleteSequence(DruidDataSource dataSource, String tableName, String sequenceName) {
        Connection conn = null;
        PreparedStatement stmt = null;
        try {
            conn = dataSource.getConnection();

            String deleteSQL = String.format("DELETE FROM %s WHERE name=?", tableName);
            stmt = conn.prepareStatement(deleteSQL);
            stmt.setString(1, sequenceName);

            stmt.executeUpdate();
        } catch (Throwable e) {
            // ignore
        } finally {
            this.closeQuietly(stmt);
            this.closeQuietly(conn);
        }
    }

    private void closeQuietly(AutoCloseable closeable) {
        if (closeable != null) {
            try {
                closeable.close();
            } catch (Throwable e) {
                // ignore
            }
        }
    }

    private void multiThreadTest(NTSequence ntSequence, String sequenceName) {
        final int threadCount = 3;
        final int valueCount = 107;

        CountDownLatch countDownLatch = new CountDownLatch(threadCount);

        Map<Integer, List<Long>> seqValues = new ConcurrentHashMap<>();
        for (int i = 0; i < threadCount; i++) {
            List<Long> sequenceValues = new ArrayList<>();
            seqValues.put(i, sequenceValues);

            new SequenceThread(countDownLatch, valueCount, ntSequence, sequenceName, sequenceValues).start();
        }

        try {
            countDownLatch.await();
        } catch (Throwable e) {
            e.printStackTrace();
        }

        // 数据检测
        Set<Long> allValues = new HashSet<>();

        Assert.assertEquals(threadCount, seqValues.size());
        for (int i = 0; i < threadCount; i++) {
            allValues.addAll(seqValues.get(i));
            Assert.assertEquals(valueCount, seqValues.get(i).size());
        }

        Assert.assertEquals(threadCount * valueCount, allValues.size());
    }

    private static class SequenceThread extends Thread {
        private final int valueCount;
        private final CountDownLatch countDownLatch;
        private final NTSequence ntSequence;
        private final String sequenceName;
        private final List<Long> sequenceValues;

        public SequenceThread(CountDownLatch countDownLatch, int valueCount, NTSequence ntSequence, String sequenceName, List<Long> sequenceValues) {
            this.countDownLatch = countDownLatch;
            this.valueCount = valueCount;
            this.ntSequence = ntSequence;
            this.sequenceName = sequenceName;
            this.sequenceValues = sequenceValues;
        }

        @Override
        public void run() {
            try {
                for (int i = 0; i < valueCount; i++) {
                    this.sequenceValues.add(ntSequence.next(this.sequenceName));
                }

                // 释放信号
                this.countDownLatch.countDown();
            } catch (Throwable e) {
                // ignore
            }
        }
    }
}