[Spring cloud 一步步实现广告系统] 15. 使用开源组件监听Binlog 实现增量索引准备

MySQL Binlog简介

• 什么是binlog?

一个二进制日志，用来记录对数据发生或潜在发生更改的SQL语句，并以而进行的形式保存在磁盘中。

• binlog 的作用？

最主要有3个用途：

• 数据复制（主从同步）
  
  Mysql 的Master-Slave协议，让Slave可以通过监听binlog实现数据复制，达到数据一致性目的
• 数据恢复
  
  通过mysqlbinlog工具恢复数据
• 增量备份

• Binlog 变量
  • log_bin (Binlog 开关，使用show variables like 'log_bin';查看)
  • binlog_format (Binlog 日志格式，使用show variables like 'binlog_format';查看)
    
    日志格式总共有三种：
    • ROW， 仅保存记录被修改的细节，不记录SQL语句上下文相关信息。（能清晰的记录下每行数据的修改细节，不需要记录上下文相关信息，因此不会发生某些特定情况下的procedure、function以及trigger 的调用无法被准确复制的问题，任何情况下都可以被复制，且能加快从库重放日志的效率，保证从库数据的一致性）
    • STATEMENT，每一条修改数据的SQL都会被记录。（只记录执行语句的细节和上下文环境，避免了记录每一行的变化，在一些修改记录较多的情况下，相比ROW类型能大大减少binlog的日志量，节约IO,提高性能。还可以用于实时的还原，同时主从版本可以不一样，从服务器版本可以比主服务器版本高）
    • MIXED， 上述2种的混合使用
• Binlog 管理
  • show master logs; 查看所有binlog的日志列表
  • show master status; 查看最后一个binlog日志编号名称，以及最后一个事件技术的位置（position）
  • Flush logs; 刷新binlog,此刻开始产生一个新编号的binlog日志文件
  • reset master; 清空所有的binlog日志
• Binlog 相关SQL show binlog events[in 'log_name'][from position][limit [offset,]row_count]
  
  
  
  
• 常用的Binlog event
  • QUERY - 与数据无关的操作，begin、drop table、truncate table等等
  • TABLE_MAP - 记录下一个操作所对应的表信息，存储了数据库名称和表名称
  • XID - 标记事务提交
  • WRITE_ROWS 插入数据，即insert操作
  • UPDATE_ROWS 更新数据，即update操作
  • DELETE_ROWS 删除数据，即delete操作

Event包含header和data两部分，header提供了event的创建时间，哪个服务器等信息，data部分提供的是针对该event的具体信息，如具体数据的修改。

Tip: binlog不会记录数据表的列名

在接下来的实现中，我们会将自己的系统包装成一个假的Mysql Slave，通过开源工具mysql-binlog-connector-java来实现监听binlog。

开源工具mysql-binlog-connector-java

• 工具源码：Github传送门
• 组件使用
  
  1.加依赖

<!-- binlog 日志监听,解析开源工具类库 -->
<dependency>
    <groupId>com.github.shyiko</groupId>
    <artifactId>mysql-binlog-connector-java</artifactId>
    <version>0.18.1</version>
</dependency>

2.创建一个测试接口

package com.sxzhongf.ad.service;

import com.github.shyiko.mysql.binlog.BinaryLogClient;
import com.github.shyiko.mysql.binlog.event.DeleteRowsEventData;
import com.github.shyiko.mysql.binlog.event.EventData;
import com.github.shyiko.mysql.binlog.event.UpdateRowsEventData;
import com.github.shyiko.mysql.binlog.event.WriteRowsEventData;

import java.io.IOException;

/**
 * BinlogServiceTest for 测试Mysql binlog 监控
 * {@code
 * Mysql8 连接提示 Client does not support authentication protocol requested by server; consider upgrading MySQL client 解决方法
 * USE mysql;
 * ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY 'password';
 * FLUSH PRIVILEGES;
 * }
 *
 * @author <a href="mailto:[e-mail]">Isaac.Zhang | 若初</a>
 */
public class BinlogServiceTest {

    /**
     * --------Update-----------
     * UpdateRowsEventData{tableId=90, includedColumnsBeforeUpdate={0, 1, 2, 3, 4, 5, 6, 7}, includedColumns={0, 1, 2, 3, 4, 5, 6, 7}, rows=[
     *     {before=[11, 10, Test Bin Log, 1, Tue Jun 25 08:00:00 CST 2019, Tue Jun 25 08:00:00 CST 2019, Tue Jun 25 08:00:00 CST 2019, Tue Jun 25 08:00:00 CST 2019], after=[11, 10, zhangpan test Binlog, 1, Tue Jun 25 08:00:00 CST 2019, Tue Jun 25 08:00:00 CST 2019, Tue Jun 25 08:00:00 CST 2019, Tue Jun 25 08:00:00 CST 2019]}
     * ]}
     *
     * --------Insert-----------
     * WriteRowsEventData{tableId=91, includedColumns={0, 1, 2, 3, 4, 5, 6, 7}, rows=[
     *     [10, 11, ad unit test binlog, 1, 0, 1236.7655, Thu Jun 27 08:00:00 CST 2019, Thu Jun 27 08:00:00 CST 2019]
     * ]}
     */

    public static void main(String[] args) throws IOException {

//        //构造BinaryLogClient，填充mysql链接信息
        BinaryLogClient client = new BinaryLogClient("127.0.0.1", 3306,
                "root", "12345678"
        );

        //设置需要读取的Binlog的文件以及位置，否则，client会从"头"开始读取Binlog并监听
//        client.setBinlogFilename("binlog.000035");
//        client.setBinlogPosition();

        //给客户端注册监听器，实现对Binlog的监听和解析
        //event 就是监听到的Binlog变化信息，event包含header & data 两部分
        client.registerEventListener(event -> {
            EventData data = event.getData();
            if (data instanceof UpdateRowsEventData) {
                System.out.println("--------Update-----------");
                System.out.println(data.toString());
            } else if (data instanceof WriteRowsEventData) {
                System.out.println("--------Insert-----------");
                System.out.println(data.toString());
            } else if (data instanceof DeleteRowsEventData) {
                System.out.println("--------Delete-----------");
                System.out.println(data.toString());
            }
        });

        client.connect();
    }
}

运行：

八月 08, 2019 9:13:32 上午 com.github.shyiko.mysql.binlog.BinaryLogClient connect
信息: Connected to 127.0.0.1:3306 at binlog.000038/951 (sid:65535, cid:336)
...

执行sql update ad_user set user_status=1 where user_id=10;

我们需要知道的是，我们的目的是实现对Mysql数据表的变更实现监听，并解析成我们想要的格式，也就是我们的java对象。根据上面我们看到的监听结果，我们知道了返回信息的大概内容，既然我们已经学会了简单的使用BinaryLogClient 来监听binlog，接下来，我们需要定义一个监听器，来实现我们自己的业务内容。

因为我们只需要Event中的内容，那么我们也就只需要通过实现com.github.shyiko.mysql.binlog.BinaryLogClient.EventListener接口，来自定义一个监听器实现我们的业务即可。通过Event的内容，来判定是否需要处理当前event以及如何处理。

构造解析binlog的模版文件

我们监听binlog来构造增量数据的根本原因，是为了将我们的广告投放系统和广告检索系统 业务解耦，由于我们的检索系统中没有定义数据库以及数据表的相关，所以，我们通过定义一份模版文件，通过解析模版文件来得到我们需要的数据库和表信息，因为binlog的监听是不区分是哪个数据库和哪个数据表信息的，我们可以通过模版来指定我们想要监听的部分。

{
  "database": "advertisement",
  "tableList": [
    {
      "tableName": "ad_plan",
      "level": 2,
      "insert": [
        {
          "column": "plan_id"
        },
        {
          "column": "user_id"
        },
        {
          "column": "plan_status"
        },
        {
          "column": "start_date"
        },
        {
          "column": "end_date"
        }
      ],
      "update": [
        {
          "column": "plan_id"
        },
        {
          "column": "user_id"
        },
        {
          "column": "plan_status"
        },
        {
          "column": "start_date"
        },
        {
          "column": "end_date"
        }
      ],
      "delete": [
        {
          "column": "plan_id"
        }
      ]
    },
    {
      "tableName": "ad_unit",
      "level": 3,
      "insert": [
        {
          "column": "unit_id"
        },
        {
          "column": "unit_status"
        },
        {
          "column": "position_type"
        },
        {
          "column": "plan_id"
        }
      ],
      "update": [
        {
          "column": "unit_id"
        },
        {
          "column": "unit_status"
        },
        {
          "column": "position_type"
        },
        {
          "column": "plan_id"
        }
      ],
      "delete": [
        {
          "column": "unit_id"
        }
      ]
    },
    {
      "tableName": "ad_creative",
      "level": 2,
      "insert": [
        {
          "column": "creative_id"
        },
        {
          "column": "type"
        },
        {
          "column": "material_type"
        },
        {
          "column": "height"
        },
        {
          "column": "width"
        },
        {
          "column": "audit_status"
        },
        {
          "column": "url"
        }
      ],
      "update": [
        {
          "column": "creative_id"
        },
        {
          "column": "type"
        },
        {
          "column": "material_type"
        },
        {
          "column": "height"
        },
        {
          "column": "width"
        },
        {
          "column": "audit_status"
        },
        {
          "column": "url"
        }
      ],
      "delete": [
        {
          "column": "creative_id"
        }
      ]
    },
    {
      "tableName": "relationship_creative_unit",
      "level": 3,
      "insert": [
        {
          "column": "creative_id"
        },
        {
          "column": "unit_id"
        }
      ],
      "update": [
      ],
      "delete": [
        {
          "column": "creative_id"
        },
        {
          "column": "unit_id"
        }
      ]
    },
    {
      "tableName": "ad_unit_district",
      "level": 4,
      "insert": [
        {
          "column": "unit_id"
        },
        {
          "column": "province"
        },
        {
          "column": "city"
        }
      ],
      "update": [
      ],
      "delete": [
        {
          "column": "unit_id"
        },
        {
          "column": "province"
        },
        {
          "column": "city"
        }
      ]
    },
    {
      "tableName": "ad_unit_hobby",
      "level": 4,
      "insert": [
        {
          "column": "unit_id"
        },
        {
          "column": "hobby_tag"
        }
      ],
      "update": [
      ],
      "delete": [
        {
          "column": "unit_id"
        },
        {
          "column": "hobby_tag"
        }
      ]
    },
    {
      "tableName": "ad_unit_keyword",
      "level": 4,
      "insert": [
        {
          "column": "unit_id"
        },
        {
          "column": "keyword"
        }
      ],
      "update": [
      ],
      "delete": [
        {
          "column": "unit_id"
        },
        {
          "column": "keyword"
        }
      ]
    }
  ]
}

上面的模版文件中，指定了一个数据库为advertisement，大家可以方便添加多个监听库。在数据库下面，我们监听了几个表的CUD操作以及每个操作所需要的字段信息。

• 实现模版 —> Java Entity

  • 定义模版文件对应的实体

  @Data
  @AllArgsConstructor
  @NoArgsConstructor
  public class BinlogTemplate {
  		//单数据库对应
      private String database;
    	//多表
      private List<JsonTable> tableList;
  }
  

  • 对应的json 中 table信息

  /**
   * JsonTable for 用于表示template.json中对应的表信息
   *
   * @author <a href="mailto:[e-mail]">Isaac.Zhang | 若初</a>
   */
  @Data
  @AllArgsConstructor
  @NoArgsConstructor
  public class JsonTable {
      private String tableName;
      private Integer level;
  
      private List<Column> insert;
      private List<Column> update;
      private List<Column> delete;
  
      @Data
      @AllArgsConstructor
      @NoArgsConstructor
      public static class Column {
          private String columnName;
      }
  }
  

  • 读取的对应表信息对象（最主要目的就是为了能将字段索引 映射到 字段名称）

  @Data
  @AllArgsConstructor
  @NoArgsConstructor
  public class TableTemplate {
      private String tableName;
      private String level;
  
    	//操作类型 -> 多列
      private Map<OperationTypeEnum, List<String>> opTypeFieldSetMap = new HashMap<>();
  
      /**
       * Binlog日志中 字段索引 -> 字段名称 的一个转换映射
       * 因为binlog中不会显示更新的列名是什么，它只会展示字段的索引，因此我们需要实现一次转换
       */
      private Map<Integer, String> posMap = new HashMap<>();
  }
  

  • 解析模版文件到java对象

  @Data
  public class ParseCustomTemplate {
  
      private String database;
  
      /**
       * key -> TableName
       * value -> {@link TableTemplate}
       */
      private Map<String, TableTemplate> tableTemplateMap;
  
      public static ParseCustomTemplate parse(BinlogTemplate _template) {
          ParseCustomTemplate template = new ParseCustomTemplate();
          template.setDatabase(_template.getDatabase());
  
          for (JsonTable jsonTable : _template.getTableList()) {
              String name = jsonTable.getTableName();
              Integer level = jsonTable.getLevel();
  
              TableTemplate tableTemplate = new TableTemplate();
              tableTemplate.setTableName(name);
              tableTemplate.setLevel(level.toString());
              template.tableTemplateMap.put(name, tableTemplate);
  
              //遍历操作类型对应的列信息
              Map<OperationTypeEnum, List<String>> operationTypeListMap = tableTemplate.getOpTypeFieldSetMap();
  
              for (JsonTable.Column column : jsonTable.getInsert()) {
                  getAndCreateIfNeed(
                          OperationTypeEnum.ADD,
                          operationTypeListMap,
                          ArrayList::new
                  ).add(column.getColumnName());
              }
  
              for (JsonTable.Column column : jsonTable.getUpdate()) {
                  getAndCreateIfNeed(
                          OperationTypeEnum.UPDATE,
                          operationTypeListMap,
                          ArrayList::new
                  ).add(column.getColumnName());
              }
  
              for (JsonTable.Column column : jsonTable.getDelete()) {
                  getAndCreateIfNeed(
                          OperationTypeEnum.DELETE,
                          operationTypeListMap,
                          ArrayList::new
                  ).add(column.getColumnName());
              }
          }
  
          return template;
      }
  
      /**
       * 从Map中获取对象，如果不存在，创建一个
       */
      private static <T, R> R getAndCreateIfNeed(T key, Map<T, R> map, Supplier<R> factory) {
          return map.computeIfAbsent(key, k -> factory.get());
      }
  }
  

  • 解析 字段索引 -> 字段名称 的一个转换映射

  首先，我们来看一下binlog的具体日志信息：

  --------Insert-----------
  WriteRowsEventData{tableId=91, includedColumns={0, 1, 2, 3, 4, 5, 6, 7}, rows=[
  [10, 11, ad unit test binlog, 1, 0, 1236.7655, Thu Jun 27 08:00:00 CST 2019, Thu Jun 27 08:00:00 CST 2019]
  --------Update-----------
  UpdateRowsEventData{tableId=81, includedColumnsBeforeUpdate={0, 1, 2, 3, 4, 5}, includedColumns={0, 1, 2, 3, 4, 5}, rows=[
      {before=[10, Isaac Zhang, 2D3ABB6F2434109A105170FB21D00453, 0, Fri Jun 21 15:07:53 CST 2019, Fri Jun 21 15:07:53 CST 2019], after=[10, Isaac Zhang, 2D3ABB6F2434109A105170FB21D00453, 1, Fri Jun 21 15:07:53 CST 2019, Fri Jun 21 15:07:53 CST 2019]}
  
  

  可以看到，在日志中includedColumns只包含了{0, 1, 2, 3, 4, 5}位置信息，那么我们怎么能知道它具体代表的是哪个字段呢，接下来我们来实现这步映射关系，在实现之前，我们先来查询一下数据库中我们的表中字段所处的具体位置：

  sql> SELECT table_schema,table_name,column_name,ordinal_position FROM information_schema.COLUMNS
  WHERE TABLE_SCHEMA = 'advertisement' AND TABLE_NAME='ad_user'
  

  

  我们可以看到ordinal_position对应的是1-6，可是上面监听到的binlog日志索引是0-5，所以我们就可以看出来之间的对应关系。

  我们开始编码实现，我们使用JdbcTemplate进行查询数据库信息：

  @Slf4j
  @Component
  public class TemplateHolder {
      private ParseCustomTemplate template;
  
      private final JdbcTemplate jdbcTemplate;
  
      private String SQL_SCHEMA = "SELECT TABLE_SCHEMA,TABLE_NAME,COLUMN_NAME,ORDINAL_POSITION FROM information_schema.COLUMNS " +
              "WHERE TABLE_SCHEMA = ? AND TABLE_NAME = ?";
  
      @Autowired
      public TemplateHolder(JdbcTemplate jdbcTemplate) {
          this.jdbcTemplate = jdbcTemplate;
      }
  
      /**
       * 需要在容器加载的时候，就载入数据信息
       */
      @PostConstruct
      private void init() {
          loadJSON("template.json");
      }
  
      /**
       * 对外提供加载服务
       */
      public TableTemplate getTable(String tableName) {
          return template.getTableTemplateMap().get(tableName);
      }
  
      /**
       * 加载需要监听的binlog json文件
       */
      private void loadJSON(String path) {
          ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
          InputStream inputStream = classLoader.getResourceAsStream(path);
  
          try {
              BinlogTemplate binlogTemplate = JSON.parseObject(
                      inputStream,
                      Charset.defaultCharset(),
                      BinlogTemplate.class
              );
  
              this.template = ParseCustomTemplate.parse(binlogTemplate);
              loadMeta();
          } catch (IOException ex) {
              log.error((ex.getMessage()));
              throw new RuntimeException("fail to parse json file");
          }
      }
  
      /**
       * 加载元信息
       * 使用表索引到列名称的映射关系
       */
      private void loadMeta() {
          for (Map.Entry<String, TableTemplate> entry : template.getTableTemplateMap().entrySet()) {
              TableTemplate table = entry.getValue();
  
              List<String> updateFields = table.getOpTypeFieldSetMap().get(
                      OperationTypeEnum.UPDATE
              );
              List<String> insertFields = table.getOpTypeFieldSetMap().get(
                      OperationTypeEnum.ADD
              );
              List<String> deleteFields = table.getOpTypeFieldSetMap().get(
                      OperationTypeEnum.DELETE
              );
  
              jdbcTemplate.query(SQL_SCHEMA, new Object[]{
                              template.getDatabase(), table.getTableName()
                      }, (rs, i) -> {
                          int pos = rs.getInt("ORDINAL_POSITION");
                          String colName = rs.getString("COLUMN_NAME");
  
                          if ((null != updateFields && updateFields.contains(colName))
                              || (null != insertFields && insertFields.contains(colName))
                              || (null != deleteFields && deleteFields.contains(colName))) {
                                       table.getPosMap().put(pos - 1, colName);
                          }
                          return null;
                      }
              );
          }
      }
  }
  

  • 监听binlog实现

    • 定义Event 解析所需要转换的java对象

    @Data
    public class BinlogRowData {
    
        private TableTemplate tableTemplate;
    
        private EventType eventType;
    
        private List<Map<String, String>> before;
    
        private List<Map<String, String>> after;
    
    }
    

    • 定义binlog client BinaryLogClient

    /**
     * CustomBinlogClient for 自定义Binlog Client
     *
     * @author <a href="mailto:[e-mail]">Isaac.Zhang | 若初</a>
     * @since 2019/6/27
     */
    @Slf4j
    @Component
    public class CustomBinlogClient {
    
        private BinaryLogClient client;
    
        private final BinlogConfig config;
        private final AggregationListener listener;
    
        @Autowired
        public CustomBinlogClient(BinlogConfig config, AggregationListener listener) {
            this.config = config;
            this.listener = listener;
        }
    
        public void connect() {
            new Thread(() -> {
                client = new BinaryLogClient(
                        config.getHost(),
                        config.getPort(),
                        config.getUsername(),
                        config.getPassword()
                );
    
                if (!StringUtils.isEmpty(config.getBinlogName()) && !config.getPosition().equals(-1L)) {
                    client.setBinlogFilename(config.getBinlogName());
                    client.setBinlogPosition(config.getPosition());
                }
    
                try {
                    log.info("connecting to mysql start...");
                    client.connect();
                    log.info("connecting to mysql done!");
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }).start();
        }
    
        public void disconnect() {
            try {
                log.info("disconnect to mysql start...");
                client.disconnect();
                log.info("disconnect to mysql done!");
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
    

    • 使用client注册事件监听器com.github.shyiko.mysql.binlog.BinaryLogClient.EventListener

    /**
     * Ilistener for 为了后续扩展不同的实现
     *
     * @author <a href="mailto:[e-mail]">Isaac.Zhang | 若初</a>
     */
    public interface Ilistener {
    
        void register();
    
        void onEvent(BinlogRowData eventData);
    }
    

    • 监听Binlog, 收集mysql binlog datas

    @Slf4j
    @Component
    public class AggregationListener implements BinaryLogClient.EventListener {
    
        private String dbName;
        private String tbName;
    
        private Map<String, Ilistener> listenerMap = new HashMap<>();
    
        @Autowired
        private TemplateHolder templateHolder;
    
        private String genKey(String dbName, String tbName) {
            return dbName + ":" + tbName;
        }
    
        /**
         * 根据表实现注册信息
         */
        public void register(String dbName, String tbName, Ilistener listener) {
            log.info("register : {}-{}", dbName, tbName);
            this.listenerMap.put(genKey(dbName, tbName), listener);
        }
    
        @Override
        public void onEvent(Event event) {
    
            EventType type = event.getHeader().getEventType();
            log.info("Event type: {}", type);
    
            //数据库增删改之前，肯定有一个table_map event 的binlog
            if (type == EventType.TABLE_MAP) {
                TableMapEventData data = event.getData();
                this.tbName = data.getTable();
                this.dbName = data.getDatabase();
                return;
            }
    
            //EXT_UPDATE_ROWS 是Mysql 8以上的type
            if (type != EventType.EXT_UPDATE_ROWS
                    && type != EventType.EXT_WRITE_ROWS
                    && type != EventType.EXT_DELETE_ROWS
                    ) {
                return;
            }
    
            // 检查表名和数据库名是否已经正确填充
            if (StringUtils.isEmpty(dbName) || StringUtils.isEmpty(tbName)) {
                log.error("Meta data got error. tablename:{},database:{}", tbName, dbName);
                return;
            }
    
            //找出对应数据表敏感的监听器
            String key = genKey(this.dbName, this.tbName);
            Ilistener ilistener = this.listenerMap.get(key);
            if (null == ilistener) {
                log.debug("skip {}", key);
            }
    
            log.info("trigger event:{}", type.name());
    
            try {
                BinlogRowData rowData = convertEventData2BinlogRowData(event.getData());
                if (null == rowData) {
                    return;
                }
                rowData.setEventType(type);
                ilistener.onEvent(rowData);
    
            } catch (Exception e) {
                e.printStackTrace();
                log.error(e.getMessage());
            } finally {
                this.dbName = "";
                this.tbName = "";
            }
        }
    
        /**
         * 解析Binlog数据到Java实体对象的映射
         *
         * @param data binlog
         * @return java 对象
         */
        private BinlogRowData convertEventData2BinlogRowData(EventData data) {
            TableTemplate tableTemplate = templateHolder.getTable(tbName);
            if (null == tableTemplate) {
                log.warn("table {} not found.", tbName);
                return null;
            }
    
            List<Map<String, String>> afterMapList = new ArrayList<>();
    
            for (Serializable[] after : getAfterValues(data)) {
                Map<String, String> afterMap = new HashMap<>();
    
                int columnLength = after.length;
                for (int i = 0; i < columnLength; ++i) {
                    //取出当前位置对应的列名
                    String colName = tableTemplate.getPosMap().get(i);
                    //如果没有，则说明不需要该列
                    if (null == colName) {
                        log.debug("ignore position: {}", i);
                        continue;
                    }
    
                    String colValue = after[i].toString();
                    afterMap.put(colName, colValue);
                }
    
                afterMapList.add(afterMap);
            }
    
            BinlogRowData binlogRowData = new BinlogRowData();
            binlogRowData.setAfter(afterMapList);
            binlogRowData.setTableTemplate(tableTemplate);
    
            return binlogRowData;
        }
    
        /**
         * 获取不同事件的变更后数据
         * Add & Delete变更前数据假定为空
         */
        private List<Serializable[]> getAfterValues(EventData eventData) {
    
            if (eventData instanceof WriteRowsEventData) {
                return ((WriteRowsEventData) eventData).getRows();
            }
    
            if (eventData instanceof UpdateRowsEventData) {
                return ((UpdateRowsEventData) eventData).getRows()
                                                        .stream()
                                                        .map(Map.Entry::getValue)
                                                        .collect(Collectors.toList()
                                                        );
            }
    
            if (eventData instanceof DeleteRowsEventData) {
                return ((DeleteRowsEventData) eventData).getRows();
            }
    
            return Collections.emptyList();
        }
    }
    

    • 解析binlog 数据对象BinlogRowData ,用于增量索引的后续处理

    /**
     * MysqlRowData for 简化{@link BinlogRowData} 以方便实现增量索引的实现
     *
     * @author <a href="mailto:[e-mail]">Isaac.Zhang | 若初</a>
     */
    @Data
    @AllArgsConstructor
    @NoArgsConstructor
    public class MysqlRowData {
    
        //实现多数据的时候，需要传递数据库名称
        //private String database;
        private String tableName;
        private String level;
        private OperationTypeEnum operationTypeEnum;
        private List<Map<String, String>> fieldValueMap = new ArrayList<>();
    }
    

    因为我们需要将Binlog EventType转换为我们的操作类型OperationTypeEnum，所以，我们在OperationTypeEnum中添加一个转换方法：

    public enum OperationTypeEnum {
    ...
        public static OperationTypeEnum convert(EventType type) {
            switch (type) {
                case EXT_WRITE_ROWS:
                    return ADD;
                case EXT_UPDATE_ROWS:
                    return UPDATE;
                case EXT_DELETE_ROWS:
                    return DELETE;
                default:
                    return OTHER;
            }
        }
    }
    

    我们还需要定义一个表包含的各个列名称的java类，方便我们后期对数据表的CUD操作：

    package com.sxzhongf.ad.mysql.constant;
    
    import java.util.HashMap;
    import java.util.Map;
    
    /**
     * Constant for 各个列名称的java类，方便我们后期对数据表的CUD操作
     *
     * @author <a href="mailto:[e-mail]">Isaac.Zhang | 若初</a>
     */
    public class Constant {
    
        private static final String DATABASE_NAME = "advertisement";
    
        public static class AD_PLAN_TABLE_INFO {
    
            public static final String TABLE_NAME = "ad_plan";
    
            public static final String COLUMN_PLAN_ID = "plan_id";
            public static final String COLUMN_USER_ID = "user_id";
            public static final String COLUMN_PLAN_STATUS = "plan_status";
            public static final String COLUMN_START_DATE = "start_date";
            public static final String COLUMN_END_DATE = "end_date";
        }
    
        public static class AD_CREATIVE_TABLE_INFO {
    
            public static final String TABLE_NAME = "ad_creative";
    
            public static final String COLUMN_CREATIVE_ID = "creative_id";
            public static final String COLUMN_TYPE = "type";
            public static final String COLUMN_MATERIAL_TYPE = "material_type";
            public static final String COLUMN_HEIGHT = "height";
            public static final String COLUMN_WIDTH = "width";
            public static final String COLUMN_AUDIT_STATUS = "audit_status";
            public static final String COLUMN_URL = "url";
        }
    
        public static class AD_UNIT_TABLE_INFO {
    
            public static final String TABLE_NAME = "ad_unit";
    
            public static final String COLUMN_UNIT_ID = "unit_id";
            public static final String COLUMN_UNIT_STATUS = "unit_status";
            public static final String COLUNN_POSITION_TYPE = "position_type";
            public static final String COLUNN_PLAN_ID = "plan_id";
        }
    
        public static class RELATIONSHIP_CREATIVE_UNIT_TABLE_INFO {
    
            public static final String TABLE_NAME = "relationship_creative_unit";
    
            public static final String COLUMN_CREATIVE_ID = "creative_id";
            public static final String COLUMN_UNIT_ID = "unit_id";
        }
    
        public static class AD_UNIT_DISTRICT_TABLE_INFO {
    
            public static final String TABLE_NAME = "ad_unit_district";
    
            public static final String COLUMN_UNIT_ID = "unit_id";
            public static final String COLUMN_PROVINCE = "province";
            public static final String COLUMN_CITY = "city";
        }
    
        public static class AD_UNIT_KEYWORD_TABLE_INFO {
    
            public static final String TABLE_NAME = "ad_unit_keyword";
    
            public static final String COLUMN_UNIT_ID = "unit_id";
            public static final String COLUMN_KEYWORD = "keyword";
        }
    
        public static class AD_UNIT_HOBBY_TABLE_INFO {
    
            public static final String TABLE_NAME = "ad_unit_hobby";
    
            public static final String COLUMN_UNIT_ID = "unit_id";
            public static final String COLUMN_HOBBY_TAG = "hobby_tag";
        }
    
        //key -> 表名
        //value -> 数据库名
        public static Map<String, String> table2db;
    
        static {
            table2db = new HashMap<>();
            table2db.put(AD_PLAN_TABLE_INFO.TABLE_NAME, DATABASE_NAME);
            table2db.put(AD_CREATIVE_TABLE_INFO.TABLE_NAME, DATABASE_NAME);
            table2db.put(AD_UNIT_TABLE_INFO.TABLE_NAME, DATABASE_NAME);
            table2db.put(RELATIONSHIP_CREATIVE_UNIT_TABLE_INFO.TABLE_NAME, DATABASE_NAME);
            table2db.put(AD_UNIT_DISTRICT_TABLE_INFO.TABLE_NAME, DATABASE_NAME);
            table2db.put(AD_UNIT_HOBBY_TABLE_INFO.TABLE_NAME, DATABASE_NAME);
            table2db.put(AD_UNIT_KEYWORD_TABLE_INFO.TABLE_NAME, DATABASE_NAME);
        }
    }