[Spring cloud 一步步实现广告系统] 15. 监听Binlog 增量索引准备

• 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。

• 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:magicianisaac@gmail.com">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。

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:magicianisaac@gmail.com">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:magicianisaac@gmail.com">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:magicianisaac@gmail.com">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:magicianisaac@gmail.com">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:magicianisaac@gmail.com">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);
      }
  }