[Spring cloud 一步步實現廣告系統] 15. 使用開源組件監聽Binlog 實現增量索引準備

時間 2019-12-19

標籤 spring cloud 步步實現廣告系統使用開源組件監聽 binlog 增量索引準備欄目 Spring 简体版

原文原文鏈接

MySQL Binlog簡介

什麼是binlog?

一個二進制日誌，用來記錄對數據發生或潛在發生更改的SQL語句，並以而進行的形式保存在磁盤中。java

binlog 的做用？

最主要有3個用途：mysql

數據複製（主從同步）git

Mysql 的Master-Slave協議，讓Slave能夠經過監聽binlog實現數據複製，達到數據一致性目的github

數據恢復sql

經過mysqlbinlog工具恢復數據數據庫

增量備份json

Binlog 變量bash
- log_bin (Binlog 開關，使用show variables like 'log_bin';查看)服務器
- binlog_format (Binlog 日誌格式，使用show variables like 'binlog_format';查看)ide
  
  日誌格式總共有三種：
  - ROW，僅保存記錄被修改的細節，不記錄SQL語句上下文相關信息。（能清晰的記錄下每行數據的修改細節，不須要記錄上下文相關信息，所以不會發生某些特定狀況下的procedure、function以及trigger 的調用沒法被準確複製的問題，任何狀況下均可以被複制，且能加快從庫重放日誌的效率，保證從庫數據的一致性）
  - STATEMENT，每一條修改數據的SQL都會被記錄。（只記錄執行語句的細節和上下文環境，避免了記錄每一行的變化，在一些修改記錄較多的狀況下，相比ROW類型能大大減小binlog的日誌量，節約IO,提升性能。還能夠用於實時的還原，同時主從版本能夠不同，從服務器版本能夠比主服務器版本高）
  - MIXED，上述2種的混合使用
Binlog 管理
- show master logs; 查看全部binlog的日誌列表
- show master status; 查看最後一個binlog日誌編號名稱，以及最後一個事件技術的位置（position）
- Flush logs; 刷新binlog,此刻開始產生一個新編號的binlog日誌文件
- reset master; 清空全部的binlog日誌
Binlog 相關SQL show binlog events[in 'log_name'][from position][limit [offset,]row_count]
經常使用的Binlog event
- QUERY - 與數據無關的操做，begin、drop table、truncate table等等
- TABLE_MAP - 記錄下一個操做所對應的表信息，存儲了數據庫名稱和表名稱
- XID - 標記事務提交
- WRITE_ROWS 插入數據，即insert操做
- UPDATE_ROWS 更新數據，即update操做
- DELETE_ROWS 刪除數據，即delete操做

Event包含header和data兩部分，header提供了event的建立時間，哪一個服務器等信息，data部分提供的是針對該event的具體信息，如具體數據的修改。

Tip: binlog不會記錄數據表的列名

在接下來的實現中，咱們會將本身的系統包裝成一個假的Mysql Slave，經過開源工具mysql-binlog-connector-java來實現監聽binlog。

開源工具`mysql-binlog-connector-java`

工具源碼：Github傳送門

組件使用

1.加依賴

<!-- binlog 日誌監聽,解析開源工具類庫 -->
<dependency>
    <groupId>com.github.shyiko</groupId>
    <artifactId>mysql-binlog-connector-java</artifactId>
    <version>0.18.1</version>
</dependency>

2.建立一個測試接口

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 測試Mysql binlog 監控
 * {@code
 * Mysql8 鏈接提示 Client does not support authentication protocol requested by server; consider upgrading MySQL client 解決方法
 * 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 {

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

        //設置須要讀取的Binlog的文件以及位置，不然，client會從"頭"開始讀取Binlog並監聽
//        client.setBinlogFilename("binlog.000035");
//        client.setBinlogPosition();

        //給客戶端註冊監聽器，實現對Binlog的監聽和解析
        //event 就是監聽到的Binlog變化信息，event包含header & data 兩部分
        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();
    }
}

運行：

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)
...

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

咱們須要知道的是，咱們的目的是實現對Mysql數據表的變動實現監聽，並解析成咱們想要的格式，也就是咱們的java對象。根據上面咱們看到的監聽結果，咱們知道了返回信息的大概內容，既然咱們已經學會了簡單的使用BinaryLogClient 來監聽binlog，接下來，咱們須要定義一個監聽器，來實現咱們本身的業務內容。

由於咱們只須要Event中的內容，那麼咱們也就只須要經過實現com.github.shyiko.mysql.binlog.BinaryLogClient.EventListener接口，來自定義一個監聽器實現咱們的業務便可。經過Event的內容，來斷定是否須要處理當前event以及如何處理。

構造解析binlog的模版文件

咱們監聽binlog來構造增量數據的根本緣由，是爲了將咱們的廣告投放系統和廣告檢索系統 業務解耦，因爲咱們的檢索系統中沒有定義數據庫以及數據表的相關，因此，咱們經過定義一份模版文件，經過解析模版文件來獲得咱們須要的數據庫和表信息，由於binlog的監聽是不區分是哪一個數據庫和哪一個數據表信息的，咱們能夠經過模版來指定咱們想要監聽的部分。

{
  "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，指定了一個數據庫爲advertisement，你們能夠方便添加多個監聽庫。在數據庫下面，咱們監聽了幾個表的CUD操做以及每一個操做所須要的字段信息。

實現模版 —> Java Entity

定義模版文件對應的實體

@Data
@AllArgsConstructor
@NoArgsConstructor
public class BinlogTemplate {
		//單數據庫對應
    private String database;
  	//多表
    private List<JsonTable> tableList;
}

對應的json 中 table信息

/**
 * JsonTable for 用於表示template.json中對應的表信息
 *
 * @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;
    }
}

讀取的對應表信息對象（最主要目的就是爲了能將字段索引 映射到 字段名稱）

@Data
@AllArgsConstructor
@NoArgsConstructor
public class TableTemplate {
    private String tableName;
    private String level;

  	//操做類型 -> 多列
    private Map<OperationTypeEnum, List<String>> opTypeFieldSetMap = new HashMap<>();

    /**
     * Binlog日誌中 字段索引 -> 字段名稱 的一個轉換映射
     * 由於binlog中不會顯示更新的列名是什麼，它只會展現字段的索引，所以咱們須要實現一次轉換
     */
    private Map<Integer, String> posMap = new HashMap<>();
}

解析模版文件到java對象

@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);

            //遍歷操做類型對應的列信息
            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;
    }

    /**
     * 從Map中獲取對象，若是不存在，建立一個
     */
    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 -> 字段名稱的一個轉換映射

首先，咱們來看一下binlog的具體日誌信息：

--------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]}

能夠看到，在日誌中includedColumns只包含了{0, 1, 2, 3, 4, 5}位置信息，那麼咱們怎麼能知道它具體表明的是哪一個字段呢，接下來咱們來實現這步映射關係，在實現以前，咱們先來查詢一下數據庫中咱們的表中字段所處的具體位置：

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

咱們能夠看到ordinal_position對應的是1-6，但是上面監聽到的binlog日誌索引是0-5，因此咱們就能夠看出來之間的對應關係。

咱們開始編碼實現，咱們使用JdbcTemplate進行查詢數據庫信息：

@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;
    }

    /**
     * 須要在容器加載的時候，就載入數據信息
     */
    @PostConstruct
    private void init() {
        loadJSON("template.json");
    }

    /**
     * 對外提供加載服務
     */
    public TableTemplate getTable(String tableName) {
        return template.getTableTemplateMap().get(tableName);
    }

    /**
     * 加載須要監聽的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");
        }
    }

    /**
     * 加載元信息
     * 使用表索引到列名稱的映射關係
     */
    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;
                    }
            );
        }
    }
}

監聽binlog實現

定義Event 解析所須要轉換的java對象

@Data
public class BinlogRowData {

    private TableTemplate tableTemplate;

    private EventType eventType;

    private List<Map<String, String>> before;

    private List<Map<String, String>> after;

}

定義binlog client BinaryLogClient

/**
 * CustomBinlogClient for 自定義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註冊事件監聽器com.github.shyiko.mysql.binlog.BinaryLogClient.EventListener

/**
 * Ilistener for 爲了後續擴展不一樣的實現
 *
 * @author <a href="mailto:magicianisaac@gmail.com">Isaac.Zhang | 若初</a>
 */
public interface Ilistener {

    void register();

    void onEvent(BinlogRowData eventData);
}

監聽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;
    }

    /**
     * 根據表實現註冊信息
     */
    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);

        //數據庫增刪改以前，確定有一個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;
        }

        // 檢查表名和數據庫名是否已經正確填充
        if (StringUtils.isEmpty(dbName) || StringUtils.isEmpty(tbName)) {
            log.error("Meta data got error. tablename:{},database:{}", tbName, dbName);
            return;
        }

        //找出對應數據表敏感的監聽器
        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數據到Java實體對象的映射
     *
     * @param data binlog
     * @return java 對象
     */
    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) {
                //取出當前位置對應的列名
                String colName = tableTemplate.getPosMap().get(i);
                //若是沒有，則說明不須要該列
                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;
    }

    /**
     * 獲取不一樣事件的變動後數據
     * Add & Delete變動前數據假定爲空
     */
    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 數據對象BinlogRowData ,用於增量索引的後續處理

/**
 * MysqlRowData for 簡化{@link BinlogRowData} 以方便實現增量索引的實現
 *
 * @author <a href="mailto:magicianisaac@gmail.com">Isaac.Zhang | 若初</a>
 */
@Data
@AllArgsConstructor
@NoArgsConstructor
public class MysqlRowData {

    //實現多數據的時候，須要傳遞數據庫名稱
    //private String database;
    private String tableName;
    private String level;
    private OperationTypeEnum operationTypeEnum;
    private List<Map<String, String>> fieldValueMap = new ArrayList<>();
}

由於咱們須要將Binlog EventType轉換爲咱們的操做類型OperationTypeEnum，因此，咱們在OperationTypeEnum中添加一個轉換方法：

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;
        }
    }
}

咱們還須要定義一個表包含的各個列名稱的java類，方便咱們後期對數據表的CUD操做：

package com.sxzhongf.ad.mysql.constant;

import java.util.HashMap;
import java.util.Map;

/**
 * Constant for 各個列名稱的java類，方便咱們後期對數據表的CUD操做
 *
 * @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 -> 數據庫名
    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);
    }
}