[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

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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]

    UTOOLS1565224352749.png

    UTOOLS1565224799877.png

  • 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: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;

UTOOLS1565227012106.png

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'
    

    UTOOLS1565311337937.png

    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);
          }
      }