Canal实现Redis缓存实时更新(二)

在上一篇中介绍了Canal的安装和简单配置，本篇介绍与SpringBoot配合实现Redis缓存实时更新

@CanalEventListener
public class CanalDataEventListener {
    //SpringCloud组件,若不使用则替换为Service/Controller即可
    @Autowired
    private ContentFeign contentFeign;
    //Redis字符串
    @Autowired
    private StringRedisTemplate stringRedisTemplate;

    //自定义数据库的 操作来监听
    //destination = "example"
    @ListenPoint(destination = "example",
            schema = "changgou-content",
            table = {"tb_content", "tb_content_category"},
            eventType = {
                    CanalEntry.EventType.UPDATE,
                    CanalEntry.EventType.DELETE,
                    CanalEntry.EventType.INSERT})
    public void onEventCustomUpdate(CanalEntry.EventType eventType, CanalEntry.RowData rowData) {
        System.out.println("Action detected!");
        //1.获取列名 为category_id的值
        String categoryId = getColumnValue(eventType, rowData);
        //2.调用feign 获取该分类下的所有的广告集合
        Result<List<Content>> categoryresut = contentFeign.findByCategory(Long.valueOf(categoryId));
        List<Content> data = categoryresut.getData();
        //3.使用redisTemplate存储到redis中
        stringRedisTemplate.boundValueOps("content_" + categoryId).set(JSON.toJSONString(data));
    }

    private String getColumnValue(CanalEntry.EventType eventType, CanalEntry.RowData rowData) {
        String categoryId = "";
        //判断 如果是删除  则获取beforlist
        if (eventType == CanalEntry.EventType.DELETE) {
            for (CanalEntry.Column column : rowData.getBeforeColumnsList()) {
                if (column.getName().equalsIgnoreCase("category_id")) {
                    categoryId = column.getValue();
                    return categoryId;
                }
            }
        } else {
            //判断 如果是添加 或者是更新 获取afterlist
            for (CanalEntry.Column column : rowData.getAfterColumnsList()) {
                if (column.getName().equalsIgnoreCase("category_id")) {
                    categoryId = column.getValue();
                    return categoryId;
                }
            }
        }
        return categoryId;
    }
}