双写一致性：ES与MySQL数据同步的直接同步与异步解决方案

// 假设已经有了数据库和Elasticsearch客户端的实例
private final JdbcTemplate jdbcTemplate;
private final ElasticsearchClient elasticsearchClient;
 
public DataSynchronizer(JdbcTemplate jdbcTemplate, ElasticsearchClient elasticsearchClient) {
    this.jdbcTemplate = jdbcTemplate;
    this.elasticsearchClient = elasticsearchClient;
}
 
// 同步数据库中的记录到Elasticsearch的方法
public void syncDatabaseToElasticsearch() {
    List<Product> products = jdbcTemplate.query(
        "SELECT id, name, price FROM products",
        (rs, rowNum) -> new Product(rs.getInt("id"), rs.getString("name"), rs.getDouble("price"))
    );
 
    // 使用Elasticsearch的BulkProcessor进行批量操作
    BulkProcessor bulkProcessor = BulkProcessor.builder(
        (actions, bulkRequest, listener) -> elasticsearchClient.bulk(bulkRequest, listener.actionListener),
        new BulkProcessor.Listener() {
            @Override
            public void beforeBulk(long executionId, BulkRequest request) {
                // 在执行批量操作前可以进行一些逻辑处理
            }
 
            @Override
            public void afterBulk(long executionId, BulkRequest request, BulkResponse response) {
                // 在批量操作后可以进行一些逻辑处理
            }
 
            @Override
            public void afterBulk(long executionId, BulkRequest request, Throwable failure) {
                // 在批量操作出错后可以进行一些逻辑处理
            }
        }
    ).build();
 
    // 将数据库中的记录添加到BulkProcessor进行批量同步
    products.forEach(product -> {
        IndexRequest indexRequest = new IndexRequest("products")
            .id(String.valueOf(product.getId()))
            .source(XContentType.JSON, "name", product.getName(), "price", product.getPrice());
        bulkProcessor.add(indexRequest);
    });
 
    // 关闭BulkProcessor，确保所有待处理的请求得到处理
    bulkProcessor.close();
}
 
// 假设Product是一个包含id，name和price属性的简单类
public static class Product {
    private int id;
    private String name;
    private double price;
 
    // 构造器、getter和setter方法
    public Product(int id, String name, double price) {
        this.id = id;
        this.name = name;
        this.price = price;
    }
 
    public int getId() {
        return id;
    }
 
    public void setId(int id) {
        this.id = id;
    }
 
    public S