Spring Data Elasticsearch：自动生成实体映射的实践指南

import org.springframework.data.elasticsearch.annotations.Document;
import org.springframework.data.elasticsearch.annotations.Field;
import org.springframework.data.elasticsearch.annotations.FieldType;
import org.springframework.data.elasticsearch.annotations.InnerField;
import org.springframework.data.elasticsearch.annotations.MultiField;
import lombok.Data;
import lombok.EqualsAndHashCode;

import java.io.Serializable;

@Document(indexName = "person")
@Data
@EqualsAndHashCode(callSuper = true)
public class Person extends BaseEntity implements Serializable {

  @Field(type=FieldType.Keyword)
  private String firstName;

  @Field(type=FieldType.Keyword)
  private String lastName;

  @MultiField(
      mainField = @Field(type = FieldType.Keyword),
      otherFields = {
          @InnerField(type = FieldType.Text, suffix = "ngrams", analyzer = "ik_max_word", searchAnalyzer = "ik_smart")
      })
  private String fullName;

  @Field
  private String maidenName;
}

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.elasticsearch.core.ElasticsearchOperations;
import org.springframework.data.elasticsearch.core.IndexOperations;
import org.springframework.stereotype.Component;

import javax.annotation.PostConstruct;

@Component
public class ElasticsearchIndexInitializer {

    private final ElasticsearchOperations elasticsearchOperations;

    @Autowired
    public ElasticsearchIndexInitializer(ElasticsearchOperations elasticsearchOperations) {
        this.elasticsearchOperations = elasticsearchOperations;
    }

    @PostConstruct
    public void initializeElasticsearchIndices() {
        // 为Person实体类创建索引和映射
        createIndexAndMapping(Person.class);
        // 可以为其他实体类重复此操作
        // createIndexAndMapping(AnotherEntity.class);
    }

    private <T> void createIndexAndMapping(Class<T> entityClass) {
        IndexOperations indexOperations = elasticsearchOperations.indexOps(entityClass);

        if (!indexOperations.exists()) {
            // 如果索引不存在，则创建索引并应用映射
            indexOperations.createWithMapping();
            System.out.println("Elasticsearch index for " + entityClass.getSimpleName() + " created with mapping.");
        } else {
            System.out.println("Elasticsearch index for " + entityClass.getSimpleName() + " already exists. Skipping creation.");
            // 注意：如果映射在现有索引上发生变化，此方法不会更新映射。
            // 此时可能需要手动删除并重建索引，或使用Elasticsearch的映射更新API。
        }
    }
}