Spring -Mongodb 将枚举存储检索为 int 而不是字符串

使用Spring和Mongodb进行开发时，我们经常需要将枚举类型的数据存储到数据库中。默认情况下，Spring会将枚举类型的值以字符串的形式存储到Mongodb中。然而，有时我们希望将枚举存储为整数而不是字符串，这样可以节省存储空间并提高查询效率。本文将介绍如何使用Spring和Mongodb将枚举存储/检索为整数而不是字符串。

java
import org.springframework.core.serializer.Serializer;
public class EnumToIntSerializer implements Serializer> {
    @Override
    public void serialize(Enum value, OutputStream outputStream) throws IOException {
        outputStream.write(value.ordinal());
    }
}

java
import org.springframework.context.annotation.Configuration;
import org.springframework.data.mongodb.config.AbstractMongoClientConfiguration;
import org.springframework.data.mongodb.core.convert.MongoCustomConversions;
import org.springframework.data.mongodb.repository.config.EnableMongoRepositories;
@Configuration
@EnableMongoRepositories
public class MongoConfig extends AbstractMongoClientConfiguration {
    @Override
    protected String getDatabaseName() {
        return "your-database-name";
    }
    @Override
    public MongoCustomConversions customConversions() {
        return new MongoCustomConversions(Collections.singletonList(new EnumToIntConverter()));
    }
}

java
public class User {
    private String name;
    private Gender gender;
    // getters and setters
}
public enum Gender {
    MALE,
    FEMALE
}

java
@JsonSerialize(using = EnumToIntSerializer.class)
public enum Gender {
    MALE,
    FEMALE
}

java
import org.springframework.core.serializer.Serializer;
import org.springframework.data.mongodb.core.convert.MongoCustomConversions;
import org.springframework.data.mongodb.repository.config.EnableMongoRepositories;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Collections;
@JsonSerialize(using = EnumToIntSerializer.class)
public enum Gender {
    MALE,
    FEMALE
}
public class User {
    private String name;
    private Gender gender;
    // getters and setters
}
@Configuration
@EnableMongoRepositories
public class MongoConfig extends AbstractMongoClientConfiguration {
    @Override
    protected String getDatabaseName() {
        return "your-database-name";
    }
    @Override
    public MongoCustomConversions customConversions() {
        return new MongoCustomConversions(Collections.singletonList(new EnumToIntConverter()));
    }
}
public class EnumToIntSerializer implements Serializer> {
    @Override
    public void serialize(Enum value, OutputStream outputStream) throws IOException {
        outputStream.write(value.ordinal());
    }
}