如何指定与Spring的MongoTemplate一起使用的ReadCommerce？

Question

var result = mongoClient.getDatabase("somedb")
                        .getCollection("collection")
                        .withReadConcern(ReadConcern.MAJORITY)
                        .find(..)

Answer 1

您似乎可以在TransactionOptions和MongoTransactionManager上设置此设置：

https://docs.spring.io/spring-data/mongoDB/docs/current/api/org/springframework/data/mongoDB/mongoTransactionManager.html

示例：

TransactionOptions transactionOptions = TransactionOptions.builder().readConcern(ReadConcern.LOCAL).writeConcern(WriteConcern.W1).build();
return new MongoTransactionManager(dbFactory.getMongoDatabaseFactory(), transactionOptions);

import com.mongodb.ConnectionString;
import com.mongodb.MongoClientSettings;
import com.mongodb.ReadConcern;
import com.mongodb.ReadPreference;
import com.mongodb.WriteConcern;
import com.mongodb.client.MongoClient;
import com.mongodb.client.MongoClients;
import org.springframework.context.annotation.Bean;
import org.springframework.data.mongodb.config.AbstractMongoClientConfiguration;
import org.springframework.data.mongodb.core.MongoTemplate;

@Configuration
public class DemoApplication extends AbstractMongoClientConfiguration {

    @Bean
    public MongoTemplate mongoTemplate() {
        return new MongoTemplate(mongoClient(), "someDbName");
    }

    @Override
    public MongoClient mongoClient() {
        final ConnectionString connectionString = new ConnectionString("mongodb://localhost:27017/someDbName");

        MongoClientSettings mongoClientSettings = MongoClientSettings.builder()
                .applyConnectionString(connectionString)
                .readConcern(ReadConcern.DEFAULT)
                .writeConcern(WriteConcern.MAJORITY)
                .readPreference(ReadPreference.primary()).build();

        return MongoClients.create(mongoClientSettings);
    }

    @Override
    protected String getDatabaseName() {
        return "someDbName";
    }
}