我应该保持数据库连接打开以处理每个请求吗？以及如何以正确的方式做到这一点

Question

public class MongoUtils {
private static final String connectionString = "mongodb://localhost:27017";
private static final MongoClient client;

static {
    client = MongoClients.create(connectionString);
}

public static MongoClient getConnection(){
    return client;
}

}

2018-10-25 11:37:36 INFO  AnnotationMBeanExporter:433 - Registering beans for JMX exposure on startup
2018-10-25 11:37:36 INFO  Http11NioProtocol:180 - Starting ProtocolHandler ["http-nio-8808"]
2018-10-25 11:37:36 INFO  NioSelectorPool:180 - Using a shared selector for servlet write/read
2018-10-25 11:37:36 INFO  TomcatWebServer:206 - Tomcat started on port(s): 8808 (http) with context path '/api'
2018-10-25 11:37:36 INFO  Backend:59 - Started Backend in 3.251 seconds (JVM running for 6.935)
2018-10-25 11:37:56 INFO  [/api]:180 - Initializing Spring FrameworkServlet 'dispatcherServlet'
2018-10-25 11:37:56 INFO  DispatcherServlet:494 - FrameworkServlet 'dispatcherServlet': initialization started
2018-10-25 11:37:56 INFO  DispatcherServlet:509 - FrameworkServlet 'dispatcherServlet': initialization completed in 39 ms
2018-10-25 11:37:56 INFO  cluster:71 - Cluster created with settings {hosts=[10.184.153.232:27017], mode=SINGLE, requiredClusterType=UNKNOWN, serverSelectionTimeout='30000 ms', maxWaitQueueSize=500}
2018-10-25 11:37:56 INFO  cluster:71 - Cluster description not yet available. Waiting for 30000 ms before timing out
2018-10-25 11:37:56 INFO  connection:71 - Opened connection [connectionId{localValue:1, serverValue:27}] to 10.184.153.232:27017
2018-10-25 11:37:56 INFO  cluster:71 - Monitor thread successfully connected to server with description ServerDescription{address=10.184.153.232:27017, type=STANDALONE, state=CONNECTED, ok=true, version=ServerVersion{versionList=[4, 0, 3]}, minWireVersion=0, maxWireVersion=7, maxDocumentSize=16777216, logicalSessionTimeoutMinutes=30, roundTripTimeNanos=3393851}
2018-10-25 11:37:56 INFO  connection:71 - Opened connection [connectionId{localValue:2, serverValue:28}] to 10.184.153.232:27017

Answer 1

直接引用com.mongodb.mongoclient的JavaDocs：

具有内部连接池的MongoDB客户端。对于大多数应用程序，您应该为整个JVM拥有一个MongoClient实例。

客户端本身具有内部连接池，并且是线程安全的。因此，您应该为应用程序使用一个MongoClient实例。这表明您已经按照建议使用了它。