spring boot怎么配置mongodb的连接池

public MongoClient createMongoClient(MongoClientOptions options)
throws UnknownHostException {
try {
if (hasCustomAddress() || hasCustomCredentials()) {
if (options == null) {
options = MongoClientOptions.builder().build();
}
List credentials = null;
if (hasCustomCredentials()) {
String database = this.authenticationDatabase == null ? getMongoClientDatabase()
: this.authenticationDatabase;
credentials = Arrays.asList(MongoCredential.createMongoCRCredential(
this.username, database, this.password));
}
String host = this.host == null ? "localhost" : this.host;
int port = this.port == null ? DEFAULT_PORT : this.port;
return new MongoClient(Arrays.asList(new ServerAddress(host, port)),
credentials, options);
}
// The options and credentials are in the URI
return new MongoClient(new MongoClientURI(this.uri, builder(options)));
}
finally {
clearPassword();
}
}