Currently OpenPatrician only allows a view of the current state of affairs for example for fleet size, reputation or available wares. Even the personal balance records only the current and the past week. For statistical purposes these data should be recorded for the whole game time. This calls for a database. This post details the findings of the evaluation of these:<\/p>\n
<\/p>\n
The whole evaluation was done based upon Spring Boot, which makes it easy to use certain databases.<\/p>\n
Some of the code is used in all the examples:<\/p>\n
The data model for the Fleet statistic:<\/p>\n
package ch.sahits.game.test.database;\r\n\r\nimport lombok.Getter;\r\nimport org.springframework.data.annotation.Id;\r\n\r\nimport java.time.LocalDate;\r\nimport java.time.format.DateTimeFormatter;\r\n\r\n@EqualsAndHashCode\r\npublic class ShipRecord {\r\n @Id\r\n private String id;\r\n @Getter\r\n private String playerUuid;\r\n @Getter\r\n private LocalDate date;\r\n @Getter\r\n private int fleetSize;\r\n\r\n public ShipRecord(String playerUuid, LocalDate date, int fleetSize) {\r\n this.playerUuid = playerUuid;\r\n this.date = date;\r\n this.fleetSize = fleetSize;\r\n }\r\n\r\n @Override\r\n public String toString() {\r\n return \"ShipRecord{\" +\r\n \"id='\" + id + '\\'' +\r\n \", playerUuid='\" + playerUuid + '\\'' +\r\n \", date=\" + date.format(DateTimeFormatter.BASIC_ISO_DATE) +\r\n \", fleetSize=\" + fleetSize +\r\n '}';\r\n }\r\n}<\/pre>\nAs all evaluations are done in the same maven module here is the pom.xml the specialties in it will be pointed out in the respective sections:<\/p>\n
MongoDB<\/h1>\nSetup<\/h2>\n
The setup is easy if you know how to tweak it.\u00a0 To enable MongoDB with Spring Boot the starter module is required:<\/p>\n
<dependency>\r\n <groupId>org.springframework.boot<\/groupId>\r\n <artifactId>spring-boot-starter-data-mongodb<\/artifactId>\r\n <version>${spring.boot.version}<\/version>\r\n<\/dependency><\/pre>\nTo enable the embedded MongoDB this dependency is needed as well:<\/p>\n
<dependency>\r\n <groupId>de.flapdoodle.embed<\/groupId>\r\n <artifactId>de.flapdoodle.embed.mongo<\/artifactId>\r\n <version>2.0.0<\/version>\r\n<\/dependency><\/pre>\nOn the first start up this will automatically download and install the MongoDB so that it can be used in embedded mode. So there is no separate installation necessary.<\/p>\n
Querying<\/h2>\n
With MongoDB the quering can be done with a Repository. This is an typed interface (based along the same premise as JpaRepository) which generates the queries automatically based on the method name. The neat thing here is that with IntelliJ (2017.1.3 Ultimate) you get suggestions how to construct the method name based on the domain model:<\/p>\n
package ch.sahits.game.test.database;\r\n\r\nimport org.springframework.data.mongodb.repository.MongoRepository;\r\n\r\nimport java.time.LocalDate;\r\nimport java.util.List;\r\n\r\npublic interface FleetRepository extends MongoRepository<ShipRecord, String> {\r\n List<ShipRecord> findAllByPlayerUuid(String playerUuid);\r\n\r\n \/**\r\n * Find all recods of a player between two dates (exclusive)\r\n *\/\r\n List<ShipRecord> findAllByPlayerUuidAndDateBetweenOrderByDate(String playerUuid, LocalDate startDate, LocalDate endDate);\r\n}\r\n<\/pre>\nFor more complex queries there is also the possibility with MongoTemplate which was not further investigated.<\/p>\n
Serializability<\/h2>\n
By default the embedded database is an in memory database. To configure the storage location these two properties have to be set:<\/p>\n
spring.mongodb.embedded.storage.database-dir=${user.home}\/.OpenPatrician\/mongodb\r\nspring.mongodb.embedded.storage.oplog-size=0\r\n<\/pre>\nThe database then can be dumped and restored with these two additional beans:<\/p>\n
private void dumpMongoDB() {\r\n \/\/ ensure directories are ok\r\n File tempDirectory = new File(mongodbDumpLocation);\r\n tempDirectory.delete();\r\n tempDirectory.mkdir();\r\n try {\r\n mongoDBDumper.start();\r\n } catch (IOException e) {\r\n e.printStackTrace();\r\n }\r\n }\r\n\r\n private void restoreMongoDB() {\r\n try {\r\n mongoDBRestorer.start();\r\n } catch (IOException e) {\r\n e.printStackTrace();\r\n }\r\n }\r\n\r\n @Bean\r\n public MongoDumpExecutable mongoDBDumper(IMongodConfig mongodConfig) throws IOException {\r\n int port = mongodConfig.net().getPort();\r\n IMongoDumpConfig mongoDumpConfig = new MongoDumpConfigBuilder()\r\n .version(Version.Main.PRODUCTION)\r\n .net(new Net(port, Network.localhostIsIPv6()))\r\n .out(mongodbDumpLocation)\r\n .build();\r\n\r\n return MongoDumpStarter.getDefaultInstance().prepare(mongoDumpConfig);\r\n }\r\n\r\n @Bean\r\n public MongoRestoreExecutable mongoDbrestorer(IMongodConfig mongodConfig) throws IOException {\r\n int port = mongodConfig.net().getPort();\r\n IMongoRestoreConfig mongoRestoreConfig = new MongoRestoreConfigBuilder()\r\n .version(Version.Main.PRODUCTION)\r\n .net(new Net(port, Network.localhostIsIPv6()))\r\n .dropCollection(true)\r\n .dir(mongodbDumpLocation)\r\n .build();\r\n\r\n return MongoRestoreStarter.getDefaultInstance().prepare(mongoRestoreConfig);\r\n }<\/pre>\nPerofmance<\/h2>\n