https://www.playframework.com/documentation/2.8.x/AccessingAnSQLDatabase


JDBC is a blocking operation 

Play provides a plugin for managing JDBC connection pools
Play uses HikariCP as the default database connection pool implementation
play.db.pool=your.own.ConnectionPool


the default JDBC data source must be called default 
the corresponding configuration properties are db.default.driver and db.default.url
db.default.driver 
db.default.url

db.default.driver=org.h2.Driver
db.default.url="jdbc:h2:mem:play"

指定数据源名字
play.db.default = "primary"
db.primary.driver=org.h2.Driver
db.primary.url="jdbc:h2:mem:play"


db.default.jndiName=DefaultDS

db.default.logSql=true



@Singleton
class JavaApplicationDatabase {

  private Database db;
  private DatabaseExecutionContext executionContext;

  @Inject
  public JavaApplicationDatabase(Database db, DatabaseExecutionContext context) {
    this.db = db;
    this.executionContext = executionContext;
  }
  

@Inject
public JavaNamedDatabase(
      // inject "orders" database instead of "default"
      @NamedDatabase("orders") Database db, DatabaseExecutionContext executionContext) {
    this.db = db;
    this.executionContext = executionContext;
  }
  
public CompletionStage< Integer > updateSomething() {
    return CompletableFuture.supplyAsync(
        () ->
            db.withConnection(
                connection -> {
                  // do whatever you need with the db connection
                  return 1;
                }),
        executionContext);
}
  
  
using withConnection, the connection will be automatically closed at the end of the block


Connection connection = db.getConnection();
...
调用close 释放连接



添加依赖
libraryDependencies += jdbc
libraryDependencies += "com.h2database" % "h2" % "1.4.192"


完整例子代码
https://gitee.com/dyyx/hellocode/blob/master/demo/scala/play-rest-hello/app/controllers/DBController.scala




CustomExecutionContext
configure a custom execution context dedicated to serving JDBC operations

play.api.libs.concurrent.CustomExecutionContext

abstract class CustomExecutionContext(system: ActorSystem, name: String) extends ExecutionContextExecutor {

trait ExecutionContextExecutor extends ExecutionContext with Executor

scala.concurrent.ExecutionContextExecutor

scala.concurrent.ExecutionContext
java.util.concurrent.Executor