/** The JDBC database driver. */指定连接驱动public static final String DB_DRIVER = "driver";/** The JDBC database URL. */  连接字符串public static final String DB_URL = "URL";/** The database user name. */ 用户名public static final String DB_USER = "user";/** The database user password. */ 密码public static final String DB_PASSWORD = "password";/** The maximum number of database connections to have in the pool.  Default is 10. */ 连接池最大连接数public static final String DB_MAX_CONNECTIONS = "maxConnections";/** * The maximum number of prepared statements that will be cached per connection in the pool.* Depending upon your JDBC Driver this may significantly help performance, or may slightly * hinder performance.   * Default is 120, as Quartz uses over 100 unique statements. 0 disables the feature. */     每个链接最多缓存多少个预编译语句public static final String DB_MAX_CACHED_STATEMENTS_PER_CONNECTION = "maxCachedStatementsPerConnection";/** * The database sql query to execute every time a connection is returned * to the pool to ensure that it is still valid. */  验证连接是否可用的查询语句public static final String DB_VALIDATION_QUERY = "validationQuery";/** * The number of seconds between tests of idle connections - only enabled* if the validation query property is set.  Default is 50 seconds. */   多久验证空闲连接public static final String DB_IDLE_VALIDATION_SECONDS = "idleConnectionValidationSeconds";/** * Whether the database sql query to validate connections should be executed every time * a connection is retrieved from the pool to ensure that it is still valid.  If false,* then validation will occur on check-in.  Default is false. */  是否每次从池中取连接时，验证连接可用性public static final String DB_VALIDATE_ON_CHECKOUT = "validateOnCheckout";/** Discard connections after they have been idle this many seconds.  0 disables the feature. Default is 0.*/   空闲连接超过多少秒丢弃private static final String DB_DISCARD_IDLE_CONNECTIONS_SECONDS = "discardIdleConnectionsSeconds"; /** Default maximum number of database connections in the pool. */  最大连接数public static final int DEFAULT_DB_MAX_CONNECTIONS = 10;/** Default maximum number of database connections in the pool. */   默认每个链接缓存120个预编译语句public static final int DEFAULT_DB_MAX_CACHED_STATEMENTS_PER_CONNECTION = 120;