小编Luc*_*uca的帖子

我想执行一个副本并获得两个不同的对象,以便我可以在不影响原始文件的情况下处理副本.

我有这个代码(groovy 2.0.5):

def a = [[1,5,2,1,1], ["one", "five", "two", "one", "one"]]
def b = a
b.add([6,6,6,6,6,6])
println a
println b

产生:

[[1, 5, 2, 1, 1], [one, five, two, one, one], [6, 6, 6, 6, 6, 6]]
[[1, 5, 2, 1, 1], [one, five, two, one, one], [6, 6, 6, 6, 6, 6]]

看起来像b和a实际上是同一个对象

我可以用这种方式解决它:

def a = [[1,5,2,1,1], ["one", "five", "two", "one", "one"]]
def b = []

a.each {
    b.add(it)
}

b.add([6,6,6,6,6])
println a
println b

产生我想要的结果:

[[1, …

我有一个Grails 2.2.3应用程序使用此配置连接到mysql数据库:

 production {
    dataSource {
        dbCreate = "update" // one of 'create', 'create-drop','update'
        url = "jdbc:mysql://localhost/database?autoReconnect=true"

        pooled = true
        properties {
            maxActive = 50
            maxIdle = 25
            minIdle = 5
            initialSize = 5
            minEvictableIdleTimeMillis = 1800000
            timeBetweenEvictionRunsMillis = 1800000
            maxWait = 10000

        }


    }

}

升级到Grails 2.3.0后,这已停止工作,在应用程序上周末不活动后,我收到此异常:

Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: The last packet successfully received from the server was 50,139,380 milliseconds ago.  The last packet sent successfully to the server was 50,139,380 milliseconds ago. is longer than the server …