小编Dav*_*veB的帖子

在ubuntu中我以标准用户身份登录(具有受限权限),我想以管理员用户身份启动.jar,从命令行执行此操作的最佳方法是什么？

非常感谢

这里有一个基本问题,但我想知道最好的方法是什么......

我有一个HashSet,我正在添加对象,.add()方法只会添加一个对象(如果它尚不存在).但我想要做的是添加所有对象,然后在最后得到以下结果..

- 独特(不同)对象的数量
- 对象的平均频率

有人能指出我正确的方向吗？

提前致谢

我试图做类似的东西这个,但与额外的复杂性,我需要按公共字段

我有两张桌子,一张用于competition_users(竞争比赛)和另一张桌子(用于competition_times存储他们最快的时间),但在同一张桌子上有许多不同的比赛.

我rank在competition_times表格中创建了一个新列,现在需要为现有用户运行更新以显示他们在竞争中的排名,我正在尝试修改其他SO答案中给出的解决方案但没有成功

表格如下......

competition_users:

competition_user_id, competition_id

competition_times:

competition_time_id,competition_user_id,time_in_seconds,rank

我不确定它是否可以使用GROUP BY？或者如果有另一种方式,到目前为止我正在尝试这样的事情......

UPDATE competition_times
SET    rank = r.rnk
FROM (
    SELECT competition_time_id
         , dense_rank() OVER (ORDER BY time_in_seconds ASC) AS rnk
    FROM competition_times, competition_users
    WHERE competition_times.competition_user_id = competition_users.competition_user_id
    GROUP BY competition_users.competition_id
    ) r
WHERE competition_times.competition_time_id = r.competition_time_id

使用postgreSQL 9

谢谢

我有一个类PasswordEncryptor,使用org.jasypt.util.password.StrongPasswordEncryptor它的领域之一,因为我试图使应用程序"集群化"的所有类都需要被序列化的会话复制,但每当PasswordEncryptor被访问我遇到以下异常:

Caused by: java.io.NotSerializableException: org.jasypt.util.password.StrongPasswordEncryptor
    at org.jboss.marshalling.river.RiverMarshaller.doWriteObject(RiverMarshaller.java:891)
    at org.jboss.marshalling.river.RiverMarshaller.doWriteFields(RiverMarshaller.java:1063)
    at org.jboss.marshalling.river.RiverMarshaller.doWriteSerializableObject(RiverMarshaller.java:1019)
    at org.jboss.marshalling.river.RiverMarshaller.doWriteObject(RiverMarshaller.java:885)
    at org.jboss.marshalling.river.RiverMarshaller.doWriteFields(RiverMarshaller.java:1063)
    at org.jboss.marshalling.river.RiverMarshaller.doWriteSerializableObject(RiverMarshaller.java:1019)
    at org.jboss.marshalling.river.RiverMarshaller.doWriteObject(RiverMarshaller.java:885)
    at org.jboss.marshalling.river.RiverMarshaller.doWriteObject(RiverMarshaller.java:680)
    at org.jboss.marshalling.AbstractObjectOutput.writeObject(AbstractObjectOutput.java:62)
    at org.jboss.marshalling.AbstractMarshaller.writeObject(AbstractMarshaller.java:119)
    at org.jboss.as.clustering.SimpleMarshalledValue.getBytes(SimpleMarshalledValue.java:74)
    at org.jboss.as.clustering.SimpleMarshalledValue.writeObject(SimpleMarshalledValue.java:172)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) [rt.jar:1.6.0_34]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) [rt.jar:1.6.0_34]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) [rt.jar:1.6.0_34]
    at java.lang.reflect.Method.invoke(Method.java:622) [rt.jar:1.6.0_34]
    at org.jboss.marshalling.reflect.SerializableClass.callWriteObject(SerializableClass.java:175)
    at org.jboss.marshalling.river.RiverMarshaller.doWriteSerializableObject(RiverMarshaller.java:1007)
    at org.jboss.marshalling.river.RiverMarshaller.doWriteObject(RiverMarshaller.java:885)
    at org.jboss.marshalling.AbstractObjectOutput.writeObject(AbstractObjectOutput.java:62)
    at org.jboss.marshalling.AbstractMarshaller.writeObject(AbstractMarshaller.java:119)
    at org.infinispan.marshall.MarshallUtil.marshallMap(MarshallUtil.java:60)
    at org.infinispan.marshall.exts.MapExternalizer.writeObject(MapExternalizer.java:63)
    at org.infinispan.marshall.exts.MapExternalizer.writeObject(MapExternalizer.java:47)
    at org.infinispan.marshall.jboss.ExternalizerTable$ExternalizerAdapter.writeObject(ExternalizerTable.java:406)
    at org.jboss.marshalling.river.RiverMarshaller.doWriteObject(RiverMarshaller.java:145)
    at org.jboss.marshalling.AbstractObjectOutput.writeObject(AbstractObjectOutput.java:62)
    at org.jboss.marshalling.AbstractMarshaller.writeObject(AbstractMarshaller.java:119)
    at org.infinispan.atomic.AtomicHashMap$Externalizer.writeObject(AtomicHashMap.java:229)
    at org.infinispan.atomic.AtomicHashMap$Externalizer.writeObject(AtomicHashMap.java:226)
    at org.infinispan.marshall.jboss.ExternalizerTable$ExternalizerAdapter.writeObject(ExternalizerTable.java:406)
    at org.jboss.marshalling.river.RiverMarshaller.doWriteObject(RiverMarshaller.java:145) …