Java DBCP中的不可序列化异常
我有DAO当我使DAO可序列化时,我得到异常:Java DBCP中的不可序列化异常,java,jsf-2,connection-pooling,tomcat7,Java,Jsf 2,Connection Pooling,Tomcat7,我有DAO当我使DAO可序列化时,我得到异常: Cannot serialize session attribute com.sun.faces.renderkit.ServerSideStateHelper.LogicalViewMap for session C354B1B6053088CBB8E8A933E5F8EAE0 java.io.NotSerializableException: org.apache.tomcat.dbcp.dbcp.PoolingDataSource$
Cannot serialize session attribute com.sun.faces.renderkit.ServerSideStateHelper.LogicalViewMap for session C354B1B6053088CBB8E8A933E5F8EAE0
java.io.NotSerializableException: org.apache.tomcat.dbcp.dbcp.PoolingDataSource$PoolGuardConnectionWrapper
我的刀:
public boolean getConnection() {
try {
InitialContext context = new InitialContext();
DataSource dataSource = (DataSource) context.lookup("java:/comp/env/jdbc/Orcl");
connection = dataSource.getConnection();
return true;
} catch (SQLException ex) {
Logger.getLogger(KPIDAO.class.getName()).log(Level.SEVERE, null, ex);
return false;
} catch (NamingException ex) {
Logger.getLogger(KPIDAO.class.getName()).log(Level.SEVERE, null, ex);
return false;
}
}
在控制器(@ViewScoped)中:
Context.xml
<Resource
name="jdbc/Orcl"
auth="Container"
type="javax.sql.DataSource"
username="username"
password="password"
driverClassName="oracle.jdbc.OracleDriver"
url="jdbc:oracle:thin:@192.168.1.10:1521:XE"
maxActive="8"
/>
什么是合适的解决方案?您不应该在会话中存储对PoolgDataSource的引用,因为PoolgDataSource不可序列化。我建议您将其存储在其他地方,例如在应用程序上下文中。例如
@ViewScoped
public class ViewBean implements Serializable{
private transient KPIDAO kpiDAO = //get singleton instance from factory
//also dont keep connection object as instance variable, fetch it from pool in methods and perform db operations.
private void readObject(java.io.ObjectInputStream stream)
throws java.io.IOException, ClassNotFoundException
{
stream.defaultReadObject();
// assign reference manually.
this.kpiDAO = //get from factory;
}
private void writeObject(java.io.ObjectOutputStream stream)
throws java.io.IOException
{
stream.defaultWriteObject();
}
}
注意:如果将连接对象从实例变量移动到
局部方法变量,您也不需要上面的代码
更新:
从您的代码片段和异常
connection = dataSource.getConnection();
它似乎是一个实例变量
i、 e
换成
public class Dao {
public List<Bean> getResult(){
//local method variable
Connection connection = //get from pool
//perform db operation with connection object
}
公共类Dao{
公共列表getResult(){
//局部方法变量
连接=//从池中获取
//使用连接对象执行数据库操作
}
}那么我在会话中存储了什么PooldDatasoruce?如何?@Kitex通过连接对象,即SessionBean->KPIDAO->connection@gbagga任何有帮助的例子吗?+1@gbagga非常好。任何教程:)我真的不知道这和“将连接对象从实例变量移动到局部方法变量”的意思是什么?
public class Dao {
private Connection connection; //instance variable
}
public class Dao {
public List<Bean> getResult(){
//local method variable
Connection connection = //get from pool
//perform db operation with connection object
}