sinat_40251690-优快云博客

原创 Java Generic Types

A generic type is a generic class or interface that is parameterized over types. It can be used to generalize the type of parameters and return value in coding without the risk to pass a wrong type to...

2012-11-16 18:10:12 123

原创 Linux Common Commands

Search text in tail or view command:/to search text, search forward?to search text, search backward GZIP,TAR,ZIP gzip is used to compress file large that 4GB, and it defaultes to preserve ...

2012-11-16 17:10:32 133

原创 Oracle Common Commands

Import/Export Database:exp username/password@tns name FILE=D:\pub.dump OWNER=(username) imp username/password name FILE=D:\pub.dump TOUSER=(username) FROMUSER=(username) Query all users i...

2012-11-16 16:53:22 121

原创 TNS:no appropriate service handler found

Error Message:Caused by: java.sql.SQLException: Listener refused the connection with the following error:ORA-12519, TNS:no appropriate service handler foundThe Connection descriptor used by the ...

2012-11-16 16:47:53 148

原创 How to change the XMLDB Http and FTP Ports for Oracle

To change the HTTP and FTP ports for Oracle XMLDB, we only need to call the following command in Oracle with DBA role. change HTTP port from 8080 to 9999call dbms_xdb.cfg_update(updateXM...

2012-11-10 12:18:08 134

原创 SQL Exists Condition

The exists condition is considered to be met if the subquery returns more than one row. It always used to test whether relevant recrods exist and filter out those extraneous results. The common case...

2012-01-17 17:54:38 154

原创 SQL Transaction Isolation Level

IntroductionTransaction is a mechanism to ensure a bunch of database operations be performed in an atomic way. Either all of the operations succeed(committed) or nothing will be persisted(rollback)....

2011-12-10 17:38:30 171

原创 Something about the sample-imagedb in Spring

Start from the web.xml Every web application has a web descriptor which will be parsed by the web server.So it is prefered to start learning with the sample application from the web.xml file.The...

2011-09-18 21:02:45 114

原创 About Java Virtual Machine

The compilation mechanism in java Unlike C and C++,java compiles the source text into binary code separately not a single executable application, which also determines the method java stores ...

2010-10-07 22:13:52 118

To Be a Humble Guy