The Value of Annotation @Temporal for Date Related Columns

The annotation @Temporal in official javadoc is described like below: This annotation must be specified for persistent fields or properties of type java.util.Date and java.util.Calendar. So when the field variable is a java.util.Date or java.util.Calendar, it MUST be annotated by @Temporal. There...

How to configure primary key's generator in JPA entity for oracle

In JPA there are 4 strategies to automatically generate value for a primary key column: Auto Identity Sequence Table To some extent, there are only 3 strategies, the last 3 ones. Because the first 'Auto' just let the JPA implementation to choose which one of the rest 3 strategies it will use. For example working with Oracle + EclipseLink 2.5.0,  the "Auto" will result in the strategy "Table"...

How to create Java classes from existing tables in database for JPA

If JPA is your persistence layer in your project and you have tables already defined in database. You can use JPA tools in Eclipse to automatically create corresponding Java Entity classes from those tables in database. In this article, Java JPA entities will be created from an oracle database on LAN....

How to add oracle DB connection in Eclipse

Have a DB connection in Eclipse will be very helpful if you need use persistence frameworks like Hibernate or JPA.  It's normally a prerequisite for other functions, for example let eclipse create java entities class from database tables automatically.  Here's how to configure oracle connection...

How to disable c3p0 from writing log to screen (stderr)

Even if you have slf4j and logback configured in your project, the c3p0 insists on writing log to system error channel like this: The Eclipse console show log from c3p0 in red, because the texts are written to stderr.  The way to dismiss those red part from c3p0 is add two lines at the beginning...

How to inject a logger variable by using annotation in Spring

In development, we need logger almost everywhere. you can inject a bean with annotation like inject other beans package com.shengwangi.demo; @Component public class MyClass { @Loggable Logger logger; public void myMethod() { // do some thing logger.info("use the logger as usual"); } } As you can see, annotation @Loggable is used to inject the logger. @Loggable is an annotation that...