Skip to main content

My Career as a Java Developer





I have been using Java since 2001(JDK 1.2)  if not in 2000 and I still remembered the time I config the jvm and tomcat(3.1).

I was single and a technical fan at that time. Hence, I have lots of time to learning Java - I went through
 the famous 'Think in Java second version) at least 5 times and I bought the forth edition(the final last edition) in 2008.

We used lots of JSP and Applet in the projects in the very beginning and the maintenance tasks was really  nightmares for every developers at that time. It's very hard as all the business logic, controller and view were mixed together.

I enjoyed reading the famous GOF design pattern(Pretty much all the current masters have read that book). However, reading is one thing, apply the pattern on real projects is total different things. I tried to created my own database connection pools, and own code producers with pattern 'factory','dao', 'builder' and java meta technologies. Still, It's hard as I was tired of maintaining the codes based on the feedback from users(the developers).

Struts1.0 is the first famous MVC framework, it helped to decouple the models from controllers(some people tried to put business logic into actions :( ) . It helped us to maintain the codes easier. Still, the codes were poor to extend when new request raised as the sql queries had to be adjusted whenever there were UI Change(Table Change followed).

Hibernate was the God for helping deal with above issue. Instead of amending the queries in the codes, adding a new property might have solved the problem.

Spring framework1.0 was published soon after Rod Johnson finished one of his great books and it changed my life as a developer. I was able to write a more easier to maintain codes by simply using the features from SpringFramework, e.g. IOC,AOP, Transactional Management, Spring MVC, JMS, JDBCTemplate, HibernateTemp, RMITemplate, and later annoatations.


I can not forget the time Java with me, just like it's already in my blood.

Comments

Post a Comment

Popular posts from this blog

Quicksort implementation by using Java

 source: http://www.algolist.net/Algorithms/Sorting/Quicksort. The divide-and-conquer strategy is used in quicksort. Below the recursion step is described: 1st: Choose a pivot value. We take the value of the middle element as pivot value, but it can be any value(e.g. some people would like to pick the first element and do the exchange in the end) 2nd: Partition. Rearrange elements in such a way, that all elements which are lesser than the pivot go to the left part of the array and all elements greater than the pivot, go to the right part of the array. Values equal to the pivot can stay in any part of the array. Apply quicksort algorithm recursively to the left and the right parts - the previous pivot element excluded! Partition algorithm in detail: There are two indices i and j and at the very beginning of the partition algorithm i points to the first element in the array and j points to the last one. Then algorithm moves i forward, until an element with value greater or equal
Post a Comment
Read more

Live - solving the jasper report out of memory and high cpu usage problems

I still can not find the solution. So I summary all the things and tell my boss about it. If any one knows the solution, please let me know. Symptom: 1.        The JVM became Out of memory when creating big consumption report 2.        Those JRTemplateElement-instances is still there occupied even if I logged out the system Reason:         1. There is a large number of JRTemplateElement-instances cached in the memory 2.     The clearobjects() method in ReportThread class has not been triggered when logging out Action I tried:      About the Virtualizer: 1.     Replacing the JRSwapFileVirtualizer with JRFileVirtualizer 2.     Not use any FileVirtualizer for cache the report in the hard disk Result: The japserreport still creating the a large number of JRTemplateElement-instances in the memory        About the work around below,      I tried: item 3(in below work around list) – result: it helps to reduce  the size of the JRTemplateElement Object        
1 comment
Read more

Stretch a row if data overflows in jasper reports

It is very common that some columns of the report need to stretch to show all the content in that column. But  if you just specify the property " stretch with overflow' to that column(we called text field in jasper report world) , it will just stretch that column and won't change other columns, so the row could be ridiculous. Haven't find the solution from internet yet. So I just review the properties in iReport one by one and find two useful properties(the bold  highlighted in example below) which resolve the problems.   example: <band height="20" splitType="Stretch" > <textField isStretchWithOverflow="true" pattern="" isBlankWhenNull="true"> <reportElement stretchType="RelativeToTallestObject" mode="Opaque" x="192" y="0" width="183" height="20"/> <box leftPadding="2"> <pen lineWidth="0.25"/>
4 comments
Read more