Skip to main content


It was a busy month, all work no play... more about polishing, both code and UI, to make a better product.

1. Code Polishing

In the current Java Spring project, there are a few things worth mentioning.

1. Service layer for MVC.

My previous projects are mostly architected under MVC pattern. There is nothing wrong about that. However, when the logic gets more complexed, handling all the logic in the controller layer would not be as clean and efficient. Another layer named Service for better data access and logic control is used in the our project.

The controller would not be handling too many logics, instead, it only handles routing and  parameter passing. Most logics will be handled in the service layer.

2. Exception handling vs error codes

In the beginning, I didn’t do any exception handling in the service layer, neither do I create many exception handlers in the controller layer.After reviewing my peers codes, I realize that it is more elegant to throw exception than returning error code.

In the project, we used exception handling in the service layer to return exceptions which are inherited from IOException. I found the logic clearer after shifting to the exception handling idea in my codes.

3. Bad thing about lazy fetch type

In hibernate, it specifies the lazy fetch type, which is intended to reduce database memory access for relationships such as @OneToOne, @OneToMany,  @ManyToMany ,etc.
In the following blog post, the author stated some good explanations about the difference of each fetch type.

FetchType.LAZY = Doesn’t load the relationships unless explicitly “asked for” via getter
FetchType.EAGER = Loads ALL relationships”

However, lazy can be very troublesome in some circumstances. I had a lot of null pointer exceptions when trying to get lazy type relationship entities. I've got to manually parse these relationship entities into Map before sending them to the view, which makes the code very dirty.

For instance, in the following code, I want to get all users and their associated roles. Simply get the user list array won't return the roles because of the lazy issue. But I still need to display the associated role information in the view. I've got to use the ugly way to parse the role list into strings before sending to the view. If you know any better approaches, please let me know. Thanks!
    public List<Map<String,String>> getUserList(){
        List<Map<String,String>> userList = new ArrayList<>();
        List<DashboardUser> allDashboardUsers = Lists.newArrayList(userDao.findAll());
        for (DashboardUser dashboardUser : allDashboardUsers) {
            Map<String, String> aMap = new HashMap<>();
            String roles ="";
            for(Role role:dashboardUser.getRoles()){
        return userList;
2. UI polishing

Switch to angular.js.

Previously, the project is developed under jQuery. The views are not structurally organised, until it becomes quite a messy.The team decided to use angular because it’s clean and structured. After one week's polishing, the codes become much more beautiful, both in the front end and the backend.

I may write another blog about angular when the project gets more polished.

3. Project management

1. We tried to explore the scrum 
meeting( inside the small team. It works quite good. The basic scrum workflow consists of sprint planning, daily scrum meeting and end review meeting.  

The daily scrum meeting is not hard to follow. We started the meeting at 9:45am for <=15 minutes everyday at the same location asking the following questions:

“1. The basic What have you done since yesterday?
2. What are you planning to do today?
3. Any impediments/stumbling blocks? “
The tasks will be noted down by the scrum master and posted on a public wall. It makes every one involved and aware of the progress.

2. Github feature branch

Previously, we develop the features under our own develop branches and make pull requests to the origin develop branch when a new feature was added. However, that’s not a good design. The new feature commits are mixed with the develop branch and you can hardly distinguish which features are added by whom in a structural manner.

Thanks Peng jun and Xu Fan for sharing this.

Another tip for using github is to use git stash for saving unfinished changes in the current branch before switching to another local branch.


Popular posts from this blog

InnovFest 2015

I attended the innovFest 2015 event. It was quite eye opening. Besides the booth, some topics in the forums also interested me. The first topic I joined was the Kopi Chat with Yossi Vardi, a famous Israeli entrepreneur and investor. He is straightforward and humorous. When talking about the most important reason why people wake up with a great idea but ended up sleeping without executing anything, he collected answers from the audiences. One answer pretty much fitted his appetite-- "People fear about losing faces". He shared his opinion with the quotes from Theodore Roosevelt, “It is not the critic who counts; not the man who points out how the strong man stumbles, or where the doer of deeds could have done them better. The credit belongs to the man who is actually in the arena, whose face is marred by dust and sweat and blood; who strives valiantly; who errs, who comes short again and again, because there is no effort without error and shortcoming; but who does actually st


I've been working as a project manager on an interesting project named " Dadafish " for quite some time. The intention is to create a sharing economy platform for lifestyle teaching/learning. Put in a more straightforward way, an Airbnb for classes. There is one assumption:  People are willing to pay to learn skills from amateur or semi-pros at a lower price. Quite some ongoing arts classes in meetups are taught in cafe shops at 15-50SGD/session. It's an indirect validation of our assumption. There are also many free language classes in meetups and facebook groups. We did an experiment to validate the assumption by introducing a Japanese friend who's organizing a free meetup to teach Japanese. She doesn't have a certificate and she's currently teaching Japanese in meetups for free. The experiment class was charged at 15 SGD/h per person for a 3-4 pax group class. We posted the class and teacher info in a NUS student/alumni SNS group and three peopl

Consistency Matters

I didn't post anything last week, which means consistency has been broken. There's a need to reflect the task management skills, otherwise I'm very likely to driving the wrong road Priority changes. A good exercise would be to list the priorities down everyday and assign reasonable time to the tasks. Then never second-doubt. 100% focusing on the task when doing it. Priority changes from time to time.  Human minds are single-threaded, thus, we'll need to keep focused when doing one particular task. Be Grateful. I received the confirmation from NOC Israel that I got admitted by the programme and I'm heading to Israel next Jan:-) Thanks a lot for Prof.Ben and Karl's help. Ultimately, it might be a plan from God. Thanks every one. The additional interview from Google went well, however, I didn't get the winter intern opportunity this time. Though it's a bit too greedy to ask for too much, I still feel a bit sad after informed that I didn't get th