Custom Exceptions

Till now we have seen why we need Exceptions and how to manage code that could throw Exceptions. We still have not learned how to throw our own Exceptions. Let us first understand the code below.


01 public class DocToPdfConverter {
02   public void convert(String src, String des) {
03     Document doc = readDoc(src);
04     writePdf(doc, des);
05   }
06 
07   private Document readDoc(String srcPath) {
08   //read the source file and verify format
09   //if format is incorrect then throw an Exception
10   }
11 
12   private void writePdf(Document doc, String des) {
13     //convert the document into pdf
14   }
15 }

Java2html


01 public class DocToPdfConverter {
02   public void convert(String src, String des) {
03     Document doc = null;
04     try {
05       Document doc = readDoc(src);
06       writePdf(doc, des);
07     } catch(InvalidFormatException ife) {
08     //print error msg for user
09     } catch(IOException ioe) {
10     //print error msg for user
11     }
12   }
13 
14   private Document readDoc(String srcPath) throws InvalidFormatException, IOException {
15     if(!verifyFormat(srcPath)) {
16       throw new InvalidFormatException("The file " + srcPath + "is not a valid word file");
17     }
18     Document document = convertDocToOM(srcPath);
19     return document;
20   }
21 
22   private void writePdf(Document doc, String des) {
23     //convert the document into pdf
24   }
25 
26   private Document convertDocToOM(String srcPath) {
27     //code
28   }
29 }

Java2html


1 public class InvalidFormatException extends Exception {
2   public InvalidFormatException() {
3      super();
4   }
5 
6   public InvalidFormatException(String msg) {
7     super(msg);
8     }
9 }

Java2html

Notes: This text was originally posted on my previous blog at http://www.adaptivelearningonline.net

Comments

Five Reasons Why Your Product Needs an Awesome User Guide

Photo Credit: Peter Merholz ( Creative Commons 2.0 SA License ) A user guide is essentially a book-length document containing instructions for installing, using or troubleshooting a hardware or software product. A user guide can be very brief - for example, only 10 or 20 pages or it can be a full-length book of 200 pages or more. -- prismnet.com As engineers, we give a lot of importance to product design, architecture, code quality, and UX. However, when it comes to the user manual, we often only manage to pay lip service. This is not good. A usable manual is as important as usable software because it is the first line of help for the user and the first line of customer service for the organization. Any organization that prides itself on great customer service must have an awesome user manual for the product. In the spirit of listicles - here are at least five reasons why you should have an awesome user manual! Enhance User Satisfaction In my fourteen years as a

Inheritance vs. composition depending on how much is same and how much differs

I am reading the excellent Django book right now. In the 4th chapter on Django templates , there is an example of includes and inheritance in Django templates. Without going into details about Django templates, the include is very similar to composition where we can include the text of another template for evaluation. Inheritance in Django templates works in a way similar to object inheritance. Django templates can specify certain blocks which can be redefined in subtemplates. The subtemplates use the rest of the parent template as is. Now we have all learned that inheritance is used when we have a is-a relationship between classes, and composition is used when we have a contains-a relationship. This is absolutely right, but while reading about Django templates, I just realized another pattern in these relationships. This is really simple and perhaps many of you may have already have had this insight... We use inheritance when we want to allow reuse of the bulk of one object in other

Planning a User Guide - Part 3/5 - Co-ordinate the Team

Photo by Helloquence on Unsplash This is the third post in a series of five posts on how to plan a user guide. In the first post , I wrote about how to conduct an audience analysis and the second post discussed how to define the overall scope of the manual. Once the overall scope of the user guide is defined, the next step is to coordinate the team that will work on creating the manual. A typical team will consist of the following roles. Many of these roles will be fulfilled by freelancers since they are one-off or intermittent work engagements. At the end of the article, I have provided a list of websites where you can find good freelancers. Creative Artist You'll need to work with a creative artist to design the cover page and any other images for the user guide. Most small to mid-sized companies don't have a dedicated creative artist on their rolls. But that's not a problem. There are several freelancing websites where you can work with great creative ar

Adaptive Software Solutions

Search This Blog