Applying Google Code Style to your Java Projects

 

Over the years I have seen how some projects upload their code with indentation or without indentation.

I learned working with teams that apply good practices, that it is good to use a style guide for the source code.

One of them and widely used in other companies, is the google java format which follows google Java style guide. This post will explain how to use it and make sure no one else uploads its code without format.

Pre-requisites

- You need to download the Google Style  and save it in a location on your PC.

- IntelliJ IDEA

- Any project using maven 

IntelliJ IDEA

The first step is add it file in IntelliJ IDEA - Preferences - Editor - Code Style - Import Scheme: 

You need to import the scheme and ready.

Maven Plugin

In the project where you need to apply it code style you need to add the fmt-maven-plugin (available in GitHub) in your pom.xml. 

 

We are configuring the plugin to apply Google format to src/main/java (our principal source code) and src/test/java (our tests cases).

Note: The plugin changed of groupId and will be soon in maven central. In the meantime, we are going to use the old groupId.

Pre-commit with Git

To make sure our format is always applied, we add a hook on the pre-commit in Git. Then when you execute a git commit -m "commit code changes", this guarantees  that the format is applied before.

vi .git/hooks/pre-commit

#! /bin/bash

mvn com.coveo:fmt-maven-plugin:format

git add -u

Don't forget to give execute permission:  chmod a+x .git/hooks/pre-commit

Test

Apply a commit and check your code before doing a push and you will see the final result.

Looks your entity:

Ready. No more code without format or indentation in your git repo.

Enjoy

Joe

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Automating Resource Management in Java

One day ago, my friend "Nazareno" showed me his code of how to call a database function and it had a structure like this:

Try-with-resources

The problem with it code is that only is managing the automatic close connection with the try-with-resources:

In it new try all the resources are closed in the reverse of the order in which they are created.  Then an improvement to it code should be:

try (var conn = ds.getConnection(); var cs = conn.prepareCall(sql)) {

        

       .... code supressed ....

      try(var rs = cs.executeQuery()){

          .... code supressed ....

     }

}

Stop doing this:

rs.close();

cs.close();

While it is a good habit to close all the three resources, it isn't strictly necessary. Closing a JDBC resource should close any resources that is created. In theory it should happens:

• Closing a connection also closes PreparedStatement (or CallableStatement) and ResultSet.
• Closing a PreparedStatement (or CalleStatement) also closes the ResultSet.

 It is important to close resources in the right order. This avoids both resource leaks and exceptions.

Bonus

Use SQL Exception instead Exception and get more information:

         ...

         } catch (SQLException e) {

            System.out.println(e.getMessage());

            System.out.println(e.getSQLState());

            System.out.println(e.getErrorCode());

         } 

I learned of it experience so much too.

Enjoy!

Joe

 

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