2. Feladatsor: Javítások És Optimalizálási Javaslatok

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2. Feladatsor: Javítások és Optimalizálási Javaslatok

Hello everyone! Let's dive into some feedback and suggestions for the 2nd assignment. We'll be looking at things like the Java compiler version, redirect issues, and overall code quality. The goal is to make your code more robust, consistent, and easier to maintain. This feedback is all about helping you create better, more professional-looking code. So, let's get started and make this code shine, shall we?

Java Compiler Version and Project Consistency

One of the first things to address is the Java compiler version in your project. Currently, there isn't a specified compiler version in the Maven pom.xml file. This is a crucial detail, guys, because it directly impacts the project's build process. When the compiler version isn't specified, Maven defaults to using the Java version available on the machine where the project is being built. The problem with this approach is it can lead to inconsistencies and potential build failures. Imagine this: you develop the code on your machine with Java 17, and then someone else tries to build it on their machine with Java 11. It's very possible that the project won't even compile because of incompatible language features or libraries.

Specifying the compiler version in the pom.xml file ensures that the project uses a consistent Java version across all development and build environments. This is a best practice in the industry. It avoids those nasty surprises when the project works on your machine but breaks on someone else's. So, how do you do it? Simple! You need to add or modify the <maven.compiler.source> and <maven.compiler.target> properties within the <properties> section of your pom.xml file. The source tag specifies the Java version used to compile the source code, while the target tag specifies the Java version for the generated bytecode. For example, if you're targeting Java 17, your pom.xml should look something like this:

<properties>
    <maven.compiler.source>17</maven.compiler.source>
    <maven.compiler.target>17</maven.compiler.target>
</properties>

By including this configuration, you ensure that everyone working on the project, and every build environment, uses the same Java version. This significantly reduces the chances of encountering build errors due to version incompatibilities. So, it's a small change with a big impact on project stability and maintainability. Remember, consistency is key in software development, and specifying the compiler version is a simple yet effective way to achieve it.

Redirect Issues and Case Sensitivity

Next up, let's address an issue with the redirect in the LoginServlet.java file. It's a small detail, but it can cause some frustration for anyone trying to use the application. The code currently redirects users to Secured/profile.html after a successful login. However, the project's folder structure uses lowercase for the secured folder. This means the redirection will fail because the server can't find the page at the specified location.

Here’s a snippet from the original code:

public void doPost(HttpServletRequest request, HttpServletResponse response) throws IOException {
    HttpSession session = request.getSession();
    if(request.getParameter("username").equals("admin") && request.getParameter("password").equals("password")){
        session.setAttribute("authenticated","true");
        response.sendRedirect(response.encodeRedirectURL("Secured/profile.html"));
    }else {
        session.setAttribute("request","Incorrect username or password");
        response.sendRedirect("login.html");
    }
}

The fix is simple: make sure the redirect path matches the actual folder name in the project. Changing "Secured/profile.html" to "secured/profile.html" will resolve the problem. Case sensitivity is an important factor when it comes to the file system. Double-check your file paths, and ensure they match the case exactly. It is a common mistake and one that can easily be overlooked. Always, pay close attention to the details, and make sure that the capitalization and spacing in your project are all up to standards. This will ensure that the server can find the correct page and redirect your users to their intended destination.

Also, during redirects, there is usually no need to encode the URL using httpServletResponse.encodeRedirectURL(...). This function is typically used when you need to handle session tracking in a URL, which might be necessary in some complex scenarios. But it is not a requirement to use it in all scenarios. Always, evaluate if there is any requirement of using the encodeRedirectURL method.

Organizing Servlets and Filters with Packages

As your project grows, organizing your code becomes increasingly important. One of the best practices is to place servlets and filters into their own packages. This may seem unnecessary when you only have a few files, but trust me, it's a lifesaver in larger projects. When you create servlets and filters in the initial phase, keep this in mind. It ensures your code remains clean, readable, and easy to maintain as it grows.

Imagine a scenario where you have several servlets handling different aspects of your application - login, user profiles, data processing, etc. If all these servlets are dumped into the same directory, the code becomes a cluttered mess. Finding a specific servlet will take longer, and you'll waste time scrolling through the code to locate the file you need. However, by organizing the servlets into their own package, like servlets, you instantly create a logical grouping. This makes it easier to navigate, understand, and modify your code.

This principle applies to filters as well. Filters are essential for tasks like authentication, authorization, and request logging. They are similar to servlets. Grouping your filters together, typically in a package called filters, provides a single place to look for all the code related to these crucial functionalities. Good organization also aids collaboration. When multiple developers are working on the project, well-organized code minimizes merge conflicts and makes it easier for everyone to understand the code. It's also a great practice for future maintenance. You'll thank yourself later when you revisit the code after a few months. That way, you won't be scratching your head to figure out where a specific piece of functionality resides.

So, create separate packages for your servlets and filters. This will improve the organization and readability of the code. It is an industry standard for professional-looking, maintainable code. It's a small effort with a massive impact on the overall quality of your project!

Code Formatting for Readability

Let's talk about the look and feel of your code. Clean and consistent formatting is a cornerstone of professional software development. Maintaining a consistent style throughout your codebase makes it easier to read, understand, and maintain. Without proper formatting, code can quickly become difficult to navigate. Several places in the project lack proper spacing and line breaks. This can lead to decreased readability and the potential for errors.

Thankfully, most IDEs have built-in features to make formatting a breeze. For example, IntelliJ IDEA has an automated formatting feature that's just a click away. You can use this to automatically format your code according to a consistent style. Usually, you can access the formatting function by going to Code -> Reformat Code. This will automatically align the code, insert spaces, and handle line breaks to improve readability.

Consistent formatting isn’t just about making the code look pretty; it's about clarity. Proper formatting helps you and others understand the code more easily. It helps to quickly identify the structure and logic. Use indentation consistently to indicate the nesting of blocks. Use spaces around operators and after commas. Break up long lines to make them readable. These small changes collectively make a huge difference in code comprehension. By leveraging your IDE's formatting features and adhering to consistent style guidelines, you can ensure that your code is not just functional, but also beautiful and easy to read. In the long run, investing time in formatting will save time and effort. It will improve code quality, and make the development process much more enjoyable.

CSS and HTML Separation

Finally, let's talk about separating your CSS styles from your HTML. Currently, the HTML includes style tags directly within the HTML code. This method works, but it's not the best approach for maintaining and scaling your project. Keeping your CSS styles in a separate file offers several advantages. The main benefit is improved organization. When CSS is separated into its own file, you can easily find and modify the styles without having to dig through your HTML files.

This separation makes it much easier to maintain your code. Imagine changing the look of your website. With CSS in a separate file, you can simply update the CSS file without touching the HTML. This is particularly useful when you need to apply the same styles to multiple pages.

By keeping the CSS in a single place, you can make global style changes. The separation allows for better reusability and maintainability. When your CSS is in its own file, you can reuse those styles across multiple HTML pages. This reduces code duplication and helps to maintain a consistent look and feel throughout your website. External CSS also makes your HTML cleaner and more readable. Removing the styles from your HTML makes it easier to focus on the structure and content of your pages. You can also leverage the power of CSS frameworks and libraries like Bootstrap. Those help to streamline your styling process, which offers pre-built components and styles.

To separate your CSS, create a .css file (e.g., styles.css) in a dedicated folder (e.g., css). Then, link the CSS file to your HTML using the <link> tag within the <head> section:

<head>
    <link rel="stylesheet" href="css/styles.css">
</head>

This way, your HTML focuses on content and structure, while your CSS handles the presentation. It’s a win-win for organization, maintainability, and code reusability.

That wraps up the feedback for this assignment. Remember to keep these points in mind as you refine your code. Keep up the great work, and happy coding!