The popularity of the Java programming language can be inferred from how widely it is used. From developing Web applications to Android applications, this programming language is frequently used to develop versatile applications/code.

When writing code, developers strive to write bug-free code with minimal complexity and maximum functionality. Whether you’re a source code beginner or an expert, there are some rules you should always follow in order to write the best code for your client. Here are some rules for writing bug-free code.

Rule 1: You don’t need to rely on initialization

In the Java world, developers always rely on initializing an object using constructors. But this is just a myth that most developers believe. There are still many ways to allocate an object without calling the constructor.

To achieve this, you can take any of the following steps:

  • You can declare all variables private. To access objects that a class cannot access directly, use the GET and SET methods.
  • For each object, write a new private Boolean variable and initialize it.
  • Writing a constructorless class ensures that every object is initialized before being called anywhere in the code.

Rule 2: Keep your classes, methods, and variables safe

In your code, you may make some classes, methods, and variables private and others public. Private classes cannot be easily accessed, making them safe points for code. But exposed methods, variables that can be easily accessed, can be vulnerable. Therefore, try to limit the accessible scope of methods and variables.

When you have no other choice, remember to make classes, methods, and variables public.

Rule 3: Always determine in advance what is accessible

Most developers rely entirely on the scope of access determined by packages, but you should always determine in advance the scope of access for your code. There are many classes that are not closed (which themselves can be accessed directly), leaving a loophole for attackers. A hacker can use simple vulnerabilities to insert his/her written classes to use sensitive information from your code to the system. The JVM is not shut down by default, which allows you to close your classes in packages.

Rule 4: Avoid inner classes

In general, when developers need to use other classes in the same package, they always use inner classes. Inner classes are usually accessible to all other classes in the same package, but as I mentioned above, you should determine in advance how widely each class you want to create will be accessed.

Rule 5: Ensure that classes cannot be cloned

The ability to clone your own classes as needed is one of the features of Java. But this feature can also be exploited by hackers. A hacker could simply use the java.lang.Cloneable class to copy instances of code and steal the necessary information from your code.

To get rid of this problem, what you do is add the following code to each class in your code:

public final void clone()throws
java.lang.CloneNotSupportedException {
    thrownewjava.lang.CloneNotSupportedException();
}Copy the code

If you want your classes to be clonable, and you’ve considered the consequences of that choice, you can still protect yourself. If you define a clone method yourself, change it to the final state.

If you rely on a non-final-state method in a superclass, define the method as follows:

public final void clone()
throwsjava.lang.CloneNotSupportedException {
    super.clone(); }

Copy the code

There is not a single person on earth who can be called a 100% Java expert. But with Java programming concepts in mind and your own experience, you can easily write code without running into any bugs.

Start coding!