Difference between Error and Exception

Methods for Error Handling

The process of locating, catching, and recovering from errors during program execution is known as error handling in Java. This involves handling exceptions with try-catch blocks and ensuring the proper steps are taken to recover from mistakes and prevent program crashes.

Per the requirements of your application and the potential types of errors, you must select the best error-handling strategy.

Typical Java error-handling techniques include:

Generating special exceptions

Java allows for generating unique exceptions, which can be used to design custom exceptions to address particular application errors. You can give more context-specific information about the error and facilitate debugging and problem-solving by creating specific exceptions.

Here's an example of generating a unique exception in Java:

CODE

public class Main {
public static void main(String[] args) {
try {
            
            // First, call the square() function with a negative number to get a NegativeNumberException 
            int result = square(-5);
            System.out.println("Result is " + result);
     } catch (NegativeNumberException e) {
            
            // catch and handle the exception
            System.out.println("Error is  " + e.getMessage());
        }
    }
		
		//The square() function will throw a NegativeNumberException if you will negative input number.
public static int square(int n) throws NegativeNumberException {
        if (n < 0) {
            throw new NegativeNumberException("Number cannot be negative");
        }
        return n * n;
    }
}
	
	// Here, the NegativeNumberException class extends the Exception class to create a custom exception for negative input numbers
class NegativeNumberException extends Exception {
    public NegativeNumberException(String message) {
        super(message);
    }
}

OUTPUT

When running, this program will call the square method with a negative number, resulting in a NegativeNumberException. The catch block will catch this exception, printing the error to the console. If you use a positive number to call the square method, the squared value of that number will be returned and printed to the console.

Using third-party frameworks and libraries 

You can implement more complex and efficient error handling in your application using third-party frameworks and libraries for Java. These frameworks and libraries offer a variety of features and tools to handle mistakes and manage them more streamlined and effectively.

Here's an example of using this library to handle errors:

CODE

// It is important to import the class from the Apache Commons Lang library 
import org.apache.commons.lang3.exception.ExceptionUtils;
public class Main {
public static void main(String[] args) {
try {
// call the divide() function for two numbers to perform division
            int result = divide(10, 0);
            System.out.println("Result: " + result);
        } catch (ArithmeticException e) {
// here, catch and handle by getting the error message and trace using the ExceptionUtils class
            String message = ExceptionUtils.getMessage(e);
            String stackTrace = ExceptionUtils.getStackTrace(e);
            System.out.println("Error message: " + message);
            System.out.println("Stack trace: " + stackTrace);
        }
    }


    public static int divide(int a, int b) {
        return a / b;
    }
}

OUTPUT

We use the org.apache.commons.lang3.exception in this example. When we try to divide by zero, the ExceptionUtils class from the Apache Commons Lang library will produce a more detailed error message. The error message and the stack trace are obtained using the getMessage and getStackTrace methods, respectively.

Methods for Exception Handling

Runtime errors, also known as exceptional events, can be handled by programmers in their programs using the exception-handling mechanism in Java. Java offers a built-in framework for handling exceptions, enabling programmers to catch and manage errors. Exception handling aims to keep the program running normally, even in unexpected events. 

Some common exception-handling techniques in Java include:

Try-catch-finally blocks

The try block contains the code that will produce an exception. The catch block contains the code that handles the exception if it occurs. The final block contains executed code, no matter whether an exception is thrown or not.

Here's an example of using a try-catch-finally block to handle exceptions in Java:

CODE

public class Example {
  public static void main(String[] args) {
    try {
    
    // An integer variable x is assigned the result of dividing 10 by 0.
      int x = 10 / 0; 
    } catch (ArithmeticException e) {
  
    // If an ArithmeticException occurs, the catch block is executed, printing an error message.
      System.out.println("An arithmetic exception occurred: " + e.getMessage());
    } finally {
    
    // The final block always executes, regardless of whether an exception occurs. 
      System.out.println("This code will always execute.");
    }
  }
}

OUTPUT

The try block in this example contains code that could raise an ArithmeticException. When this exception is thrown, the catch block will catch and handle it by printing a message. The final block's code is always carried out regardless of whether an exception was raised.

Handling with exception handlers

It has the try block, which contains the code that may produce an exception. The catch block contains the code that handles the exception if it occurs.

Here's an example of handling a particular exception type with an exception handler:

CODE

public class Main {
    public static void main(String[] args) {
        try {
			
			// Here, we create an integer array with three elements, and the fourth element (index 3) is accessed.
            int[] arr = {1, 2, 3};
            int x = arr[3];
        } catch (ArrayIndexOutOfBoundsException e) {
			
			// If an exception occurs, the catch block will be executed, printing an error message.
            System.out.println("Array index out of bounds: " + e.getMessage());
        }
    }
}

OUTPUT 

In this illustration, we're attempting to access the element at index 3 of an array with only three other elements. As a result, an ArrayIndexOutOfBoundsException will be thrown. 

Comparison Table between Error and Exception

Here is a comparison table between Errors and Exceptions in Java:

As of now, you might have gotten the idea of the difference between error and exception in Java. Now we move into the FAQ section.

Frequently Asked Questions

What is the difference between error and exception in Java?

Problems with hardware or operating system failures cause errors. The exceptions are caused by issues within the program itself, such as incorrect user input or network failures.

Can you describe the stack trace concept in exception handling?

The method calls that the application was in the middle of when an exception was thrown are listed in a stack trace. It can help developers identify the error's location and root cause.

In Java, how do you make your unique exception?

You can create a class in Java that extends the Exception class or one of its subclasses and include a constructor with a message to make a custom exception. Then, you can throw an instance whenever a custom exception is required.

What does the finally block in exception handling accomplish?

The finally block is used in exception handling to hold critical statements that must be carried out whether or not an exception occurs. It helps clean up resources allocated in the try block because it is executed regardless of whether an exception is thrown or caught.

What function does the try-catch block serve in handling exceptions?

The try-catch block's function in exception handling is to catch and deal with any exceptions that might arise in the try block. The code that might throw an exception is contained in the try block, and the catch block specifies how to handle the thrown exception. 

Conclusion

In conclusion, errors and exceptions are essential for locating and managing coding errors in Java programming. The definitions, distinctions, and types of errors and exceptions in Java have all been covered in this article. Practical error-handling strategies have also been covered, such as using try-catch blocks, creating notable exceptions, and relying on third-party libraries.

Below are some articles to deepen your knowledge and understanding of Java's error and exception handling. 

• Exception Handling in C++ and Java
   
• Exception Handling In Java Using Try-Catch And Finally,
   

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