Tutorial Playlist
191 Lessons1. Introduction to Java
2. What is Java?
3. History of Java
4. Java Tutorial for Beginners
5. How Do Java Programs Work?
6. JDK in Java
7. C++ Vs Java
8. Java vs. Python
9. Java vs. JavaScript
10. From Java Source Code to Executable
11. How to Install Java in Linux
12. How to Install Java in Windows 10
13. Java Hello World Program
14. Structure of Java Program and Java Syntax
15. Operators in Java
16. Java If-else
17. Switch Case In Java
18. Loops in Java
19. Infinite loop in Java
20. For Loop in Java
21. For Each Loop in Java
22. Constructor in Java
23. Constructor Overloading in Java
24. Copy Constructor in Java
25. Default Constructor in Java
26. Parameterized Constructors in Java
27. Constructor Chaining In Java
28. Finalize Method in Java
29. Static Method in Java
30. Equals Method in Java
31. Abstract Method in Java
32. toString() Method in Java
33. Difference between equals method in Java
34. Inheritance in Java
35. Multiple Inheritance in Java
36. Hierarchical Inheritance in Java
37. Java Classes and Objects
38. Scanner Class in java
39. All classes in java are inherited from which class
40. What is Nested Class in Java
41. POJO Class in Java
42. Anonymous Class in Java
43. Final Class in Java
44. Object Class in Java
45. Packages in Java
46. Access Modifiers in Java
47. Static Keyword In Java
48. Final Keyword in Java
49. Checked and Unchecked Exceptions in Java
50. User Defined Exception in Java
51. Error vs. Exception in Java
52. Java Collection
53. Collections in Java
54. Garbage Collection in Java
55. Generics In Java
56. Java Interfaces
57. Functional Interface in Java
58. Marker Interface in Java
59. Streams in Java
60. Byte stream in java
61. File Handling in Java
62. Thread in Java
63. Thread Lifecycle In Java
64. Daemon Thread in Java
65. Thread Priority in Java
66. Deadlock in Java
67. String Pool in Java
68. Java Database Connectivity(JDBC)
69. Design Patterns in Java
70. Functional Programming in Java
71. OOP vs Functional vs Procedural
72. Heap Memory and Stack Memory in Java
73. Applet in Java
74. Java Swing
75. Java Frameworks
76. Hibernate Framework
77. JUnit Testing
78. How to Install Eclipse IDE for Java?
79. Command line arguments in Java
80. Jar file in Java
81. Java Clean Code
82. OOPs Concepts in Java
83. Java OOPs Concepts
84. Overloading vs Overriding in Java
85. Java 8 features
86. String in Java
87. String to int in Java
88. Why String Is Immutable in Java?
89. Primitive Data Types in Java
90. Non-Primitive Data Types in Java
91. This and Super Keyword in Java
92. HashMap in Java
93. Comparable And Comparator in Java
94. Type Casting in Java
95. Arrays Sort in Java with Examples
96. Variable Hiding and Variable Shadowing in Java
97. Enum in Java
98. Substring in Java
99. Pattern Programs in Java
100. Hashcode in Java
101. What is ByteCode in Java?
102. How To Take Input From User in Java
103. GCD of Two Numbers in Java
104. Linked List in Java
105. Arithmetic Operators in Java
106. Conditional Operators in Java
107. Stack and Queue in Java
108. Array Length in Java
109. Number Pattern Program in Java
110. Split in java
111. Map In Java
112. Difference Between Throw and Throws in Java
113. Difference Between Data Hiding and Abstraction
114. HashSet in Java
115. String Length in Java
116. Factorial Using Recursion in Java
117. DateFormat in Java
118. StringBuilder Class in java
119. Instance variables in Java
120. Java List Size
121. Java APIs
122. Reverse an Array in Java
123. StringBuffer and StringBuilder Difference in Java
124. Java Program to Add Two Numbers
125. String to Array in Java
126. Regular Expressions in Java
127. Identifiers in Java
128. Data Structures in Java
129. Set in Java
130. Pass By Value and Call By Reference in Java
131. Try Catch in Java
Now Reading
132. Bubble Sort in Java
133. Caesar Cipher Program in Java
134. Queue in Java
135. Object Creation in Java
136. Multidimensional Array in Java
137. How to Read a File in Java
138. String Comparison in Java
139. Volatile Keyword in Java
140. Control Statements in Java
141. Jagged Array in Java
142. Two-Dimensional Array in Java
143. Java String Format
144. Replace in Java
145. charAt() in Java
146. CompareTo in Java
147. Matrix Multiplication in Java
148. Static Variable in Java
149. Event Handling in Java
150. parseInt in Java
151. Java ArrayList forEach
152. Abstraction in Java
153. String Input in Java
154. Logical Operators in Java
155. instanceof in Java
156. Math Floor in Java
157. Selection Sort Java
158. int to char in Java
159. Stringtokenizer in java
160. Implementing and Manipulating Abs in Java
161. Char array to string in java
162. Convert Double To String In Java
163. Deque in Java
164. Converting a List to an Array in Java
165. The Max function in java
166. Removing whitespace from string in java
167. String arrays in Java
168. Strings in Java Vs Strings in Cpp
169. Sum of digits of a number in Java
170. Art of Graphical User Interfaces
171. Trim in Java
172. RxJava
173. Recursion in Java
174. HashSet Java
175. Difference Between Java and Python
176. Square Root in Java
177. Reverse A String in Java
178. Even Odd Program in Java
179. Fibonacci Series in Java
180. Prime Number Program in Java
181. Java Program to Print Prime Numbers in a Given Range
182. Java Leap Year Program
183. Swapping of Two Numbers in Java
184. LCM of Two Numbers in Java
185. Math.sqrt() Function in Java
186. Area of Triangle in Java
187. Sort a String In Java
188. Factorial Program in Java
189. Javafx
190. Lambda expression in java
191. Setup Java Home and IDE on macOS
Exception handling is a crucial aspect of writing robust and reliable code in Java. Java provides a powerful mechanism called try-catch to handle exceptions effectively. This article will go into the realm of Java's try-catch construct, examining its numerous elements, syntax, and significance in the development of reliable software.
Exceptions are things that happen while a program is running that stop it from going as planned. They may be brought on by a number of things, including bad input, unavailable resources, or programming mistakes. Checked Exceptions, Unchecked Exceptions, and Errors are the three categories into which Java divides exceptions.
Checked exceptions are exceptions that the Java compiler forces the programmer to handle explicitly. Except for RuntimeException and its subclasses, all of these exceptions are descended from the Exception class. The calling code must either catch and manage the exception or indicate that it throws the exception higher up the call stack when a method throws a checked exception.
java
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
public class FileReadExample {
public static void main(String[] args) {
BufferedReader reader = null;
try {
reader = new BufferedReader(new FileReader("file.txt"));
String line;
while ((line = reader.readLine()) != null) {
System.out.println(line);
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if (reader != null)
reader.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
In this example, We put the code that could cause an exception in a try block so that we can address it. If an exception arises, the catch block will capture it, enabling us to manage it gracefully. The final phase is when we take care of any cleanup tasks.
Unchecked exceptions, usually referred to as runtime exceptions, are different from checked exceptions in that they don't have to be explicitly taught or stated. These exceptions are descended from the subclasses of the RuntimeException class. Unchecked exceptions often represent coding mistakes or unanticipated events that can't be logically handled at runtime.
java
public class DivisionExample {
public static void main(String[] args) {
int numerator = 10;
int denominator = 0;
int result = numerator / denominator; // ArithmeticException: division by zero
System.out.println(result);
}
}
In this model, we partition the numerator by the denominator, which is set to zero. This division operation leads to an ArithmeticException, an unchecked exception. Since this exception is not handled or declared, it results in program termination and an error message.
Errors represent exceptional conditions that are typically beyond the control of the programmer. They demonstrate difficult issues that may not be recoverable, like virtual machine mistakes, out-of-memory circumstances, or framework disappointments. Error is gotten from the Error class and its subclasses.
For example:
java
public class OutOfMemoryExample {
public static void main(String[] args) {
List<Integer> numbers = new ArrayList<>();
while (true) {
numbers.add(1);
}
}
}
In this model, the program consistently adds numbers to a rundown, in the long run prompting an OutOfMemoryError. Since this error is not caught or declared, it causes the program to terminate.
Exceptions are essential in Java because they provide a structured approach to handling abnormal conditions in a program. Instead of crashing or providing incorrect results, exceptions allow us to gracefully handle errors, recover from exceptional situations, and provide meaningful feedback to users.
Consider a scenario where a user inputs a non-numeric value in a calculator application that expects numerical input. By using exception handling, we can catch this input mismatch exception and inform the user about the error, allowing them to correct it. With exception handling, the application would crash, leaving the user knowledgeable about the cause of the problem.
The try block is the core component of the try-catch mechanism. It encapsulates the code that may throw an exception. When an exception occurs within the try block, the normal flow of the program is disrupted, and the control is transferred to the appropriate catch block.
The syntax of the try block is as follows:
java
try {
// Code that may raise an exception
} catch (ExceptionType1 exception1) {
// Handle exception1
} catch (ExceptionType2 exception2) {
// Handle exception2
} finally {
// Optional cleanup code
}
The catch blocks are used to catch and handle specific types of exceptions that the code may throw within the try block. Multiple catch blocks can be chained together to handle different types of exceptions.
java
import java.util.Scanner;
public class DivisionExample {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
System.out.print("Enter the numerator: ");
int numerator = scanner.nextInt();
System.out.print("Enter the denominator: ");
int denominator = scanner.nextInt();
try {
int result = numerator / denominator;
System.out.println("Result: " result);
} catch (ArithmeticException e) {
System.out.println("Error: Division by zero is not allowed.");
}
scanner.close();
}
}
In this model, the code inside the attempt block endeavors to play out the division activity. Assuming the denominator is zero, it raises an ArithmeticException, which the catch block catches. The catch block handles the exception by printing an error message.
The catch block is responsible for catching and handling exceptions thrown within the try block. It determines the sort of exception it can deal with and the code to execute when that particular special case happens. Various catch blocks can be utilized to deal with various sorts of exceptions.
java
try {
// Code that may raise an exception
} catch (ExceptionType exception) {
// Handle the exception
}
In the above syntax, ExceptionType represents the type of exception that the catch block can handle. It can be any exception class or one of its superclasses.
For example:
java
import java.util.InputMismatchException;
import java.util.Scanner;
public class InputExample {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
try {
System.out.print("Enter an integer: ");
int number = scanner.nextInt();
System.out.println("You entered: " number);
} catch (InputMismatchException e) {
System.out.println("Error: Invalid input. Please enter an integer.");
}
scanner.close();
}
}
In this example, if the user enters a non-integer value, the scanner throws an InputMismatchException. The catch block catches this exception and displays an appropriate error message.
A try-catch statement might employ several catch blocks to handle various error kinds individually. This provides more precise exception handling, allowing us to send certain error messages or take various actions depending on the kind of exception.
java
try {
// Code that may raise an exception
} catch (ExceptionType1 exception1) {
// Handle exception1
} catch (ExceptionType2 exception2) {
// Handle exception2
} catch (ExceptionType3 exception3) {
// Handle exception3
} // ...
It is important to order the catch blocks from specific to general. In the event that a catch block for a more specific exception type shows up after a catch block for a more broad exception type, it won't ever be executed on the grounds that the more broad catch block will, as of now, get the exception.
For instance, consider the accompanying code scrap that shows various catch blocks:
java
public class MultipleCatchExample {
public static void main(String[] args) {
try {
int[] numbers = {1, 2, 3};
System.out.println(numbers[4]);
} catch (ArrayIndexOutOfBoundsException e) {
System.out.println("Error: Array index out of bounds.");
} catch (Exception e) {
System.out.println("Error: Something went wrong.");
}
}
}
In this illustration, the code within the try block tries to get at an element in an array that is at index 4. The first catch block is able to handle the ArrayIndexOutOfBoundsException that is raised by the array's only three entries. The second catch block, which manages all general exceptions, will be called if any further exceptions arise.
In Java, exceptions can be raised anywhere in the code, and they can propagate up the call stack until they are caught and handled.
Example:
java
public class ExceptionPropagationExample {
public static void method1() {
method2();
}
public static void method2() {
method3();
}
public static void method3() {
int result = 10 / 0; // ArithmeticException: division by zero
}
public static void main(String[] args) {
try {
method1();
} catch (ArithmeticException e) {
System.out.println("Error: Division by zero.");
}
}
}
In this model, method3() endeavors to divide a number by zero, which brings about an ArithmeticException. Since the exception isn't caught inside method3(), it engenders up the call stack until it arrives at the fundamental strategy, where it is caught and dealt with by the catch block.
Exception handling is a vital part of writing robust Java programs. We can gently manage exceptions thanks to the try-catch technique, which also prevents crashes and gives users useful feedback. The syntax of try-catch blocks, the idea of exception propagation, and the many exception kinds may all be understood by developers in order to produce more dependable, upkeep-friendly, and user-friendly software.
1. What is a try-catch block in Java?
In Java, a try-catch block is a method for taking care of issues or special cases that could emerge while a program is being executed. The code that could cause an exception is remembered for the attempted block, and the catch block is where the special case is gotten and managed.
2. How does a Java try-catch block operate?
A program instantly moves to the matching catch block when an exception occurs within a try block. The code to handle the exception, such as showing an error message or performing a fix, is found in the catch block.
3. Can a try-catch block have multiple catch blocks?
Yes, a try-catch block can have multiple catch blocks. Each catch block can handle a specific type of exception. The catch blocks are examined one at a time, starting with the first one that matches the exception type.
4. What happens if a try-catch block does not capture an exception?
In the event that an attempt try-catch doesn't catch a special case, the exception engenders up the call stack until it does or until it arrives at the high-level special case overseer, whichever starts things out. The program will end, and a mistaken notice will be shown on the off chance that the exception isn't dealt with at any level.
5. Can a try block exist without a catch block?
Try blocks without catch blocks are feasible, but they must be followed by either a catch block or a final block. By running code that must be done whether an error occurred or not, the final block offers a way to free up resources or complete necessary tasks.
PAVAN VADAPALLI
Director of Engineering
Director of Engineering @ upGrad. Motivated to leverage technology to solve problems. Seasoned leader for startups and fast moving orgs. Working …Read More
Popular
Talk to our experts. We’re available 24/7.
Indian Nationals
1800 210 2020
Foreign Nationals
+918045604032
upGrad does not grant credit; credits are granted, accepted or transferred at the sole discretion of the relevant educational institution offering the diploma or degree. We advise you to enquire further regarding the suitability of this program for your academic, professional requirements and job prospects before enrolling. upGrad does not make any representations regarding the recognition or equivalence of the credits or credentials awarded, unless otherwise expressly stated. Success depends on individual qualifications, experience, and efforts in seeking employment.
upGrad does not grant credit; credits are granted, accepted or transferred at the sole discretion of the relevant educational institution offering the diploma or degree. We advise you to enquire further regarding the suitability of this program for your academic, professional requirements and job prospects before enr...