Java finally block is a block that is used to execute important code such as closing connection, stream etc.

Java finally block is always executed whether exception is handled or not. Java finally block follows try or catch block.

public class TestFinallyBlock2{
public static void main(String args[]){
try{
int data=25/0;
System.out.println(data);
}
catch(ArithmeticException e){
System.out.println(e);
}
finally{
System.out.println("finally block is always executed"); 

 }
System.out.println("rest of the code...");
}
}

Output:

Exception in thread main java.lang.ArithmeticException:/ by zero
finally block is always executed
rest of the code... 

Java Multi-catch block

A try block can be followed by one or more catch blocks. Each catch block must contain a different exception handler. So, if you have to perform different tasks at the occurrence of different exceptions, use java multi-catch block.

  • At a time only one exception occurs and at a time only one catch block is executed.
  • All catch blocks must be ordered from most specific to most general, i.e. catch for ArithmeticException must come before catching for Exception.

public class MultipleCatchBlock1 {
public static void main(String[] args) {
try{
int a[]=new int[5];
a[5]=30/0;
}
catch(ArithmeticException e)
{
System.out.println("Arithmetic Exception occurs");
}
catch(ArrayIndexOutOfBoundsException e)
{
System.out.println("ArrayIndexOutOfBounds Exception occurs");
}
catch(Exception e)
{
System.out.println("Parent Exception occurs");
}
System.out.println("rest of the code");
}
}

Output:

Arithmetic Exception occurs
rest of the code 

public class MultipleCatchBlock2 {
public static void main(String[] args) {
try{
int a[]=new int[5];
System.out.println(a[10]);
}
catch(ArithmeticException e)
{
System.out.println("Arithmetic Exception occurs");
}
catch(ArrayIndexOutOfBoundsException e)
{
System.out.println("ArrayIndexOutOfBounds Exception occurs");
}
catch(Exception e)
{
System.out.println("Parent Exception occurs");
}
System.out.println("rest of the code");
}
}

Output:

ArrayIndexOutOfBounds Exception occurs
rest of the code 

Java Nested try block

The try block within a try block is known as nested try block in java. Sometimes a situation may arise where a part of a block may cause one error and the entire block itself may cause another error. In such cases, exception handlers have to be nested.

Syntax:

try
{
statement 1;
statement 2;
try
{
statement 1;
statement 2;
} 

 catch(Exception e)
{
}
}
catch(Exception e)
{ }