Is it possible to throw an exception in a constructor?

Question

I have a constructor that calls its super contructor, but I want to check its variable before passing a variable to the super contructor.
Something like:
public FlatPanelTV(int inches)
super(inches);
How can I check "inches" before passing it to the super(), when the super has to be the first statement of a constructor?
Any help would be great!
Thanks

Answer 1

Hi! Its me Ronillo.
Yes it is possible. The validation must be after invoking the superclass constructor or let the superclass validates it. For example:
* @(#)NegativeInchException.java     05/06/15
package com.yahoo.ronilloang.demo;
* The runtime exception that is thrown by <code>InchBean</code>.
* @see          InchBean
* @author     Ronillo Ang
public final class NegativeInchException extends RuntimeException{
      * Construct a new NegativeInchException with null as its detail message.
     public NegativeInchException(){
          super();
      * Construct a new NegativeInchException with the specified detail message.
      * @param     message the detail message.
     public NegativeInchException(String message){
          super(message);
* @(#)InchNotSetException.java           05/16/15
package com.yahoo.ronilloang.demo;
* The runtime exception that is thrown by <code>InchBean</code>.
* @see          InchBean
* @author     Ronillo Ang
public final class InchNotSetException extends RuntimeException{
      * Construct a new InchNotSetException with null as its detail message.
     public InchNotSetException(){
          super();
      * Construct a new InchNotSetException with the specified detail message.
      * @param     message the detail message.
     public InchNotSetException(String message){
          super(message);
* @(#)InchBean.java     05/06/15
package com.yahoo.ronilloang.demo;
* A java bean for storing and retrieving an inch.
* @author     Ronillo Ang
public class InchBean{
     private int inch; // as it name implies, this is the inch.
      * Construct a new empty InchBean.
     public InchBean(){
          this(0);
      * Construct a new InchBean with the specified inch.
      * @param     inch the inch to be store. Must be 0 and up.
      * @throws     NegativeInchException when param inch is less than 0.
     public InchBean(int inch){
          setInch(inch);
      * This method is use to set the inch. This will set the new inch if<br>
      * <ul>
      *     <li> The new inch is not less than 0.
      *     <li> The current inch is not equal to the new inch.
      * </ul>
      * @param     inch the new inch must be 0 and up.
      * @throws     NegativeInchException when param inch is less than 0.
     public void setInch(int inch){
          if(inch < 0)
               throw new NegativeInchException("Inch Bean");
          if(this.inch != inch)
               this.inch = inch;
      * This method is use to retrieve the current inch. This method will return the current inch if
      * and only if the current inch is not 0.
      * @throws     InchNotSetException when the inch is not set or the current inch value is 0.
      * @return     the current inch.
     public int getInch(){
          if(inch <= 0)
               throw new InchNotSetException("Inch Bean: Unable to get inch");
          return inch;
* @(#)SubInchBean.java          05/06/15
package com.yahoo.ronilloang.demo;
* An abstract subclass of <code>InchBean</code>.
* @see          InchBean
* @author     Ronillo Ang
public abstract class SubInchBean extends InchBean{
      * Construct a new empty SubInchBean.
     public SubInchBean(){
          this(0);
      * Construct a new SubInchBean with the specified inch.
      * @param     inch the inch to be store. Must be 0 and up.
      * @throws     NegativeInchException when param inch is less than 0.
     public SubInchBean(int inch){
          super(inch);
      * Use to store this bean into an XML file.
      * @return     0 if successful, -1 if not.
     abstract public int storeToXML();
      * Use to store the specified <code>InchBean</code> into an XML file.
      * @param     inchBean the bean to be store.
      * @return     0 if successful, -1 if not.
     abstract public int storeToXML(InchBean inchBean);
}I hope it helps. Take care and God bless you ^_^