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Discuss in fragments

This program is a little longer than the previous programs, so I will break it down and discuss it in fragments. A complete listing of the program is shownin Listing 10 .

The class definition shown in Listing 6 is used to construct a custom exception object that encapsulates a message. Note that thisclass extends Exception . (Therefore, it is a checked exception.)

Listing 6 . The class named MyException .
class MyException extends Exception{ MyException(String message){//constrsuper(message); }//end constructor}//end MyException class

The constructor for this class receives an incoming String message parameter and passes it to the constructor for the superclass. This makesthe message available for access by the getMessage method called in the catch block.

The try block

Listing 7 shows the beginning of the main method, including the entire try block

Listing 7 . The try block.
class Excep16{//controlling class public static void main(String[] args){try{ for(int cnt = 0; cnt<5; cnt++){ //Throw a custom exception, and// pass message when cnt == 3 if(cnt == 3) thrownew MyException("3"); //Transfer control before// processing for cnt == 3 System.out.println("Processing data for cnt = " + cnt);}//end for-loop }//end try block

The main method executes a for loop (inside the try block) that guarantees that the variable named cnt will reach a value of 3 after a couple of iterations.

Once during each iteration, (until the value of cnt reaches 3) a print statement inside the for loop displays the value of cnt . This results in the output shown in Figure 11 .

Figure 11 . Output from the for loop.
Processing data for cnt = 0 Processing data for cnt = 1Processing data for cnt = 2

What happens when cnt equals 3?

However, when the value of cnt equals 3, the throw statement in Listing 7 is executed. This causes control to transfer immediately to the matching catch block following the try block (see Listing 8 ). During this iteration, the print statement following the throw statement is not executed. Therefore, the output never shows a value for cnt greater than 2, as shown in Figure 11 .

The catch block

Listing 8 shows a catch block whose type matches the type of exception thrown in Listing 7 .

Listing 8 . A matching catch block.
catch(MyException e){ System.out.println("In exception handler, " + "get the message\n"+ e.getMessage()); }//end catch block

When the throw statement is executed in Listing 7 , control is transferred immediately to the catch block in Listing 8 . No further code is executed within the try block.

A reference to the object instantiated as the argument to the throw keyword in Listing 7 is passed as a parameter to the catch block. That reference is known locally by the name e inside the catch block.

Using the incoming parameter

The code in the catch block calls the method named getMessage (inherited from the Throwable class) on the incoming parameter and displays that message on the screen. This produces the output shown in Figure 12 .

Questions & Answers

what is microbiology
Agebe Reply
What is a cell
Odelana Reply
what is cell
Mohammed
how does Neisseria cause meningitis
Nyibol Reply
what is microbiologist
Muhammad Reply
what is errata
Muhammad
is the branch of biology that deals with the study of microorganisms.
Ntefuni Reply
What is microbiology
Mercy Reply
studies of microbes
Louisiaste
when we takee the specimen which lumbar,spin,
Ziyad Reply
How bacteria create energy to survive?
Muhamad Reply
Bacteria doesn't produce energy they are dependent upon their substrate in case of lack of nutrients they are able to make spores which helps them to sustain in harsh environments
_Adnan
But not all bacteria make spores, l mean Eukaryotic cells have Mitochondria which acts as powerhouse for them, since bacteria don't have it, what is the substitution for it?
Muhamad
they make spores
Louisiaste
what is sporadic nd endemic, epidemic
Aminu Reply
the significance of food webs for disease transmission
Abreham
food webs brings about an infection as an individual depends on number of diseased foods or carriers dully.
Mark
explain assimilatory nitrate reduction
Esinniobiwa Reply
Assimilatory nitrate reduction is a process that occurs in some microorganisms, such as bacteria and archaea, in which nitrate (NO3-) is reduced to nitrite (NO2-), and then further reduced to ammonia (NH3).
Elkana
This process is called assimilatory nitrate reduction because the nitrogen that is produced is incorporated in the cells of microorganisms where it can be used in the synthesis of amino acids and other nitrogen products
Elkana
Examples of thermophilic organisms
Shu Reply
Give Examples of thermophilic organisms
Shu
advantages of normal Flora to the host
Micheal Reply
Prevent foreign microbes to the host
Abubakar
they provide healthier benefits to their hosts
ayesha
They are friends to host only when Host immune system is strong and become enemies when the host immune system is weakened . very bad relationship!
Mark
what is cell
faisal Reply
cell is the smallest unit of life
Fauziya
cell is the smallest unit of life
Akanni
ok
Innocent
cell is the structural and functional unit of life
Hasan
is the fundamental units of Life
Musa
what are emergency diseases
Micheal Reply
There are nothing like emergency disease but there are some common medical emergency which can occur simultaneously like Bleeding,heart attack,Breathing difficulties,severe pain heart stock.Hope you will get my point .Have a nice day ❣️
_Adnan
define infection ,prevention and control
Innocent
I think infection prevention and control is the avoidance of all things we do that gives out break of infections and promotion of health practices that promote life
Lubega
Heyy Lubega hussein where are u from?
_Adnan
en français
Adama
which site have a normal flora
ESTHER Reply
Many sites of the body have it Skin Nasal cavity Oral cavity Gastro intestinal tract
Safaa
skin
Asiina
skin,Oral,Nasal,GIt
Sadik
How can Commensal can Bacteria change into pathogen?
Sadik
How can Commensal Bacteria change into pathogen?
Sadik
all
Tesfaye
by fussion
Asiina
what are the advantages of normal Flora to the host
Micheal
what are the ways of control and prevention of nosocomial infection in the hospital
Micheal
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Source:  OpenStax, Object-oriented programming (oop) with java. OpenStax CNX. Jun 29, 2016 Download for free at https://legacy.cnx.org/content/col11441/1.201
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