Java factory mode example

1. Simple Factory:

(1). Create an output interface

Package stone;
Public interface output {
Public int max_count = 10; // maximum number of records that can be printed
Public void show (); // print
Public void adddata (string MSG); // Add the records to be printed to the print order.
}

 

(2) create a printer class, which inherits the output interface

Package stone;
Public class printer implements output {
Private string [] data_array = new string [max_count]; // Save the array for printing information
Private int datanum = 0; // number of information to print
Public void adddata (string MSG ){
If (datanum> max_count) // The information to be printed cannot exceed the maximum value
System. Out. println ("print queue is Max ");
Else
Data_array [datanum ++] = MSG;
}
Public void show (){
While (datanum> 0 ){
System. Out. println ("Print:" + data_array [0]);
System. arraycopy (data_array, 1, data_array, 0, datanum --);
}
}
}

 

(3). Create an output in the factory, which defines which printer is used for printing.

Package stone;
Public class outputfactory {
Public static output (){
Return new printer ();
}
}

 

(4). Print the factory model:

Package stone;
Public class testsimplefactory {
Private output;
Public testsimplefactory (output ){
This. Output = output;
}
Private void dataIn (string MSG ){
Output. adddata (MSG );
}
Private void dataout (){
Output. Show ();
}
Public static void main (string [] ARGs ){
Testsimplefactory Sf = new testsimplefactory (outputfactory. Output ());
SF. dataIn ("Stone test simple factory 1 ");
SF. dataIn ("Stone test simple factory 2 ");
SF. dataout ();
}
}

 

The output result is as follows:

Print: Stone test simple factory 1
Print: Stone test simple factory 2

 

(5) add another printer class:

Package stone;
Public class printer2 implements output {
Private string [] data_array = new string [max_count];
Private int datanum = 0;
Public void adddata (string MSG ){
If (datanum> max_count)
System. Out. println ("print queue is Max ");
Else
Data_array [datanum ++] = MSG;
}
Public void show (){
While (datanum> 0 ){
System. Out. println ("OtherPrint: "+ data_array [0]);
System. arraycopy (data_array, 1, data_array, 0, datanum --);
}
}
}

 

(6) to use another printer, you only need to change the factory class.

Package stone;
Public class outputfactory {
Public static output (){
// Return new printer ();
Return new printer2 ();
}
}

 

(7) Run testsimplefactory and the result is as follows:

Other print: Stone test simple factory 1
Other print: Stone test simple factory 2

 

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2. Factory method

(8) Add a printer in the factory:

Package stone;
Public class printerfactory {
Public static output (){
Return new printer ();
}
}

 

Package stone;
Public class printer2factory {
Public static output (){
Return new printer2 ();
}
}

 

(9). Add a factory for the printer Factory:

Package stone;
Public class outputfactoryfactory {
Public static output outputfactory (string MSG ){
If (msg. inclusignorecase ("printer2 "))
Return printer2factory. Output ();
Else
Return printerfactory. Output ();
}
}

 

(10) Run testfactorymethod to test the factory method:

Package stone;
Public class testfactorymethod {
Private output;
Public testfactorymethod (output ){
This. Output = output;
}
Private void dataIn (string MSG ){
Output. adddata (MSG );
}
Private void dataout (){
Output. Show ();
}
Public static void main (string [] ARGs ){
Testfactorymethod Sf = new testfactorymethod (outputfactoryfactory. outputfactory ("printer2 "));
SF. dataIn ("Stone test simple factory 1 ");
SF. dataIn ("Stone test simple factory 2 ");
SF. dataout ();
}
}

 

The test results are as follows:

Other print: Stone test simple factory 1
Other print: Stone test simple factory 2