design pattern

design pattern

build

  • java
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//Computer

public class Computer {

//required parameters
private String HDD;
private String RAM;

//optional parameters
private boolean isGraphicsCardEnabled;
private boolean isBluetoothEnabled;


public String getHDD() {
    return HDD;
}

public String getRAM() {
    return RAM;
}

public boolean isGraphicsCardEnabled() {
    return isGraphicsCardEnabled;
}

public boolean isBluetoothEnabled() {
    return isBluetoothEnabled;
}

private Computer(ComputerBuilder builder) {
    this.HDD=builder.HDD;
    this.RAM=builder.RAM;
    this.isGraphicsCardEnabled=builder.isGraphicsCardEnabled;
    this.isBluetoothEnabled=builder.isBluetoothEnabled;
}

//Builder Class
public static class ComputerBuilder{

    // required parameters
    private String HDD;
    private String RAM;

    // optional parameters
    private boolean isGraphicsCardEnabled;
    private boolean isBluetoothEnabled;

    public ComputerBuilder(String hdd, String ram){
        this.HDD=hdd;
        this.RAM=ram;
    }

    public ComputerBuilder setGraphicsCardEnabled(boolean isGraphicsCardEnabled) {
        this.isGraphicsCardEnabled = isGraphicsCardEnabled;
        return this;
    }

    public ComputerBuilder setBluetoothEnabled(boolean isBluetoothEnabled) {
        this.isBluetoothEnabled = isBluetoothEnabled;
        return this;
    }

    public Computer build(){
        return new Computer(this);
    }

}

//ComputerBuilder

import com.journaldev.design.builder.Computer;

public class TestBuilderPattern {

public static void main(String[] args) {
    //Using builder to get the object in a single line of code and 
            //without any inconsistent state or arguments management issues        
    Computer comp = new Computer.ComputerBuilder(
            "500 GB", "2 GB").setBluetoothEnabled(true)
            .setGraphicsCardEnabled(true).build();
}