设计模式--简单工厂模式

（1）抽象运算类

package com.liutao.design.model.simpleFactoryModel;/** * abstract operation class * this demo is a caculator to show how to use simple factory mode * * @author LIUTAO * @version 2017/10/25 * @see */public abstract class Operation {    private double numberA;    private double numberB;    public Operation() {    }    public Operation(double numberA, double numberB){        this.numberA = numberA;        this.numberB = numberB;    }    public double getNumberA() {        return numberA;    }    public void setNumberA(double numberA) {        this.numberA = numberA;    }    public double getNumberB() {        return numberB;    }    public void setNumberB(double numberB) {        this.numberB = numberB;    }    /**     * get the result of operation     * @return     */    public abstract double getResult();}

（2）加法运算类

package com.liutao.design.model.simpleFactoryModel;/** * add operation class * this demo is a caculator to show how to use simple factory mode * * @author LIUTAO * @version 2017/10/25 * @see */public class AddOperation extends Operation {    @Override    public double getResult() {        return getNumberA()+getNumberB();    }}

（3）减法运算类

package com.liutao.design.model.simpleFactoryModel;/** * sub operation class * this demo is a caculator to show how to use simple factory mode * * @author LIUTAO * @version 2017/10/25 * @see */public class SubOperation extends Operation {    @Override    public double getResult() {        return getNumberA() - getNumberB();    }}

（4）运算工厂类

package com.liutao.design.model.simpleFactoryModel;/** * operation factory class * this demo is a caculator to show how to use simple factory mode * * the class is used to product the operation object * * @author LIUTAO * @version 2017/10/25 * @see */public class OperationFactory {    public static Operation productOperation(String operationStr){        Operation operation = null;        switch (operationStr){            case "+":operation = new AddOperation();            break;            case "-":operation = new SubOperation();            break;        }        return operation;    }}

（5）测试类

package com.liutao.design.model.simpleFactoryModel;/** * the class is used to test factory mode * * @author LIUTAO * @version 2017/10/25 * @see */public class TestDemo {    public static void main(String[] args) {        //if you want get the result of 2 plus 1        Operation operationPlus = OperationFactory.productOperation("+");        operationPlus.setNumberA(1);        operationPlus.setNumberB(2);        System.out.println("1+2="+operationPlus.getResult());        //if you want get the result of 2 minus 1        Operation operationMinus = OperationFactory.productOperation("-");        operationMinus.setNumberA(2);        operationMinus.setNumberB(1);        System.out.println("2-1="+operationMinus.getResult());    }}