Test.java
public class Test {
public static void main(String[] args) {
MultipleOperation m1 = new MultipleOperation("+");
SimpleOperation s1 = new SimpleOperation(12);
SimpleOperation s2 = new SimpleOperation(2);
m1.addOperate(s1);
m1.addOperate(s2);
MultipleOperation m2 = new MultipleOperation("*");
SimpleOperation s3 = new SimpleOperation(3);
m2.addOperate(s3);
m2.addOperate(m1);
System.out.println(m2.calculate());
}
}
这里模拟了(12+2)*3的计算。
Calculate.java
public abstract class Calculate {
protected Calculate next;
public abstract double cal(String oper, double num1, double num2);
}
这里运用到了责任链模式，这个是责任接口。
AddCalculate.java
public class AddCalculate extends Calculate {
@Override
public double cal(String oper, double num1, double num2) {
if(oper.equals("+")){
return num1 + num2;
}else{
return super.next.cal(oper, num1, num2);
}
}
}
加法运算，减法和乘除都一样，这里省略。
CalculateChain
public class CalculateChain {
private List<Calculate> calculates;
public CalculateChain(List<Calculate> calculates) {
super();
this.calculates = calculates;
}
private void sort(){
for(int i=0; i< this.calculates.size(); i++){
if(i == this.calculates.size() -1 ){
return;
}
this.calculates.get(i).next = this.calculates.get(i+1);
}
}
public double calculate(String oper, double num1, double num2){
this.sort();
return this.calculates.get(0).cal(oper, num1, num2);
}
}
负责将各个算法穿起来的操作。
Operation.java
public interface Operation {
public void addOperate(Operation operation);
public void removeOperate(Operation operation);
public Iterator<Operation> getChild();
public double calculate();
}
抽象构件角色。
SimpleOperation.java
public class SimpleOperation implements Operation {
private double number;
public double getNumber() {
return number;
}
public void setNumber(double number) {
this.number = number;
}
public SimpleOperation(double number) {
super();
this.number = number;
}
@Override
public void addOperate(Operation operation) {
}
@Override
public void removeOperate(Operation operation) {
}
@Override
public Iterator<Operation> getChild() {
return null;
}
@Override
public double calculate() {
return this.number;
}
}
叶子构件角色。
MultipleOperation.java
public class MultipleOperation implements Operation {
private Vector<Operation> operations = new Vector<Operation>();
private String oper;
public MultipleOperation(String oper) {
super();
this.oper = oper;
}
@Override
public void addOperate(Operation operation) {
if(this.operations.size() == 2){
this.operations.remove(1);
}
this.operations.add(operation);
}
@Override
public void removeOperate(Operation operation) {
this.operations.remove(operation);
}
@Override
public Iterator<Operation> getChild() {
return this.operations.iterator();
}
@Override
public double calculate() {
double num1 = this.operations.get(0).calculate();
double num2 = this.operations.get(1).calculate();
List<Calculate> cals = new ArrayList<Calculate>();
AddCalculate add = new AddCalculate();
SubtractCalculate sub = new SubtractCalculate();
MultiplyCalculate mul = new MultiplyCalculate();
DivideCalculate divide = new DivideCalculate();
cals.add(add);
cals.add(sub);
cals.add(mul);
cals.add(divide);
return new CalculateChain(cals).calculate(oper, num1, num2);
}
}
树枝构件角色。
