结构型模式之对象适配器模式（算法适配）

女爷i 2022-08-10 03:56 156阅读 0赞

题目：现有一个接口DataOperation定义了排序方法sort(int\[\])和查找方法search(int\[\],int)，已知类QuickSort的quickSort(int\[\])方法实现了快速排序算法，类BinarySearch的binarySearch(int\[\],int)方法实现了二分查找算法。现使用适配器模式设计一个系统，在不修改源代码的情况下将类QuickSort和类BinarySearch的方法适配到DataOperation接口中。绘制类图并编程实现。

类图

![20151110143806738][]

代码

package 适配器模式实例之算法适配;
    
    public interface DataOperation {		//目标类
    	public void sort(int sort[], int i, int j);
    	public int search(int search[], int n);
    }

package 适配器模式实例之算法适配;
    
    public class AlgotithmAdapter implements DataOperation{		//适配器类
    	private QuickSort quick;
    	private BinarySearch binary;
    	
    	public AlgotithmAdapter(QuickSort quick) {
    		this.quick = quick;
    	}
    	
    	public AlgotithmAdapter(BinarySearch binary) {
    		this.binary = binary;
    	}
    	
    	public void sort(int sort[], int i, int j) {
    		quick.quickSort(sort, i, j);
    	}
    
    	public int search(int search[], int n) {
    		return binary.binarySearch(search, n);
    	}
    }

package 适配器模式实例之算法适配;
    
    public class QuickSort {		//适配者类
    	//划分数组
    	int partion(int array[], int p, int r) {
    		int x = array[r];
    		int i = p - 1;//注意这点，把i设成负值，然后作为移动的标志
    		int j;
    			for (j = p; j < r; j++) {
    				if (array[j] <= x) {
    					i++;
    					int temp = array[j];
    					array[j] = array[i];
    					array[i] = temp;
    				}
    			}
    		int temp = array[j];
    		array[j] = array[i + 1];
    		array[i + 1] = temp;
    		return i+1;//返回的应该是交换后的哨兵的位置
    	}
    	//递归解决每个划分后的小数组
    	void quickSort(int[] array, int p, int r) {
    		if (p < r) {
    			int q = partion(array, p, r);
    			quickSort(array, p, q - 1);
    			quickSort(array, q + 1, r);
    		}
    	}
    }

package 适配器模式实例之算法适配;
    
    public class BinarySearch { 		//适配者类
       public int binarySearch(int[] srcArray, int des){   
          
            int low = 0;   
            int high = srcArray.length-1;   
            while(low <= high) {   
                int middle = (low + high)/2;   
                if(des == srcArray[middle]) {   
                    return middle;   
                }else if(des <srcArray[middle]) {   
                    high = middle - 1;   
                }else {   
                    low = middle + 1;   
                }  
            }  
            return -1;  
       }  
    }

package 适配器模式实例之算法适配;
    
    public class Client {		//客户端类
    	public static void main(String[] args) {
    		int[] array = { 4, 3, 5, 2, 3, 6, 8, 9, 18, 12, 53, 20};
    		int i;
    		System.out.print("排序前：");
    		for (i=0; i<array.length; i++)
    			System.out.print(array[i]+" ");
    		BinarySearch binary = new BinarySearch();
    		AlgotithmAdapter algotithm1 = new AlgotithmAdapter(binary);
            System.out.println("\n通过二分查找得到数字5：位于数组的第"+(algotithm1.search(array, 5)+1)+"位");  
    		QuickSort sort = new QuickSort();
    		AlgotithmAdapter algotithm2 = new AlgotithmAdapter(sort);
    		algotithm2.sort(array, 0, array.length - 1);
    		
    		System.out.println("------------------------------");
    		System.out.print("排序后：");
    		for (i=0; i<array.length; i++)
    			System.out.print(array[i]+" ");
    		//int[] src = new int[] {1, 3, 5, 7, 8, 9};   
            System.out.println("\n通过二分查找得到数字5：位于数组的第"+(algotithm1.search(array, 5)+1)+"位");  
    	}
    }

运行效果图

![20151110145736899][]

[20151110143806738]: /images/20220731/3c9b5a472c174f75aedd4c11df02e35b.png
[20151110145736899]: /images/20220731/ebb5a9c401834d18b3bc28a7c4808f9d.png