java设计模式之适配器模式

//抽象成绩操作类：目标接口  
interface ScoreOperation {  
    public int[] sort(int array[]); //成绩排序  
    public int search(int array[],int key); //成绩查找  
}  
  
//快速排序类：适配者  
class QuickSort {  
    public int[] quickSort(int array[]) {  
        sort(array,0,array.length-1);  
        return array;  
    }  
  
    public void sort(int array[],int p, int r) {  
        int q=0;  
        if(p<r) {  
            q=partition(array,p,r);  
            sort(array,p,q-1);  
            sort(array,q+1,r);  
        }  
    }  
  
    public int partition(int[] a, int p, int r) {  
        int x=a[r];  
        int j=p-1;  
        for (int i=p;i<=r-1;i++) {  
            if (a[i]<=x) {  
                j++;  
                swap(a,j,i);  
            }  
        }  
        swap(a,j+1,r);  
        return j+1;   
    }  
  
    public void swap(int[] a, int i, int j) {     
        int t = a[i];     
        a[i] = a[j];     
        a[j] = t;     
    }  
}  
  
//二分查找类：适配者  
class BinarySearch {  
    public int binarySearch(int array[],int key) {  
        int low = 0;  
        int high = array.length -1;  
        while(low <= high) {  
            int mid = (low + high) / 2;  
            int midVal = array[mid];  
            if(midVal < key) {    
low = mid +1;    
}  
            else if (midVal > key) {    
high = mid -1;    
}  
            else {    
return 1; //找到元素返回1    
}  
        }  
        return -1;  //未找到元素返回-1  
    }  
}  
  
//操作适配器：适配器  
class OperationAdapter implements ScoreOperation {  
    private QuickSort sortObj; //定义适配者QuickSort对象  
    private BinarySearch searchObj; //定义适配者BinarySearch对象  
  
    public OperationAdapter() {  
        sortObj = new QuickSort();  
        searchObj = new BinarySearch();  
    }  
  
    public int[] sort(int array[]) {    
return sortObj.quickSort(array); //调用适配者类QuickSort的排序方法  
}  
  
    public int search(int array[],int key) {    
return searchObj.binarySearch(array,key); //调用适配者类BinarySearch的查找方法  
}  
}  

import javax.xml.parsers.*;  
import org.w3c.dom.*;  
import org.xml.sax.SAXException;  
import java.io.*;  
class XMLUtil {  
//该方法用于从XML配置文件中提取具体类类名，并返回一个实例对象  
    public static Object getBean() {  
        try {  
            //创建文档对象  
            DocumentBuilderFactory dFactory = DocumentBuilderFactory.newInstance();  
            DocumentBuilder builder = dFactory.newDocumentBuilder();  
            Document doc;                             
            doc = builder.parse(new File("config.xml"));   
          
            //获取包含类名的文本节点  
            NodeList nl = doc.getElementsByTagName("className");  
            Node classNode=nl.item(0).getFirstChild();  
            String cName=classNode.getNodeValue();  
              
            //通过类名生成实例对象并将其返回  
            Class c=Class.forName(cName);  
            Object obj=c.newInstance();  
            return obj;  
        }     
        catch(Exception e) {  
            e.printStackTrace();  
            return null;  
        }  
    }  
}  

class Client {  
    public static void main(String args[]) {  
        ScoreOperation operation;  //针对抽象目标接口编程  
        operation = (ScoreOperation)XMLUtil.getBean(); //读取配置文件，反射生成对象  
        int scores[] = {84,76,50,69,90,91,88,96}; //定义成绩数组  
        int result[];  
        int score;  
          
        System.out.println("成绩排序结果：");  
        result = operation.sort(scores);  
  
        //遍历输出成绩  
        for(int i : scores) {  
            System.out.print(i + ",");  
        }  
        System.out.println();  
          
        System.out.println("查找成绩90：");  
        score = operation.search(result,90);  
        if (score != -1) {  
            System.out.println("找到成绩90。");  
        }  
        else {  
            System.out.println("没有找到成绩90。");  
        }  
          
        System.out.println("查找成绩92：");  
        score = operation.search(result,92);  
        if (score != -1) {  
            System.out.println("找到成绩92。");  
        }  
        else {  
            System.out.println("没有找到成绩92。");  
        }  
    }  
}