如题,小弟近日遇到这个难题,望高人给予答复.不胜感激假如说我现在创建了如下列表ArrayList list = new ArrayList();HashMap record1 = new HashMap();
record1.put("A",1);
record1.put("B",2);
record1.put("C",3);
HashMap record2 = new HashMap();
record1.put("A",4);
record1.put("B",5);
record1.put("C",6);
HashMap record3 = new HashMap();
record1.put("A",7);
record1.put("B",8);
record1.put("C",9);
请问假如我想对这个列表中的A列进行排序该如何操作.谢谢
record1.put("A",1);
record1.put("B",2);
record1.put("C",3);
HashMap record2 = new HashMap();
record1.put("A",4);
record1.put("B",5);
record1.put("C",6);
HashMap record3 = new HashMap();
record1.put("A",7);
record1.put("B",8);
record1.put("C",9);
请问假如我想对这个列表中的A列进行排序该如何操作.谢谢
class MyComparator implements Comparator {
public int compare(Object obj1, Object obj2) {
if(obj1.get("A")>obj2.get("A"))return 1;
......
}
public class HashMapDecorator extends HashMap implements Comparator {
private HashMap map;
public HashMapDecorator(HashMap map){
this.map=map;
}
实现
public int compare(Object obj1, Object obj2) {
.............
比较的时候根据A就可以了
}
}
利用Decorator模式就可以了
public class HashMapDecorator extends HashMap implements Comparator {
private HashMap map;
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这算是继承还是聚合?