泛型方法，java map按照value值来比较大小并且返回最终结果

泛型方法 public static <T> void display(T t)

public class Test01 implements Comparator<Long>{

Map<Long,Double> base;

public Test01(Map<Long,Double> base){

this.base = base;

}

@Override

public int compare(Long a,Long b) {

if(base.get(a).doubleValue() >= base.get(b).doubleValue()){

return -1;

}else{

return 1;

}

}

//泛型方法 public static <T> void display(T t)

public static <K,V extends Comparable<V>> Map<K,V> sortByValues(final Map<K,V> map){

Comparator<K> valueComparator = new Comparator<K>(){

public int compare(K k1,K k2){

int compare = map.get(k2).compareTo(map.get(k1));

if(compare == 0)

return 1;

else

return compare;

}

};

Map<K,V> sortedByValues = new TreeMap<K,V>(valueComparator);

sortedByValues.putAll(map);

return sortedByValues;

}

public static void main(String args[]){

HashMap<Long,Double> map = new HashMap<Long,Double>();

map.put(1L, 99.5);

map.put(2L, 67.2);

map.put(3L, 67.5);

map.put(4L, 67.6);

Test01 bvc = new Test01(map);

TreeMap<Long,Double> sorted_map = new TreeMap<Long,Double>(bvc);

System.out.println("unsorted map:"+map);

sorted_map.putAll(map);

System.out.println("results:" + sorted_map);

Map<Long,Double> sorted_map2 = sortByValues(map);

System.out.println("results2:" + sorted_map2);

}

}