排序的两种方式一是implement comparable接口，二是重写Comparator方法

第一种

static class T implements Comparable<T>{
private String name;
private int count;
public T(String name, int count) {
super();
this.name = name;
this.count = count;
}

public String getName() {
return name;
}

public void setName(String name) {
this.name = name;
}

public int getCount() {
return count;
}

public void setCount(int count) {
this.count = count;
}

@Override
public String toString() {
return name+"_"+count;
}
@Override
public int compareTo(T o) {
if(this.count!=o.count)
return o.count - this.count;降序，后面的减前面的降序，前面的减后面的升序
return this.name.compareTo(o.name);前面的减后面的升序
}

}

 

第二种

public static TreeSet<T> sortStudent(){
TreeSet<T> ts = new TreeSet<T>(new Comparator<T>() {

@Override
public int compare(T o1, T o2) {
if(o1.getCount()!=o2.getCount())
return o2.getCount()-o1.getCount();后面的减前面的降序
return o2.getName().compareTo(o1.getName());后面的减前面的降序，前面的见后面的升序
}

});