1. For TreeSet, the data elements are required to be sorted, and they cannot be repeated . 2. TreeMap is
required to sort
the Both TreeSe and TreeMap are sorted when adding data. So set a comparator on it, for example:
package treeset;
import java.util.Comparator;
import java.util.TreeSet;
public class TreeMapText {
public static void main(String[] args) {
PeoPle peoPle1=new PeoPle("案件",24);
PeoPle peoPle2=new PeoPle("案发",23);
PeoPle peoPle3=new PeoPle("十分",54);
PeoPle peoPle4=new PeoPle("是个",44);
TreeSet<PeoPle> sTreeSet=new TreeSet<PeoPle>(
new Comparator<PeoPle>() {//添加比较器
@Override
public int compare(PeoPle o1, PeoPle o2) {
return o1.getAge()-o2.getAge();//升序排序
}
}
);
//添加数据时排序
sTreeSet.add(peoPle1);
sTreeSet.add(peoPle2);
sTreeSet.add(peoPle3);
sTreeSet.add(peoPle4);
System.out.println(sTreeSet);
//数据修改不会改变排序的顺序,若修改的数据与原来的数据相同,则会出现数据的重复
// peoPle1.setAge(10);
}
}