Java SortedSet TreeSet按指定方式排序 不同方式排序的列子
//实现Things类
class Things{
public String name;
public String id;
String location;
public String arrivetime;
Things(String id, String name,String location,String arrivetime){
this.id=id;
this.name=name;
this.location=location;
this.arrivetime=arrivetime;
}
public String toString(){
return"id:"+id+"\tname:"+name+"\tlocation:"+location+"\tarrivetime:"+arrivetime+"\n";
}
}
//实现按ID进行比较
import java.util.Comparator;
public class SortById implements Comparator{
@Override
public int compare(Object o1, Object o2) {
Things th1=(Things)o1;
Things th2=(Things)o2;
return th1.id.compareTo(th2.id);
}
}
//实现按Time进行比较
import java.util.Comparator;
public class SortByTime implements Comparator{
@Override
public int compare(Object o1, Object o2) {
Things th1=(Things)o1;
Things th2=(Things)o2;
return th1.arrivetime.compareTo(th2.arrivetime);
}
}
//测试
import java.util.*;
class Demo5{
public static void main(String args[]) {
SortedSet ssa=new TreeSet(new SortById());//创建一个按照Id排序的TreeSet实例a
SortedSet ssb=new TreeSet(new SortByTime());//创建一个按照Time排序的TreeSet实例b
ssa.add(new Things("001","A","库1","2001-01-10"));//添加的时候时间必须标准比如2011-11-1必须写成2011-11-01
ssa.add(new Things("002","A","库1","2011-10-31"));
ssa.add(new Things("003","B","库1","2011-10-03"));
ssa.add(new Things("006","A","库2","2011-10-01"));
ssa.add(new Things("007","B","库2","2011-10-30"));
ssa.add(new Things("008","B","库2","2011-09-12"));
ssa.add(new Things("004","B","库1","2011-09-02"));
ssa.add(new Things("005","A","库2","2001-01-09"));
int count1=0,count2=0,count3=0,count4=0;
System.out.println("按ID排序:");
Iterator it = ssa.iterator();
while(it.hasNext()){
Things c = it.next();
ssb.add(c);//从a中不断读取的时候就在b中添加
System.out.print(c);
if(c.name=="A" && c.location=="库1")
count1++;
else
if(c.name=="A" && c.location=="库2")
count2++;
else
if(c.name=="B" && c.location=="库1")
count3++;
else
if(c.name=="B" && c.location=="库2")
count4++;
}
System.out.println("按时间排序:");
it = ssb.iterator();
while(it.hasNext()){
Things c = it.next();
System.out.print(c);
}
System.out.println("A物料在库1的库存量为："+count1);
System.out.println("A物料在库2的库存量为："+count2);
System.out.println("B物料在库1的库存量为："+count3);
System.out.println("B物料在库2的库存量为："+count4);
}
}