package lltse.java.collection; import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Random; public class ListDemo { /**
* @param args
*/
public static void main(String[] args)
{
System.out.println("---------------开始-----------------------");
List<Map<String, Object>> students = getSortStudentList();
for(Map<String,Object> map:students)
{
System.out.println("Student:>>>"+map.get("Student"));
System.out.println("distance:>>>"+map.get("distance"));
} System.out.println("---------------分割线-----------------------"); List<Object> persons = getSortPerson();
for(Object p :persons)
{
System.out.println("Person Name:>>>"+((Person)p).getName());
System.out.println("Person Sex:>>>"+((Person)p).getSex());
System.out.println("Person Age:>>>"+((Person)p).getAge());
}
System.out.println("---------------结束-----------------------");
} /**
* 对List中的对象按照距离进行排序
* @return
*/
public static List<Map<String, Object>> getSortStudentList()
{
List<Map<String, Object>> list = new ArrayList<Map<String, Object>>();
Random rd = new Random(100);
for (int i = 0; i < 5; i++)
{
Map<String, Object> map = new HashMap<String, Object>();
map.put("Student", "Student" + i);
map.put("distance", rd.nextDouble()); list.add(map);
} //Collections.synchronizedList(list);
//自定义排序规则,进行排序
Collections.sort(list, new Comparator<Map<String, Object>>()
{
@Override
public int compare(Map<String, Object> o1, Map<String, Object> o2)
{
Double d1 = (Double)o1.get("distance");
Double d2 = (Double)o2.get("distance");
return d1.compareTo(d2);
}
}); return list;
} /**
* 引用外部比较器,将人员按年龄排序
* @return
*/
public static List<Object> getSortPerson()
{
List<Object> list = new ArrayList<Object>();
Random rd = new Random();
for(int s = 1;s <= 10; s++)
{
Person p = new Person();
p.setAge(rd.nextInt(100));
p.setName("Person"+s);
String sex = "男";
if(s % 2 > 0)
{
sex = "女";
}
p.setSex(sex); list.add(p);
}
TestCompartor tc = new TestCompartor();
Collections.sort(list, tc); return list;
}
} /**
* 比较器类,按年龄升序排列
* @author Administrator
*
*/
class TestCompartor implements Comparator<Object>
{
@Override
public int compare(Object o1, Object o2) { Person p1 = (Person)o1;
Person p2 = (Person)o2;
if(p1.getAge()>p2.getAge())
{
return 1;
}
else
{
return -1;
}
}
}
测试输出结果如下:
---------------开始-----------------------
Student:>>>Student1
distance:>>>0.19497605734770518
Student:>>>Student4
distance:>>>0.6186076060240648
Student:>>>Student2
distance:>>>0.6671595726539502
Student:>>>Student0
distance:>>>0.7220096548596434
Student:>>>Student3
distance:>>>0.7784408674101491
---------------分割线-----------------------
Person Name:>>>Person8
Person Sex:>>>男
Person Age:>>>11
Person Name:>>>Person7
Person Sex:>>>女
Person Age:>>>15
Person Name:>>>Person6
Person Sex:>>>男
Person Age:>>>19
Person Name:>>>Person10
Person Sex:>>>男
Person Age:>>>33
Person Name:>>>Person4
Person Sex:>>>男
Person Age:>>>46
Person Name:>>>Person9
Person Sex:>>>女
Person Age:>>>53
Person Name:>>>Person3
Person Sex:>>>女
Person Age:>>>66
Person Name:>>>Person5
Person Sex:>>>女
Person Age:>>>74
Person Name:>>>Person2
Person Sex:>>>男
Person Age:>>>79
Person Name:>>>Person1
Person Sex:>>>女
Person Age:>>>82
---------------结束-----------------------