通过代码来看看吧
1.Employee 对象
package test;
public
Employee { private
id ; private String name;
public
getId
{ 
id; }
public void
Id( id) { this.id = id;
}
public String getName
{ name; }
public void
Name(String name) { this.name = name;
}
}
2.对象比较器
package test;
import java.util.Comparator;
public
DemoComparator implements Comparator { public
compare(Object o1, Object o2) { 
(((Employee)o1).getId > ((Employee)o2).getId) { -1;//DESC }
(((Employee)o1).getId < ((Employee)o2).getId) { 1;//ASC }
{ 0; }
}
}
3.测试类
package test;
import java.util.Vector;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
public
testVector { /**
* @param args
*/
public
void 
(String
args) { List vc = getEmList
; 
.out.prln("
=before sort"); for(
j =0;j < vc.size;j
){ Employee em = (Employee)vc.get(j);
.out.prln("id :" + em.getId + " name:" + em.getName); }
DemoComparator com =
DemoComparator; Collections.sort(vc, com);
.out.prln("=after sort"); for(
j =0;j < vc.size;j){ Employee em = (Employee)vc.get(j);
.out.prln("id :" + em.getId + " name:" + em.getName); }
}
//
public
List getEmList{ //这里用Vector做测试
当然你可以使用list所有
子类 List v =
Vector; Employee em = null; em =
Employee; em.
Id(59); em.
Name("test001"); v.add(em);
em =
Employee; em.
Id(23); em.
Name("test002"); v.add(em);
for(
i = 30; i < 40; i){ em =
Employee; em.
Id(i); em.
Name("chenfeng" + i); v.add(em);
}
v; }
}
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