java" id="highlighter_673763">
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package com;
import java.util.Comparator;
import java.util.TreeMap;
public class Test5 {
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
TreeMap<String, String> tree = new TreeMap<String, String>(
new Comparator<Object>() {
@Override
public int compare(Object o1, Object o2) {
// TODO Auto-generated method stub
if (o1 == null || o2 == null ){
return 0 ;
}
return o1.toString().compareTo(o2.toString());
}
}
);
tree.put( "k" , "1" );
tree.put( "ba" , "2" );
tree.put( "z" , "3" );
tree.put( "d" , "4" );
tree.put( "e" , "5" );
tree.put( "an" , "6" );
tree.put( "c" , "7" );
for (String str : tree.keySet()){
System.out.println(str);
}
}
}
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经测试默认是按照 KEY 进行排序的。
但是可以写对象比较器,进行自定义排序。
TreeSet : 自定义倒序排序,默认按照正序排序,1,2,3,4,5,6
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package com;
import java.util.Comparator;
import java.util.TreeSet;
public class Test6 {
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
TreeSet<Object> tree = new TreeSet<Object>( new Comparator<Object>() {
@Override
public int compare(Object o1, Object o2) {
// TODO Auto-generated method stub
if (o1 == null || o2 == null ){
return 0 ;
}
if (Integer.parseInt(o1.toString()) > Integer.parseInt(o2.toString())){
return - 1 ;
} else if (Integer.parseInt(o1.toString()) < Integer.parseInt(o2.toString())){
return 1 ;
} else {
return 0 ;
}
}
});
tree.add( 4 );
tree.add( 5 );
tree.add( 6 );
tree.add( 1 );
tree.add( 2 );
tree.add( 3 );
for (Object o : tree){
System.out.println(o);
}
}
}
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以上这篇浅谈java中的TreeMap 排序与TreeSet 排序就是小编分享给大家的全部内容了,希望能给大家一个参考,也希望大家多多支持服务器之家。