java中可以排序的工具类和接口共有五个SortedMap 、SortedSet、TreeMap 、TreeSet和Collections,Collections中需要显式调用sort()方法。
事例如下:
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import java.util.List;
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import java.util.ArrayList;
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import java.util.Arrays;
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import java.util.Collections;
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import myUtil.myArrayComparator;
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import java.util.Map;
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import java.util.HashMap;
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import java.util.TreeMap;
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import java.util.Collection;
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import java.util.Iterator;
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import myUtil.myMapComparator;
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public class mySort {
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public mySort() {
- }
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public void arraySort() {
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- String[] sortArray = {"中山",
"汕尾", "广州", "汕头",
"阳江"};
- Arrays.sort(sortArray);
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for (int i =
0; i < 5; i++) {
- System.out.println( (String) sortArray[i]);
- }
import java.util.List;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import myUtil.myArrayComparator;
import java.util.Map;
import java.util.HashMap;
import java.util.TreeMap;
import java.util.Collection;
import java.util.Iterator;
import myUtil.myMapComparator;
public class mySort {
public mySort() {
}
/**
* 数组的中文排序
*/
public void arraySort() {
String[] sortArray = {"中山", "汕尾", "广州", "汕头", "阳江"};
Arrays.sort(sortArray);
for (int i = 0; i < 5; i++) {
System.out.println( (String) sortArray[i]);
}
//结果排序为:中山,广州,汕头,汕尾,阳江。按照每个单词最后一个字母的降序进行排列。
- String[] reverseArray = {"中山",
"汕尾", "广州", "汕头",
"阳江"};
- Collections.reverse(Arrays.asList(reverseArray));
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for (int i =
0; i < 5; i++) {
- System.out.println( (String) reverseArray[i]);
- }
String[] reverseArray = {"中山", "汕尾", "广州", "汕头", "阳江"};
Collections.reverse(Arrays.asList(reverseArray));
for (int i = 0; i < 5; i++) {
System.out.println( (String) reverseArray[i]);
}
//结果排序为:阳江,汕头,广州,汕尾,中山。Coleections的反序(reverse)是指单词进行首末对换
//按照中文第一个字母升序排列的实现
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import java.text.Collator;
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import java.util.Arrays;
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import java.util.Comparator;
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public class test {
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public static
void main(String[] args) {
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- Comparator<Object> com=Collator.getInstance(java.util.Locale.CHINA);
- String[] newArray={"中山","汕头","广州","安庆","阳江","南京","武汉","北京","安阳","北方"};
- Arrays.sort(newArray,com);
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for(String i:newArray){
- System.out.print(i+" ");
- }
- }
- }
import java.text.Collator;
import java.util.Arrays;
import java.util.Comparator;
public class test {
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
Comparator<Object> com=Collator.getInstance(java.util.Locale.CHINA);
String[] newArray={"中山","汕头","广州","安庆","阳江","南京","武汉","北京","安阳","北方"};
Arrays.sort(newArray,com);
for(String i:newArray){
System.out.print(i+" ");
}
}
}
//结果的排序为:安庆 安阳 北方 北京 广州 南京 汕头 武汉 阳江 中山
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public void listSort(){
- List sortList=new ArrayList();
- sortList.add("中山");
- sortList.add("汕尾");
- sortList.add("广州");
- sortList.add("汕头");
- sortList.add("阳江");
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- myArrayComparator comparator = new myArrayComparator();
- Collections.sort(sortList,comparator);
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for(int i=0;i<sortList.size();i++){
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- System.out.println(sortList.get(i));
- }
public void listSort(){
List sortList=new ArrayList();
sortList.add("中山");
sortList.add("汕尾");
sortList.add("广州");
sortList.add("汕头");
sortList.add("阳江");
myArrayComparator comparator = new myArrayComparator();
Collections.sort(sortList,comparator);
for(int i=0;i<sortList.size();i++){
//因为ArrayList实现的是RandomAccess 随机访问接口。使用get()要比迭代的效率高。
//如果实现的是SequenceAccess(顺序访问接口。如:LinkList),使用迭代的效率高。
System.out.println(sortList.get(i));
}
//结果的排序为:广州,汕头,汕尾,阳江,中山。
//也可以使用Object[] listToArray=sortList.toArray();转换成数组后再进行排序
- Object[] listToArray=sortList.toArray();
- Arrays.sort(listToArray, comparator);
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for (int i =
0; i < listToArray.length; i++) {
- System.out.println( (String) listToArray[i]);
- }
Object[] listToArray=sortList.toArray();
Arrays.sort(listToArray, comparator);
for (int i = 0; i < listToArray.length; i++) {
System.out.println( (String) listToArray[i]);
}
//结果的排序为:广州,汕头,汕尾,阳江,中山。
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public void mapSort(){
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- myArrayComparator comparator = new myArrayComparator();
- Map sortMap= new TreeMap(comparator);
- sortMap.put("中山", "a");
- sortMap.put("广州", "b");
- sortMap.put("潮州", "c");
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- Collection col = sortMap.keySet();
- Iterator it = col.iterator();
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while (it.hasNext()) {
- System.out.println(it.next());
- }
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- }
public void mapSort(){
// 按照键值排序
myArrayComparator comparator = new myArrayComparator();
Map sortMap= new TreeMap(comparator);
sortMap.put("中山", "a");
sortMap.put("广州", "b");
sortMap.put("潮州", "c");
//注意:每次对TreeMap进行put()时,TreeMap都会自动调用它的compare(key,Entry.key)
//按照key进行排序
Collection col = sortMap.keySet();
Iterator it = col.iterator();
while (it.hasNext()) {
System.out.println(it.next());
}
}
//排序结果是:潮州,广州,中山。
public static void main(String[] args){
mySort mysort=new mySort();
//看看数组的中文排序
mysort.arraySort();
//看看链表的中文排序
mysort.listSort();
//看看map的中文排序
mysort.mapSort();
}
}
//重写compare方法
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package myUtil;
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import java.util.Comparator;
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import java.text.Collator;
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import java.text.CollationKey;
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public class myComparator
implements Comparator {
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private Collator collator = Collator.getInstance();
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public myComparator() {
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public int compare(Object o1, Object o2) {
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- CollationKey key1=collator.getCollationKey(o1.toString());
- CollationKey key2=collator.getCollationKey(o2.toString());
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return key1.compareTo(key2);
- }
- }