Java 如何在忽略区分大小写的情况下按字母顺序排序?
我有这个代码,但只适用于小写字母。我想让它在忽略大写字母的同时对列表进行排序Java 如何在忽略区分大小写的情况下按字母顺序排序?,java,android,collections,Java,Android,Collections,我有这个代码,但只适用于小写字母。我想让它在忽略大写字母的同时对列表进行排序 package sortarray.com; import java.util.ArrayList; import java.util.List; import android.app.Activity; import android.os.Bundle; import android.util.Log; import android.widget.TextView; public class SortArray
package sortarray.com;
import java.util.ArrayList;
import java.util.List;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.widget.TextView;
public class SortArray extends Activity {
ArrayList<String[]> matchedFruits = new ArrayList<String[]>();
TextView selection;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
String fruits[] = new String[7];// Sorted array
fruits[0] = "apple";
fruits[1] = "apricot";
fruits[2] = "banana";
fruits[3] = "mango";
fruits[4] = "melon";
fruits[5] = "pineapple";
fruits[6] = "peach";
char currChar = fruits[0].charAt(0);// Get first char of first element
boolean match = false;
int len = fruits.length;
List<String> tmp = new ArrayList<String>();
for (int i = 1; i < len; i++) {
Log.d("Comparing ", fruits[i].charAt(0) + "," + currChar);
if (fruits[i].charAt(0) == currChar) {
if (match == false)// new match?
{
match = true;// Reset search
tmp.clear();// clear existing items
tmp.add(fruits[i - 1]);
Log.d("Started new list ", fruits[i - 1]);
} else {
tmp.add(fruits[i - 1]);
Log.d("Added to list ", fruits[i - 1]);
}
} else {
match = false;
tmp.add(fruits[i - 1]);
matchedFruits.add(tmp.toArray(new String[tmp.size()]));// add to
// final
// list
Log.d("Finished a list ", fruits[i - 1]);
tmp.clear();// clear existing items
}
currChar = fruits[i].charAt(0);
}
tmp.add(fruits[len - 1]);
matchedFruits.add(tmp.toArray(new String[tmp.size()]));// add left over
// items
printList();
}
void printList()
{
//Print the list
TextView selection = (TextView) findViewById(R.id.tv);
String mssg="";
for(int i=0;i<matchedFruits.size();i++)
{
String tmp2[]= matchedFruits.get(i);
for (int j = 0; j < tmp2.length; j++) {
//Log.d("Final list", "Array #" + i + "[" + j + "]," + tmp2[j]);
mssg += tmp2[j].toString();
}
//selection.setText("\n");
selection.setText(mssg);
}
}
}
package sortarray.com;
导入java.util.ArrayList;
导入java.util.List;
导入android.app.Activity;
导入android.os.Bundle;
导入android.util.Log;
导入android.widget.TextView;
公共类Sortaray扩展活动{
ArrayList matchedFruits=新的ArrayList();
文本视图选择;
@凌驾
创建时的公共void(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
字符串结果[]=新字符串[7];//已排序数组
水果[0]=“苹果”;
水果[1]=“杏”;
水果[2]=“香蕉”;
水果[3]=“芒果”;
水果[4]=“甜瓜”;
水果[5]=“菠萝”;
水果[6]=“桃”;
char currChar=fruits[0]。charAt(0);//获取第一个元素的第一个字符
布尔匹配=假;
int len=水果长度;
List tmp=new ArrayList();
对于(int i=1;i 对于(int i=0;i您是否尝试过在if(fruits[i].charAt(0)=currChar)
和char currChar=fruits[0].charAt(0)
语句中将字符串的第一个字符转换为小写?不清楚您想做什么,但您可以对列表进行如下排序:
List<String> fruits = new ArrayList<String>(7);
fruits.add("Pineapple");
fruits.add("apple");
fruits.add("apricot");
fruits.add("Banana");
fruits.add("mango");
fruits.add("melon");
fruits.add("peach");
System.out.println("Unsorted: " + fruits);
Collections.sort(fruits, new Comparator<String>() {
@Override
public int compare(String o1, String o2) {
return o1.compareToIgnoreCase(o2);
}
});
System.out.println("Sorted: " + fruits);
private static final Comparator<String> MYSTRING_COMPARATOR = new Comparator<String>() {
@Override
public int compare(String s1, String s2) {
return s1.compareToIgnoreCase(s2);
}
};
public static Comparator<String> getMyStringComparator() {
return MYSTRING_COMPARATOR;
List<String> myArray = new ArrayList<String>();
//fill your array here
Collections.sort(MyArray, MyComparators. getMyStringComparator());
public class UserBean implements Comparable<UserBean> {
private String name;
private String surname;
private Integer phone;
// GETTERS AND SETTERS
public int compareTo(UserBean bean) {
return name.compareToIgnoreCase(bean.name);
}
}
myList.sort(String.CASE_INSENSITIVE_ORDER); // reads as the problem statement and cleaner
List fruits=newarraylist(7);
水果。加入(“菠萝”);
水果。添加(“苹果”);
水果。添加(“杏”);
水果。添加(“香蕉”);
水果。添加(“芒果”);
水果。添加(“甜瓜”);
水果。添加(“桃子”);
System.out.println(“未分类:+水果);
Collections.sort(水果,新比较器(){
@凌驾
公共整数比较(字符串o1,字符串o2){
返回o1.比较信号(o2);
}
});
System.out.println(“分类:+水果);
下面是一个简单的java示例,它说明了最好的方法:
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
public class Sorter {
String fruits[] = new String[7];
List<String> lst;
Sorter() {
lst = new ArrayList<String>();
// initialise UNSORTED array
fruits[0] = "Melon"; fruits[1] = "apricot"; fruits[2] = "peach";
fruits[3] = "mango"; fruits[4] = "Apple"; fruits[5] = "pineapple";
fruits[6] = "banana";
}
public static void main(String[] args) {
Sorter srt = new Sorter();
srt.anyOldUnstaticMethod();
}
public void anyOldUnstaticMethod() {
Collections.addAll(lst, fruits);
System.out.println("Initial List");
for (String s : lst)
System.out.println(s);
Collections.sort(lst);
System.out.println("\nSorted List");
for (String s : lst)
System.out.println(s);
Collections.sort(lst, new SortIgnoreCase());
System.out.println("\nSorted Ignoring Case List");
for (String s : lst)
System.out.println(s);
}
public class SortIgnoreCase implements Comparator<Object> {
public int compare(Object o1, Object o2) {
String s1 = (String) o1;
String s2 = (String) o2;
return s1.toLowerCase().compareTo(s2.toLowerCase());
}
}
}
import java.util.ArrayList;
导入java.util.Collections;
导入java.util.Comparator;
导入java.util.List;
公共类分拣机{
串水果[]=新串[7];
列表lst;
分拣机(){
lst=新的ArrayList();
//初始化未排序的数组
水果[0]=“瓜”;水果[1]=“杏”;水果[2]=“桃”;
水果[3]=“芒果”;水果[4]=“苹果”;水果[5]=“菠萝”;
水果[6]=“香蕉”;
}
公共静态void main(字符串[]args){
分拣机srt=新分拣机();
srt.anyOldUnstaticMethod();
}
public void anyOldUnstaticMethod(){
集合。添加所有(第一阶段,水果);
System.out.println(“初始列表”);
用于(字符串s:lst)
系统输出打印项次;
集合。排序(lst);
System.out.println(“\n被选中的列表”);
用于(字符串s:lst)
系统输出打印项次;
Collections.sort(lst,new SortIgnoreCase());
System.out.println(“\n忽略案例列表”);
用于(字符串s:lst)
系统输出打印项次;
}
公共类SortIgnoreCase实现了Comparator{
公共整数比较(对象o1、对象o2){
字符串s1=(字符串)o1;
字符串s2=(字符串)o2;
返回s1.toLowerCase().compareTo(s2.toLowerCase());
}
}
}
我喜欢comparator类SortIgnoreCase
,但我会使用它
public class SortIgnoreCase implements Comparator<String> {
public int compare(String s1, String s2) {
return s1.compareToIgnoreCase(s2); // Cleaner :)
}
}
公共类SortIgnoreCase实现了Comparator{
公共整数比较(字符串s1、字符串s2){
返回s1.compareToIgnoreCase(s2);//Cleaner:)
}
}
使用集合和数组列表的示例:
开发一个实习生静态类,如“CompareStrings”示例
在main方法中调用intern静态类
易于理解,工作良好
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
public class MainClass {
public static void main(String[] args) {
ArrayList<String> myArray = new ArrayList<String>();
myArray.add("zzz");
myArray.add("xxx");
myArray.add("Aaa");
myArray.add("bb");
myArray.add("BB");
Collections.sort(myArray, new MainClass.CompareStrings());
for(String s : myArray) {
System.out.println(s);
}
}
public static class CompareStrings implements Comparator<String> {
@Override
public int compare(String s1, String s2) {
return s1.compareToIgnoreCase(s2);
}
}
}
import java.util.ArrayList;
导入java.util.Collections;
导入java.util.Comparator;
公共类主类{
公共静态void main(字符串[]args){
ArrayList myArray=新的ArrayList();
myArray.add(“zzz”);
myArray.add(“xxx”);
myArray.add(“Aaa”);
myArray.add(“bb”);
myArray.add(“BB”);
Collections.sort(myArray,newmainclass.CompareStrings());
for(字符串s:myArray){
系统输出打印项次;
}
}
公共静态类CompareStrings实现Comparator{
@凌驾
公共整数比较(字符串s1、字符串s2){
返回s1.compareToIgnoreCase(s2);
}
}
}
在comparator factory类中,执行以下操作:
Collections.sort(caps, String.CASE_INSENSITIVE_ORDER);
ArrayList<String> myArray = new ArrayList<String>();
myArray.add("zzz");
myArray.add("xxx");
myArray.add("Aaa");
myArray.add("bb");
myArray.add("BB");
Collections.sort(myArray,Collator.getInstance());
public class UserBean implements Comparable<UserBean> {
private String name;
private String surname;
private Integer phone;
// GETTERS AND SETTERS
public int compareTo(UserBean bean) {
return name.compareToIgnoreCase(bean.name);
}
}
import java.text.Collator;
import java.util.Arrays;
public class Main {
public static void main(String args[]) {
String[] myArray = new String[] { "A", "B", "b" };
Arrays.sort(myArray, Collator.getInstance());
System.out.println(Arrays.toString(myArray));
}
}
List<String> fruits = Arrays.asList("apple", "Apricot", "banana");
List<String> sortedFruit = fruits.stream()
.sorted(String.CASE_INSENSITIVE_ORDER)
.collect(Collectors.toList())
myList.sort(String.CASE_INSENSITIVE_ORDER); // reads as the problem statement and cleaner
myList.sort(String::compareToIgnoreCase); // reads as the problem statement and cleaner
String[] names = {"Alexis", "Tim", "Kyleen", "KRISTY"};
Arrays.sort(names, String::compareToIgnoreCase);