本文介绍了如何按字母顺序对我的数组列表进行排序的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
限时送ChatGPT账号..我想按字母顺序对我的数组列表进行排序,但我不明白...也许你可以帮助我.我不知道为什么,但我不能使用 collections.sort...我编码错了什么?非常感谢你的帮助和时间,Vinzenz
I want to sort my arraylist alphabetical but I don't get it...maybe you can help me. I dont know why but i cant work with collections.sort...what am i coding wrong? thanks a lot for all your help and time, Vinzenz
public class SongsManager {
final String MEDIA_PATH = Environment.getExternalStorageDirectory()
.getPath() + "/";
private ArrayList<HashMap<String, String>> songsList = new ArrayList<HashMap<String, String>>();
private String mp3Pattern = ".mp3";
private String mp4Pattern = ".mp4";
private String MP3Pattern = ".MP3";
private String MP4Pattern = ".MP4";
private String m4aPattern = ".m4a";
// Constructor
public SongsManager() {
}
/**
* Function to read all mp3 files and store the details in
* ArrayList
* */
public ArrayList<HashMap<String, String>> getPlayList() {
System.out.println(MEDIA_PATH);
if (MEDIA_PATH != null) {
File home = new File(MEDIA_PATH);
File[] listFiles = home.listFiles();
if (listFiles != null && listFiles.length > 0) {
for (File file : listFiles) {
System.out.println(file.getAbsolutePath());
if (file.isDirectory()) {
scanDirectory(file);
} else {
addSongToList(file);
}
}
}
}
// return songs list array
return songsList;
}
private void scanDirectory(File directory) {
if (directory != null) {
File[] listFiles = directory.listFiles();
if (listFiles != null && listFiles.length > 0) {
for (File file : listFiles) {
if (file.isDirectory()) {
scanDirectory(file);
} else {
addSongToList(file);
}
}
}
}
}
private void addSongToList(File song) {
if (song.getName().endsWith(mp3Pattern) || song.getName().endsWith(mp4Pattern) || song.getName().endsWith(MP4Pattern) || song.getName().endsWith(MP3Pattern) || song.getName().endsWith(m4aPattern)) {
HashMap<String, String> songMap = new HashMap<String, String>();
songMap.put("songTitle",
song.getName().substring(0, (song.getName().length() - 4)));
songMap.put("songPath", song.getPath());
// Adding each song to SongList
songsList.add(songMap);
}
}
}
推荐答案
使用 Collections.sort
Collections.sort(listOfStrings, String.CASE_INSENSITIVE_ORDER);
详情请参阅以下内容:
String.CASE_INSENSITIVE_ORDER
Collections.sort
您还可以创建自定义比较器,而不是使用 String.CASE_INSENSITIVE_ORDER
You can also create a custom Comparator, instead of using String.CASE_INSENSITIVE_ORDER
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