写在20110830：排序

定义一个抽象类文件（目录）排序
private abstract class FileComparator implements Comparator<FileInfo> {
@Override
public int compare(FileInfo obj1, FileInfo obj2) {
if (obj1.IsDir == obj2.IsDir) {
return doCompare(obj1, obj2);
}
return obj1.IsDir ? -1 : 1;
}
protected abstract int doCompare(FileInfo obj1, FileInfo obj2);
}
文件的排序一般有四种：
1.按首字母排序，需要支持中文
private Comparator cmpName = new FileComparator() {
@Override
public int doCompare(FileInfo obj1, FileInfo obj2) {
/*RuleBasedCollator collator=(RuleBasedCollator)Collator.getInstance(Locale.CHINA);
return collator.compare(obj1.fileName,obj2.fileName)<0?-1:1;*/
return obj1.fileName.compareToIgnoreCase(obj2.fileName);
}
};
2.按文件大小排序，一般文件夹此时默认是按首字母排序
private Comparator cmpSize = new FileComparator() {
@Override
public int doCompare(FileInfo obj1, FileInfo obj2) {
return (obj1.fileSize - obj2.fileSize)> 0 ? 1 : ((obj1.fileSize - obj2.fileSize)< 0 ? -1 : 0);
}
};
3.按文件的最后修改时间排序，重命名不会改变修改时间
private Comparator cmpDate = new FileComparator() {
@Override
public int doCompare(FileInfo obj1, FileInfo obj2) {
return (obj2.ModifiedDate - obj1.ModifiedDate)> 0 ? 1 : ((obj2.ModifiedDate - obj1.ModifiedDate)< 0 ? -1 : 0);
};
}
4.按文件类型排序，大则按图片、音频、视频等排序，小则按后缀名首字母区分排序，例如aac、bmp、jpg等。
private Comparator cmpType = new FileComparator() {
@Override
public int doCompare(FileInfo obj1, FileInfo obj2) {
int result = Util.getExtFromFileName(obj1.fileName).compareToIgnoreCase(
Util.getExtFromFileName(obj2.fileName));
if (result != 0)
return result;

return Util.getNameFromFileName(obj1.fileName). compareToIgnoreCase(
Util.getNameFromFileName(obj2.fileName));
}
}