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我編寫了一個程序來打印具有doc或pdf擴展名的文件。但它不工作。相同的正則表達式使用直接文件名而不是文件系統檢索的文件名，它正在工作。 什麼是錯的：java io - 正則表達式無法正常工作 - 爲什麼
import static java.nio.file.FileVisitResult.CONTINUE;
import java.io.IOException;
import java.nio.file.FileSystems;
import java.nio.file.FileVisitResult;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.PathMatcher;
import java.nio.file.Paths;
import java.nio.file.SimpleFileVisitor;
import java.nio.file.attribute.BasicFileAttributes;
public class FindDuplicateFiles {
public static void main(String[] args) throws IOException {
String startingDirStr ="/Users/ravi/documents/LATEST SOURCE";//".";
String pattern ="([^\\s]+(\\.(?i)(doc|docx|pdf))$)";//"*.doc*";//"((\\.(?i)(pdf|doc))$)";//"^(?:.*\\.(?:docx|pdf)$";// ".*\\.(?:doc|pdf)$";//
Path startingDir = Paths.get(startingDirStr);
Finder finder = new Finder(pattern);
Files.walkFileTree(startingDir, finder);
finder.done();
}
public static class Finder extends SimpleFileVisitor<Path> {
private final PathMatcher matcher;
private int numMatches = 0;
Finder(String pattern) {
matcher = FileSystems.getDefault().getPathMatcher("glob:" + pattern);
}
// Compares the glob pattern against
// the file or directory name.
void find(Path file) {
Path name = file.getFileName();
if (name != null && matcher.matches(name)) {
numMatches++;
System.out.println(name);
//System.out.println(file);
}
}
// Prints the total number of
// matches to standard out.
void done() {
System.out.println("Matched: " + numMatches);
}
// Invoke the pattern matching
// method on each file.
@Override
public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) {
find(file);
return CONTINUE;
}
// Invoke the pattern matching
// method on each directory.
@Override
public FileVisitResult preVisitDirectory(Path dir, BasicFileAttributes attrs) {
find(dir);
return CONTINUE;
}
@Override
public FileVisitResult visitFileFailed(Path file, IOException exc) {
System.err.println(exc);
return CONTINUE;
}
}
}
，但它工作正常：
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class FindDocuments {
private Pattern pattern;
private Matcher matcher;
private static final String IMAGE_PATTERN = "([^\\s]+(\\.(?i)(doc|docx|pdf))$)";
public FindDocuments() {
pattern = Pattern.compile(IMAGE_PATTERN);
}
public boolean validate(final String image) {
matcher = pattern.matcher(image);
return matcher.matches();
}
public static void main(String[] args) {
FindDocuments fd = new FindDocuments();
String[] aaa = new String[] { "a.doc", "a.docx", "a.pdf", "a.PDF", "..DOC", "..PDF" };
for (String temp : aaa) {
boolean valid = fd.validate(temp);
System.out.println("Image is valid : " + temp + " , " + valid);
}
}
}