感谢您的解决方案！对于其他人，以下解决方案不使用辅助类（除了StringUtils）
/我为这个解决方案添加了额外的信息，请查看代码结尾，Zegor V/
public class FileUtils {
public static boolean copyFile(final File toCopy, final File destFile) {
try {
return FileUtils.copyStream(new FileInputStream(toCopy),
new FileOutputStream(destFile));
} catch (final FileNotFoundException e) {
e.printStackTrace();
}
return false;
}
private static boolean copyFilesRecusively(final File toCopy,
final File destDir) {
assert destDir.isDirectory();
if (!toCopy.isDirectory()) {
return FileUtils.copyFile(toCopy, new File(destDir, toCopy.getName()));
} else {
final File newDestDir = new File(destDir, toCopy.getName());
if (!newDestDir.exists() && !newDestDir.mkdir()) {
return false;
}
for (final File child : toCopy.listFiles()) {
if (!FileUtils.copyFilesRecusively(child, newDestDir)) {
return false;
}
}
}
return true;
}
public static boolean copyJarResourcesRecursively(final File destDir,
final JarURLConnection jarConnection) throws IOException {
final JarFile jarFile = jarConnection.getJarFile();
for (final Enumeration<JarEntry> e = jarFile.entries(); e.hasMoreElements();) {
final JarEntry entry = e.nextElement();
if (entry.getName().startsWith(jarConnection.getEntryName())) {
final String filename = StringUtils.removeStart(entry.getName(),
jarConnection.getEntryName());
final File f = new File(destDir, filename);
if (!entry.isDirectory()) {
final InputStream entryInputStream = jarFile.getInputStream(entry);
if(!FileUtils.copyStream(entryInputStream, f)){
return false;
}
entryInputStream.close();
} else {
if (!FileUtils.ensureDirectoryExists(f)) {
throw new IOException("Could not create directory: "
+ f.getAbsolutePath());
}
}
}
}
return true;
}
public static boolean copyResourcesRecursively( //
final URL originUrl, final File destination) {
try {
final URLConnection urlConnection = originUrl.openConnection();
if (urlConnection instanceof JarURLConnection) {
return FileUtils.copyJarResourcesRecursively(destination,
(JarURLConnection) urlConnection);
} else {
return FileUtils.copyFilesRecusively(new File(originUrl.getPath()),
destination);
}
} catch (final IOException e) {
e.printStackTrace();
}
return false;
}
private static boolean copyStream(final InputStream is, final File f) {
try {
return FileUtils.copyStream(is, new FileOutputStream(f));
} catch (final FileNotFoundException e) {
e.printStackTrace();
}
return false;
}
private static boolean copyStream(final InputStream is, final OutputStream os) {
try {
final byte[] buf = new byte[1024];
int len = 0;
while ((len = is.read(buf)) > 0) {
os.write(buf, 0, len);
}
is.close();
os.close();
return true;
} catch (final IOException e) {
e.printStackTrace();
}
return false;
}
private static boolean ensureDirectoryExists(final File f) {
return f.exists() || f.mkdir();
}
}
它仅使用来自Apache Software Foundation的一个外部库，但是所使用的函数仅限于：
public static String removeStart(String str, String remove) {
if (isEmpty(str) || isEmpty(remove)) {
return str;
}
if (str.startsWith(remove)){
return str.substring(remove.length());
}
return str;
}
public static boolean isEmpty(CharSequence cs) {
return cs == null || cs.length() == 0;
}
我对Apache许可证的了解有限，但是您可以在代码中使用这些方法而无需使用库。然而，如果出现许可问题，我不负责。
