Java Utililty Methods Zip File Check

ZipFile zipFile = new ZipFile(zip);
try {
    Enumeration en = zipFile.entries();
    while (en.hasMoreElements()) {
        ZipEntry zipEntry = (ZipEntry) en.nextElement();
        if (relativePath.equals(zipEntry.getName())) {
            return true;
    zipFile.close();
    return false;
} finally {
    zipFile.close();

if (str.length() < 18)
    return false;
String t = cleanPath(str);
String tmp = t.substring(0, 18);
String test = "replicate" + File.separator + "inbound" + File.separator;
if (tmp.equals(test)) {
    tmp = str.substring(str.length() - 4, str.length());
    if (tmp.equals(".zip"))
...

String s = null;
if ((null == f) || (null == (s = f.getPath()))) {
    return false;
} else {
    return (f.canRead() && !f.isDirectory() && (s.endsWith(".zip") || (s.endsWith(".jar"))));

if (f == null)
    return false;
return isZipFile(f.getName());

if (f != null) {
    if (f.getName().contains(".zip") || f.getAbsolutePath().contains(".zip")) {
        return true;
return false;

RandomAccessFile r;
try {
    r = new RandomAccessFile(f, "r");
    if (r.readInt() == 0x504b0304) {
        r.close();
        return true;
    } else {
        r.close();
...

boolean isZip = true;
byte[] buffer = new byte[MAGIC.length];
try {
    RandomAccessFile raf = new RandomAccessFile(f, "r");
    raf.readFully(buffer);
    for (int i = 0; i < MAGIC.length; i++) {
        if (buffer[i] != MAGIC[i]) {
            isZip = false;
...

return new ZipInputStream(new FileInputStream(file)).getNextEntry() != null;

if (file.isDirectory()) {
    return false;
if (!file.canRead()) {
    throw new IOException("Cannot read file " + file.getAbsolutePath());
if (file.length() < 4) {
    return false;
...

final byte[] sig = new byte[] { 0x50, 0x4B, 0x3, 0x4 };
if (file.canRead()) {
    byte[] buf = new byte[4];
    FileInputStream is = null;
    try {
        is = new FileInputStream(file);
        is.read(buf);
    } finally {
...