Hi Java!

/**
 * 压缩文件夹
 * @param sourceDIR 文件夹名称（包含路径）
 * @param targetZipFile 生成zip文件名
 * @author liuxiangwei
 */
public static void zipDIR(String sourceDIR, String targetZipFile) {
	try {
		FileOutputStream target = new FileOutputStream(targetZipFile);
		ZipOutputStream out = new ZipOutputStream(new BufferedOutputStream(target));
		int BUFFER_SIZE = 1024;
		byte buff[] = new byte[BUFFER_SIZE];
		File dir = new File(sourceDIR);
		if (!dir.isDirectory()) {
			throw new IllegalArgumentException(sourceDIR+" is not a directory!");
		}
		File files[] = dir.listFiles();
 
		for (int i = 0; i < files.length; i++) {
			FileInputStream fi = new FileInputStream(files[i]);
			BufferedInputStream origin = new BufferedInputStream(fi);
			ZipEntry entry = new ZipEntry(files[i].getName());
			out.putNextEntry(entry);
			int count;
			while ((count = origin.read(buff)) != -1) {
				out.write(buff, 0, count);
			}
			origin.close();
		}
		out.close();
 
	} catch (IOException e) {
		throw new MsgException("");
	}
}

	ByteArrayOutputStream  byteOut = new ByteArrayOutputStream();
        ObjectOutputStream out = new ObjectOutputStream(byteOut);
        out.writeObject(obj);
        ByteArrayInputStream byteIn = new ByteArrayInputStream(byteOut.toByteArray());
        ObjectInputStream in =new ObjectInputStream(byteIn);
        Object newObj=in.readObject();

public class HashSet<E>
    extends AbstractSet<E>
    implements Set<E>, Cloneable, java.io.Serializable
{
    private transient HashMap<E,Object> map;
 
    // Dummy value to associate with an Object in the backing Map
    private static final Object PRESENT = new Object();
 
    public HashSet() {
	map = new HashMap<E,Object>();
    }
 
    public boolean contains(Object o) {
	return map.containsKey(o);
    }
 
    public boolean add(E e) {
	return map.put(e, PRESENT)==null;
    }
}

    public V put(K key, V value) {
        if (key == null)
            return putForNullKey(value);
        int hash = hash(key.hashCode());
        int i = indexFor(hash, table.length);
        for (Entry<K,V> e = table[i]; e != null; e = e.next) {
            Object k;
            if (e.hash == hash && ((k = e.key) == key || key.equals(k))) {
                V oldValue = e.value;
                e.value = value;
                e.recordAccess(this);
                return oldValue;
            }
        }

/**
 * 按照指定属性，对List集合进行排序。
 * 
 * @param list bean集合
 * @param sortBy 要进行排序的bean中的属性
 * @param sort 升序或降序
 */
public static <T> void sort(List<T> list, final String sortBy,final String sort)  {
	if (list == null || sortBy == null ||sortBy.equals("")|| list.isEmpty())
		return;
	Collections.sort(list, new Comparator<T>() {
		@SuppressWarnings("unchecked")
		public int compare(T t1, T t2) {
			Object o1 = null;
			Object o2 = null;
			try {
				o1 = ReflexUtil.getObjFieldValue(t1, sortBy);
				o2 = ReflexUtil.getObjFieldValue(t2, sortBy);
			} catch (Exception e) {
				e.printStackTrace();
			}
			int result = 0;
			if(o1==null){
				result=-1;
			}
			else if(o2==null){
				result=1;
			}
			//字符串按照拼音排序
			else if (o1 instanceof String) {
				result = Collator.getInstance(Locale.CHINA).compare(o1, o2);
			} else {
				result = ((Comparable) o1).compareTo(o2);
			}
 
			if(DESC.equalsIgnoreCase(sort)){
				result=0-result;
			}
			return result;
 
		}
	});
 
}