package com.baosight.util;

/**
 * 
 * @author steven
 * @version 2005-2-2
 */
public class StringUtil {
    
    /**
     * 將一個數組中的內容連接成一個字符串，各個數組中的元素使用參數delim分隔
     * @param arr
     * @param delim
     * @return
     */
	public static String arrayToString(String[] arr, String delim) {
		if (arr == null)
			return "null";
		else {
			StringBuffer sb = new StringBuffer();
			for (int i = 0; i < arr.length; i++) {
				if (i > 0)
					sb.append(delim);
				sb.append(arr[i]);
			}
			return sb.toString();
		}
	}
	
	/**
	 * 本地字符集轉換成unicode。
	 * @return java.lang.String
	 */
	public static String native2unicode(String s) {
		if(s==null || s.length()==0) {
			return null;
		}
		byte [] buffer = new byte[s.length()];

		for(int i=0;i<s.length();i++) {
			if( s.charAt(i)>=0x100 ) {
				return s;
			}
			buffer[i] = (byte)s.charAt(i);
		}
		return new String(buffer);
	}

	/**
	 * unicode轉為本地字符集
	 * @ param String Unicode編碼的字符串
	 * @ return String
	 */
	public static String unicode2native(String s) {
		if(s==null || s.length()==0) {
			return null;
		}
		char [] buffer = new char[s.length() * 2];
		char c;
		int j=0;
		for(int i=0;i<s.length();i++) {
			if(s.charAt(i)>=0x100){
				c = s.charAt(i);
				byte [] buf = (""+c).getBytes();
				buffer[j++] = (char)buf[0];
				buffer[j++] = (char)buf[1];
			} else {
				buffer[j++] = s.charAt(i);
			}
		}
		return new String(buffer,0,j);
	}	
	
	
	public static String replace(String inString, String oldPattern, String newPattern) {
		if (inString == null) {
			return null;
		}
		if (oldPattern == null || newPattern == null) {
			return inString;
		}

		StringBuffer sbuf = new StringBuffer();
		// output StringBuffer we'll build up
		int pos = 0; // Our position in the old string
		int index = inString.indexOf(oldPattern);
		// the index of an occurrence we've found, or -1
		int patLen = oldPattern.length();
		while (index >= 0) {
			sbuf.append(inString.substring(pos, index));
			sbuf.append(newPattern);
			pos = index + patLen;
			index = inString.indexOf(oldPattern, pos);
		}
		sbuf.append(inString.substring(pos));

		// remember to append any characters to the right of a match
		return sbuf.toString();
	}
	
	/**
	 * 替換輸入字符串中的HTML字符< 和 >
	 * @param old
	 * @return
	 */
	public static String replaceHtml(String old){
	    String rt = replace(old,"<","&lt;");
	    rt = replace(rt,">","&gt;");
	    rt = replace(rt,"'","&quot;");
	    rt = replace(rt,"'","&quot;");
	    rt = replace(rt,"\"","&quot;");
	    return rt;
	}
	
	public static void main(String[] args){
	    String old = null;
	    System.out.println(replaceHtml(old) );
	    
	}
}