JAVA字符串处理工具类集合

//Java拼接字符串时,去掉最后一个多余的逗号
String str[] = { "hello", "beijing", "world", "shenzhen" };
StringBuffer buf = new StringBuffer();

for (int i = 0; i < str.length; i++) {
    buf.append(str[i]).append(",");
}

if (buf.length() > 0) {
    //方法一  : substring
    System.out.println(buf.substring(0, buf.length()-1));
    //方法二 ：replace
    System.out.println(buf.replace(buf.length() - 1, buf.length(), ""));
    //方法三： deleteCharAt
    System.out.println(buf.deleteCharAt(buf.length()-1));
}

//不产生多余的逗号
StringBuffer s = new StringBuffer();
        Iterator it = list.iterator();
        while(it.hasNext()){
            Object o = it.next();
            if(s.length() > 0){
                s.append(",");
                s.append(o);
            } else{
                s.append(o);
            }
        }
        String ss = s.toString();
        System.out.println(ss);