JavaSE String

public class StringTest {
    public static void main(String[] args) {
        // 如何将一个byte数组转换成字符串
        byte[] bs = { 97, 122, 45, 32, 0, 100, 98 };
        String s = new String(bs);
        System.out.println(s);
        // 怎么将String字符串转换成byte数组
        String bb = "张三";
        try {
            // 编码转换问题 GBK->UTF-8
            byte[] bbs = bb.getBytes("UTF-8");
            String r = new String(bbs, "UTF-8");
            System.out.println(r);
            // 将UTF-8 ->GBK
            byte[] bbs2 = r.getBytes("GBK");
            String rr = new String(bbs2, "GBK");
            System.out.println(rr);
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
        // 返回指定下标的字符
        char c = bb.charAt(1);
        System.out.println(c);
        System.out.println(bb.codePointAt(1));
        String ls = "李四";
        int i = ls.compareTo(bb);
        System.out.println(i);
        // 将李四连接到张三的后面
        String n = bb.concat(ls);
        System.out.println(n);
        // 判断是否拥有此字符串
        System.out.println(bb.contains("李"));
        // 将char数组转换为String字符串
        char cc[] = { '我', '和', '你', '都', '我', '是' };
        String ncc = String.copyValueOf(cc);
        System.out.println(ncc);
        // 判断字符最后一位
        boolean ew = ncc.endsWith("你");
        System.out.println(ew);
        // 忽略大小写的内容比较
        System.out.println(ncc.equalsIgnoreCase(bb));
        // 国际化 i18n zh_CH en_US
        String format = String.format(new Locale("zh_TW"), "张三");
        System.out.println(format);
        // 返回指定字符串的下标
        int indexOf = ncc.indexOf("三");
        System.out.println(indexOf);
        // 从下标3（包含）的位置往后找第一个出现的下标
        int indexOf2 = ncc.indexOf("我", 3);
        System.out.println(indexOf2);
        // 倒着找第一个出现的下标
        int lastIndexOf = ncc.lastIndexOf("我");
        System.out.println(lastIndexOf);
        // 判断字符串是否是空房子
        String nn = "";
        System.out.println(nn.isEmpty());
        // join 特殊拼接
        String join = String.join("#", "张三", "李四", "王五");
        System.out.println(join);
        // 返回字符串的长度
        System.out.println(join.length());
        // 正则表达式
        String tel = "^((13[0-9])|(14[5|7])|(15([0-3]|[5-9]))|(18[0,5-9]))\\d{8}$";// 手机号
        String email = "^[a-zA-Z0-9_.-]+@[a-zA-Z0-9-]+(\\.[a-zA-Z0-9-]+)*\\.[a-zA-Z0-9]{2,6}$";
        String idCard = "(^[1-9]\\d{5}(18|19|([23]\\d))\\d{2}((0[1-9])|(10|11|12))(([0-2][1-9])|10|20|30|31)\\d{3}[0-9Xx]$)|(^[1-9]\\d{5}\\d{2}((0[1-9])|(10|11|12))(([0-2][1-9])|10|20|30|31)\\d{2}$)";
        boolean b = Pattern.compile(tel).matcher("13838389438").matches();
        boolean b1 = Pattern.compile(email).matcher("373828882@qq.com").matches();
        String sfz = "41270119900916353X";
        boolean b2 = sfz.matches(idCard);
        System.out.println(b2);
        // 字符串的替换
        String nnnn = join.replace("#", "@");
        System.out.println(nnnn);
        // 正则表达式进行正则表达式替换
        String replaceAll = join.replaceAll("\\W", "8");
        System.out.println(replaceAll);
        // 只替换第一个
        String reString = join.replaceFirst("#", "8");
        System.out.println(reString);
        // 按照指定正则表达式拆分字符串
        String[] ss = join.split("#");
        System.out.println(Arrays.toString(ss));
        String eg = "张三#20#男@李四#21#男@王五#22#女";
        String[] split = eg.split("@");
        for (String egs : split) {
            String[] split2 = egs.split("#");
            System.out.println(Arrays.toString(split2));
        }
        // 判断字符串以什么开头
        System.out.println(join.startsWith("张"));
        // 截取字符串
        CharSequence cs = join.subSequence(0, 3);
        System.out.println(cs);
        // 截取字符串
        String substring = join.substring(1);
        System.out.println(substring);
        String substring2 = join.substring(2, 5);
        System.out.println(substring2);
        // 截取李四
        String lss = join.substring(join.indexOf("李四"), join.indexOf("李四") + 2);
        System.out.println(lss);
        // 截取三到四
        String substring3 = join.substring(join.indexOf("三"), join.indexOf("四") + 1);
        System.out.println(substring3);
        // 字符串转换为char的数组
        char[] charArray = join.toCharArray();
        System.out.println(Arrays.toString(charArray));
        String xx = "abc";
        // 转大写
        String dxx = xx.toUpperCase();
        System.out.println(dxx);
        // 转小写
        xx = dxx.toLowerCase();
        System.out.println(xx);
        String sn = "     张 三 ";
        // 去空格
        String trim = sn.trim();
        System.out.println(trim);
        // String ->boolean
        String be = "TRUE";
        Boolean valueOf = Boolean.valueOf(be);
        System.out.println(valueOf);
        be = String.valueOf(valueOf);
        System.out.println(be);

    }

}