{"id":921,"date":"2018-09-17T18:25:40","date_gmt":"2018-09-17T09:25:40","guid":{"rendered":"https:\/\/chat-messenger.com\/?p=921"},"modified":"2018-12-23T02:00:59","modified_gmt":"2018-12-22T17:00:59","slug":"string-lpad-rpad","status":"publish","type":"post","link":"https:\/\/chat-messenger.com\/vi\/blog\/java\/chuoi-lpad-rpad","title":{"rendered":"\u0110\u1ecbnh d\u1ea1ng b\u1eb1ng Java LPAD, RPAD"},"content":{"rendered":"<h2 class=\"common_title\"><a name=\"0\">\u0110\u01b0\u1ee3c \u0111\u1ecbnh d\u1ea1ng b\u1eb1ng Java LPAD, RPAD. \u0110i\u1ec1n c\u00e1c k\u00fd t\u1ef1 \u0111\u01b0\u1ee3c ch\u1ec9 \u0111\u1ecbnh v\u00e0o b\u00ean tr\u00e1i v\u00e0 b\u00ean ph\u1ea3i c\u1ee7a chu\u1ed7i<\/a><\/h2>\n<p>\n<strong>Java<\/strong>Sau \u0111\u00f3, b\u1ea1n c\u00f3 th\u1ec3 s\u1eed d\u1ee5ng h\u00e0m SQL cho chu\u1ed7i.<strong>LPAD<\/strong>,<strong>RPAD<\/strong>\u0110\u00e2y l\u00e0 m\u1ed9t ngu\u1ed3n m\u1eabu th\u1ef1c hi\u1ec7n qu\u00e1 tr\u00ecnh t\u01b0\u01a1ng t\u1ef1.<br \/>\n\u0111\u00f3 l\u00e0<strong>\u0111\u1ecbnh d\u1ea1ng c\u00f3 \u0111\u1ed9 d\u00e0i c\u1ed1 \u0111\u1ecbnh<\/strong>R\u1ea5t h\u1eefu \u00edch khi x\u1eed l\u00fd.\n<\/p>\n<ul>\n<li><strong>LPAD<\/strong>...Tr\u1ea3 v\u1ec1 m\u1ed9t chu\u1ed7i ch\u1ee9a c\u00e1c k\u00fd t\u1ef1 l\u1eb7p l\u1ea1i \u1edf b\u00ean tr\u00e1i c\u1ee7a chu\u1ed7i sao cho t\u1ed5ng s\u1ed1 k\u00fd t\u1ef1 l\u00e0 s\u1ed1 ch\u1eef s\u1ed1 \u0111\u00e3 ch\u1ec9 \u0111\u1ecbnh.<\/li>\n<li><strong>RPAD<\/strong>...\u0110i\u1ec1n v\u00e0 tr\u1ea3 v\u1ec1 m\u1ed9t chu\u1ed7i l\u1eb7p l\u1ea1i \u1edf b\u00ean ph\u1ea3i c\u1ee7a chu\u1ed7i sao cho t\u1ed5ng s\u1ed1 k\u00fd t\u1ef1 l\u00e0 s\u1ed1 ch\u1eef s\u1ed1 \u0111\u00e3 ch\u1ec9 \u0111\u1ecbnh.<\/li>\n<\/ul>\n<p><script type=\"text\/javascript\" src=\"https:\/\/chat-messenger.com\/js\/common.js?dd12sssas2223\" charset=\"UTF-8\"><\/script><br \/>\n<script type=\"text\/javascript\"> writePR(); <\/script><\/p>\n<h2 class=\"common_title\"><a name=\"1\">ch\u01b0\u01a1ng tr\u00ecnh m\u1eabu<\/a><\/h2>\n<p><textarea readonly=\"readonly\" style=\"font-size: 13px;height: 400px;\" class=\"src\" onclick=\"this.focus();this.select()\">\/**<br \/>\n * LPAD\u3092\u884c\u3044\u307e\u3059\u3002<br \/>\n * \u6587\u5b57\u5217[str]\u306e\u5de6\u306b\u6307\u5b9a\u3057\u305f\u6587\u5b57\u5217[addStr]\u3092[len]\u306b<br \/>\n * \u6e80\u305f\u3059\u307e\u3067\u633f\u5165\u3057\u307e\u3059\u3002<br \/>\n * @param str \u5bfe\u8c61\u6587\u5b57\u5217<br \/>\n * @param len \u88dc\u5145\u3059\u308b\u307e\u3067\u306e\u6841\u6570\uff08LPAD\u3092\u884c\u3063\u305f\u5f8c\u306e\u30b5\u30a4\u30ba\u3092\u6307\u5b9a\u3057\u307e\u3059\u3002\uff09<br \/>\n * @param addStr \u633f\u5165\u3059\u308b\u6587\u5b57\u5217<br \/>\n * @return \u5909\u63db\u5f8c\u306e\u6587\u5b57\u5217\u3002<br \/>\n *\/<br \/>\npublic static String lpad(String str, int len, String addStr) {<br \/>\n    return fillString(str, &#8220;L&#8221;, len, addStr);<br \/>\n}<\/p>\n<p>\/**<br \/>\n * Th\u1ef1c hi\u1ec7n RPAD.<br \/>\n * Th\u00eam chu\u1ed7i \u0111\u00e3 ch\u1ec9 \u0111\u1ecbnh [addStr] v\u00e0o b\u00ean ph\u1ea3i chu\u1ed7i [str] v\u00e0o [len]<br \/>\n * Ch\u00e8n cho \u0111\u1ebfn khi \u0111\u1ea7y \u0111\u1ee7.<br \/>\n * @param str chu\u1ed7i m\u1ee5c ti\u00eau<br \/>\n * @param len S\u1ed1 ch\u1eef s\u1ed1 c\u1ea7n n\u1ea1p l\u1ea1i (ch\u1ec9 \u0111\u1ecbnh k\u00edch th\u01b0\u1edbc sau khi th\u1ef1c hi\u1ec7n RPAD)<br \/>\n * @param addStr Chu\u1ed7i \u0111\u1ec3 ch\u00e8n<br \/>\n * @return Chu\u1ed7i sau khi chuy\u1ec3n \u0111\u1ed5i.<br \/>\n *\/<br \/>\npublic static String rpad(String str, int len, String addStr) {<br \/>\n    return fillString(str, \u201cR\u201d, len, addStr);<br \/>\n}<\/p>\n<p>\/**<br \/>\n * Th\u00eam chu\u1ed7i [addStr] \u0111\u1ec3 th\u00eam v\u00e0o chu\u1ed7i [str]<br \/>\n * Ch\u00e8n t\u1ea1i [v\u1ecb tr\u00ed] cho \u0111\u1ebfn khi [len] \u0111\u01b0\u1ee3c l\u1ea5p \u0111\u1ea7y.<br \/>\n *<br \/>\n * *Ngay c\u1ea3 khi [str] l\u00e0 null ho\u1eb7c b\u1eb1ng ch\u1eef tr\u1ed1ng, h\u00e3y s\u1eed d\u1ee5ng [addStr]<br \/>\n * Tr\u1ea3 v\u1ec1 k\u1ebft qu\u1ea3 \u0111\u01b0\u1ee3c ch\u00e8n cho \u0111\u1ebfn khi [len] \u0111\u01b0\u1ee3c \u0111i\u1ec1n.<br \/>\n * @param str chu\u1ed7i m\u1ee5c ti\u00eau<br \/>\n * @param location Ch\u00e8n tr\u01b0\u1edbc \u21d2 L ho\u1eb7c l Ch\u00e8n sau \u21d2 R ho\u1eb7c r<br \/>\n * @param len S\u1ed1 ch\u1eef s\u1ed1 c\u1ea7n b\u1ed5 sung<br \/>\n * @param addStr Chu\u1ed7i \u0111\u1ec3 ch\u00e8n<br \/>\n * @return Chu\u1ed7i sau khi chuy\u1ec3n \u0111\u1ed5i.<br \/>\n *\/<br \/>\nchu\u1ed7i t\u0129nh c\u00f4ng khai fillString(Chu\u1ed7i str, V\u1ecb tr\u00ed chu\u1ed7i,<br \/>\n        int len,<br \/>\n        Chu\u1ed7i addStr) {<br \/>\n    if (addStr == null || addStr.length() == 0) {<br \/>\n        n\u00e9m IllegalArgumentException m\u1edbi<br \/>\n            (\u201cGi\u00e1 tr\u1ecb c\u1ee7a chu\u1ed7i \u0111\u01b0\u1ee3c ch\u00e8n kh\u00f4ng h\u1ee3p l\u1ec7. addStr=\u201d+addStr);<br \/>\n    }<br \/>\n    n\u1ebfu (str == null) {<br \/>\n        str = \u201c\u201d;<br \/>\n    }<br \/>\n    B\u1ed9 \u0111\u1ec7m StringBuffer = StringBuffer m\u1edbi(str);<br \/>\n    while (len &gt; buffer.length()) {<br \/>\n        if (position.equalsIgnoreCase(\u201cl\u201d)) {<br \/>\n            int sum = buffer.length() + addStr.length();<br \/>\n            if (t\u1ed5ng &gt; len) {<br \/>\n                addStr = addStr.substring<br \/>\n                    (0,addStr.length() \u2013 (t\u1ed5ng \u2013 len));<br \/>\n                buffer.insert(0, addStr);<br \/>\n            }kh\u00e1c{<br \/>\n                buffer.insert(0, addStr);<br \/>\n            }<br \/>\n        } kh\u00e1c {<br \/>\n            \u0111\u1ec7m.append(addStr);<br \/>\n        }<br \/>\n    }<br \/>\n    if (buffer.length() == len) {<br \/>\n        tr\u1ea3 v\u1ec1 b\u1ed9 \u0111\u1ec7m.toString();<br \/>\n    }<br \/>\n    return buffer.toString().substring(0, len);<br \/>\n}<br \/>\n<\/textarea><br \/>\n<\/p>\n<h2 class=\"common_title\"><a name=\"2\">K\u1ebft qu\u1ea3 th\u1ef1c hi\u1ec7n<\/a><\/h2>\n<p>\u25c6V\u00ed d\u1ee5 th\u1ef1c thi<\/p>\n<pre class=\"sample_src\">public static void main(String[] args) { \/\/ D\u00e0nh cho lpad. \u0110i\u1ec1n v\u00e0o ch\u1ed7 tr\u1ed1ng b\u00ean tr\u00e1i cho \u0111\u1ebfn khi b\u1ea1n \u0111\u1ea1t \u0111\u01b0\u1ee3c 5 ch\u1eef s\u1ed1. Chu\u1ed7i ret = lpad(&quot;abc&quot;, 5 , &quot; &quot;); System.out.println(&quot;&#039;&quot; + ret + &quot;&#039;&quot;); \/\/ D\u00e0nh cho rpad. \u0110i\u1ec1n v\u00e0o ch\u1ed7 tr\u1ed1ng b\u00ean ph\u1ea3i cho \u0111\u1ebfn khi \u0111\u1ea1t \u0111\u01b0\u1ee3c 5 ch\u1eef s\u1ed1. ret = rpad(&quot;abc&quot;, 5 , &quot; &quot;); System.out.println(&quot;&#039;&quot; + ret + &quot;&#039;&quot;); \/\/ N\u1ebfu null ret = rpad(null, 5 , &quot; &quot;); System. out .println(&quot;&#039;&quot; + ret + &quot;&#039;&quot;); }\r\n<\/pre>\n<p>\u25c6K\u1ebft qu\u1ea3 \u0111\u1ea7u ra<\/p>\n<pre class=\"console\">&#039; abc&#039; &#039;abc&#039; &#039; &#039;\r\n<\/pre>","protected":false},"excerpt":{"rendered":"<p>\u0110\u01b0\u1ee3c \u0111\u1ecbnh d\u1ea1ng b\u1eb1ng Java LPAD, RPAD. \u0110i\u1ec1n c\u00e1c k\u00fd t\u1ef1 \u0111\u01b0\u1ee3c ch\u1ec9 \u0111\u1ecbnh v\u00e0o b\u00ean tr\u00e1i v\u00e0 b\u00ean ph\u1ea3i c\u1ee7a chu\u1ed7i Trong Java, s\u1eed d\u1ee5ng h\u00e0m SQL L [\u2026]<\/p>","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"swell_btn_cv_data":""},"categories":[19],"tags":[],"_links":{"self":[{"href":"https:\/\/chat-messenger.com\/vi\/wp-json\/wp\/v2\/posts\/921"}],"collection":[{"href":"https:\/\/chat-messenger.com\/vi\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/chat-messenger.com\/vi\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/chat-messenger.com\/vi\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/chat-messenger.com\/vi\/wp-json\/wp\/v2\/comments?post=921"}],"version-history":[{"count":4,"href":"https:\/\/chat-messenger.com\/vi\/wp-json\/wp\/v2\/posts\/921\/revisions"}],"predecessor-version":[{"id":1892,"href":"https:\/\/chat-messenger.com\/vi\/wp-json\/wp\/v2\/posts\/921\/revisions\/1892"}],"wp:attachment":[{"href":"https:\/\/chat-messenger.com\/vi\/wp-json\/wp\/v2\/media?parent=921"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/chat-messenger.com\/vi\/wp-json\/wp\/v2\/categories?post=921"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/chat-messenger.com\/vi\/wp-json\/wp\/v2\/tags?post=921"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}