AEStringUtils.java

package com.realmo.utils;

import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import java.net.URLEncoder;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * String Utils
 *
 * @author <a href="http://www.trinea.cn" target="_blank">Trinea</a>
 */
public class AEStringUtils {

 /**
 * is null or its length is 0 or it is made by space
 *
 * <pre>
 * isBlank(null) = true;
 * isBlank(&quot;&quot;) = true;
 * isBlank(&quot; &quot;) = true;
 * isBlank(&quot;a&quot;) = false;
 * isBlank(&quot;a &quot;) = false;
 * isBlank(&quot; a&quot;) = false;
 * isBlank(&quot;a b&quot;) = false;
 * </pre>
 *
 * @param str
 * @return if string is null or its size is 0 or it is made by space, return
 * true, else return false.
 */
 public static boolean isBlank(String str) {
 return (str == null || str.trim().length() == 0);
 }

 /**
 * is null or its length is 0
 *
 * <pre>
 * isEmpty(null) = true;
 * isEmpty(&quot;&quot;) = true;
 * isEmpty(&quot; &quot;) = false;
 * </pre>
 *
 * @param str
 * @return if string is null or its size is 0, return true, else return
 * false.
 */
 public static boolean isEmpty(String str) {
 return (str == null || str.length() == 0);
 }

 /**
 * null string to empty string
 *
 * <pre>
 * nullStrToEmpty(null) = &quot;&quot;;
 * nullStrToEmpty(&quot;&quot;) = &quot;&quot;;
 * nullStrToEmpty(&quot;aa&quot;) = &quot;aa&quot;;
 * </pre>
 *
 * @param str
 * @return
 */
 public static String nullStrToEmpty(String str) {
 return (str == null ? "" : str);
 }

 /**
 * capitalize first letter
 *
 * <pre>
 * capitalizeFirstLetter(null) = null;
 * capitalizeFirstLetter("") = "";
 * capitalizeFirstLetter("2ab") = "2ab"
 * capitalizeFirstLetter("a") = "A"
 * capitalizeFirstLetter("ab") = "Ab"
 * capitalizeFirstLetter("Abc") = "Abc"
 * </pre>
 *
 * @param str
 * @return
 */
 public static String capitalizeFirstLetter(String str) {
 if (isEmpty(str)) {
 return str;
 }

 char c = str.charAt(0);
 return (!Character.isLetter(c) || Character.isUpperCase(c)) ? str
 : new StringBuilder(str.length())
 .append(Character.toUpperCase(c))
 .append(str.substring(1)).toString();
 }

 /**
 * encoded in utf-8
 *
 * <pre>
 * utf8Encode(null) = null
 * utf8Encode("") = "";
 * utf8Encode("aa") = "aa";
 * utf8Encode("啊啊啊啊") = "%E5%95%8A%E5%95%8A%E5%95%8A%E5%95%8A";
 * </pre>
 *
 * @param str
 * @return
 * @throws UnsupportedEncodingException
 * if an error occurs
 */
 public static String utf8Encode(String str) {
 if (!isEmpty(str) && str.getBytes().length != str.length()) {
 try {
 return URLEncoder.encode(str, "UTF-8");
 } catch (UnsupportedEncodingException e) {
 throw new RuntimeException(
 "UnsupportedEncodingException occurred. ", e);
 }
 }
 return str;
 }

 /**
 * encoded in utf-8, if exception, return defultReturn
 *
 * @param str
 * @param defultReturn
 * @return
 */
 public static String utf8Encode(String str, String defultReturn) {
 if (!isEmpty(str) && str.getBytes().length != str.length()) {
 try {
 return URLEncoder.encode(str, "UTF-8");
 } catch (UnsupportedEncodingException e) {
 return defultReturn;
 }
 }
 return str;
 }

 /**
 * decode in utf-8
 *
 * <pre>
 * utf8Decoder(null) = null
 * utf8Decoder("") = "";
 * utf8Decoder("aa") = "aa";
 * utf8Decoder("%E5%95%8A%E5%95%8A%E5%95%8A%E5%95%8A") = "啊啊啊啊";
 * </pre>
 *
 * @param str
 * @return
 * @throws UnsupportedEncodingException
 * if an error occurs
 */
 public static String utf8Decoder(String str){
 if (!isEmpty(str) && str.getBytes().length != str.length()) {
 try {
 return URLDecoder.decode(str, "UTF-8");
 } catch (UnsupportedEncodingException e) {
 throw new RuntimeException(
 "UnsupportedEncodingException occurred. ", e);
 }
 }
 return str;
 }

 /**
 * get innerHtml from href
 *
 * <pre>
 * getHrefInnerHtml(null) = ""
 * getHrefInnerHtml("") = ""
 * getHrefInnerHtml("mp3") = "mp3";
 * getHrefInnerHtml("&lt;a innerHtml&lt;/a&gt;") = "&lt;a innerHtml&lt;/a&gt;";
 * getHrefInnerHtml("&lt;a&gt;innerHtml&lt;/a&gt;") = "innerHtml";
 * getHrefInnerHtml("&lt;a&lt;a&gt;innerHtml&lt;/a&gt;") = "innerHtml";
 * getHrefInnerHtml("&lt;a href="baidu.com"&gt;innerHtml&lt;/a&gt;") = "innerHtml";
 * getHrefInnerHtml("&lt;a href="baidu.com" title="baidu"&gt;innerHtml&lt;/a&gt;") = "innerHtml";
 * getHrefInnerHtml(" &lt;a&gt;innerHtml&lt;/a&gt; ") = "innerHtml";
 * getHrefInnerHtml("&lt;a&gt;innerHtml&lt;/a&gt;&lt;/a&gt;") = "innerHtml";
 * getHrefInnerHtml("jack&lt;a&gt;innerHtml&lt;/a&gt;&lt;/a&gt;") = "innerHtml";
 * getHrefInnerHtml("&lt;a&gt;innerHtml1&lt;/a&gt;&lt;a&gt;innerHtml2&lt;/a&gt;") = "innerHtml2";
 * </pre>
 *
 * @param href
 * @return <ul>
 * <li>if href is null, return ""</li>
 * <li>if not match regx, return source</li>
 * <li>return the last string that match regx</li>
 * </ul>
 */
 public static String getHrefInnerHtml(String href) {
 if (isEmpty(href)) {
 return "";
 }

 String hrefReg = ".*<[\\s]*a[\\s]*.*>(.+?)<[\\s]*/a[\\s]*>.*";
 Pattern hrefPattern = Pattern
 .compile(hrefReg, Pattern.CASE_INSENSITIVE);
 Matcher hrefMatcher = hrefPattern.matcher(href);
 if (hrefMatcher.matches()) {
 return hrefMatcher.group(1);
 }
 return href;
 }

 /**
 * process special char in html
 *
 * <pre>
 * htmlEscapeCharsToString(null) = null;
 * htmlEscapeCharsToString("") = "";
 * htmlEscapeCharsToString("mp3") = "mp3";
 * htmlEscapeCharsToString("mp3&lt;") = "mp3<";
 * htmlEscapeCharsToString("mp3&gt;") = "mp3\>";
 * htmlEscapeCharsToString("mp3&amp;mp4") = "mp3&mp4";
 * htmlEscapeCharsToString("mp3&quot;mp4") = "mp3\"mp4";
 * htmlEscapeCharsToString("mp3&lt;&gt;&amp;&quot;mp4") = "mp3\<\>&\"mp4";
 * </pre>
 *
 * @param source
 * @return
 */
 public static String htmlEscapeCharsToString(String source) {
 return AEStringUtils.isEmpty(source) ? source : source
 .replaceAll("&lt;", "<").replaceAll("&gt;", ">")
 .replaceAll("&amp;", "&").replaceAll("&quot;", "\"");
 }

 /**
 * transform half width char to full width char
 *
 * <pre>
 * fullWidthToHalfWidth(null) = null;
 * fullWidthToHalfWidth("") = "";
 * fullWidthToHalfWidth(new String(new char[] {12288})) = " ";
 * fullWidthToHalfWidth("！＂＃＄％＆) = "!\"#$%&";
 * </pre>
 *
 * @param s
 * @return
 */
 public static String fullWidthToHalfWidth(String s) {
 if (isEmpty(s)) {
 return s;
 }

 char[] source = s.toCharArray();
 for (int i = 0; i < source.length; i++) {
 if (source[i] == 12288) {
 source[i] = ' ';
 // } else if (source[i] == 12290) {
 // source[i] = '.';
 } else if (source[i] >= 65281 && source[i] <= 65374) {
 source[i] = (char) (source[i] - 65248);
 } else {
 source[i] = source[i];
 }
 }
 return new String(source);
 }

 /**
 * transform full width char to half width char
 *
 * <pre>
 * halfWidthToFullWidth(null) = null;
 * halfWidthToFullWidth("") = "";
 * halfWidthToFullWidth(" ") = new String(new char[] {12288});
 * halfWidthToFullWidth("!\"#$%&) = "！＂＃＄％＆";
 * </pre>
 *
 * @param s
 * @return
 */
 public static String halfWidthToFullWidth(String s) {
 if (isEmpty(s)) {
 return s;
 }

 char[] source = s.toCharArray();
 for (int i = 0; i < source.length; i++) {
 if (source[i] == ' ') {
 source[i] = (char) 12288;
 // } else if (source[i] == '.') {
 // source[i] = (char)12290;
 } else if (source[i] >= 33 && source[i] <= 126) {
 source[i] = (char) (source[i] + 65248);
 } else {
 source[i] = source[i];
 }
 }
 return new String(source);
 }



 public static String escape(String src) {
 int i;
 char j;
 StringBuffer tmp = new StringBuffer();
 tmp.ensureCapacity(src.length() * 6);
 for (i = 0; i < src.length(); i++) {
 j = src.charAt(i);
 if (Character.isDigit(j) || Character.isLowerCase(j)
 || Character.isUpperCase(j))
 tmp.append(j);
 else if (j < 256) {
 tmp.append("%");
 if (j < 16)
 tmp.append("0");
 tmp.append(Integer.toString(j, 16));
 } else {
 tmp.append("%u");
 tmp.append(Integer.toString(j, 16));
 }
 }
 return tmp.toString();
 }

 public static String unescape(String src) {
 StringBuffer tmp = new StringBuffer();
 tmp.ensureCapacity(src.length());
 int lastPos = 0, pos = 0;
 char ch;
 while (lastPos < src.length()) {
 pos = src.indexOf("%", lastPos);
 if (pos == lastPos) {
 if (src.charAt(pos + 1) == 'u') {
 ch = (char) Integer.parseInt(
 src.substring(pos + 2, pos + 6), 16);
 tmp.append(ch);
 lastPos = pos + 6;
 } else {
 ch = (char) Integer.parseInt(
 src.substring(pos + 1, pos + 3), 16);
 tmp.append(ch);
 lastPos = pos + 3;
 }
 } else {
 if (pos == -1) {
 tmp.append(src.substring(lastPos));
 lastPos = src.length();
 } else {
 tmp.append(src.substring(lastPos, pos));
 lastPos = pos;
 }
 }
 }
 return tmp.toString();
 }


}