项目中经常需要用到String的一些操作，结合看到的一些前人的工具类抽取，编写了如下针对String的常用操作的工具类，供大家参考。
package com.mkyong.common;
import java.util.ArrayList;
import java.util.List;
/**
*
* String工具类. <br>
*
* @author jiangshuai
* @date 2017年04月24日
*/
public class StringUtil {
private static final int INDEX_NOT_FOUND = -1;
private static final String EMPTY = "";
/**
* <p>
* The maximum size to which the padding constant(s) can expand.
* </p>
*/
private static final int PAD_LIMIT = 8192;
/**
* 功能：将半角的符号转换成全角符号.(即英文字符转中文字符)
*
* @author jiangshuai
* @param str
* 源字符串
* @return String
* @date 2017年04月24日
*/
public static String changeToFull(String str) {
String source = "1234567890!@#$%^&*()abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ-_=+\\|[];:'\",<.>/?";
String[] decode = { "１", "２", "３", "４", "５", "６", "７", "８", "９", "０",
"！", "＠", "＃", "＄", "％", "︿", "＆", "＊", "（", "）", "ａ", "ｂ",
"ｃ", "ｄ", "ｅ", "ｆ", "ｇ", "ｈ", "ｉ", "ｊ", "ｋ", "ｌ", "ｍ", "ｎ",
"ｏ", "ｐ", "ｑ", "ｒ", "ｓ", "ｔ", "ｕ", "ｖ", "ｗ", "ｘ", "ｙ", "ｚ",
"Ａ", "Ｂ", "Ｃ", "Ｄ", "Ｅ", "Ｆ", "Ｇ", "Ｈ", "Ｉ", "Ｊ", "Ｋ", "Ｌ",
"Ｍ", "Ｎ", "Ｏ", "Ｐ", "Ｑ", "Ｒ", "Ｓ", "Ｔ", "Ｕ", "Ｖ", "Ｗ", "Ｘ",
"Ｙ", "Ｚ", "－", "＿", "＝", "＋", "＼", "｜", "【", "】", "；", "：",
"'", "\"", "，", "〈", "。", "〉", "／", "？" };
String result = "";
for (int i = 0; i < str.length(); i++) {
int pos = source.indexOf(str.charAt(i));
if (pos != -1) {
result += decode[pos];
} else {
result += str.charAt(i);
}
}
return result;
}
/**
* 功能：cs串中是否一个都不包含字符数组searchChars中的字符。
*
* @author jiangshuai
* @param cs
* 字符串
* @param searchChars
* 字符数组
* @return boolean 都不包含返回true，否则返回false。
* @date 2017年04月24日
*/
public static boolean containsNone(CharSequence cs, char... searchChars) {
if (cs == null || searchChars == null) {
return true;
}
int csLen = cs.length();
int csLast = csLen - 1;
int searchLen = searchChars.length;
int searchLast = searchLen - 1;
for (int i = 0; i < csLen; i++) {
char ch = cs.charAt(i);
for (int j = 0; j < searchLen; j++) {
if (searchChars[j] == ch) {
if (Character.isHighSurrogate(ch)) {
if (j == searchLast) {
// missing low surrogate, fine, like
// String.indexOf(String)
return false;
}
if (i < csLast
&& searchChars[j + 1] == cs.charAt(i + 1)) {
return false;
}
} else {
// ch is in the Basic Multilingual Plane
return false;
}
}
}
}
return true;
}
/**
* <p>
* 编码为Unicode，格式 '\u0020'.
* </p>
*
* @author jiangshuai
*
* <pre>
* CharUtils.unicodeEscaped(' ') = "\u0020"
* CharUtils.unicodeEscaped('A') = "\u0041"
* </pre>
*
* @param ch
* 源字符串
* @return 转码后的字符串
* @date 2017年04月24日
*/
public static String unicodeEscaped(char ch) {
if (ch < 0x10) {
return "\\u000" + Integer.toHexString(ch);
} else if (ch < 0x100) {
return "\\u00" + Integer.toHexString(ch);
} else if (ch < 0x1000) {
return "\\u0" + Integer.toHexString(ch);
}
return "\\u" + Integer.toHexString(ch);
}
/**
* <p>
* 进行tostring操作，如果传入的是null，返回空字符串。
* </p>
*
* <pre>
* ObjectUtils.toString(null) = ""
* ObjectUtils.toString("") = ""
* ObjectUtils.toString("bat") = "bat"
* ObjectUtils.toString(Boolean.TRUE) = "true"
* </pre>
*
* @param obj
* 源
* @return String
*/
public static String toString(Object obj) {
return obj == null ? "" : obj.toString();
}
/**
* <p>
* 进行tostring操作，如果传入的是null，返回指定的默认值。
* </p>
*
* <pre>
* ObjectUtils.toString(null, null) = null
* ObjectUtils.toString(null, "null") = "null"
* ObjectUtils.toString("", "null") = ""
* ObjectUtils.toString("bat", "null") = "bat"
* ObjectUtils.toString(Boolean.TRUE, "null") = "true"
* </pre>
*
* @param obj
* 源
* @param nullStr
* 如果obj为null时返回这个指定值
* @return String
*/
public static String toString(Object obj, String nullStr) {
return obj == null ? nullStr : obj.toString();
}
/**
* <p>
* 只从源字符串中移除指定开头子字符串.
* </p>
*
* <pre>
* StringUtil.removeStart(null, *) = null
* StringUtil.removeStart("", *) = ""
* StringUtil.removeStart(*, null) = *
* StringUtil.removeStart("www.domain.com", "www.") = "domain.com"
* StringUtil.removeStart("domain.com", "www.") = "domain.com"
* StringUtil.removeStart("www.domain.com", "domain") = "www.domain.com"
* StringUtil.removeStart("abc", "") = "abc"
* </pre>
*
* @param str
* 源字符串
* @param remove
* 将要被移除的子字符串
* @return String
*/
public static String removeStart(String str, String remove) {
if (isEmpty(str) || isEmpty(remove)) {
return str;
}
if (str.startsWith(remove)) {
return str.substring(remove.length());
}
return str;
}
/**
* <p>
* 只从源字符串中移除指定结尾的子字符串.
* </p>
*
* <pre>
* StringUtil.removeEnd(null, *) = null
* StringUtil.removeEnd("", *) = ""
* StringUtil.removeEnd(*, null) = *
* StringUtil.removeEnd("www.domain.com", ".com.") = "www.domain.com"
* StringUtil.removeEnd("www.domain.com", ".com") = "www.domain"
* StringUtil.removeEnd("www.domain.com", "domain") = "www.domain.com"
* StringUtil.removeEnd("abc", "") = "abc"
* </pre>
*
* @param str
* 源字符串
* @param remove
* 将要被移除的子字符串
* @return String
*/
public static String removeEnd(String str, String remove) {
if (isEmpty(str) || isEmpty(remove)) {
return str;
}
if (str.endsWith(remove)) {
return str.substring(0, str.length() - remove.length());
}
return str;
}
/**
* <p>
* 将一个字符串重复N次
* </p>
*
* <pre>
* StringUtil.repeat(null, 2) = null
* StringUtil.repeat("", 0) = ""
* StringUtil.repeat("", 2) = ""
* StringUtil.repeat("a", 3) = "aaa"
* StringUtil.repeat("ab", 2) = "abab"
* StringUtil.repeat("a", -2) = ""
* </pre>
*
* @param str
* 源字符串
* @param repeat
* 重复的次数
* @return String
*/
public static String repeat(String str, int repeat) {
// Performance tuned for 2.0 (JDK1.4)
if (str == null) {
return null;
}
if (repeat <= 0) {
return EMPTY;
}
int inputLength = str.length();
if (repeat == 1 || inputLength == 0) {
return str;
}
if (inputLength == 1 && repeat <= PAD_LIMIT) {
return repeat(str.charAt(0), repeat);
}
int outputLength = inputLength * repeat;
switch (inputLength) {
case 1:
return repeat(str.charAt(0), repeat);
case 2:
char ch0 = str.charAt(0);
char ch1 = str.charAt(1);
char[] output2 = new char[outputLength];
for (int i = repeat * 2 - 2; i >= 0; i--, i--) {
output2[i] = ch0;
output2[i + 1] = ch1;
}
return new String(output2);
default:
StringBuilder buf = new StringBuilder(outputLength);
for (int i = 0; i < repeat; i++) {
buf.append(str);
}
return buf.toString();
}
}
/**
* <p>
* 将一个字符串重复N次，并且中间加上指定的分隔符
* </p>
*
* <pre>
* StringUtil.repeat(null, null, 2) = null
* StringUtil.repeat(null, "x", 2) = null
* StringUtil.repeat("", null, 0) = ""
* StringUtil.repeat("", "", 2) = ""
* StringUtil.repeat("", "x", 3) = "xxx"
* StringUtil.repeat("?", ", ", 3) = "?, ?, ?"
* </pre>
*
* @param str
* 源字符串
* @param separator
* 分隔符
* @param repeat
* 重复次数
* @return String
*/
public static String repeat(String str, String separator, int repeat) {
if (str == null || separator == null) {
return repeat(str, repeat);
} else {
// given that repeat(String, int) is quite optimized, better to rely
// on it than try and splice this into it
String result = repeat(str + separator, repeat);
return removeEnd(result, separator);
}
}
/**
* <p>
* 将某个字符重复N次.
* </p>
*
* @param ch
* 某个字符
* @param repeat
* 重复次数
* @return String
*/
public static String repeat(char ch, int repeat) {
char[] buf = new char[repeat];
for (int i = repeat - 1; i >= 0; i--) {
buf[i] = ch;
}
return new String(buf);
}
/**
* <p>
* 字符串长度达不到指定长度时，在字符串右边补指定的字符.
* </p>
*
* <pre>
* StringUtil.rightPad(null, *, *) = null
* StringUtil.rightPad("", 3, 'z') = "zzz"
* StringUtil.rightPad("bat", 3, 'z') = "bat"
* StringUtil.rightPad("bat", 5, 'z') = "batzz"
* StringUtil.rightPad("bat", 1, 'z') = "bat"
* StringUtil.rightPad("bat", -1, 'z') = "bat"
* </pre>
*
* @param str
* 源字符串
* @param size
* 指定的长度
* @param padChar
* 进行补充的字符
* @return String
*/
public static String rightPad(String str, int size, char padChar) {
if (str == null) {
return null;
}
int pads = size - str.length();
if (pads <= 0) {
return str; // returns original String when possible
}
if (pads > PAD_LIMIT) {
return rightPad(str, size, String.valueOf(padChar));
}
return str.concat(repeat(padChar, pads));
}
/**
* <p>
* 扩大字符串长度，从左边补充指定字符
* </p>
*
* <pre>
* StringUtil.rightPad(null, *, *) = null
* StringUtil.rightPad("", 3, "z") = "zzz"
* StringUtil.rightPad("bat", 3, "yz") = "bat"
* StringUtil.rightPad("bat", 5, "yz") = "batyz"
* StringUtil.rightPad("bat", 8, "yz") = "batyzyzy"
* StringUtil.rightPad("bat", 1, "yz") = "bat"
* StringUtil.rightPad("bat", -1, "yz") = "bat"
* StringUtil.rightPad("bat", 5, null) = "bat "
* StringUtil.rightPad("bat", 5, "") = "bat "
* </pre>
*
* @param str
* 源字符串
* @param size
* 扩大后的长度
* @param padStr
* 在右边补充的字符串
* @return String
*/
public static String rightPad(String str, int size, String padStr) {
if (str == null) {
return null;
}
if (isEmpty(padStr)) {
padStr = " ";
}
int padLen = padStr.length();
int strLen = str.length();
int pads = size - strLen;
if (pads <= 0) {
return str; // returns original String when possible
}
if (padLen == 1 && pads <= PAD_LIMIT) {
return rightPad(str, size, padStr.charAt(0));
}
if (pads == padLen) {
return str.concat(padStr);
} else if (pads < padLen) {
return str.concat(padStr.substring(0, pads));
} else {
char[] padding = new char[pads];
char[] padChars = padStr.toCharArray();
for (int i = 0; i < pads; i++) {
padding[i] = padChars[i % padLen];
}
return str.concat(new String(padding));
}
}
/**
* <p>
* 扩大字符串长度，从左边补充空格
* </p>
*
* <pre>
* StringUtil.leftPad(null, *) = null
* StringUtil.leftPad("", 3) = " "
* StringUtil.leftPad("bat", 3) = "bat"
* StringUtil.leftPad("bat", 5) = " bat"
* StringUtil.leftPad("bat", 1) = "bat"
* StringUtil.leftPad("bat", -1) = "bat"
* </pre>
*
* @param str
* 源字符串
* @param size
* 扩大后的长度
* @return String
*/
public static String leftPad(String str, int size) {
return leftPad(str, size, ' ');
}
/**
* <p>
* 扩大字符串长度，从左边补充指定的字符
* </p>
*
* <pre>
* StringUtil.leftPad(null, *, *) = null
* StringUtil.leftPad("", 3, 'z') = "zzz"
* StringUtil.leftPad("bat", 3, 'z') = "bat"
* StringUtil.leftPad("bat", 5, 'z') = "zzbat"
* StringUtil.leftPad("bat", 1, 'z') = "bat"
* StringUtil.leftPad("bat", -1, 'z') = "bat"
* </pre>
*
* @param str
* 源字符串
* @param size
* 扩大后的长度
* @param padStr
* 补充的字符
* @return String
*/
public static String leftPad(String str, int size, char padChar) {
if (str == null) {
return null;
}
int pads = size - str.length();
if (pads <= 0) {
return str; // returns original String when possible
}
if (pads > PAD_LIMIT) {
return leftPad(str, size, String.valueOf(padChar));
}
return repeat(padChar, pads).concat(str);
}
/**
* <p>
* 扩大字符串长度，从左边补充指定的字符
* </p>
*
* <pre>
* StringUtil.leftPad(null, *, *) = null
* StringUtil.leftPad("", 3, "z") = "zzz"
* StringUtil.leftPad("bat", 3, "yz") = "bat"
* StringUtil.leftPad("bat", 5, "yz") = "yzbat"
* StringUtil.leftPad("bat", 8, "yz") = "yzyzybat"
* StringUtil.leftPad("bat", 1, "yz") = "bat"
* StringUtil.leftPad("bat", -1, "yz") = "bat"
* StringUtil.leftPad("bat", 5, null) = " bat"
* StringUtil.leftPad("bat", 5, "") = " bat"
* </pre>
*
* @param str
* 源字符串
* @param size
* 扩大后的长度
* @param padStr
* 补充的字符串
* @return String
*/
public static String leftPad(String str, int size, String padStr) {
if (str == null) {
return null;
}
if (isEmpty(padStr)) {
padStr = " ";
}
int padLen = padStr.length();
int strLen = str.length();
int pads = size - strLen;
if (pads <= 0) {
return str; // returns original String when possible
}
if (padLen == 1 && pads <= PAD_LIMIT) {
return leftPad(str, size, padStr.charAt(0));
}
if (pads == padLen) {
return padStr.concat(str);
} else if (pads < padLen) {
return padStr.substring(0, pads).concat(str);
} else {
char[] padding = new char[pads];
char[] padChars = padStr.toCharArray();
for (int i = 0; i < pads; i++) {
padding[i] = padChars[i % padLen];
}
return new String(padding).concat(str);
}
}
/**
* <p>
* 扩大字符串长度并将现在的字符串居中，被扩大部分用空格填充。
* <p>
*
* <pre>
* StringUtil.center(null, *) = null
* StringUtil.center("", 4) = " "
* StringUtil.center("ab", -1) = "ab"
* StringUtil.center("ab", 4) = " ab "
* StringUtil.center("abcd", 2) = "abcd"
* StringUtil.center("a", 4) = " a "
* </pre>
*
* @param str
* 源字符串
* @param size
* 扩大后的长度
* @return String
*/
public static String center(String str, int size) {
return center(str, size, ' ');
}
/**
* <p>
* 将字符串长度修改为指定长度，并进行居中显示。
* </p>
*
* <pre>
* StringUtil.center(null, *, *) = null
* StringUtil.center("", 4, ' ') = " "
* StringUtil.center("ab", -1, ' ') = "ab"
* StringUtil.center("ab", 4, ' ') = " ab"
* StringUtil.center("abcd", 2, ' ') = "abcd"
* StringUtil.center("a", 4, ' ') = " a "
* StringUtil.center("a", 4, 'y') = "yayy"
* </pre>
*
* @param str
* 源字符串
* @param size
* 指定的长度
* @param padStr
* 长度不够时补充的字符串
* @return String
* @throws IllegalArgumentException
* 如果被补充字符串为 null或者 empty
*/
public static String center(String str, int size, char padChar) {
if (str == null || size <= 0) {
return str;
}
int strLen = str.length();
int pads = size - strLen;
if (pads <= 0) {
return str;
}
str = leftPad(str, strLen + pads / 2, padChar);
str = rightPad(str, size, padChar);
return str;
}
/**
* <p>
* 将字符串长度修改为指定长度，并进行居中显示。
* </p>
*
* <pre>
* StringUtil.center(null, *, *) = null
* StringUtil.center("", 4, " ") = " "
* StringUtil.center("ab", -1, " ") = "ab"
* StringUtil.center("ab", 4, " ") = " ab"
* StringUtil.center("abcd", 2, " ") = "abcd"
* StringUtil.center("a", 4, " ") = " a "
* StringUtil.center("a", 4, "yz") = "yayz"
* StringUtil.center("abc", 7, null) = " abc "
* StringUtil.center("abc", 7, "") = " abc "
* </pre>
*
* @param str
* 源字符串
* @param size
* 指定的长度
* @param padStr
* 长度不够时补充的字符串
* @return String
* @throws IllegalArgumentException
* 如果被补充字符串为 null或者 empty
*/
public static String center(String str, int size, String padStr) {
if (str == null || size <= 0) {
return str;
}
if (isEmpty(padStr)) {
padStr = " ";
}
int strLen = str.length();
int pads = size - strLen;
if (pads <= 0) {
return str;
}
str = leftPad(str, strLen + pads / 2, padStr);
str = rightPad(str, size, padStr);
return str;
}
/**
* <p>
* 检查字符串是否全部为小写.
* </p>
*
* <pre>
* StringUtil.isAllLowerCase(null) = false
* StringUtil.isAllLowerCase("") = false
* StringUtil.isAllLowerCase(" ") = false
* StringUtil.isAllLowerCase("abc") = true
* StringUtil.isAllLowerCase("abC") = false
* </pre>
*
* @param cs
* 源字符串
* @return String
*/
public static boolean isAllLowerCase(String cs) {
if (cs == null || isEmpty(cs)) {
return false;
}
int sz = cs.length();
for (int i = 0; i < sz; i++) {
if (Character.isLowerCase(cs.charAt(i)) == false) {
return false;
}
}
return true;
}
/**
* <p>
* 检查是否都是大写.
* </p>
*
* <pre>
* StringUtil.isAllUpperCase(null) = false
* StringUtil.isAllUpperCase("") = false
* StringUtil.isAllUpperCase(" ") = false
* StringUtil.isAllUpperCase("ABC") = true
* StringUtil.isAllUpperCase("aBC") = false
* </pre>
*
* @param cs
* 源字符串
* @return String
*/
public static boolean isAllUpperCase(String cs) {
if (cs == null || StringUtil.isEmpty(cs)) {
return false;
}
int sz = cs.length();
for (int i = 0; i < sz; i++) {
if (Character.isUpperCase(cs.charAt(i)) == false) {
return false;
}
}
return true;
}
/**
* <p>
* 反转字符串.
* </p>
*
* <pre>
* StringUtil.reverse(null) = null
* StringUtil.reverse("") = ""
* StringUtil.reverse("bat") = "tab"
* </pre>
*
* @param str
* 源字符串
* @return String
*/
public static String reverse(String str) {
if (str == null) {
return null;
}
return new StringBuilder(str).reverse().toString();
}
/**
* <p>
* 字符串达不到一定长度时在右边补空白.
* </p>
*
* <pre>
* StringUtil.rightPad(null, *) = null
* StringUtil.rightPad("", 3) = " "
* StringUtil.rightPad("bat", 3) = "bat"
* StringUtil.rightPad("bat", 5) = "bat "
* StringUtil.rightPad("bat", 1) = "bat"
* StringUtil.rightPad("bat", -1) = "bat"
* </pre>
*
* @param str
* 源字符串
* @param size
* 指定的长度
* @return String
*/
public static String rightPad(String str, int size) {
return rightPad(str, size, ' ');
}
/**
* 从右边截取字符串.</p>
*
* <pre>
* StringUtil.right(null, *) = null
* StringUtil.right(*, -ve) = ""
* StringUtil.right("", *) = ""
* StringUtil.right("abc", 0) = ""
* StringUtil.right("abc", 2) = "bc"
* StringUtil.right("abc", 4) = "abc"
* </pre>
*
* @param str
* 源字符串
* @param len
* 长度
* @return String
*/
public static String right(String str, int len) {
if (str == null) {
return null;
}
if (len < 0) {
return EMPTY;
}
if (str.length() <= len) {
return str;
}
return str.substring(str.length() - len);
}
/**
* <p>
* 截取一个字符串的前几个.
* </p>
*
* <pre>
* StringUtil.left(null, *) = null
* StringUtil.left(*, -ve) = ""
* StringUtil.left("", *) = ""
* StringUtil.left("abc", 0) = ""
* StringUtil.left("abc", 2) = "ab"
* StringUtil.left("abc", 4) = "abc"
* </pre>
*
* @param str
* 源字符串
* @param len
* 截取的长度
* @return the String
*/
public static String left(String str, int len) {
if (str == null) {
return null;
}
if (len < 0) {
return EMPTY;
}
if (str.length() <= len) {
return str;
}
return str.substring(0, len);
}
/**
* <p>
* 得到tag字符串中间的子字符串，只返回第一个匹配项。
* </p>
*
* <pre>
* StringUtil.substringBetween(null, *) = null
* StringUtil.substringBetween("", "") = ""
* StringUtil.substringBetween("", "tag") = null
* StringUtil.substringBetween("tagabctag", null) = null
* StringUtil.substringBetween("tagabctag", "") = ""
* StringUtil.substringBetween("tagabctag", "tag") = "abc"
* </pre>
*
* @param str
* 源字符串。
* @param tag
* 标识字符串。
* @return String 子字符串, 如果没有符合要求的，返回{@code null}。
*/
public static String substringBetween(String str, String tag) {
return substringBetween(str, tag, tag);
}
/**
* <p>
* 得到两个字符串中间的子字符串，只返回第一个匹配项。
* </p>
*
* <pre>
* StringUtil.substringBetween("wx[b]yz", "[", "]") = "b"
* StringUtil.substringBetween(null, *, *) = null
* StringUtil.substringBetween(*, null, *) = null
* StringUtil.substringBetween(*, *, null) = null
* StringUtil.substringBetween("", "", "") = ""
* StringUtil.substringBetween("", "", "]") = null
* StringUtil.substringBetween("", "[", "]") = null
* StringUtil.substringBetween("yabcz", "", "") = ""
* StringUtil.substringBetween("yabcz", "y", "z") = "abc"
* StringUtil.substringBetween("yabczyabcz", "y", "z") = "abc"
* </pre>
*
* @param str
* 源字符串
* @param open
* 起字符串。
* @param close
* 末字符串。
* @return String 子字符串, 如果没有符合要求的，返回{@code null}。
*/
public static String substringBetween(String str, String open, String close) {
if (str == null || open == null || close == null) {
return null;
}
int start = str.indexOf(open);
if (start != INDEX_NOT_FOUND) {
int end = str.indexOf(close, start + open.length());
if (end != INDEX_NOT_FOUND) {
return str.substring(start + open.length(), end);
}
}
return null;
}
/**
* <p>
* 得到两个字符串中间的子字符串，所有匹配项组合为数组并返回。
* </p>
*
* <pre>
* StringUtil.substringsBetween("[a][b][c]", "[", "]") = ["a","b","c"]
* StringUtil.substringsBetween(null, *, *) = null
* StringUtil.substringsBetween(*, null, *) = null
* StringUtil.substringsBetween(*, *, null) = null
* StringUtil.substringsBetween("", "[", "]") = []
* </pre>
*
* @param str
* 源字符串
* @param open
* 起字符串。
* @param close
* 末字符串。
* @return String 子字符串数组, 如果没有符合要求的，返回{@code null}。
*/
public static String[] substringsBetween(String str, String open,
String close) {
if (str == null || isEmpty(open) || isEmpty(close)) {
return null;
}
int strLen = str.length();
if (strLen == 0) {
return new String[0];
}
int closeLen = close.length();
int openLen = open.length();
List<String> list = new ArrayList<String>();
int pos = 0;
while (pos < strLen - closeLen) {
int start = str.indexOf(open, pos);
if (start < 0) {
break;
}
start += openLen;
int end = str.indexOf(close, start);
if (end < 0) {
break;
}
list.add(str.substring(start, end));
pos = end + closeLen;
}
if (list.isEmpty()) {
return null;
}
return list.toArray(new String[list.size()]);
}
/**
* 功能：切换字符串中的所有字母大小写。<br/>
*
* <pre>
* StringUtil.swapCase(null) = null
* StringUtil.swapCase("") = ""
* StringUtil.swapCase("The dog has a BONE") = "tHE DOG HAS A bone"
* </pre>
*
*
* @param str
* 源字符串
* @return String
*/
public static String swapCase(String str) {
if (StringUtil.isEmpty(str)) {
return str;
}
char[] buffer = str.toCharArray();
boolean whitespace = true;
for (int i = 0; i < buffer.length; i++) {
char ch = buffer[i];
if (Character.isUpperCase(ch)) {
buffer[i] = Character.toLowerCase(ch);
whitespace = false;
} else if (Character.isTitleCase(ch)) {
buffer[i] = Character.toLowerCase(ch);
whitespace = false;
} else if (Character.isLowerCase(ch)) {
if (whitespace) {
buffer[i] = Character.toTitleCase(ch);
whitespace = false;
} else {
buffer[i] = Character.toUpperCase(ch);
}
} else {
whitespace = Character.isWhitespace(ch);
}
}
return new String(buffer);
}
/**
* 功能：截取出最后一个标志位之后的字符串.<br/>
* 如果sourceStr为empty或者expr为null，直接返回源字符串。<br/>
* 如果expr长度为0，直接返回sourceStr。<br/>
* 如果expr在sourceStr中不存在，直接返回sourceStr。<br/>
*
* @author jiangshuai
* @date 2017年04月24日
* @param sourceStr
* 被截取的字符串
* @param expr
* 分隔符
* @return String
*/
public static String substringAfterLast(String sourceStr, String expr) {
if (isEmpty(sourceStr) || expr == null) {
return sourceStr;
}
if (expr.length() == 0) {
return sourceStr;
}
int pos = sourceStr.lastIndexOf(expr);
if (pos == -1) {
return sourceStr;
}
return sourceStr.substring(pos + expr.length());
}
/**
* 功能：截取出最后一个标志位之前的字符串.<br/>
* 如果sourceStr为empty或者expr为null，直接返回源字符串。<br/>
* 如果expr长度为0，直接返回sourceStr。<br/>
* 如果expr在sourceStr中不存在，直接返回sourceStr。<br/>
*
* @author jiangshuai
* @date 2017年04月24日
* @param sourceStr
* 被截取的字符串
* @param expr
* 分隔符
* @return String
*/
public static String substringBeforeLast(String sourceStr, String expr) {
if (isEmpty(sourceStr) || expr == null) {
return sourceStr;
}
if (expr.length() == 0) {
return sourceStr;
}
int pos = sourceStr.lastIndexOf(expr);
if (pos == -1) {
return sourceStr;
}
return sourceStr.substring(0, pos);
}
/**
* 功能：截取出第一个标志位之后的字符串.<br/>
* 如果sourceStr为empty或者expr为null，直接返回源字符串。<br/>
* 如果expr长度为0，直接返回sourceStr。<br/>
* 如果expr在sourceStr中不存在，直接返回sourceStr。<br/>
*
* @author jiangshuai
* @date 2017年04月24日
* @param sourceStr
* 被截取的字符串
* @param expr
* 分隔符
* @return String
*/
public static String substringAfter(String sourceStr, String expr) {
if (isEmpty(sourceStr) || expr == null) {
return sourceStr;
}
if (expr.length() == 0) {
return sourceStr;
}
int pos = sourceStr.indexOf(expr);
if (pos == -1) {
return sourceStr;
}
return sourceStr.substring(pos + expr.length());
}
/**
* 功能：截取出第一个标志位之前的字符串.<br/>
* 如果sourceStr为empty或者expr为null，直接返回源字符串。<br/>
* 如果expr长度为0，直接返回sourceStr。<br/>
* 如果expr在sourceStr中不存在，直接返回sourceStr。<br/>
* 如果expr在sourceStr中存在不止一个，以第一个位置为准。
*
* @author jiangshuai
* @date 2017年04月24日
* @param sourceStr
* 被截取的字符串
* @param expr
* 分隔符
* @return String
*/
public static String substringBefore(String sourceStr, String expr) {
if (isEmpty(sourceStr) || expr == null) {
return sourceStr;
}
if (expr.length() == 0) {
return sourceStr;
}
int pos = sourceStr.indexOf(expr);
if (pos == -1) {
return sourceStr;
}
return sourceStr.substring(0, pos);
}
/**
* 功能：检查这个字符串是不是空字符串。<br/>
* 如果这个字符串为null或者trim后为空字符串则返回true，否则返回false。
*
* @author jiangshuai
* @date 2017年04月24日
* @param chkStr
* 被检查的字符串
* @return boolean
*/
public static boolean isEmpty(String chkStr) {
if (chkStr == null) {
return true;
} else {
return "".equals(chkStr.trim()) ? true : false;
}
}
/**
* 如果字符串没有超过最长显示长度返回原字符串，否则从开头截取指定长度并加...返回。
*
* @param str
* 原字符串
* @param length
* 字符串最长显示的长度
* @return 转换后的字符串
*/
public static String trimString(String str, int length) {
if (str == null) {
return "";
} else if (str.length() > length) {
return str.substring(0, length - 3) + "...";
} else {
return str;
}
}
} 
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