Custom encapsulation of common tool classes for your reference, the specific content is as follows
package com.demo.utils;import java.util.ArrayList;import java.util.List;import java.util.Map;/** * String operation tool class* @author dongyangyang * @Date 2016/12/28 23:12 * @Version 1.0 * */public class StringUtils { /** * The initial letter is lowercase* @param str * @return */ public static String firstCharToLowerCase(String str) { char firstChar = str.charAt(0); if (firstChar >= 'A' && firstChar <= 'Z') { char[] arr = str.toCharArray(); arr[0] += ('a' - 'A'); return new String(arr); } return str; } /** * The initial letter becomes capitalized* @param str * @return */ public static String firstCharToUpperCase(String str) { char firstChar = str.charAt(0); if (firstChar >= 'a' && firstChar <= 'z') { char[] arr = str.toCharArray(); arr[0] -= ('a' - 'A'); return new String(arr); } return str; } /** * Determine whether it is empty* @param str * @return */ public static boolean isEmpty(final String str) { return (str == null) || (str.length() == 0); } /** * Determine whether it is not empty* @param str * @return */ public static boolean isNotEmpty(final String str) { return !isEmpty(str); } /** * 1. Determine whether it is blank* @param str * @return */ public static boolean isBlank(final String str) { int strLen; if ((str == null) || ((strLen = str.length()) == 0)) return true; for (int i = 0; i < strLen; i++) { if (!Character.isWhitespace(str.charAt(i))) { return false; } } return true; } /** * Determine whether it is not blank* @param str * @return */ public static boolean isNotBlank(final String str) { return !isBlank(str); } /** * Determine whether all multiple strings are empty* @param strings * @return */ public static boolean isAllEmpty(String... strings) { if (strings == null) { return true; } for (String str : strings) { if (isNotEmpty(str)) { return false; } } return true; } /** * Determine whether any of multiple strings is empty* @param strings * @return */ public static boolean isHasEmpty(String... strings) { if (strings == null) { return true; } for (String str : strings) { if (isEmpty(str)) { return true; } } return false; } /** * defaultValue is null or "" * @param checkValue * @param defaultValue * @return */ public static String isEmpty(String checkValue, String defaultValue) { return isEmpty(checkValue) ? defaultValue : checkValue; } /** * The string is not null and not "" and is equal to other * @param str * @param other * @return */ public static boolean isNotEmptyAndEquelsOther(String str, String other) { if (isEmpty(str)) { return false; } return str.equals(other); } /** * The string is not null and not "" and is not equal to other * @param str * @param other * @return */ public static boolean isNotEmptyAndNotEquelsOther(String str, String... other) { if (isEmpty(str)) { return false; } for (int i = 0; i < other.length; i++) { if (str.equals(other[i])) { return false; } } return true; } /** * String is not equal to other * @param str * @param other * @return */ public static boolean isNotEquelsOther(String str, String... other) { for (int i = 0; i < other.length; i++) { if (other[i].equals(str)) { return false; } } return true; } /** * Judge the string not empty* @param strings * @return */ public static boolean isNotEmpty(String... strings) { if (strings == null) { return false; } for (String str : strings) { if (str == null || "".equals(str.trim())) { return false; } } return true; } /** * Comparison characters equal* @param value * @param equals * @return */ public static boolean equals(String value, String equals) { if (isAllEmpty(value, equals)) { return true; } return value.equals(equals); } /** * Comparison strings are not equal* @param value * @param equals * @return */ public static boolean isNotEquals(String value, String equals) { return !equals(value, equals); } public static String[] split(String content, String separatorChars) { return splitWorker(content, separatorChars, -1, false); } public static String[] split(String str, String separatorChars, int max) { return splitWorker(str, separatorChars, max, false); } public static final String[] EMPTY_STRING_ARRAY = new String[0]; private static String[] splitWorker(String str, String separatorChars, int max, boolean preserveAllTokens) { if (str == null) { return null; } int len = str.length(); if (len == 0) { return EMPTY_STRING_ARRAY; } List<String> list = new ArrayList<String>(); int sizePlus1 = 1; int i = 0, start = 0; boolean match = false; boolean lastMatch = false; if (separatorChars == null) { while (i < len) { if (Character.isWhitespace(str.charAt(i))) { if (match || preserveAllTokens) { lastMatch = true; if (sizePlus1++ == max) { i = len; lastMatch = false; } list.add(str.substring(start, i)); match = false; } start = ++i; continue; } lastMatch = false; match = true; i++; } } else if (separatorChars.length() == 1) { char sep = separatorChars.charAt(0); while (i < len) { if (str.charAt(i) == sep) { if (match || preserveAllTokens) { lastMatch = true; if (sizePlus1++ == max) { i = len; lastMatch = false; } list.add(str.substring(start, i)); match = false; } start = ++i; continue; } lastMatch = false; match = true; i++; } } else { while (i < len) { if (separatorChars.indexOf(str.charAt(i)) >= 0) { if (match || preserveAllTokens) { lastMatch = true; if (sizePlus1++ == max) { i = len; lastMatch = false; } list.add(str.substring(start, i)); match = false; } start = ++i; continue; } lastMatch = false; match = true; i++; } } if (match || (preserveAllTokens && lastMatch)) { list.add(str.substring(start, i)); } return (String[]) list.toArray(EMPTY_STRING_ARRAY); } /** * Eliminate escape characters* @param str * @return */ public static String escapeXML(String str) { if (str == null) return ""; StringBuilder sb = new StringBuilder(); for (int i = 0; i < str.length(); ++i) { char c = str.charAt(i); switch (c) { case '/u00FF': case '/u0024': break; case '&': sb.append("&"); break; case '<': sb.append("<"); break; case '>': sb.append(">"); break; case '/"': sb.append(""); break; case '/'': sb.append(""); break; case '/'': sb.append("'"); break; default: if (c >= '/u0000' && c <= '/u001F') break; if (c >= '/uE000' && c <= '/uF8FF') break; if (c >= '/uFFF0' && c <= '/uFFF') break; sb.append(c); break; } } return sb.toString(); } /** * Convert characters in a specific pattern in a string to the corresponding value in the map* * @param s * String to be converted* @param map * Set of key-value pairs required for conversion* @return Converted string*/ public static String replace(String s, Map<String, Object> map) { StringBuilder ret = new StringBuilder((int) (s.length() * 1.5)); int cursor = 0; for (int start, end; (start = s.indexOf("${", cursor)) != -1 && (end = s.indexOf("}", start)) != -1;) { ret.append(s.substring(cursor, start)).append(map.get(s.substring(start + 2, end))); cursor = end + 1; } ret.append(s.substring(cursor, s.length())); return ret.toString(); } public static String replace(String s, Object... objs) { if (objs == null || objs.length == 0) return s; if (s.indexOf("{}") == -1) return s; StringBuilder ret = new StringBuilder((int) (s.length() * 1.5)); int cursor = 0; int index = 0; for (int start; (start = s.indexOf("{}", cursor)) != -1;) { ret.append(s.substring(cursor, start)); if (index < objs.length) ret.append(objs[index]); else ret.append("{}"); cursor = start + 2; index++; } ret.append(s.substring(cursor, s.length())); return ret.toString(); } /** * String formatting tool, parameters must be marked in a style like {0}. The numbers in braces start from 0. * * @param source * Source string * @param params * The list of parameters that need to be replaced will be called toString() of each parameter when writing. * @return The replaced string. If the original string is empty or the parameter is empty, the original string will be directly returned. */ public static String replaceArgs(String source, Object... params) { if (params == null || params.length == 0 || source == null || source.isEmpty()) { return source; } StringBuilder buff = new StringBuilder(source); StringBuilder temp = new StringBuilder(); int startIndex = 0; int endIndex = 0; String param = null; for (int count = 0; count < params.length; count++) { if (params[count] == null) { param = null; } else { param = params[count].toString(); } temp.delete(0, temp.length()); temp.append("{"); temp.append(count); temp.append("}"); while (true) { startIndex = buff.indexOf(temp.toString(), endIndex); if (startIndex == -1) { break; } endIndex = startIndex + temp.length(); buff.replace(startIndex, endIndex, param == null ? "" : param); } startIndex = 0; endIndex = 0; } return buff.toString(); } public static String substringBefore(final String s, final String separator) { if (isEmpty(s) || separator == null) { return s; } if (separator.isEmpty()) { return ""; } final int pos = s.indexOf(separator); if (pos < 0) { return s; } return s.substring(0, pos); } public static String substringBetween(final String str, final String open, final String close) { if (str == null || open == null || close == null) { return null; } final int start = str.indexOf(open); if (start != -1) { final int end = str.indexOf(close, start + open.length()); if (end != -1) { return str.substring(start + open.length(), end); } } return null; } public static String substringAfter(final String str, final String separator) { if (isEmpty(str)) { return str; } if (separator == null) { return ""; } final int pos = str.indexOf(separator); if (pos == -1) { return ""; } return str.substring(pos + separator.length()); } /** * Convert to byte array* @param str * @return */ public static String toString(byte[] bytes){ try { return new String(bytes, "utf-8"); } catch (UnsupportedEncodingException e) { return null; } } /** * Convert to byte array* @param str * @return */ public static byte[] getBytes(String str){ if (str != null){ try { return str.getBytes("utf-8"); } catch (UnsupportedEncodingException e) { return null; } }else{ return null; } } public static void main(String[] a){ String escapeXML = escapeXML("//"); System.out.println(escapeXML); }}The above is all the content of this article. 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