com.binfast.adpter.core.kit.StrKit Maven / Gradle / Ivy
/**
* Copyright (c) 2011-2023, James Zhan 詹波 ([email protected]).
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.binfast.adpter.core.kit;
/**
* StrKit.
*/
public class StrKit {
/**
* 首字母变小写
*/
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;
}
/**
* 首字母变大写
*/
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;
}
/**
* 字符串为 null 或者内部字符全部为 ' ' '\t' '\n' '\r' 这四类字符时返回 true
*/
public static boolean isBlank(String str) {
if (str == null) {
return true;
}
for (int i = 0, len = str.length(); i < len; i++) {
if (str.charAt(i) > ' ') {
return false;
}
}
return true;
}
public static boolean notBlank(String str) {
return !isBlank(str);
}
public static boolean notBlank(String... strings) {
if (strings == null || strings.length == 0) {
return false;
}
for (String str : strings) {
if (isBlank(str)) {
return false;
}
}
return true;
}
public static boolean hasBlank(String... strings) {
if (strings == null || strings.length == 0) {
return true;
}
for (String str : strings) {
if (isBlank(str)) {
return true;
}
}
return false;
}
public static boolean notNull(Object... paras) {
if (paras == null) {
return false;
}
for (Object obj : paras) {
if (obj == null) {
return false;
}
}
return true;
}
public static String defaultIfBlank(String str, String defaultValue) {
return isBlank(str) ? defaultValue : str;
}
/**
* 将包含下划线字符 '_' 的字符串转换成驼峰格式，不包含下划线则原样返回
*/
public static String toCamelCase(String str) {
return toCamelCase(str, false);
}
/**
* 字符串转换成驼峰格式
*
*
* toLowerCaseAnyway 参数的作用如下：
*
* 1：当待转换字符串中包含下划线字符 '_' 时，无需关心 toLowerCaseAnyway 参数的值，转换结果始终一样
*
* 2：当待转换字符串中不包含下划线字符 '_' 时，toLowerCaseAnyway 参数规则如下：
* true 值: 将待转换字符串全部转换成小与字母，适用于 oralce 数据库字段转换的场景
* 因为 oracle 字段全是大写字母
*
* false 值: 则原样返回待转换字符串，适用于待转换字符串可能原本就是驼峰格式的场景
* 如果原本就是驼峰，全部转成小写字母显然不合理
*
*/
public static String toCamelCase(String str, boolean toLowerCaseAnyway) {
int len = str.length();
if (len <= 1) {
return str;
}
char ch;
int index = 0;
char[] buf = new char[len];
int i = 0;
for (; i < len; i++) {
ch = str.charAt(i);
if (ch == '_') {
// 当前字符为下划线时，将指针后移一位，将紧随下划线后面一个字符转成大写并存放
i++;
if (i < len) {
ch = str.charAt(i);
buf[index] = (
index == 0 ? // 首字母无条件变小写
Character.toLowerCase(ch) :
Character.toUpperCase(ch)
);
index++;
}
}
else {
buf[index++] = Character.toLowerCase(ch);
}
}
if (toLowerCaseAnyway) {
return new String(buf, 0, index);
}
// i == index 时，表明字符串中不存在字符 '_'
// 无下划线的字符串原本可能就是驼峰形式，所以原样返回
return i == index ? str : new String(buf, 0, index);
}
public static String join(String[] stringArray) {
StringBuilder sb = new StringBuilder();
for (String s : stringArray) {
sb.append(s);
}
return sb.toString();
}
public static String join(String[] stringArray, String separator) {
StringBuilder sb = new StringBuilder();
for (int i=0; i 0) {
sb.append(separator);
}
sb.append(stringArray[i]);
}
return sb.toString();
}
public static String join(java.util.List list, String separator) {
StringBuilder sb = new StringBuilder();
for (int i=0, len=list.size(); i 0) {
sb.append(separator);
}
sb.append(list.get(i));
}
return sb.toString();
}
// public static boolean slowEquals(String a, String b) {
// byte[] aBytes = (a != null ? a.getBytes() : null);
// byte[] bBytes = (b != null ? b.getBytes() : null);
// return HashKit.slowEquals(aBytes, bBytes);
// }
public static boolean equals(String a, String b) {
return a == null ? b == null : a.equals(b);
}
public static String getRandomUUID() {
return java.util.UUID.randomUUID().toString().replace("-", "");
}
}