org.ttzero.excel.util.StringUtil Maven / Gradle / Ivy
/*
* Copyright (c) 2017, [email protected] All Rights Reserved.
*
* 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 org.ttzero.excel.util;
/**
* string util
*
* @author guanquan.wang on 2017/9/30.
*/
public class StringUtil {
private StringUtil() { }
/**
* Const `""` string
*/
public final static String EMPTY = "";
/**
* Returns {@code true} if it is null or {@link String#length()} is {@code 0}.
*
* @param s string value to check
* @return {@code true} if null or {@link String#length()} is {@code 0}, otherwise
* {@code false}
*/
public static boolean isEmpty(String s) {
return s == null || s.isEmpty();
}
/**
* Returns {@code true} if, and only if, {@link String#length()} greater than {@code 0}.
*
* @param s string value to check
* @return {@code true} if {@link String#length()} greater than {@code 0}, otherwise
* {@code false}
*/
public static boolean isNotEmpty(String s) {
return s != null && s.length() > 0;
}
/**
* Returns the index within this string array of the first occurrence of
* the specified string.
*
* If no such string occurs in this array, then {@code -1} is returned.
*
* @param array array to search
* @param v the specify string
* @return the index of the first occurrence of the string in array, or
* {@code -1} if the string does not occur.
*/
public static int indexOf(String[] array, String v) {
if (v != null) {
for (int i = 0; i < array.length; i++) {
if (v.equals(array[i])) {
return i;
}
}
} else {
for (int i = 0; i < array.length; i++) {
if (array[i] == null) {
return i;
}
}
}
return -1;
}
/**
* Turn the first character into an upper case. It means if the first
* character is between 97 and 122, it will be minus {@code 32}.
*
* @param key a string to processor
* @return a string witch the first character is upper case
*/
public static String uppFirstKey(String key) {
char first = key.charAt(0);
if (first >= 97 && first <= 122) {
char[] _v = key.toCharArray();
_v[0] -= 32;
return new String(_v);
}
return key;
}
/**
* Turn the first character into an lower case. It means if the first
* character is between 65 and 90, it will be plus {@code 32}.
*
* @param key a string to processor
* @return a string witch the first character is lower case
*/
public static String lowFirstKey(String key) {
char first = key.charAt(0);
if (first >= 65 && first <= 90) {
char[] _v = key.toCharArray();
_v[0] += 32;
return new String(_v);
}
return key;
}
/**
* Convert to camel case string.
*
* @param name a string to processor
* @return a camel case string
*/
public static String toPascalCase(String name) {
if (name.indexOf('_') < 0) return name;
char[] oldValues = name.toLowerCase().toCharArray();
final int len = oldValues.length;
int i = 1, idx = i;
for (int n = len - 1; i < n; i++) {
char c = oldValues[i], cc = oldValues[i + 1];
if (c == '_' && cc >= 'a' && cc <= 'z') {
oldValues[idx++] = (char) (cc - 32);
i++;
}
else {
oldValues[idx++] = c;
}
}
if (i < len) oldValues[idx++] = oldValues[i];
return new String(oldValues, 0, idx);
}
// public static String append(String src, String a, int n, int origin) {
// StringBuilder buf = new StringBuilder();
// // Insert header
// if (origin == -1) {
// for (; n-- > 0; ) {
// buf.append(a);
// }
// buf.append(src);
// } else {
// buf.append(src);
// for (; n-- > 0; ) {
// buf.append(a);
// }
// }
//
// return buf.toString();
// }
/**
* Wrap value in string array
*
* @param values the array to warp
* @param a from index
* @param b to index
*/
public static void swap(String[] values, int a, int b) {
String t = values[a];
values[a] = values[b];
values[b] = t;
}
}