org.apache.ivy.util.StringUtils Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.apache.ivy.util;
import java.io.ByteArrayOutputStream;
import java.io.PrintWriter;
import java.lang.reflect.InvocationTargetException;
import java.util.Locale;
/**
* Convenient class used only for uncapitalization Usually use commons lang but here we do not want
* to have such a dependency for only one feature
*/
public final class StringUtils {
private StringUtils() {
//Utility class
}
public static String uncapitalize(String string) {
if (string == null || string.length() == 0) {
return string;
}
if (string.length() == 1) {
return string.toLowerCase(Locale.US);
}
return string.substring(0, 1).toLowerCase(Locale.US) + string.substring(1);
}
/**
* Returns the error message associated with the given Throwable. The error message returned
* will try to be as precise as possible, handling cases where e.getMessage() is not meaningful,
* like {@link NullPointerException} for instance.
*
* @param t
* the throwable to get the error message from
* @return the error message of the given exception
*/
public static String getErrorMessage(Throwable t) {
if (t == null) {
return "";
}
if (t instanceof InvocationTargetException) {
InvocationTargetException ex = (InvocationTargetException) t;
t = ex.getTargetException();
}
String errMsg = t instanceof RuntimeException ? t.getMessage() : t.toString();
if (errMsg == null || errMsg.length() == 0 || "null".equals(errMsg)) {
errMsg = t.getClass().getName() + " at " + t.getStackTrace()[0].toString();
}
return errMsg;
}
/**
* Returns the exception stack trace as a String.
*
* @param e
* the exception to get the stack trace from.
* @return the exception stack trace
*/
public static String getStackTrace(Exception e) {
if (e == null) {
return "";
}
ByteArrayOutputStream baos = new ByteArrayOutputStream();
PrintWriter printWriter = new PrintWriter(baos);
e.printStackTrace(printWriter);
printWriter.flush();
String stackTrace = new String(baos.toByteArray());
printWriter.close();
return stackTrace;
}
/**
* Joins the given object array in one string, each separated by the given separator.
*
* Example:
*
* join(new String[] {"one", "two", "three"}, ", ") -> "one, two, three"
*
*
* @param objs The array of objects (toString() is used).
* @param sep The separator to use.
* @return The concatinated string.
*/
public static String join(Object[] objs, String sep) {
StringBuffer buf = new StringBuffer();
for (int i = 0; i < objs.length; i++) {
buf.append(objs[i]).append(sep);
}
if (objs.length > 0) {
buf.setLength(buf.length() - sep.length()); // delete sep
}
return buf.toString();
}
// basic string codec (same algo as CVS passfile, inspired by ant CVSPass class
/** Array contain char conversion data */
private static final char[] SHIFTS = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,
17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 114, 120, 53, 79, 96, 109,
72, 108, 70, 64, 76, 67, 116, 74, 68, 87, 111, 52, 75, 119, 49, 34, 82, 81, 95, 65,
112, 86, 118, 110, 122, 105, 41, 57, 83, 43, 46, 102, 40, 89, 38, 103, 45, 50, 42, 123,
91, 35, 125, 55, 54, 66, 124, 126, 59, 47, 92, 71, 115, 78, 88, 107, 106, 56, 36, 121,
117, 104, 101, 100, 69, 73, 99, 63, 94, 93, 39, 37, 61, 48, 58, 113, 32, 90, 44, 98,
60, 51, 33, 97, 62, 77, 84, 80, 85, 223, 225, 216, 187, 166, 229, 189, 222, 188, 141,
249, 148, 200, 184, 136, 248, 190, 199, 170, 181, 204, 138, 232, 218, 183, 255, 234,
220, 247, 213, 203, 226, 193, 174, 172, 228, 252, 217, 201, 131, 230, 197, 211, 145,
238, 161, 179, 160, 212, 207, 221, 254, 173, 202, 146, 224, 151, 140, 196, 205, 130,
135, 133, 143, 246, 192, 159, 244, 239, 185, 168, 215, 144, 139, 165, 180, 157, 147,
186, 214, 176, 227, 231, 219, 169, 175, 156, 206, 198, 129, 164, 150, 210, 154, 177,
134, 127, 182, 128, 158, 208, 162, 132, 167, 209, 149, 241, 153, 251, 237, 236, 171,
195, 243, 233, 253, 240, 194, 250, 191, 155, 142, 137, 245, 235, 163, 242, 178, 152};
/**
* Encrypt the given string in a way which anybody having access to this method algorithm can
* easily decrypt. This is useful only to avoid clear string storage in a file for example, but
* shouldn't be considered as a real mean of security. This only works with simple characters
* (char < 256).
*
* @param str
* the string to encrypt
* @return the encrypted version of the string
*/
public static final String encrypt(String str) {
if (str == null) {
return null;
}
StringBuffer buf = new StringBuffer();
for (int i = 0; i < str.length(); i++) {
char c = str.charAt(i);
if (c >= SHIFTS.length) {
throw new IllegalArgumentException(
"encrypt method can only be used with simple characters. '" + c
+ "' not allowed");
}
buf.append(SHIFTS[c]);
}
return buf.toString();
}
/**
* Decrypts a string encrypted with encrypt.
*
* @param str
* the encrypted string to decrypt
* @return The decrypted string.
*/
public static final String decrypt(String str) {
if (str == null) {
return null;
}
StringBuffer buf = new StringBuffer();
for (int i = 0; i < str.length(); i++) {
buf.append(decrypt(str.charAt(i)));
}
return buf.toString();
}
private static char decrypt(char c) {
for (char i = 0; i < SHIFTS.length; i++) {
if (SHIFTS[i] == c) {
return i;
}
}
throw new IllegalArgumentException("Impossible to decrypt '" + c
+ "'. Unhandled character.");
}
public static String repeat(String str, int count) {
StringBuffer sb = new StringBuffer();
for (int i = 0; i < count; i++) {
sb.append(str);
}
return sb.toString();
}
}
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