org.apache.tomcat.util.codec.binary.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.tomcat.util.codec.binary;
import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;
/**
* Converts String to and from bytes using the encodings required by the Java specification. These encodings are
* specified in
* Standard charsets.
*
* This class is immutable and thread-safe.
*
* @see Standard charsets
* @since 1.4
*/
public class StringUtils {
/**
* Calls {@link String#getBytes(Charset)}
*
* @param string
* The string to encode (if null, return null).
* @param charset
* The {@link Charset} to encode the {@code String}
* @return the encoded bytes
*/
private static byte[] getBytes(final String string, final Charset charset) {
if (string == null) {
return null;
}
return string.getBytes(charset);
}
/**
* Encodes the given string into a sequence of bytes using the UTF-8 charset, storing the result into a new byte
* array.
*
* @param string
* the String to encode, may be {@code null}
* @return encoded bytes, or {@code null} if the input string was {@code null}
* @throws NullPointerException
* Thrown if {@link StandardCharsets#UTF_8} is not initialized, which should never happen
* since it is required by the Java platform specification.
* @since As of 1.7, throws {@link NullPointerException} instead of UnsupportedEncodingException
* @see Standard charsets
*/
public static byte[] getBytesUtf8(final String string) {
return getBytes(string, StandardCharsets.UTF_8);
}
/**
* Constructs a new {@code String} by decoding the specified array of bytes using the given charset.
*
* @param bytes
* The bytes to be decoded into characters
* @param charset
* The {@link Charset} to encode the {@code String}; not {@code null}
* @return A new {@code String} decoded from the specified array of bytes using the given charset,
* or {@code null} if the input byte array was {@code null}.
* @throws NullPointerException
* Thrown if charset is {@code null}
*/
private static String newString(final byte[] bytes, final Charset charset) {
return bytes == null ? null : new String(bytes, charset);
}
/**
* Constructs a new {@code String} by decoding the specified array of bytes using the US-ASCII charset.
*
* @param bytes
* The bytes to be decoded into characters
* @return A new {@code String} decoded from the specified array of bytes using the US-ASCII charset,
* or {@code null} if the input byte array was {@code null}.
* @throws NullPointerException
* Thrown if {@link StandardCharsets#US_ASCII} is not initialized, which should never happen
* since it is required by the Java platform specification.
* @since As of 1.7, throws {@link NullPointerException} instead of UnsupportedEncodingException
*/
public static String newStringUsAscii(final byte[] bytes) {
return newString(bytes, StandardCharsets.US_ASCII);
}
/**
* Constructs a new {@code String} by decoding the specified array of bytes using the UTF-8 charset.
*
* @param bytes
* The bytes to be decoded into characters
* @return A new {@code String} decoded from the specified array of bytes using the UTF-8 charset,
* or {@code null} if the input byte array was {@code null}.
* @throws NullPointerException
* Thrown if {@link StandardCharsets#UTF_8} is not initialized, which should never happen since it is
* required by the Java platform specification.
* @since As of 1.7, throws {@link NullPointerException} instead of UnsupportedEncodingException
*/
public static String newStringUtf8(final byte[] bytes) {
return newString(bytes, StandardCharsets.UTF_8);
}
}