michael@0: /*
michael@0:  * ====================================================================
michael@0:  * Licensed to the Apache Software Foundation (ASF) under one
michael@0:  * or more contributor license agreements.  See the NOTICE file
michael@0:  * distributed with this work for additional information
michael@0:  * regarding copyright ownership.  The ASF licenses this file
michael@0:  * to you under the Apache License, Version 2.0 (the
michael@0:  * "License"); you may not use this file except in compliance
michael@0:  * with the License.  You may obtain a copy of the License at
michael@0:  *
michael@0:  *   http://www.apache.org/licenses/LICENSE-2.0
michael@0:  *
michael@0:  * Unless required by applicable law or agreed to in writing,
michael@0:  * software distributed under the License is distributed on an
michael@0:  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
michael@0:  * KIND, either express or implied.  See the License for the
michael@0:  * specific language governing permissions and limitations
michael@0:  * under the License.
michael@0:  * ====================================================================
michael@0:  *
michael@0:  * This software consists of voluntary contributions made by many
michael@0:  * individuals on behalf of the Apache Software Foundation.  For more
michael@0:  * information on the Apache Software Foundation, please see
michael@0:  * <http://www.apache.org/>.
michael@0:  *
michael@0:  */
michael@0: package ch.boye.httpclientandroidlib.util;
michael@0: 
michael@0: import java.io.UnsupportedEncodingException;
michael@0: 
michael@0: import ch.boye.httpclientandroidlib.protocol.HTTP;
michael@0: 
michael@0: /**
michael@0:  * The home for utility methods that handle various encoding tasks.
michael@0:  *
michael@0:  *
michael@0:  * @since 4.0
michael@0:  */
michael@0: public final class EncodingUtils {
michael@0: 
michael@0:     /**
michael@0:      * Converts the byte array of HTTP content characters to a string. If
michael@0:      * the specified charset is not supported, default system encoding
michael@0:      * is used.
michael@0:      *
michael@0:      * @param data the byte array to be encoded
michael@0:      * @param offset the index of the first byte to encode
michael@0:      * @param length the number of bytes to encode
michael@0:      * @param charset the desired character encoding
michael@0:      * @return The result of the conversion.
michael@0:      */
michael@0:     public static String getString(
michael@0:         final byte[] data,
michael@0:         int offset,
michael@0:         int length,
michael@0:         String charset
michael@0:     ) {
michael@0: 
michael@0:         if (data == null) {
michael@0:             throw new IllegalArgumentException("Parameter may not be null");
michael@0:         }
michael@0: 
michael@0:         if (charset == null || charset.length() == 0) {
michael@0:             throw new IllegalArgumentException("charset may not be null or empty");
michael@0:         }
michael@0: 
michael@0:         try {
michael@0:             return new String(data, offset, length, charset);
michael@0:         } catch (UnsupportedEncodingException e) {
michael@0:             return new String(data, offset, length);
michael@0:         }
michael@0:     }
michael@0: 
michael@0: 
michael@0:     /**
michael@0:      * Converts the byte array of HTTP content characters to a string. If
michael@0:      * the specified charset is not supported, default system encoding
michael@0:      * is used.
michael@0:      *
michael@0:      * @param data the byte array to be encoded
michael@0:      * @param charset the desired character encoding
michael@0:      * @return The result of the conversion.
michael@0:      */
michael@0:     public static String getString(final byte[] data, final String charset) {
michael@0:         if (data == null) {
michael@0:             throw new IllegalArgumentException("Parameter may not be null");
michael@0:         }
michael@0:         return getString(data, 0, data.length, charset);
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Converts the specified string to a byte array.  If the charset is not supported the
michael@0:      * default system charset is used.
michael@0:      *
michael@0:      * @param data the string to be encoded
michael@0:      * @param charset the desired character encoding
michael@0:      * @return The resulting byte array.
michael@0:      */
michael@0:     public static byte[] getBytes(final String data, final String charset) {
michael@0: 
michael@0:         if (data == null) {
michael@0:             throw new IllegalArgumentException("data may not be null");
michael@0:         }
michael@0: 
michael@0:         if (charset == null || charset.length() == 0) {
michael@0:             throw new IllegalArgumentException("charset may not be null or empty");
michael@0:         }
michael@0: 
michael@0:         try {
michael@0:             return data.getBytes(charset);
michael@0:         } catch (UnsupportedEncodingException e) {
michael@0:             return data.getBytes();
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Converts the specified string to byte array of ASCII characters.
michael@0:      *
michael@0:      * @param data the string to be encoded
michael@0:      * @return The string as a byte array.
michael@0:      */
michael@0:     public static byte[] getAsciiBytes(final String data) {
michael@0: 
michael@0:         if (data == null) {
michael@0:             throw new IllegalArgumentException("Parameter may not be null");
michael@0:         }
michael@0: 
michael@0:         try {
michael@0:             return data.getBytes(HTTP.US_ASCII);
michael@0:         } catch (UnsupportedEncodingException e) {
michael@0:             throw new Error("HttpClient requires ASCII support");
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Converts the byte array of ASCII characters to a string. This method is
michael@0:      * to be used when decoding content of HTTP elements (such as response
michael@0:      * headers)
michael@0:      *
michael@0:      * @param data the byte array to be encoded
michael@0:      * @param offset the index of the first byte to encode
michael@0:      * @param length the number of bytes to encode
michael@0:      * @return The string representation of the byte array
michael@0:      */
michael@0:     public static String getAsciiString(final byte[] data, int offset, int length) {
michael@0: 
michael@0:         if (data == null) {
michael@0:             throw new IllegalArgumentException("Parameter may not be null");
michael@0:         }
michael@0: 
michael@0:         try {
michael@0:             return new String(data, offset, length, HTTP.US_ASCII);
michael@0:         } catch (UnsupportedEncodingException e) {
michael@0:             throw new Error("HttpClient requires ASCII support");
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Converts the byte array of ASCII characters to a string. This method is
michael@0:      * to be used when decoding content of HTTP elements (such as response
michael@0:      * headers)
michael@0:      *
michael@0:      * @param data the byte array to be encoded
michael@0:      * @return The string representation of the byte array
michael@0:      */
michael@0:     public static String getAsciiString(final byte[] data) {
michael@0:         if (data == null) {
michael@0:             throw new IllegalArgumentException("Parameter may not be null");
michael@0:         }
michael@0:         return getAsciiString(data, 0, data.length);
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * This class should not be instantiated.
michael@0:      */
michael@0:     private EncodingUtils() {
michael@0:     }
michael@0: 
michael@0: }