/*
* ====================================================================
* 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.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
*/
package org.apache.http.entity;
import java.io.Serializable;
import java.nio.charset.Charset;
import java.nio.charset.UnsupportedCharsetException;
import java.util.Locale;
import org.apache.http.Consts;
import org.apache.http.Header;
import org.apache.http.HeaderElement;
import org.apache.http.HttpEntity;
import org.apache.http.NameValuePair;
import org.apache.http.ParseException;
import org.apache.http.annotation.Immutable;
import org.apache.http.message.BasicHeaderValueParser;
/**
* Content type information consisting of a MIME type and an optional charset.
* <p/>
* This class makes no attempts to verify validity of the MIME type.
* The input parameters of the {@link #create(String, String)} method, however, may not
* contain characters <">, <;>, <,> reserved by the HTTP specification.
*
* @since 4.2
*/
@Immutable
public final class ContentType implements Serializable {
private static final long serialVersionUID = -7768694718232371896L;
// constants
public static final ContentType APPLICATION_ATOM_XML = create(
"application/atom+xml", Consts.ISO_8859_1);
public static final ContentType APPLICATION_FORM_URLENCODED = create(
"application/x-www-form-urlencoded", Consts.ISO_8859_1);
public static final ContentType APPLICATION_JSON = create(
"application/json", Consts.UTF_8);
public static final ContentType APPLICATION_OCTET_STREAM = create(
"application/octet-stream", (Charset) null);
public static final ContentType APPLICATION_SVG_XML = create(
"application/svg+xml", Consts.ISO_8859_1);
public static final ContentType APPLICATION_XHTML_XML = create(
"application/xhtml+xml", Consts.ISO_8859_1);
public static final ContentType APPLICATION_XML = create(
"application/xml", Consts.ISO_8859_1);
public static final ContentType MULTIPART_FORM_DATA = create(
"multipart/form-data", Consts.ISO_8859_1);
public static final ContentType TEXT_HTML = create(
"text/html", Consts.ISO_8859_1);
public static final ContentType TEXT_PLAIN = create(
"text/plain", Consts.ISO_8859_1);
public static final ContentType TEXT_XML = create(
"text/xml", Consts.ISO_8859_1);
public static final ContentType WILDCARD = create(
"*/*", (Charset) null);
// defaults
public static final ContentType DEFAULT_TEXT = TEXT_PLAIN;
public static final ContentType DEFAULT_BINARY = APPLICATION_OCTET_STREAM;
private final String mimeType;
private final Charset charset;
/**
* Given a MIME type and a character set, constructs a ContentType.
* @param mimeType The MIME type to use for the ContentType header.
* @param charset The optional character set to use with the ContentType header.
* @throws UnsupportedCharsetException
* If no support for the named charset is available in this Java virtual machine
*/
ContentType(final String mimeType, final Charset charset) {
this.mimeType = mimeType;
this.charset = charset;
}
public String getMimeType() {
return this.mimeType;
}
public Charset getCharset() {
return this.charset;
}
/**
* Converts a ContentType to a string which can be used as a ContentType header.
* If a charset is provided by the ContentType, it will be included in the string.
*/
@Override
public String toString() {
StringBuilder buf = new StringBuilder();
buf.append(this.mimeType);
if (this.charset != null) {
buf.append("; charset=");
buf.append(this.charset.name());
}
return buf.toString();
}
private static boolean valid(final String s) {
for (int i = 0; i < s.length(); i++) {
char ch = s.charAt(i);
if (ch == '"' || ch == ',' || ch == ';') {
return false;
}
}
return true;
}
/**
* Creates a new instance of {@link ContentType}.
*
* @param mimeType MIME type. It may not be <code>null</code> or empty. It may not contain
* characters <">, <;>, <,> reserved by the HTTP specification.
* @param charset charset.
* @return content type
*/
public static ContentType create(final String mimeType, final Charset charset) {
if (mimeType == null) {
throw new IllegalArgumentException("MIME type may not be null");
}
String type = mimeType.trim().toLowerCase(Locale.US);
if (type.length() == 0) {
throw new IllegalArgumentException("MIME type may not be empty");
}
if (!valid(type)) {
throw new IllegalArgumentException("MIME type may not contain reserved characters");
}
return new ContentType(type, charset);
}
/**
* Creates a new instance of {@link ContentType} without a charset.
*
* @param mimeType MIME type. It may not be <code>null</code> or empty. It may not contain
* characters <">, <;>, <,> reserved by the HTTP specification.
* @return content type
*/
public static ContentType create(final String mimeType) {
return new ContentType(mimeType, (Charset) null);
}
/**
* Creates a new instance of {@link ContentType}.
*
* @param mimeType MIME type. It may not be <code>null</code> or empty. It may not contain
* characters <">, <;>, <,> reserved by the HTTP specification.
* @param charset charset. It may not contain characters <">, <;>, <,> reserved by the HTTP
* specification. This parameter is optional.
* @return content type
*/
public static ContentType create(
final String mimeType, final String charset) throws UnsupportedCharsetException {
return create(mimeType, charset != null ? Charset.forName(charset) : null);
}
private static ContentType create(final HeaderElement helem) {
String mimeType = helem.getName();
String charset = null;
NameValuePair param = helem.getParameterByName("charset");
if (param != null) {
charset = param.getValue();
}
return create(mimeType, charset);
}
/**
* Parses textual representation of <code>Content-Type</code> value.
*
* @param s text
* @return content type
* @throws ParseException if the given text does not represent a valid
* <code>Content-Type</code> value.
*/
public static ContentType parse(
final String s) throws ParseException, UnsupportedCharsetException {
if (s == null) {
throw new IllegalArgumentException("Content type may not be null");
}
HeaderElement[] elements = BasicHeaderValueParser.parseElements(s, null);
if (elements.length > 0) {
return create(elements[0]);
} else {
throw new ParseException("Invalid content type: " + s);
}
}
/**
* Extracts <code>Content-Type</code> value from {@link HttpEntity} exactly as
* specified by the <code>Content-Type</code> header of the entity. Returns <code>null</code>
* if not specified.
*
* @param entity HTTP entity
* @return content type
* @throws ParseException if the given text does not represent a valid
* <code>Content-Type</code> value.
*/
public static ContentType get(
final HttpEntity entity) throws ParseException, UnsupportedCharsetException {
if (entity == null) {
return null;
}
Header header = entity.getContentType();
if (header != null) {
HeaderElement[] elements = header.getElements();
if (elements.length > 0) {
return create(elements[0]);
}
}
return null;
}
/**
* Extracts <code>Content-Type</code> value from {@link HttpEntity} or returns default value
* if not explicitly specified.
*
* @param entity HTTP entity
* @return content type
* @throws ParseException if the given text does not represent a valid
* <code>Content-Type</code> value.
*/
public static ContentType getOrDefault(final HttpEntity entity) throws ParseException {
ContentType contentType = get(entity);
return contentType != null ? contentType : DEFAULT_TEXT;
}
}