io.prestosql.jdbc.$internal.okhttp3.MediaType Maven / Gradle / Ivy
/*
* Copyright (C) 2013 Square, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package io.prestosql.jdbc.$internal.okhttp3;
import java.nio.charset.Charset;
import java.util.Locale;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import io.prestosql.jdbc.$internal.javax.annotation.Nullable;
/**
* An RFC 2045 Media Type, appropriate to describe
* the content type of an HTTP request or response body.
*/
public final class MediaType {
private static final String TOKEN = "([a-zA-Z0-9-!#$%&'*+.^_`{|}~]+)";
private static final String QUOTED = "\"([^\"]*)\"";
private static final Pattern TYPE_SUBTYPE = Pattern.compile(TOKEN + "/" + TOKEN);
private static final Pattern PARAMETER = Pattern.compile(
";\\s*(?:" + TOKEN + "=(?:" + TOKEN + "|" + QUOTED + "))?");
private final String mediaType;
private final String type;
private final String subtype;
private final @Nullable String charset;
private MediaType(String mediaType, String type, String subtype, @Nullable String charset) {
this.mediaType = mediaType;
this.type = type;
this.subtype = subtype;
this.charset = charset;
}
/**
* Returns a media type for {@code string}, or null if {@code string} is not a well-formed media
* type.
*/
public static @Nullable MediaType parse(String string) {
Matcher typeSubtype = TYPE_SUBTYPE.matcher(string);
if (!typeSubtype.lookingAt()) return null;
String type = typeSubtype.group(1).toLowerCase(Locale.US);
String subtype = typeSubtype.group(2).toLowerCase(Locale.US);
String charset = null;
Matcher parameter = PARAMETER.matcher(string);
for (int s = typeSubtype.end(); s < string.length(); s = parameter.end()) {
parameter.region(s, string.length());
if (!parameter.lookingAt()) return null; // This is not a well-formed media type.
String name = parameter.group(1);
if (name == null || !name.equalsIgnoreCase("charset")) continue;
String charsetParameter;
String token = parameter.group(2);
if (token != null) {
// If the token is 'single-quoted' it's invalid! But we're lenient and strip the quotes.
charsetParameter = (token.startsWith("'") && token.endsWith("'") && token.length() > 2)
? token.substring(1, token.length() - 1)
: token;
} else {
// Value is "double-quoted". That's valid and our regex group already strips the quotes.
charsetParameter = parameter.group(3);
}
if (charset != null && !charsetParameter.equalsIgnoreCase(charset)) {
return null; // Multiple different charsets!
}
charset = charsetParameter;
}
return new MediaType(string, type, subtype, charset);
}
/**
* Returns the high-level media type, such as "text", "image", "audio", "video", or
* "application".
*/
public String type() {
return type;
}
/**
* Returns a specific media subtype, such as "plain" or "png", "mpeg", "mp4" or "xml".
*/
public String subtype() {
return subtype;
}
/**
* Returns the charset of this media type, or null if this media type doesn't specify a charset.
*/
public @Nullable Charset charset() {
return charset(null);
}
/**
* Returns the charset of this media type, or {@code defaultValue} if either this media type
* doesn't specify a charset, of it its charset is unsupported by the current runtime.
*/
public @Nullable Charset charset(@Nullable Charset defaultValue) {
try {
return charset != null ? Charset.forName(charset) : defaultValue;
} catch (IllegalArgumentException e) {
return defaultValue; // This charset is invalid or unsupported. Give up.
}
}
/**
* Returns the encoded media type, like "text/plain; charset=utf-8", appropriate for use in a
* Content-Type header.
*/
@Override public String toString() {
return mediaType;
}
@Override public boolean equals(@Nullable Object other) {
return other instanceof MediaType && ((MediaType) other).mediaType.equals(mediaType);
}
@Override public int hashCode() {
return mediaType.hashCode();
}
}