Http Header Helper : HttpURLConnection « Network Protocol « Java






Http Header Helper

  

/**
 * 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.
 */


import java.nio.charset.Charset;
import java.nio.charset.IllegalCharsetNameException;
import java.nio.charset.UnsupportedCharsetException;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

public final class HttpHeaderHelper {
    public static final String ACCEPT_ENCODING = "Accept-Encoding";
    public static final String CONTENT_TYPE = "Content-Type";
    public static final String CONTENT_ID = "Content-ID";
    public static final String CONTENT_ENCODING = "Content-Encoding";
    public static final String CONTENT_TRANSFER_ENCODING = "Content-Transfer-Encoding";
    public static final String COOKIE = "Cookie";
    public static final String TRANSFER_ENCODING = "Transfer-Encoding";
    public static final String CHUNKED = "chunked";
    public static final String CONNECTION = "Connection";
    public static final String CLOSE = "close";
    public static final String AUTHORIZATION = "Authorization";
    private static final Charset UTF8 = Charset.forName("utf-8"); 

    
    private static Map<String, String> internalHeaders = new HashMap<String, String>();
    private static Map<String, String> encodings = new ConcurrentHashMap<String, String>();
    
    static {
        internalHeaders.put("Accept-Encoding", "accept-encoding");
        internalHeaders.put("Content-Encoding", "content-encoding");
        internalHeaders.put("Content-Type", "content-type");
        internalHeaders.put("Content-ID", "content-id");
        internalHeaders.put("Content-Transfer-Encoding", "content-transfer-encoding"); 
        internalHeaders.put("Transfer-Encoding", "transfer-encoding");
        internalHeaders.put("Connection", "connection");
        internalHeaders.put("authorization", "Authorization");
        internalHeaders.put("soapaction", "SOAPAction");
        internalHeaders.put("accept", "Accept");
    }
    
    private HttpHeaderHelper() {
        
    }
    
    public static List getHeader(Map<String, List<String>> headerMap, String key) {
        return headerMap.get(getHeaderKey(key));
    }
    
    public static String getHeaderKey(String key) {
        if (internalHeaders.containsKey(key)) {
            return internalHeaders.get(key);
        } else {
            return key;
        }
    }
    
    //helper to map the charsets that various things send in the http Content-Type header 
    //into something that is actually supported by Java and the Stax parsers and such.
    public static String mapCharset(String enc) {
        if (enc == null) {
            return UTF8.name();
        }
        //older versions of tomcat don't properly parse ContentType headers with stuff
        //after charset="UTF-8"
        int idx = enc.indexOf(";");
        if (idx != -1) {
            enc = enc.substring(0, idx);
        }
        // Charsets can be quoted. But it's quite certain that they can't have escaped quoted or
        // anything like that.
        enc = enc.replace("\"", "").trim();
        enc = enc.replace("'", "");
        if ("".equals(enc)) {
            return UTF8.name();
        }
        String newenc = encodings.get(enc);
        if (newenc == null) {
            try {
                newenc = Charset.forName(enc).name();
            } catch (IllegalCharsetNameException icne) {
                return null;
            } catch (UnsupportedCharsetException uce) {
                return null;
            }
            encodings.put(enc, newenc);
        }
        return newenc;
    }
}

   
    
  








Related examples in the same category

1.Get the date of a url connection
2.Get the document expiration date
3.Get the document Last-modified date
4.Show the content type
5.Show the content length
6.Display request method
7.Get response code
8.Display response message
9.Display header information
10.Download and display the content
11.A Web Page Source Viewer
12.Reading from a URLConnection
13.Use BufferedReader to read content from a URL
14.Check if a page exists
15.Identify ourself to a proxy
16.Connect through a Proxy
17.Preventing Automatic Redirects in a HTTP Connection
18.Converting x-www-form-urlencoded Data
19.Getting the Cookies from an HTTP Connection
20.Sending a Cookie to an HTTP Server
21.Getting the Response Headers from an HTTP Connection
22.java.net.Authenticator can be used to send the credentials when needed
23.Grabbing a page using socket
24.Http connection Utilities
25.Available Port Finder