Android example source code file (Headers.java)

This example Android source code file (Headers.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Android by Example" ^TM.

Java - Android tags/keywords

android, arraylist, cache_control, conn_close, hash_content_type, hash_etag, hash_last_modified, hash_proxy_authenticate, hash_refresh, last_modified, no_content_length, pragma, string, util, utilities, utils, www_authenticate, x_permitted_cross_domain_policies

The Headers.java Android example source code

/*
 * Copyright (C) 2006 The Android Open Source Project
 *
 * 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 android.net.http;

import android.util.Config;
import android.util.Log;

import java.util.ArrayList;

import org.apache.http.HeaderElement;
import org.apache.http.entity.ContentLengthStrategy;
import org.apache.http.message.BasicHeaderValueParser;
import org.apache.http.message.ParserCursor;
import org.apache.http.protocol.HTTP;
import org.apache.http.util.CharArrayBuffer;

/**
 * Manages received headers
 *
 * {@hide}
 */
public final class Headers {
    private static final String LOGTAG = "Http";

    // header parsing constant
    /**
     * indicate HTTP 1.0 connection close after the response
     */
    public final static int CONN_CLOSE = 1;
    /**
     * indicate HTTP 1.1 connection keep alive
     */
    public final static int CONN_KEEP_ALIVE = 2;

    // initial values.
    public final static int NO_CONN_TYPE = 0;
    public final static long NO_TRANSFER_ENCODING = 0;
    public final static long NO_CONTENT_LENGTH = -1;

    // header strings
    public final static String TRANSFER_ENCODING = "transfer-encoding";
    public final static String CONTENT_LEN = "content-length";
    public final static String CONTENT_TYPE = "content-type";
    public final static String CONTENT_ENCODING = "content-encoding";
    public final static String CONN_DIRECTIVE = "connection";

    public final static String LOCATION = "location";
    public final static String PROXY_CONNECTION = "proxy-connection";

    public final static String WWW_AUTHENTICATE = "www-authenticate";
    public final static String PROXY_AUTHENTICATE = "proxy-authenticate";
    public final static String CONTENT_DISPOSITION = "content-disposition";
    public final static String ACCEPT_RANGES = "accept-ranges";
    public final static String EXPIRES = "expires";
    public final static String CACHE_CONTROL = "cache-control";
    public final static String LAST_MODIFIED = "last-modified";
    public final static String ETAG = "etag";
    public final static String SET_COOKIE = "set-cookie";
    public final static String PRAGMA = "pragma";
    public final static String REFRESH = "refresh";
    public final static String X_PERMITTED_CROSS_DOMAIN_POLICIES = "x-permitted-cross-domain-policies";

    // following hash are generated by String.hashCode()
    private final static int HASH_TRANSFER_ENCODING = 1274458357;
    private final static int HASH_CONTENT_LEN = -1132779846;
    private final static int HASH_CONTENT_TYPE = 785670158;
    private final static int HASH_CONTENT_ENCODING = 2095084583;
    private final static int HASH_CONN_DIRECTIVE = -775651618;
    private final static int HASH_LOCATION = 1901043637;
    private final static int HASH_PROXY_CONNECTION = 285929373;
    private final static int HASH_WWW_AUTHENTICATE = -243037365;
    private final static int HASH_PROXY_AUTHENTICATE = -301767724;
    private final static int HASH_CONTENT_DISPOSITION = -1267267485;
    private final static int HASH_ACCEPT_RANGES = 1397189435;
    private final static int HASH_EXPIRES = -1309235404;
    private final static int HASH_CACHE_CONTROL = -208775662;
    private final static int HASH_LAST_MODIFIED = 150043680;
    private final static int HASH_ETAG = 3123477;
    private final static int HASH_SET_COOKIE = 1237214767;
    private final static int HASH_PRAGMA = -980228804;
    private final static int HASH_REFRESH = 1085444827;
    private final static int HASH_X_PERMITTED_CROSS_DOMAIN_POLICIES = -1345594014;

    // keep any headers that require direct access in a presized
    // string array
    private final static int IDX_TRANSFER_ENCODING = 0;
    private final static int IDX_CONTENT_LEN = 1;
    private final static int IDX_CONTENT_TYPE = 2;
    private final static int IDX_CONTENT_ENCODING = 3;
    private final static int IDX_CONN_DIRECTIVE = 4;
    private final static int IDX_LOCATION = 5;
    private final static int IDX_PROXY_CONNECTION = 6;
    private final static int IDX_WWW_AUTHENTICATE = 7;
    private final static int IDX_PROXY_AUTHENTICATE = 8;
    private final static int IDX_CONTENT_DISPOSITION = 9;
    private final static int IDX_ACCEPT_RANGES = 10;
    private final static int IDX_EXPIRES = 11;
    private final static int IDX_CACHE_CONTROL = 12;
    private final static int IDX_LAST_MODIFIED = 13;
    private final static int IDX_ETAG = 14;
    private final static int IDX_SET_COOKIE = 15;
    private final static int IDX_PRAGMA = 16;
    private final static int IDX_REFRESH = 17;
    private final static int IDX_X_PERMITTED_CROSS_DOMAIN_POLICIES = 18;

    private final static int HEADER_COUNT = 19;

    /* parsed values */
    private long transferEncoding;
    private long contentLength; // Content length of the incoming data
    private int connectionType;
    private ArrayList<String> cookies = new ArrayList(2);

    private String[] mHeaders = new String[HEADER_COUNT];
    private final static String[] sHeaderNames = {
        TRANSFER_ENCODING,
        CONTENT_LEN,
        CONTENT_TYPE,
        CONTENT_ENCODING,
        CONN_DIRECTIVE,
        LOCATION,
        PROXY_CONNECTION,
        WWW_AUTHENTICATE,
        PROXY_AUTHENTICATE,
        CONTENT_DISPOSITION,
        ACCEPT_RANGES,
        EXPIRES,
        CACHE_CONTROL,
        LAST_MODIFIED,
        ETAG,
        SET_COOKIE,
        PRAGMA,
        REFRESH,
        X_PERMITTED_CROSS_DOMAIN_POLICIES
    };

    // Catch-all for headers not explicitly handled
    private ArrayList<String> mExtraHeaderNames = new ArrayList(4);
    private ArrayList<String> mExtraHeaderValues = new ArrayList(4);

    public Headers() {
        transferEncoding = NO_TRANSFER_ENCODING;
        contentLength = NO_CONTENT_LENGTH;
        connectionType = NO_CONN_TYPE;
    }

    public void parseHeader(CharArrayBuffer buffer) {
        int pos = CharArrayBuffers.setLowercaseIndexOf(buffer, ':');
        if (pos == -1) {
            return;
        }
        String name = buffer.substringTrimmed(0, pos);
        if (name.length() == 0) {
            return;
        }
        pos++;

        String val = buffer.substringTrimmed(pos, buffer.length());
        if (HttpLog.LOGV) {
            HttpLog.v("hdr " + buffer.length() + " " + buffer);
        }

        switch (name.hashCode()) {
        case HASH_TRANSFER_ENCODING:
            if (name.equals(TRANSFER_ENCODING)) {
                mHeaders[IDX_TRANSFER_ENCODING] = val;
                HeaderElement[] encodings = BasicHeaderValueParser.DEFAULT
                        .parseElements(buffer, new ParserCursor(pos,
                                buffer.length()));
                // The chunked encoding must be the last one applied RFC2616,
                // 14.41
                int len = encodings.length;
                if (HTTP.IDENTITY_CODING.equalsIgnoreCase(val)) {
                    transferEncoding = ContentLengthStrategy.IDENTITY;
                } else if ((len > 0)
                        && (HTTP.CHUNK_CODING
                                .equalsIgnoreCase(encodings[len - 1].getName()))) {
                    transferEncoding = ContentLengthStrategy.CHUNKED;
                } else {
                    transferEncoding = ContentLengthStrategy.IDENTITY;
                }
            }
            break;
        case HASH_CONTENT_LEN:
            if (name.equals(CONTENT_LEN)) {
                mHeaders[IDX_CONTENT_LEN] = val;
                try {
                    contentLength = Long.parseLong(val);
                } catch (NumberFormatException e) {
                    if (Config.LOGV) {
                        Log.v(LOGTAG, "Headers.headers(): error parsing"
                                + " content length: " + buffer.toString());
                    }
                }
            }
            break;
        case HASH_CONTENT_TYPE:
            if (name.equals(CONTENT_TYPE)) {
                mHeaders[IDX_CONTENT_TYPE] = val;
            }
            break;
        case HASH_CONTENT_ENCODING:
            if (name.equals(CONTENT_ENCODING)) {
                mHeaders[IDX_CONTENT_ENCODING] = val;
            }
            break;
        case HASH_CONN_DIRECTIVE:
            if (name.equals(CONN_DIRECTIVE)) {
                mHeaders[IDX_CONN_DIRECTIVE] = val;
                setConnectionType(buffer, pos);
            }
            break;
        case HASH_LOCATION:
            if (name.equals(LOCATION)) {
                mHeaders[IDX_LOCATION] = val;
            }
            break;
        case HASH_PROXY_CONNECTION:
            if (name.equals(PROXY_CONNECTION)) {
                mHeaders[IDX_PROXY_CONNECTION] = val;
                setConnectionType(buffer, pos);
            }
            break;
        case HASH_WWW_AUTHENTICATE:
            if (name.equals(WWW_AUTHENTICATE)) {
                mHeaders[IDX_WWW_AUTHENTICATE] = val;
            }
            break;
        case HASH_PROXY_AUTHENTICATE:
            if (name.equals(PROXY_AUTHENTICATE)) {
                mHeaders[IDX_PROXY_AUTHENTICATE] = val;
            }
            break;
        case HASH_CONTENT_DISPOSITION:
            if (name.equals(CONTENT_DISPOSITION)) {
                mHeaders[IDX_CONTENT_DISPOSITION] = val;
            }
            break;
        case HASH_ACCEPT_RANGES:
            if (name.equals(ACCEPT_RANGES)) {
                mHeaders[IDX_ACCEPT_RANGES] = val;
            }
            break;
        case HASH_EXPIRES:
            if (name.equals(EXPIRES)) {
                mHeaders[IDX_EXPIRES] = val;
            }
            break;
        case HASH_CACHE_CONTROL:
            if (name.equals(CACHE_CONTROL)) {
                // In case where we receive more than one header, create a ',' separated list.
                // This should be ok, according to RFC 2616 chapter 4.2
                if (mHeaders[IDX_CACHE_CONTROL] != null &&
                    mHeaders[IDX_CACHE_CONTROL].length() > 0) {
                    mHeaders[IDX_CACHE_CONTROL] += (',' + val);
                } else {
                    mHeaders[IDX_CACHE_CONTROL] = val;
                }
            }
            break;
        case HASH_LAST_MODIFIED:
            if (name.equals(LAST_MODIFIED)) {
                mHeaders[IDX_LAST_MODIFIED] = val;
            }
            break;
        case HASH_ETAG:
            if (name.equals(ETAG)) {
                mHeaders[IDX_ETAG] = val;
            }
            break;
        case HASH_SET_COOKIE:
            if (name.equals(SET_COOKIE)) {
                mHeaders[IDX_SET_COOKIE] = val;
                cookies.add(val);
            }
            break;
        case HASH_PRAGMA:
            if (name.equals(PRAGMA)) {
                mHeaders[IDX_PRAGMA] = val;
            }
            break;
        case HASH_REFRESH:
            if (name.equals(REFRESH)) {
                mHeaders[IDX_REFRESH] = val;
            }
            break;
        case HASH_X_PERMITTED_CROSS_DOMAIN_POLICIES:
            if (name.equals(X_PERMITTED_CROSS_DOMAIN_POLICIES)) {
                mHeaders[IDX_X_PERMITTED_CROSS_DOMAIN_POLICIES] = val;
            }
            break;
        default:
            mExtraHeaderNames.add(name);
            mExtraHeaderValues.add(val);
        }
    }

    public long getTransferEncoding() {
        return transferEncoding;
    }

    public long getContentLength() {
        return contentLength;
    }

    public int getConnectionType() {
        return connectionType;
    }

    public String getContentType() {
        return mHeaders[IDX_CONTENT_TYPE];
    }

    public String getContentEncoding() {
        return mHeaders[IDX_CONTENT_ENCODING];
    }

    public String getLocation() {
        return mHeaders[IDX_LOCATION];
    }

    public String getWwwAuthenticate() {
        return mHeaders[IDX_WWW_AUTHENTICATE];
    }

    public String getProxyAuthenticate() {
        return mHeaders[IDX_PROXY_AUTHENTICATE];
    }

    public String getContentDisposition() {
        return mHeaders[IDX_CONTENT_DISPOSITION];
    }

    public String getAcceptRanges() {
        return mHeaders[IDX_ACCEPT_RANGES];
    }

    public String getExpires() {
        return mHeaders[IDX_EXPIRES];
    }

    public String getCacheControl() {
        return mHeaders[IDX_CACHE_CONTROL];
    }

    public String getLastModified() {
        return mHeaders[IDX_LAST_MODIFIED];
    }

    public String getEtag() {
        return mHeaders[IDX_ETAG];
    }

    public ArrayList<String> getSetCookie() {
        return this.cookies;
    }

    public String getPragma() {
        return mHeaders[IDX_PRAGMA];
    }

    public String getRefresh() {
        return mHeaders[IDX_REFRESH];
    }

    public String getXPermittedCrossDomainPolicies() {
        return mHeaders[IDX_X_PERMITTED_CROSS_DOMAIN_POLICIES];
    }

    public void setContentLength(long value) {
        this.contentLength = value;
    }

    public void setContentType(String value) {
        mHeaders[IDX_CONTENT_TYPE] = value;
    }

    public void setContentEncoding(String value) {
        mHeaders[IDX_CONTENT_ENCODING] = value;
    }

    public void setLocation(String value) {
        mHeaders[IDX_LOCATION] = value;
    }

    public void setWwwAuthenticate(String value) {
        mHeaders[IDX_WWW_AUTHENTICATE] = value;
    }

    public void setProxyAuthenticate(String value) {
        mHeaders[IDX_PROXY_AUTHENTICATE] = value;
    }

    public void setContentDisposition(String value) {
        mHeaders[IDX_CONTENT_DISPOSITION] = value;
    }

    public void setAcceptRanges(String value) {
        mHeaders[IDX_ACCEPT_RANGES] = value;
    }

    public void setExpires(String value) {
        mHeaders[IDX_EXPIRES] = value;
    }

    public void setCacheControl(String value) {
        mHeaders[IDX_CACHE_CONTROL] = value;
    }

    public void setLastModified(String value) {
        mHeaders[IDX_LAST_MODIFIED] = value;
    }

    public void setEtag(String value) {
        mHeaders[IDX_ETAG] = value;
    }

    public void setXPermittedCrossDomainPolicies(String value) {
        mHeaders[IDX_X_PERMITTED_CROSS_DOMAIN_POLICIES] = value;
    }

    public interface HeaderCallback {
        public void header(String name, String value);
    }

    /**
     * Reports all non-null headers to the callback
     */
    public void getHeaders(HeaderCallback hcb) {
        for (int i = 0; i < HEADER_COUNT; i++) {
            String h = mHeaders[i];
            if (h != null) {
                hcb.header(sHeaderNames[i], h);
            }
        }
        int extraLen = mExtraHeaderNames.size();
        for (int i = 0; i < extraLen; i++) {
            if (Config.LOGV) {
                HttpLog.v("Headers.getHeaders() extra: " + i + " " +
                          mExtraHeaderNames.get(i) + " " + mExtraHeaderValues.get(i));
            }
            hcb.header(mExtraHeaderNames.get(i),
                       mExtraHeaderValues.get(i));
        }

    }

    private void setConnectionType(CharArrayBuffer buffer, int pos) {
        if (CharArrayBuffers.containsIgnoreCaseTrimmed(
                buffer, pos, HTTP.CONN_CLOSE)) {
            connectionType = CONN_CLOSE;
        } else if (CharArrayBuffers.containsIgnoreCaseTrimmed(
                buffer, pos, HTTP.CONN_KEEP_ALIVE)) {
            connectionType = CONN_KEEP_ALIVE;
        }
    }
}