io.joshworks.restclient.http.utils.ResponseUtils Maven / Gradle / Ivy

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package io.joshworks.restclient.http.utils;

import io.joshworks.restclient.Constants;
import org.apache.http.Header;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class ResponseUtils {

    private static final Pattern charsetPattern = Pattern.compile("(?i)\\bcharset=\\s*\"?([^\\s;\"]*)");

    /**
     * Parse out a charset from a content type header.
     *
     * @param contentType e.g. "text/html; charset=EUC-JP"
     * @return "EUC-JP", or null if not found. Charset is trimmed and uppercased.
     */
    public static String getCharsetFromContentType(String contentType) {
        if (contentType == null)
            return null;

        Matcher m = charsetPattern.matcher(contentType);
        if (m.find()) {
            return m.group(1).trim().toUpperCase();
        }
        return null;
    }

    public static byte[] readBytes(InputStream is) throws IOException {
        int len;
        int size = 8192;
        byte[] buf;

        if (is instanceof ByteArrayInputStream) {
            size = is.available();
            buf = new byte[size];
            len = is.read(buf, 0, size);
        } else {
            ByteArrayOutputStream bos = new ByteArrayOutputStream();
            buf = new byte[size];
            while ((len = is.read(buf, 0, size)) != -1)
                bos.write(buf, 0, len);
            buf = bos.toByteArray();
        }
        return buf;
    }

    public static boolean isGzipped(Header contentEncoding) {
        if (contentEncoding != null) {
            String value = contentEncoding.getValue();
            if (value != null && Constants.GZIP.equals(value.toLowerCase().trim())) {
                return true;
            }
        }
        return false;
    }

}