WebbUtils.java
package com.goebl.david;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.net.HttpURLConnection;
import java.net.URLEncoder;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.Locale;
import java.util.Map;
import java.util.TimeZone;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;
import java.util.zip.Inflater;
import java.util.zip.InflaterInputStream;
/**
* Static utility method and tools for HTTP traffic parsing and encoding.
*
* @author hgoebl
*/
public class WebbUtils {
protected WebbUtils() {}
/**
* Convert a Map to a query string.
* @param values the map with the values
* <code>null</code> will be encoded as empty string, all other objects are converted to
* String by calling its <code>toString()</code> method.
* @return e.g. "key1=value&key2=&email=max%40example.com"
*/
public static String queryString(Map<String, Object> values) {
StringBuilder sbuf = new StringBuilder();
String separator = "";
for (Map.Entry<String, Object> entry : values.entrySet()) {
Object entryValue = entry.getValue();
if (entryValue instanceof Object[]) {
for (Object value : (Object[]) entryValue) {
appendParam(sbuf, separator, entry.getKey(), value);
separator = "&";
}
} else if (entryValue instanceof Iterable) {
for (Object multiValue : (Iterable) entryValue) {
appendParam(sbuf, separator, entry.getKey(), multiValue);
separator = "&";
}
} else {
appendParam(sbuf, separator, entry.getKey(), entryValue);
separator = "&";
}
}
return sbuf.toString();
}
private static void appendParam(StringBuilder sbuf, String separator, String entryKey, Object value) {
String sValue = value == null ? "" : String.valueOf(value);
sbuf.append(separator);
sbuf.append(urlEncode(entryKey));
sbuf.append('=');
sbuf.append(urlEncode(sValue));
}
/**
* Convert a byte array to a JSONObject.
* @param bytes a UTF-8 encoded string representing a JSON object.
* @return the parsed object
* @throws WebbException in case of error (usually a parsing error due to invalid JSON)
*/
public static JSONObject toJsonObject(byte[] bytes) {
String json;
try {
json = new String(bytes, Const.UTF8);
return new JSONObject(json);
} catch (UnsupportedEncodingException e) {
throw new WebbException(e);
} catch (JSONException e) {
throw new WebbException("payload is not a valid JSON object", e);
}
}
/**
* Convert a byte array to a JSONArray.
* @param bytes a UTF-8 encoded string representing a JSON array.
* @return the parsed JSON array
* @throws WebbException in case of error (usually a parsing error due to invalid JSON)
*/
public static JSONArray toJsonArray(byte[] bytes) {
String json;
try {
json = new String(bytes, Const.UTF8);
return new JSONArray(json);
} catch (UnsupportedEncodingException e) {
throw new WebbException(e);
} catch (JSONException e) {
throw new WebbException("payload is not a valid JSON array", e);
}
}
/**
* Read an <code>InputStream</code> into <code>byte[]</code> until EOF.
* <br>
* Does not close the InputStream!
*
* @param is the stream to read the bytes from
* @return all read bytes as an array
* @throws IOException when read or write operation fails
*/
public static byte[] readBytes(InputStream is) throws IOException {
if (is == null) {
return null;
}
ByteArrayOutputStream baos = new ByteArrayOutputStream();
copyStream(is, baos);
return baos.toByteArray();
}
/**
* Copy complete content of <code>InputStream</code> to <code>OutputStream</code> until EOF.
* <br>
* Does not close the InputStream nor OutputStream!
*
* @param input the stream to read the bytes from
* @param output the stream to write the bytes to
* @throws IOException when read or write operation fails
*/
public static void copyStream(InputStream input, OutputStream output) throws IOException {
byte[] buffer = new byte[1024];
int count;
while ((count = input.read(buffer)) != -1) {
output.write(buffer, 0, count);
}
}
/**
* Creates a new instance of a <code>DateFormat</code> for RFC1123 compliant dates.
* <br>
* Should be stored for later use but be aware that this DateFormat is not Thread-safe!
* <br>
* If you have to deal with dates in this format with JavaScript, it's easy, because the JavaScript
* Date object has a constructor for strings formatted this way.
* @return a new instance
*/
public static DateFormat getRfc1123DateFormat() {
DateFormat format = new SimpleDateFormat(
"EEE, dd MMM yyyy HH:mm:ss z", Locale.ENGLISH);
format.setLenient(false);
format.setTimeZone(TimeZone.getTimeZone("UTC"));
return format;
}
static String urlEncode(String value) {
try {
return URLEncoder.encode(value, "UTF-8");
} catch (UnsupportedEncodingException e) {
return value;
}
}
static void addRequestProperties(HttpURLConnection connection, Map<String, Object> map) {
if (map == null || map.isEmpty()) {
return;
}
for (Map.Entry<String, Object> entry : map.entrySet()) {
addRequestProperty(connection, entry.getKey(), entry.getValue());
}
}
static void addRequestProperty(HttpURLConnection connection, String name, Object value) {
if (name == null || name.length() == 0 || value == null) {
throw new IllegalArgumentException("name and value must not be empty");
}
String valueAsString;
if (value instanceof Date) {
valueAsString = getRfc1123DateFormat().format((Date) value);
} else if (value instanceof Calendar) {
valueAsString = getRfc1123DateFormat().format(((Calendar) value).getTime());
} else {
valueAsString = value.toString();
}
connection.addRequestProperty(name, valueAsString);
}
static void ensureRequestProperty(HttpURLConnection connection, String name, Object value) {
if (!connection.getRequestProperties().containsKey(name)) {
addRequestProperty(connection, name, value);
}
}
static byte[] getPayloadAsBytesAndSetContentType(
HttpURLConnection connection,
Request request,
boolean compress,
int jsonIndentFactor) throws JSONException, UnsupportedEncodingException {
byte[] requestBody = null;
String bodyStr = null;
if (request.params != null) {
WebbUtils.ensureRequestProperty(connection, Const.HDR_CONTENT_TYPE, Const.APP_FORM);
bodyStr = WebbUtils.queryString(request.params);
} else if (request.payload == null) {
return null;
} else if (request.payload instanceof JSONObject) {
WebbUtils.ensureRequestProperty(connection, Const.HDR_CONTENT_TYPE, Const.APP_JSON);
bodyStr = jsonIndentFactor >= 0
? ((JSONObject) request.payload).toString(jsonIndentFactor)
: request.payload.toString();
} else if (request.payload instanceof JSONArray) {
WebbUtils.ensureRequestProperty(connection, Const.HDR_CONTENT_TYPE, Const.APP_JSON);
bodyStr = jsonIndentFactor >= 0
? ((JSONArray) request.payload).toString(jsonIndentFactor)
: request.payload.toString();
} else if (request.payload instanceof byte[]) {
WebbUtils.ensureRequestProperty(connection, Const.HDR_CONTENT_TYPE, Const.APP_BINARY);
requestBody = (byte[]) request.payload;
} else {
WebbUtils.ensureRequestProperty(connection, Const.HDR_CONTENT_TYPE, Const.TEXT_PLAIN);
bodyStr = request.payload.toString();
}
if (bodyStr != null) {
requestBody = bodyStr.getBytes(Const.UTF8);
}
if (requestBody == null) {
throw new IllegalStateException();
}
// only compress if the new body is smaller than uncompressed body
if (compress && requestBody.length > Const.MIN_COMPRESSED_ADVANTAGE) {
byte[] compressedBody = gzip(requestBody);
if (requestBody.length - compressedBody.length > Const.MIN_COMPRESSED_ADVANTAGE) {
requestBody = compressedBody;
connection.setRequestProperty(Const.HDR_CONTENT_ENCODING, "gzip");
}
}
connection.setFixedLengthStreamingMode(requestBody.length);
return requestBody;
}
static void setContentTypeAndLengthForStreaming(
HttpURLConnection connection,
Request request,
boolean compress) {
long length;
if (request.payload instanceof File) {
length = compress ? -1L : ((File) request.payload).length();
} else if (request.payload instanceof InputStream) {
length = -1L;
} else {
throw new IllegalStateException();
}
if (length > Integer.MAX_VALUE) {
length = -1L; // use chunked streaming mode
}
WebbUtils.ensureRequestProperty(connection, Const.HDR_CONTENT_TYPE, Const.APP_BINARY);
if (length < 0) {
connection.setChunkedStreamingMode(-1); // use default chunk size
if (compress) {
connection.setRequestProperty(Const.HDR_CONTENT_ENCODING, "gzip");
}
} else {
connection.setFixedLengthStreamingMode((int) length);
}
}
static byte[] gzip(byte[] input) {
GZIPOutputStream gzipOS = null;
try {
ByteArrayOutputStream byteArrayOS = new ByteArrayOutputStream();
gzipOS = new GZIPOutputStream(byteArrayOS);
gzipOS.write(input);
gzipOS.flush();
gzipOS.close();
gzipOS = null;
return byteArrayOS.toByteArray();
} catch (Exception e) {
throw new WebbException(e);
} finally {
if (gzipOS != null) {
try { gzipOS.close(); } catch (Exception ignored) {}
}
}
}
static InputStream wrapStream(String contentEncoding, InputStream inputStream) throws IOException {
if (contentEncoding == null || "identity".equalsIgnoreCase(contentEncoding)) {
return inputStream;
}
if ("gzip".equalsIgnoreCase(contentEncoding)) {
return new GZIPInputStream(inputStream);
}
if ("deflate".equalsIgnoreCase(contentEncoding)) {
return new InflaterInputStream(inputStream, new Inflater(false), 512);
}
throw new WebbException("unsupported content-encoding: " + contentEncoding);
}
static <T> void parseResponseBody(Class<T> clazz, Response<T> response, InputStream responseBodyStream)
throws UnsupportedEncodingException, IOException {
if (responseBodyStream == null || clazz == Void.class) {
return;
} else if (clazz == InputStream.class) {
response.setBody(responseBodyStream);
return;
}
byte[] responseBody = WebbUtils.readBytes(responseBodyStream);
// we are ignoring headers describing the content type of the response, instead
// try to force the content based on the type the client is expecting it (clazz)
if (clazz == String.class) {
response.setBody(new String(responseBody, Const.UTF8));
} else if (clazz == Const.BYTE_ARRAY_CLASS) {
response.setBody(responseBody);
} else if (clazz == JSONObject.class) {
response.setBody(WebbUtils.toJsonObject(responseBody));
} else if (clazz == JSONArray.class) {
response.setBody(WebbUtils.toJsonArray(responseBody));
}
}
static <T> void parseErrorResponse(Class<T> clazz, Response<T> response, InputStream responseBodyStream)
throws UnsupportedEncodingException, IOException {
if (responseBodyStream == null) {
return;
} else if (clazz == InputStream.class) {
response.errorBody = responseBodyStream;
return;
}
byte[] responseBody = WebbUtils.readBytes(responseBodyStream);
String contentType = response.connection.getContentType();
if (contentType == null || contentType.startsWith(Const.APP_BINARY) || clazz == Const.BYTE_ARRAY_CLASS) {
response.errorBody = responseBody;
return;
}
if (contentType.startsWith(Const.APP_JSON) && clazz == JSONObject.class) {
try {
response.errorBody = WebbUtils.toJsonObject(responseBody);
return;
} catch (Exception ignored) {
// ignored - was just a try!
}
}
// fallback to String if bytes are valid UTF-8 characters ...
try {
response.errorBody = new String(responseBody, Const.UTF8);
return;
} catch (Exception ignored) {
// ignored - was just a try!
}
// last fallback - return error object as byte[]
response.errorBody = responseBody;
}
}