--- a/src/java.net.http/share/classes/java/net/http/HttpHeaders.java Wed Jun 20 17:15:16 2018 +0200
+++ b/src/java.net.http/share/classes/java/net/http/HttpHeaders.java Wed Jun 20 09:05:57 2018 -0700
@@ -25,62 +25,68 @@
package java.net.http;
+import java.util.ArrayList;
import java.util.List;
+import java.util.Locale;
import java.util.Map;
import java.util.Optional;
import java.util.OptionalLong;
-import static java.util.Collections.emptyList;
-import static java.util.Collections.unmodifiableList;
+import java.util.TreeMap;
+import java.util.TreeSet;
+import java.util.function.BiPredicate;
+import static java.lang.String.CASE_INSENSITIVE_ORDER;
+import static java.util.Collections.unmodifiableMap;
import static java.util.Objects.requireNonNull;
/**
* A read-only view of a set of HTTP headers.
*
- * <p> An {@code HttpHeaders} is not created directly, but rather returned from
- * an {@link HttpResponse HttpResponse}. Specific HTTP headers can be set for
- * {@linkplain HttpRequest requests} through the one of the request builder's
- * {@link HttpRequest.Builder#header(String, String) headers} methods.
+ * <p> An {@code HttpHeaders} is not typically created directly, but rather
+ * returned from an {@link HttpRequest#headers() HttpRequest} or an
+ * {@link HttpResponse#headers() HttpResponse}. Specific HTTP headers can be
+ * set for a {@linkplain HttpRequest request} through one of the request
+ * builder's {@link HttpRequest.Builder#header(String, String) headers} methods.
*
* <p> The methods of this class ( that accept a String header name ), and the
- * Map returned by the {@link #map() map} method, operate without regard to
- * case when retrieving the header value.
+ * {@code Map} returned by the {@link #map() map} method, operate without regard
+ * to case when retrieving the header value(s).
+ *
+ * <p> An HTTP header name may appear more than once in the HTTP protocol. As
+ * such, headers are represented as a name and a list of values. Each occurrence
+ * of a header value is added verbatim, to the appropriate header name list,
+ * without interpreting its value. In particular, {@code HttpHeaders} does not
+ * perform any splitting or joining of comma separated header value strings. The
+ * order of elements in a header value list is preserved when {@link
+ * HttpRequest.Builder#header(String, String) building} a request. For
+ * responses, the order of elements in a header value list is the order in which
+ * they were received. The {@code Map} returned by the {@code map} method,
+ * however, does not provide any guarantee with regard to the ordering of its
+ * entries.
*
* <p> {@code HttpHeaders} instances are immutable.
*
* @since 11
*/
-public abstract class HttpHeaders {
-
- /**
- * Creates an HttpHeaders.
- */
- protected HttpHeaders() {}
+public final class HttpHeaders {
/**
- * Returns an {@link Optional} containing the first value of the given named
- * (and possibly multi-valued) header. If the header is not present, then
- * the returned {@code Optional} is empty.
- *
- * @implSpec
- * The default implementation invokes
- * {@code allValues(name).stream().findFirst()}
+ * Returns an {@link Optional} containing the first header string value of
+ * the given named (and possibly multi-valued) header. If the header is not
+ * present, then the returned {@code Optional} is empty.
*
* @param name the header name
- * @return an {@code Optional<String>} for the first named value
+ * @return an {@code Optional<String>} containing the first named header
+ * string value, if present
*/
public Optional<String> firstValue(String name) {
return allValues(name).stream().findFirst();
}
/**
- * Returns an {@link OptionalLong} containing the first value of the
- * named header field. If the header is not present, then the Optional is
- * empty. If the header is present but contains a value that does not parse
- * as a {@code Long} value, then an exception is thrown.
- *
- * @implSpec
- * The default implementation invokes
- * {@code allValues(name).stream().mapToLong(Long::valueOf).findFirst()}
+ * Returns an {@link OptionalLong} containing the first header string value
+ * of the named header field. If the header is not present, then the
+ * Optional is empty. If the header is present but contains a value that
+ * does not parse as a {@code Long} value, then an exception is thrown.
*
* @param name the header name
* @return an {@code OptionalLong}
@@ -92,23 +98,19 @@
}
/**
- * Returns an unmodifiable List of all of the values of the given named
- * header. Always returns a List, which may be empty if the header is not
- * present.
- *
- * @implSpec
- * The default implementation invokes, among other things, the
- * {@code map().get(name)} to retrieve the list of header values.
+ * Returns an unmodifiable List of all of the header string values of the
+ * given named header. Always returns a List, which may be empty if the
+ * header is not present.
*
* @param name the header name
- * @return a List of String values
+ * @return a List of headers string values
*/
public List<String> allValues(String name) {
requireNonNull(name);
List<String> values = map().get(name);
// Making unmodifiable list out of empty in order to make a list which
// throws UOE unconditionally
- return values != null ? values : unmodifiableList(emptyList());
+ return values != null ? values : List.of();
}
/**
@@ -116,7 +118,9 @@
*
* @return the Map
*/
- public abstract Map<String, List<String>> map();
+ public Map<String,List<String>> map() {
+ return headers;
+ }
/**
* Tests this HTTP headers instance for equality with the given object.
@@ -149,7 +153,11 @@
* @return the hash-code value for this HTTP headers
*/
public final int hashCode() {
- return map().hashCode();
+ int h = 0;
+ for (Map.Entry<String, List<String>> e : map().entrySet()) {
+ h += entryHash(e);
+ }
+ return h;
}
/**
@@ -165,4 +173,93 @@
sb.append(" }");
return sb.toString();
}
+
+ /**
+ * Returns an HTTP headers from the given map. The given map's key
+ * represents the header name, and its value the list of string header
+ * values for that header name.
+ *
+ * <p> An HTTP header name may appear more than once in the HTTP protocol.
+ * Such, <i>multi-valued</i>, headers must be represented by a single entry
+ * in the given map, whose entry value is a list that represents the
+ * multiple header string values. Leading and trailing whitespaces are
+ * removed from all string values retrieved from the given map and its lists
+ * before processing. Only headers that, after filtering, contain at least
+ * one, possibly empty string, value will be added to the HTTP headers.
+ *
+ * @apiNote The primary purpose of this method is for testing frameworks.
+ * Per-request headers can be set through one of the {@code HttpRequest}
+ * {@link HttpRequest.Builder#header(String, String) headers} methods.
+ *
+ * @param headerMap the map containing the header names and values
+ * @param filter a filter that can be used to inspect each
+ * header-name-and-value pair in the given map to determine if
+ * it should, or should not, be added to the to the HTTP
+ * headers
+ * @return an HTTP headers instance containing the given headers
+ * @throws NullPointerException if any of: {@code headerMap}, a key or value
+ * in the given map, or an entry in the map's value list, or
+ * {@code filter}, is {@code null}
+ * @throws IllegalArgumentException if the given {@code headerMap} contains
+ * any two keys that are equal ( without regard to case ); or if the
+ * given map contains any key whose length, after trimming
+ * whitespaces, is {@code 0}
+ */
+ public static HttpHeaders of(Map<String,List<String>> headerMap,
+ BiPredicate<String,String> filter) {
+ requireNonNull(headerMap);
+ requireNonNull(filter);
+ return headersOf(headerMap, filter);
+ }
+
+ // --
+
+ private static final HttpHeaders NO_HEADERS = new HttpHeaders(Map.of());
+
+ private final Map<String,List<String>> headers;
+
+ private HttpHeaders(Map<String,List<String>> headers) {
+ this.headers = headers;
+ }
+
+ private static final int entryHash(Map.Entry<String, List<String>> e) {
+ String key = e.getKey();
+ List<String> value = e.getValue();
+ // we know that by construction key and values can't be null
+ int keyHash = key.toLowerCase(Locale.ROOT).hashCode();
+ int valueHash = value.hashCode();
+ return keyHash ^ valueHash;
+ }
+
+ // Returns a new HTTP headers after performing a structural copy and filtering.
+ private static HttpHeaders headersOf(Map<String,List<String>> map,
+ BiPredicate<String,String> filter) {
+ TreeMap<String,List<String>> other = new TreeMap<>(CASE_INSENSITIVE_ORDER);
+ TreeSet<String> notAdded = new TreeSet<>(CASE_INSENSITIVE_ORDER);
+ ArrayList<String> tempList = new ArrayList<>();
+ map.forEach((key, value) -> {
+ String headerName = requireNonNull(key).trim();
+ if (headerName.isEmpty()) {
+ throw new IllegalArgumentException("empty key");
+ }
+ List<String> headerValues = requireNonNull(value);
+ headerValues.forEach(headerValue -> {
+ headerValue = requireNonNull(headerValue).trim();
+ if (filter.test(headerName, headerValue)) {
+ tempList.add(headerValue);
+ }
+ });
+
+ if (tempList.isEmpty()) {
+ if (other.containsKey(headerName)
+ || notAdded.contains(headerName.toLowerCase(Locale.ROOT)))
+ throw new IllegalArgumentException("duplicate key: " + headerName);
+ notAdded.add(headerName.toLowerCase(Locale.ROOT));
+ } else if (other.put(headerName, List.copyOf(tempList)) != null) {
+ throw new IllegalArgumentException("duplicate key: " + headerName);
+ }
+ tempList.clear();
+ });
+ return other.isEmpty() ? NO_HEADERS : new HttpHeaders(unmodifiableMap(other));
+ }
}