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package org.glassfish.jersey.message.internal;
import java.util.Collections;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.ws.rs.core.AbstractMultivaluedMap;
import javax.ws.rs.core.MultivaluedMap;
import javax.ws.rs.ext.RuntimeDelegate;
import javax.ws.rs.ext.RuntimeDelegate.HeaderDelegate;
import org.glassfish.jersey.internal.LocalizationMessages;
import org.glassfish.jersey.internal.util.collection.ImmutableMultivaluedMap;
import org.glassfish.jersey.internal.util.collection.StringKeyIgnoreCaseMultivaluedMap;
import jersey.repackaged.com.google.common.base.Function;
import jersey.repackaged.com.google.common.collect.Lists;
import jersey.repackaged.com.google.common.collect.Maps;
import jersey.repackaged.com.google.common.collect.ImmutableMap;
/**
* Utility class supporting the processing of message headers.
*
* @author Marek Potociar (marek.potociar at oracle.com)
* @author Michal Gajdos (michal.gajdos at oracle.com)
* @author Libor Kramolis (libor.kramolis at oracle.com)
*/
public final class HeaderUtils {
private final static Logger LOGGER = Logger.getLogger(HeaderUtils.class.getName());
/**
* Create an empty inbound message headers container. Created container is mutable.
*
* @return a new empty mutable container for storing inbound message headers.
*/
public static AbstractMultivaluedMap<String, String> createInbound() {
return new StringKeyIgnoreCaseMultivaluedMap<String>();
}
/**
* Get immutable empty message headers container. The factory method can be
* used to for both message header container types – inbound
* as well as outbound.
*
* @param <V> header value type. Typically {@link Object} in case of the outbound
* headers and {@link String} in case of the inbound headers.
* @return an immutable empty message headers container.
*/
public static <V> MultivaluedMap<String, V> empty() {
return ImmutableMultivaluedMap.empty();
}
/**
* Create an empty outbound message headers container. Created container is mutable.
*
* @return a new empty mutable container for storing outbound message headers.
*/
public static AbstractMultivaluedMap<String, Object> createOutbound() {
return new StringKeyIgnoreCaseMultivaluedMap<Object>();
}
/**
* Convert a message header value, represented as a general object, to it's
* string representation. If the supplied header value is {@code null},
* this method returns {@code null}.
* <p>
* This method defers to {@link RuntimeDelegate#createHeaderDelegate} to
* obtain a {@link HeaderDelegate} to convert the value to a {@code String}.
* If a {@link HeaderDelegate} is not found then the {@code toString()}
* method on the header object is utilized.
*
* @param headerValue the header value represented as an object.
* @param rd runtime delegate instance to be used for header delegate
* retrieval. If {@code null}, a default {@code RuntimeDelegate}
* instance will be {@link RuntimeDelegate#getInstance() obtained} and
* used.
* @return the string representation of the supplied header value or {@code null}
* if the supplied header value is {@code null}.
*/
@SuppressWarnings("unchecked")
public static String asString(final Object headerValue, RuntimeDelegate rd) {
if (headerValue == null) {
return null;
}
if (headerValue instanceof String) {
return (String) headerValue;
}
if (rd == null) {
rd = RuntimeDelegate.getInstance();
}
final HeaderDelegate hp = rd.createHeaderDelegate(headerValue.getClass());
return (hp != null) ? hp.toString(headerValue) : headerValue.toString();
}
/**
* Returns string view of list of header values. Any modifications to the underlying list are visible to the view,
* the view also supports removal of elements. Does not support other modifications.
*
* @param headerValues header values.
* @param rd RuntimeDelegate instance or {@code null} (in that case {@link RuntimeDelegate#getInstance()}
* will be called for before element conversion.
* @return String view of header values.
*/
public static List<String> asStringList(final List<Object> headerValues, final RuntimeDelegate rd) {
if (headerValues == null || headerValues.isEmpty()) {
return Collections.emptyList();
}
final RuntimeDelegate delegate;
if (rd == null) {
delegate = RuntimeDelegate.getInstance();
} else {
delegate = rd;
}
return Lists.transform(headerValues, new Function<Object, String>() {
@Override
public String apply(Object input) {
return (input == null) ? "[null]" : HeaderUtils.asString(input, delegate);
}
});
}
/**
* Returns string view of passed headers. Any modifications to the headers are visible to the view, the view also
* supports removal of elements. Does not support other modifications.
*
* @param headers headers.
* @return String view of headers or {@code null} if {code headers} input parameter is {@code null}.
*/
public static MultivaluedMap<String, String> asStringHeaders(final MultivaluedMap<String, Object> headers) {
if (headers == null) {
return null;
}
final RuntimeDelegate rd = RuntimeDelegate.getInstance();
return new AbstractMultivaluedMap<String, String>(
Maps.transformValues(headers, new Function<List<Object>, List<String>>() {
@Override
public List<String> apply(List<Object> input) {
return HeaderUtils.asStringList(input, rd);
}
})
) {
};
}
/**
* Transforms multi value map of headers to single {@code String} value map.
*
* Returned map is immutable. Map values are formatted using method {@link #asHeaderString}.
*
* @param headers headers to be formatted
* @return immutable single {@code String} value map or
* {@code null} if {@code headers} input parameter is {@code null}.
*/
public static Map<String, String> asStringHeadersSingleValue(final MultivaluedMap<String, Object> headers) {
if (headers == null) {
return null;
}
final RuntimeDelegate rd = RuntimeDelegate.getInstance();
ImmutableMap.Builder<String, String> immutableMapBuilder = new ImmutableMap.Builder<String, String>();
for (Map.Entry<? extends String, ? extends List<Object>> entry : headers.entrySet()) {
immutableMapBuilder.put(entry.getKey(), asHeaderString(entry.getValue(), rd));
}
return immutableMapBuilder.build();
}
/**
* Converts a list of message header values to a single string value (with individual values separated by
* {@code ','}).
*
* Each single header value is converted to String using a
* {@link javax.ws.rs.ext.RuntimeDelegate.HeaderDelegate} if one is available
* via {@link javax.ws.rs.ext.RuntimeDelegate#createHeaderDelegate(java.lang.Class)}
* for the header value class or using its {@code toString()} method if a header
* delegate is not available.
*
* @param values list of individual header values.
* @param rd {@link RuntimeDelegate} instance or {@code null} (in that case {@link RuntimeDelegate#getInstance()}
* will be called for before conversion of elements).
* @return single string consisting of all the values passed in as a parameter. If values parameter is {@code null},
* {@code null} is returned. If the list of values is empty, an empty string is returned.
*/
public static String asHeaderString(List<Object> values, RuntimeDelegate rd) {
if (values == null) {
return null;
}
final Iterator<String> stringValues = asStringList(values, rd).iterator();
if (!stringValues.hasNext()) {
return "";
}
StringBuilder buffer = new StringBuilder(stringValues.next());
while (stringValues.hasNext()) {
buffer.append(',').append(stringValues.next());
}
return buffer.toString();
}
/**
* Compares two snapshots of headers from jersey {@code ClientRequest} and logs {@code WARNING} in case of difference.
*
* Current container implementations does not support header modification in {@link javax.ws.rs.ext.WriterInterceptor}
* and {@link javax.ws.rs.ext.MessageBodyWriter}. The method checks there are some newly added headers
* (probably by WI or MBW) and logs {@code WARNING} message about it.
*
* @param headersSnapshot first immutable snapshot of headers
* @param currentHeaders current instance of headers tobe compared to
* @param connectorName name of connector the method is invoked from, used just in logged message
* @see <a href="https://java.net/jira/browse/JERSEY-2341">JERSEY-2341</a>
*/
public static void checkHeaderChanges(final Map<String, String> headersSnapshot,
final MultivaluedMap<String, Object> currentHeaders,
final String connectorName) {
if (HeaderUtils.LOGGER.isLoggable(Level.WARNING)) {
final RuntimeDelegate rd = RuntimeDelegate.getInstance();
Set<String> changedHeaderNames = new HashSet<String>();
for (Map.Entry<? extends String, ? extends List<Object>> entry : currentHeaders.entrySet()) {
if (!headersSnapshot.containsKey(entry.getKey())) {
changedHeaderNames.add(entry.getKey());
} else {
String prevValue = headersSnapshot.get(entry.getKey());
String newValue = asHeaderString(currentHeaders.get(entry.getKey()), rd);
if (!prevValue.equals(newValue)) {
changedHeaderNames.add(entry.getKey());
}
}
}
if (!changedHeaderNames.isEmpty()) {
if (HeaderUtils.LOGGER.isLoggable(Level.WARNING)) {
HeaderUtils.LOGGER.warning(LocalizationMessages.SOME_HEADERS_NOT_SENT(connectorName,
changedHeaderNames.toString()));
}
}
}
}
/**
* Preventing instantiation.
*/
private HeaderUtils() {
}
}