/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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 org.apache.cxf.management.web.browser.client.service.browser;
import javax.annotation.Nonnull;
import javax.annotation.Nullable;
import com.google.gwt.xml.client.Document;
import com.google.gwt.xml.client.Node;
import com.google.gwt.xml.client.NodeList;
public class Links {
public static final Links EMPTY = new Links();
@Nullable
private String first;
@Nullable
private String previous;
@Nullable
private String self;
@Nullable
private String next;
@Nullable
private String last;
private Links() {
}
public Links(@Nonnull final Document document) {
new XmlParser().parseLinks(document);
}
public boolean firstAvailable() {
return available(first);
}
public boolean previousAvailable() {
return available(previous);
}
public boolean selfAvailable() {
return available(self);
}
public boolean nextAvailable() {
return available(next);
}
public boolean lastAvailable() {
return available(last);
}
@Nullable
public String getFirst() {
return first;
}
@Nullable
public String getPrevious() {
return previous;
}
@Nullable
public String getSelf() {
return self;
}
@Nullable
public String getNext() {
return next;
}
@Nullable
public String getLast() {
return last;
}
private boolean available(@Nullable final String link) {
return link != null && !"".equals(link);
}
private final class XmlParser {
private static final String FEED_TAG = "feed";
private static final String LINK_TAG = "link";
private static final String TYPE_ATTRIBUTE = "rel";
private static final String URL_ATTRIBUTE = "href";
private static final String FIRST_LINK = "first";
private static final String PREVIOUS_LINK = "previous";
private static final String SELF_LINK = "self";
private static final String NEXT_LINK = "next";
private static final String LAST_LINK = "last";
private XmlParser() {
}
private void parseLinks(@Nonnull final Document document) {
NodeList linkNodes = document.getElementsByTagName(LINK_TAG);
if (linkNodes != null) {
Node linkNode;
for (int i = 0; i < linkNodes.getLength(); i++) {
linkNode = linkNodes.item(i);
if (isLinkBelongToFeed(linkNode)) {
setLink(linkNode);
}
}
}
}
private boolean isLinkBelongToFeed(@Nonnull final Node node) {
return node.getParentNode() != null && FEED_TAG.equals(node.getParentNode().getNodeName());
}
private void setLink(@Nonnull final Node node) {
Node typeNode = node.getAttributes().getNamedItem(TYPE_ATTRIBUTE);
Node urlNode = node.getAttributes().getNamedItem(URL_ATTRIBUTE);
if (typeNode != null && urlNode != null) {
String typeValue = typeNode.getNodeValue();
String urlValue = urlNode.getNodeValue();
if (FIRST_LINK.equals(typeValue)) {
first = urlValue;
} else if (PREVIOUS_LINK.equals(typeValue)) {
previous = urlValue;
} else if (SELF_LINK.equals(typeValue)) {
self = urlValue;
} else if (NEXT_LINK.equals(typeValue)) {
next = urlValue;
} else if (LAST_LINK.equals(typeValue)) {
last = urlValue;
}
}
}
}
}