org.opencastproject.mediapackage.EName Maven / Gradle / Ivy
/*
* Licensed to The Apereo Foundation under one or more contributor license
* agreements. See the NOTICE file distributed with this work for additional
* information regarding copyright ownership.
*
*
* The Apereo Foundation licenses this file to you under the Educational
* Community 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://opensource.org/licenses/ecl2.txt
*
* 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.opencastproject.mediapackage;
import static java.lang.String.format;
import static org.opencastproject.util.EqualsUtil.eq;
import static org.opencastproject.util.EqualsUtil.hash;
import org.opencastproject.util.RequireUtil;
import org.apache.commons.lang3.StringUtils;
import java.io.Serializable;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import javax.xml.XMLConstants;
/**
* An XML Expanded Name, cf. W3C definition.
*
* Expanded names in XML consists of a namespace name (URI) and a local part. In opposite to Qualified Names,
* cf. W3C definition - which are made from an optional
* prefix and the local part - expanded names are not subject to namespace interpretation.
*
* Please see http://www.w3.org/TR/xml-names/ for a complete definition
* and reference.
*/
public final class EName implements Serializable, Comparable {
private static final long serialVersionUID = -5494762745288614634L;
private final String namespaceURI;
private final String localName;
/**
* A pattern to parse strings as ENames. A String representing an EName may start with a Namespace among curly braces
* ("{" and "}") and then it must contain a local name *without* any curly braces.
*/
private static final Pattern pattern = Pattern.compile("^(?:\\{(?[^{}\\s]*)\\})?(?[^{}\\s]+)$");
/**
* Create a new expanded name.
*
* @param namespaceURI
* the name of the namespace this EName belongs to. If set to {@link javax.xml.XMLConstants#NULL_NS_URI},
* this name does not belong to any namespace. Use this option with care.
* @param localName
* the local part of the name. Must not be empty.
*/
public EName(String namespaceURI, String localName) {
RequireUtil.notNull(namespaceURI, "namespaceURI");
RequireUtil.notEmpty(localName, "localName");
this.namespaceURI = namespaceURI;
this.localName = localName;
}
public static EName mk(String namespaceURI, String localName) {
return new EName(namespaceURI, localName);
}
/**
* Create a new expanded name which does not belong to a namespace. The namespace name is set to
* {@link javax.xml.XMLConstants#NULL_NS_URI}.
*/
public static EName mk(String localName) {
return new EName(XMLConstants.NULL_NS_URI, localName);
}
/**
* Return the namespace name. Usually the name will be a URI.
*
* @return the namespace name or {@link javax.xml.XMLConstants#NULL_NS_URI} if the name does not belong to a namespace
*/
public String getNamespaceURI() {
return namespaceURI;
}
/** Return the local part of the name. */
public String getLocalName() {
return localName;
}
/**
* Check, if this name belongs to a namespace, i.e. its namespace URI is not
* {@link javax.xml.XMLConstants#NULL_NS_URI}.
*/
public boolean hasNamespace() {
return !XMLConstants.NULL_NS_URI.equals(namespaceURI);
}
@Override
public int hashCode() {
return hash(namespaceURI, localName);
}
@Override
public boolean equals(Object that) {
return (this == that) || (that instanceof EName && eqFields((EName) that));
}
private boolean eqFields(EName that) {
return eq(localName, that.localName) && eq(namespaceURI, that.namespaceURI);
}
/** Return a W3C compliant string representation {namespaceURI}localname. */
@Override
public String toString() {
return format("{%s}%s", namespaceURI, localName);
}
@Override
public int compareTo(EName o) {
final int r = getNamespaceURI().compareTo(o.getNamespaceURI());
if (r == 0) {
return getLocalName().compareTo(o.getLocalName());
} else {
return r;
}
}
/**
* Parse a W3C compliant string representation {namespaceURI}localname.
*
* A String representing an EName may start with a namespace among curly braces ("{" and "}") and then it must contain
* a local name *without* any blank characters or curly braces.
*
* This is a superset of the character restrictions defined by the XML standard, where neither namespaces nor local
* names may contain curly braces or spaces.
*
* Examples:
*
*
* - {http://my-namespace}mylocalname
*
- {}localname-with-explicit-empty-namespace
*
- localname-without-namespace
*
*
* Incorrect examples:
*
*
* - {namespace-only}
*
- contains{curly}braces
*
*
* @param strEName
* A {@link java.lang.String} representing an {@code EName}
* @param defaultNameSpace
* A NameSpace to apply if the provided {@code String} does not have any. Please note that a explicit empty
* NameSpace **is** a NameSpace. If this argument is blank or {@code null}, it has no effect.
*/
public static EName fromString(String strEName, String defaultNameSpace) throws IllegalArgumentException {
if (strEName == null) {
throw new IllegalArgumentException("Cannot parse 'null' as EName");
}
Matcher m = pattern.matcher(strEName);
if (m.matches()) {
if (StringUtils.isNotBlank(defaultNameSpace) && m.group("namespace") == null)
return new EName(defaultNameSpace, m.group("localname"));
else
return new EName(StringUtils.trimToEmpty(m.group("namespace")), m.group("localname"));
}
throw new IllegalArgumentException(format("Cannot parse '%s' as EName", strEName));
}
/**
* Parse a W3C compliant string representation {namespaceURI}localname.
*
* A String representing an EName may start with a namespace among curly braces ("{" and "}") and then it must contain
* a local name *without* any curly braces.
*
* This is a superset of the character restrictions defined by the XML standard, where neither namespaces nor local
* names may contain curly braces.
*
* Examples:
*
*
* - {http://my-namespace}mylocalname
*
- localname-without-namespace
*
*
* Incorrect examples:
*
*
* - {namespace-only}
*
- contains{curly}braces
*
*
* @param strEName
* A {@link java.lang.String} representing an {@code EName}
*
*/
public static EName fromString(String strEName) throws IllegalArgumentException {
return EName.fromString(strEName, null);
}
}