Play Framework/Scala example source code file (XPath.java)

This example Play Framework source code file (XPath.java) is included in my "Source Code Warehouse" project. The intent of this project is to help you more easily find Play Framework (and Scala) source code examples by using tags.

All credit for the original source code belongs to Play Framework; I'm just trying to make examples easier to find. (For my Scala work, see my Scala examples and tutorials.)

Play Framework tags/keywords

exception, lib, library, map, node, nodelist, object, play, play framework, runtimeexception, simplenamespacecontext, string, xpath, xpathfactory

The XPath.java Play Framework example source code

/*
 * Copyright (C) 2009-2013 Typesafe Inc. <http://www.typesafe.com>
 */
package play.libs;

import java.util.List;
import java.util.Map;

import javax.xml.xpath.*;

import org.springframework.util.xml.SimpleNamespaceContext;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.w3c.dom.Text;


/**
 * XPath for parsing
 */
public class XPath {

    /**
     * Select all nodes that are selected by this XPath expression. If multiple nodes match,
     * multiple nodes will be returned. Nodes will be returned in document-order,
     * @param path
     * @param node
     * @param namespaces Namespaces that need to be available in the xpath, where the key is the
     * prefix and the value the namespace URI
     * @return
     */
    public static NodeList selectNodes(String path, Object node, Map<String, String> namespaces) {
        try {
            XPathFactory factory = XPathFactory.newInstance();
            javax.xml.xpath.XPath xpath = factory.newXPath();
            
            if (namespaces != null) {
                SimpleNamespaceContext nsContext = new SimpleNamespaceContext();
                bindUnboundedNamespaces(nsContext, namespaces);
                xpath.setNamespaceContext(nsContext);
            }

            return (NodeList) xpath.evaluate(path, node, XPathConstants.NODESET);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    /**
     * Select all nodes that are selected by this XPath expression. If multiple nodes match,
     * multiple nodes will be returned. Nodes will be returned in document-order,
     * @param path
     * @param node
     * @return
     */
    public static NodeList selectNodes(String path, Object node) {
        return selectNodes(path, node, null);
    }

    public static Node selectNode(String path, Object node, Map<String, String> namespaces) {
        try {
            XPathFactory factory = XPathFactory.newInstance();
            javax.xml.xpath.XPath xpath = factory.newXPath();
            
            if (namespaces != null) {
                SimpleNamespaceContext nsContext = new SimpleNamespaceContext();
                bindUnboundedNamespaces(nsContext, namespaces);
                xpath.setNamespaceContext(nsContext);
            }

            return (Node) xpath.evaluate(path, node, XPathConstants.NODE);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    public static Node selectNode(String path, Object node) {
        return selectNode(path, node, null);
    }

    private static void bindUnboundedNamespaces(SimpleNamespaceContext nsContext, Map<String, String> namespaces) {
        for (Map.Entry<String, String> entry : namespaces.entrySet()) {
            //making sure that namespace is not already bound. Otherwise UnsupportedException happens
            if(nsContext.getPrefix(entry.getValue()) == null) {
                nsContext.bindNamespaceUri(entry.getKey(), entry.getValue());
            }
        }
    }

    /**
     * Return the text of a node, or the value of an attribute
     * @param path the XPath to execute
     * @param node the node, node-set or Context object for evaluation. This value can be null.
     */
    public static String selectText(String path, Object node, Map<String, String> namespaces) {
        try {
            XPathFactory factory = XPathFactory.newInstance();
            javax.xml.xpath.XPath xpath = factory.newXPath();

            if (namespaces != null) {
                SimpleNamespaceContext nsContext = new SimpleNamespaceContext();
                bindUnboundedNamespaces(nsContext, namespaces);
                xpath.setNamespaceContext(nsContext);
            }

            return (String) xpath.evaluate(path, node, XPathConstants.STRING);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    /**
     * Return the text of a node, or the value of an attribute
     * @param path the XPath to execute
     * @param node the node, node-set or Context object for evaluation. This value can be null.
     */
    public static String selectText(String path, Object node) {
        return selectText(path, node, null);
    }

}