Apache CXF example source code file (XMLSource.java)

This example Apache CXF source code file (XMLSource.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Apache CXF tags/keywords

class, class, dom, domsource, io, ioexception, map, map, namespacecontextimpl, network, no_source_mark, node, string, string, t, t, uri, util, xml, xpath

The Apache CXF XMLSource.java source code

/**
 * 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.jaxrs.ext.xml;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.lang.reflect.Array;
import java.net.URI;
import java.util.Collections;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.ResourceBundle;
import java.util.logging.Logger;

import javax.xml.bind.JAXBContext;
import javax.xml.bind.Unmarshaller;
import javax.xml.namespace.NamespaceContext;
import javax.xml.namespace.QName;
import javax.xml.transform.Source;
import javax.xml.transform.dom.DOMSource;
import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathExpressionException;
import javax.xml.xpath.XPathFactory;

import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

import org.xml.sax.InputSource;

import org.apache.cxf.common.i18n.BundleUtils;
import org.apache.cxf.common.logging.LogUtils;
import org.apache.cxf.helpers.CastUtils;
import org.apache.cxf.helpers.IOUtils;
import org.apache.cxf.helpers.XMLUtils;
import org.apache.cxf.jaxrs.provider.JAXBElementProvider;
import org.apache.cxf.jaxrs.utils.InjectionUtils;

/**
 * Utility class for manipulating XML response using XPath and XSLT
 *
 */
public class XMLSource {
    private static final Logger LOG = LogUtils.getL7dLogger(XMLSource.class);
    private static final ResourceBundle BUNDLE = BundleUtils.getBundle(XMLSource.class);
    
    private static final String XML_NAMESPACE = "http://www.w3.org/XML/1998/namespace"; 
    
    private InputStream stream; 
    private boolean buffering;
    private boolean markFailed;
    
    public XMLSource(InputStream is) {
        stream = is;
    }
    
    public void setBuffering(boolean enable) {
        buffering = enable;
        if (!stream.markSupported()) {
            try {
                stream = IOUtils.loadIntoBAIS(stream);
            } catch (IOException ex) {
                LOG.warning(new org.apache.cxf.common.i18n.Message("NO_SOURCE_MARK", BUNDLE).toString());
            }
        }
    }
    
    public <T> T getNode(String expression, Class cls) {
        return getNode(expression, CastUtils.cast(Collections.emptyMap(), String.class, String.class), cls);
    }
    
    public <T> T getNode(String expression, Map namespaces, Class cls) {
        Node node = (Node)evaluate(expression, namespaces, XPathConstants.NODE);
        if (node == null) {
            return null;
        }
        if (cls.isPrimitive() || cls == String.class) {
            return readPrimitiveValue(node, cls);    
        } else {
            return readFromSource(new DOMSource(node), cls);
        }
    }
    
    public <T> T[] getNodes(String expression, Class cls) {
        return getNodes(expression, CastUtils.cast(Collections.emptyMap(), String.class, String.class), cls);
    }
    
    @SuppressWarnings("unchecked")
    public <T> T[] getNodes(String expression, Map namespaces, Class cls) {
        
        NodeList nodes = (NodeList)evaluate(expression, namespaces, XPathConstants.NODESET);
        if (nodes == null || nodes.getLength() == 0) {
            return null;
        }
        T[] values = (T[])Array.newInstance(cls, nodes.getLength());
        for (int i = 0; i < nodes.getLength(); i++) {
            Node node = nodes.item(i);
            if (InjectionUtils.isPrimitive(cls)) {
                values[i] = readPrimitiveValue(node, cls);
            } else {
                values[i] = readFromSource(new DOMSource(node), cls);
            }
        }
        return values;
    }

    public URI getLink(String expression) {
        return getLink(expression, CastUtils.cast(Collections.emptyMap(), String.class, String.class));
    }
    
    public URI getLink(String expression, Map<String, String> namespaces) {
        String value = getValue(expression, namespaces);
        return value == null ? null : URI.create(value);
    }
    
    public URI[] getLinks(String expression, Map<String, String> namespaces) {
        String[] values = getValues(expression, namespaces);
        if (values == null) {
            return null;
        }
        URI[] uris = new URI[values.length];
        for (int i = 0; i < values.length; i++) {
            uris[i] = URI.create(values[i]);
        }
        return uris;
    }
    
    public URI getBaseURI() {
        Map<String, String> map = new LinkedHashMap();
        map.put("xml", XML_NAMESPACE);
        return getLink("/*/@xml:base", map);
    }
    
    public String getValue(String expression) {
        return getValue(expression, CastUtils.cast(Collections.emptyMap(), String.class, String.class));
    }
    
    public String getValue(String expression, Map<String, String> namespaces) {
        return getValue(expression, namespaces, String.class);
    }
    
    public <T> T getValue(String expression, Map namespaces, Class cls) {
        Object result = evaluate(expression, namespaces, XPathConstants.STRING);
        return result == null ? null : InjectionUtils.convertStringToPrimitive(result.toString(), cls); 
    }
    
    
    private Object evaluate(String expression, Map<String, String> namespaces, QName type) {
        XPath xpath = XPathFactory.newInstance().newXPath();
        xpath.setNamespaceContext(new NamespaceContextImpl(namespaces));
        try {
            return xpath.evaluate(expression, getSource(), type);
        } catch (XPathExpressionException ex) {
            throw new IllegalArgumentException("Illegal XPath expression '" + expression + "'", ex);
        }
    }
    
    
    public String[] getValues(String expression) {
        return getValues(expression, CastUtils.cast(Collections.emptyMap(), String.class, String.class));
    }
    
    public String[] getValues(String expression, Map<String, String> namespaces) {
        return getNodes(expression, namespaces, String.class);
    }
    
    private static class NamespaceContextImpl implements NamespaceContext {
        
        private Map<String, String> namespaces;
        
        public NamespaceContextImpl(Map<String, String> namespaces) {
            this.namespaces = namespaces;    
        }

        public String getNamespaceURI(String prefix) {
            return namespaces.get(prefix);
        }

        public String getPrefix(String namespace) {
            for (Map.Entry<String, String> entry : namespaces.entrySet()) {
                if (entry.getValue().equals(namespace)) {
                    return entry.getKey();
                }
            }
            return null;
        }

        public Iterator getPrefixes(String namespace) {
            String prefix = namespaces.get(namespace);
            if (prefix == null) {
                return null;
            }
            return Collections.singletonList(prefix).iterator();
        }
    }
    
    private <T> T readPrimitiveValue(Node node, Class cls) {
        if (String.class == cls) {
            if (node.getNodeType() == Node.ELEMENT_NODE) {
                ByteArrayOutputStream bos = new ByteArrayOutputStream();
                XMLUtils.writeTo(new DOMSource(node), bos, 0, "", "yes");
                try {
                    return cls.cast(bos.toString("UTF-8"));
                } catch (UnsupportedEncodingException ex) {
                    // won't happen
                }
            } else {
                return cls.cast(node.getNodeValue());
            }
        } 
        
        return InjectionUtils.convertStringToPrimitive(node.getNodeValue(), cls);
    }
    
    
    private <T> T readFromSource(Source s, Class cls) {
        try {
            JAXBElementProvider provider = new JAXBElementProvider();
            JAXBContext c = provider.getPackageContext(cls);
            if (c == null) {
                c = provider.getClassContext(cls);
            }
            Unmarshaller u = c.createUnmarshaller();
            return cls.cast(u.unmarshal(s));
        } catch (Exception ex) {
            throw new RuntimeException(ex);
        }
    }
    
    private InputSource getSource() {
        try {
            if (!markFailed && buffering) {
                try {
                    stream.reset();
                    stream.mark(stream.available());
                } catch (IOException ex) {
                    markFailed = true;
                    LOG.warning(new org.apache.cxf.common.i18n.Message("NO_SOURCE_MARK", BUNDLE).toString());
                    stream = IOUtils.loadIntoBAIS(stream);
                }
            }
        } catch (IOException ex) {
            LOG.warning(new org.apache.cxf.common.i18n.Message("NO_SOURCE_MARK", BUNDLE).toString());
        }
        return new InputSource(stream);
    }
}