org.xmlbeam.io.XBFileIO Maven / Gradle / Ivy
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The coolest XML library for Java around. Define typesafe views (projections) to xml. Use XPath to read and write XML. Bind XML to Java collections. Requires at least Java6, supports Java8 features and has no further runtime dependencies.
/**
* Copyright 2013 Sven Ewald
*
* Licensed 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.xmlbeam.io;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import org.w3c.dom.Document;
import org.xml.sax.SAXException;
import org.xmlbeam.XBProjector;
import org.xmlbeam.evaluation.CanEvaluate;
import org.xmlbeam.evaluation.DocumentResolver;
import org.xmlbeam.evaluation.DefaultXPathEvaluator;
import org.xmlbeam.evaluation.XPathEvaluator;
import org.xmlbeam.util.IOHelper;
/**
* @author Sven Ewald
*/
public class XBFileIO implements CanEvaluate {
private final XBProjector projector;
private boolean append = false;
private final File file;
/**
* Constructor for file input.
*
* @param xmlProjector
* @param file
*/
public XBFileIO(final XBProjector xmlProjector, final File file) {
if (xmlProjector == null) {
throw new NullPointerException("Parameter xmlProjector must not be null.");
}
if (file == null) {
throw new NullPointerException("Parameter file must not be null.");
}
if (file.isDirectory()) {
throw new IllegalArgumentException("File " + file + " is a directory.");
}
this.projector = xmlProjector;
this.file = file;
}
/**
* Convenient constructor using a filename.
*
* @param xmlProjector
* @param fileName
*/
public XBFileIO(final XBProjector xmlProjector, final String fileName) {
this(xmlProjector, new File(fileName));
}
/**
* Read a XML document and return a projection to it.
*
* @param projectionInterface
* @return a new projection pointing to the content of the file.
* @throws IOException
*/
public T read(final Class projectionInterface) throws IOException {
try {
Document document = projector.config().createDocumentBuilder().parse(file);
return projector.projectDOMNode(document, projectionInterface);
} catch (SAXException e) {
throw new RuntimeException(e);
}
}
/**
* @param projection
* @throws IOException
* @return this to provide a fluent API.
*/
public XBFileIO write(final Object projection) throws IOException {
FileOutputStream os = new FileOutputStream(file, append);
new XBStreamOutput(projector, os).write(projection);
os.close();
return this;
}
/**
* Set whether output should be append to existing file.
* When this method is not invoked, or invoked with 'false',
* The file will be replaced on writing operations.
*
* @param append optional parameter, default is true.
* @return this to provide a fluent API.
*/
public XBFileIO setAppend(final boolean... append) {
this.append = (append!=null) && (append.length>0) && append[0] ;
return this;
}
@Override
public XPathEvaluator evalXPath(final String xpath) {
return new DefaultXPathEvaluator(projector, new DocumentResolver() {
@Override
public Document resolve(final Class... resourceAwareClass) throws IOException {
FileInputStream fileInputStream = new FileInputStream(file);
Document doc = IOHelper.loadDocument(projector, fileInputStream);
fileInputStream.close();
return doc;
}
}, xpath);
}
}