com.redis.riot.file.xml.XmlResourceItemWriter Maven / Gradle / Ivy
/*
* Copyright 2018 the original author or authors.
*
* 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
*
* https://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 com.redis.riot.file.xml;
import java.util.Iterator;
import org.springframework.batch.item.Chunk;
import org.springframework.batch.item.json.JsonObjectMarshaller;
import org.springframework.batch.item.support.AbstractFileItemWriter;
import org.springframework.core.io.Resource;
import org.springframework.core.io.WritableResource;
import org.springframework.util.Assert;
import org.springframework.util.ClassUtils;
import com.fasterxml.jackson.dataformat.xml.XmlMapper;
/**
* Item writer that writes data in XML format to an output file. The location of
* the output file is defined by a {@link Resource} and must represent a
* writable file. Items are transformed to XML format using a {@link XmlMapper}.
* Items will be enclosed in a XML element as follows:
*
*
* {@code
*
* ...
* ...
* ...
*
* }
*
*
* The implementation is not thread-safe.
*
*/
public class XmlResourceItemWriter extends AbstractFileItemWriter {
private JsonObjectMarshaller xmlObjectMarshaller;
/**
* Create a new {@link XmlResourceItemWriter} instance.
*
* @param resource to write XML data to
* @param rootName XML root element tag name
* @param xmlObjectMarshaller used to marshal object into XML representation
*/
public XmlResourceItemWriter(WritableResource resource, String rootName,
JsonObjectMarshaller xmlObjectMarshaller) {
Assert.notNull(resource, "resource must not be null");
Assert.notNull(rootName, "root name must not be null");
Assert.notNull(xmlObjectMarshaller, "xml object writer must not be null");
setResource(resource);
setRootName(rootName);
setXmlObjectMarshaller(xmlObjectMarshaller);
setExecutionContextName(ClassUtils.getShortName(XmlResourceItemWriter.class));
}
public void setRootName(String rootName) {
setHeaderCallback(writer -> writer.write("<" + rootName + ">"));
setFooterCallback(writer -> writer.write(this.lineSeparator + "" + this.lineSeparator));
}
/**
* Assert that mandatory properties (xmlObjectMarshaller) are set.
*
* @see org.springframework.beans.factory.InitializingBean#afterPropertiesSet()
*/
@Override
public void afterPropertiesSet() throws Exception {
if (this.append) {
this.shouldDeleteIfExists = false;
}
}
/**
* Set the {@link JsonObjectMarshaller} to use to marshal object to XML.
*
* @param objectMarshaller the marshaller to use
*/
public void setXmlObjectMarshaller(JsonObjectMarshaller objectMarshaller) {
this.xmlObjectMarshaller = objectMarshaller;
}
@Override
public String doWrite(Chunk items) {
StringBuilder lines = new StringBuilder();
Iterator iterator = items.iterator();
if (!items.isEmpty() && state.getLinesWritten() > 0) {
lines.append(this.lineSeparator);
}
while (iterator.hasNext()) {
T item = iterator.next();
lines.append(' ').append(this.xmlObjectMarshaller.marshal(item));
if (iterator.hasNext()) {
lines.append(this.lineSeparator);
}
}
return lines.toString();
}
}