Spring Cloud Stream Processor Unit Testing - #Autowire not working - spring

Question

I am trying to write a spring cloud stream processor class that takes an XML in through using the #StreamListener(Processor.INPUT) annotation.
The processor then extracts smaller XML messages and sends them to the output via this.processor.output().send(message);
I have not yet deployed this to dataflow because I wanted to test it with junit. When I run this with junit I can not seem to get my Processor object to instantiate.
I have tried using #Autowired which is how I have seen it done in may examples but I can't seem to get it to work. Any ideas would be appreciated.
My code is below.
package io.spring.dataflow.sample.usagecostprocessor;
import java.io.File;
import java.io.StringReader;
import java.io.StringWriter;
import java.util.ArrayList;
import java.util.List;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathExpression;
import javax.xml.xpath.XPathExpressionException;
import javax.xml.xpath.XPathFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.stream.annotation.EnableBinding;
import org.springframework.cloud.stream.annotation.StreamListener;
import org.springframework.cloud.stream.messaging.Processor;
import org.springframework.messaging.Message;
import org.springframework.messaging.support.MessageBuilder;
import org.springframework.stereotype.Component;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.InputSource;
import lombok.AllArgsConstructor;
#AllArgsConstructor
#EnableBinding(Processor.class)
public class REDACTXMLSplitter {
private Processor processor;
//#Autowired
//private SendingBean sendingBean;
#SuppressWarnings("unchecked")
#StreamListener(Processor.INPUT)
public void parseForREDACTApplications(String redactXML) {
InputSource doc = new InputSource( new StringReader( redactXML ) );
try
{
DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
factory.setNamespaceAware(true); // never forget this!
XPathFactory xfactory = XPathFactory.newInstance();
XPath xpath = xfactory.newXPath();
String xpathQuery = "//REDACT/Application";
xpath = xfactory.newXPath();
XPathExpression query = xpath.compile(xpathQuery);
NodeList productNodesFiltered = (NodeList) query.evaluate(doc, XPathConstants.NODESET);
for (int i=0; i<productNodesFiltered.getLength(); ++i)
{
Document suppXml = dBuilder.newDocument();
//we have to recreate the root node <products>
Element root = suppXml.createElement("REDACT");
Node productNode = productNodesFiltered.item(i);
//we append a product (cloned) to the new file
Node clonedNode = productNode.cloneNode(true);
suppXml.adoptNode(clonedNode); //We adopt the orphan :)
root.appendChild(clonedNode);
suppXml.appendChild(root);
//write out files
//At the end, we save the file XML on disk
// TransformerFactory transformerFactory = TransformerFactory.newInstance();
// Transformer transformer = transformerFactory.newTransformer();
// transformer.setOutputProperty(OutputKeys.INDENT, "yes");
// DOMSource source = new DOMSource(suppXml);
// StreamResult result = new StreamResult(new File("test_" + i + ".xml"));
// transformer.transform(source, result);
TransformerFactory tf = TransformerFactory.newInstance();
Transformer transformer = tf.newTransformer();
transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
StringWriter writer = new StringWriter();
transformer.transform(new DOMSource(suppXml), new StreamResult(writer));
String output = writer.getBuffer().toString().replaceAll("\n|\r", "");
System.out.println(output);
Message<String> message = (Message<String>) suppXml;
this.processor.output().send(message);
}
}
catch (XPathExpressionException | ParserConfigurationException | TransformerException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
package io.spring.dataflow.sample.usagecostprocessor;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
#SpringBootApplication
public class REDACTXMLSplitterApplication {
public static void main(String[] args) {
SpringApplication.run(REDACTXMLSplitterApplication.class, args);
}
}
package io.spring.dataflow.sample.usagecostprocessor;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.cloud.stream.messaging.Processor;
import org.springframework.test.annotation.DirtiesContext;
import org.springframework.test.context.junit4.SpringRunner;
import org.springframework.test.context.web.WebAppConfiguration;
import org.springframework.util.ResourceUtils;
import org.w3c.dom.Document;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;
#RunWith(SpringRunner.class)
#SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
#DirtiesContext
public class MAIPXMLSplitterApplicationTests {
#Autowired
private Processor myProcessor;
#Test
public void contextLoads() {
}
#Test
public void parseXML() {
try {
String cmErrorPayloadXML = readFile(ResourceUtils.getFile(this.getClass().getResource("/XMLSamples/REDACTApplicationXMLSamples/redact.xml")));
REDACTXMLSplitter redactXMLSplitter = new REDACTXMLSplitter(myProcessor);
redactXMLSplitter.parseForREDACTApplications(cmErrorPayloadXML);
} catch (IOException e) {
e.printStackTrace();
}
}
public String readFile(File file) {
StringBuffer stringBuffer = new StringBuffer();
if (file.exists())
try {
//read data from file
FileInputStream fileInputStream = new FileInputStream(file);
int c;
while ((c = fileInputStream.read()) != -1){
stringBuffer.append((char) c);
}
} catch (IOException e) {
e.printStackTrace();
}
return stringBuffer.toString();
}
}
Update,
I tried this but myProcessor is still null
package io.spring.dataflow.sample.usagecostprocessor;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.cloud.stream.annotation.EnableBinding;
import org.springframework.cloud.stream.messaging.Processor;
import org.springframework.test.context.junit4.SpringRunner;
import org.springframework.util.ResourceUtils;
import org.w3c.dom.Document;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;
#RunWith(SpringRunner.class)
#SpringBootTest(classes = MAIPXMLSplitterApplicationTests.TestProcessor.class, webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
public class MAIPXMLSplitterApplicationTests {
#Autowired
private Processor myProcessor;
#Test
public void contextLoads() {
}
#Test
public void parseXML() {
try {
String cmErrorPayloadXML = readFile(ResourceUtils.getFile(this.getClass().getResource("/XMLSamples/MAIPApplicationXMLSamples/354_20191126_MAIP.xml")));
MAIPXMLSplitter maipXMLSplitter = new MAIPXMLSplitter(myProcessor);
maipXMLSplitter.parseForMAIPApplications(cmErrorPayloadXML);
} catch (IOException e) {
e.printStackTrace();
}
}
public String readFile(File file) {
StringBuffer stringBuffer = new StringBuffer();
if (file.exists())
try {
//read data from file
FileInputStream fileInputStream = new FileInputStream(file);
int c;
while ((c = fileInputStream.read()) != -1){
stringBuffer.append((char) c);
}
} catch (IOException e) {
e.printStackTrace();
}
return stringBuffer.toString();
}
#EnableBinding(Processor.class)
#EnableAutoConfiguration
public static class TestProcessor {
}
}

Answer 1

You need to have #EnableBinding(Processor.class) in one of the configuration classes used by the Test class.
Typically, you can have a simple #Configuration subclass and have it part of the #SpringBootTest classes list. You can see an example here