package com.cloudera.cdk.examples.logging.webapp;
import com.cloudera.cdk.data.DatasetRepositories;
import com.cloudera.cdk.data.DatasetRepository;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.concurrent.atomic.AtomicLong;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.avro.Schema;
import org.apache.avro.generic.GenericData;
import org.apache.avro.generic.GenericRecordBuilder;
import org.apache.log4j.Logger;
public class LoggingServlet extends HttpServlet {
private static AtomicLong id = new AtomicLong();
private Logger logger = Logger.getLogger(LoggingServlet.class);
private Schema schema;
@Override
public void init() throws ServletException {
// Find the schema from the repository
DatasetRepository repo = DatasetRepositories.open("repo:hdfs:/tmp/data");
this.schema = repo.load("events").getDescriptor().getSchema();
}
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse
response) throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter pw = response.getWriter();
pw.println("<html>");
pw.println("<head><title>CDK Example</title></title>");
pw.println("<body>");
String message = request.getParameter("message");
if (message == null) {
pw.println("<p>No message specified.</p>");
} else {
pw.println("<p>Message: " + message + "</p>");
GenericData.Record event = new GenericRecordBuilder(schema)
.set("id", id.incrementAndGet())
.set("message", message)
.build();
logger.info(event);
}
pw.println("<p><a href=\"/logging-webapp\">Home</a></p>");
pw.println("</body></html>");
}
}