import java.io.File;
import java.io.InputStream;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.OutputStream;

import java.util.Iterator;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.ServletConfig;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.*;
import javax.servlet.*;

import java.sql.*;

import net.sf.jasperreports.view.JasperViewer;
import net.sf.jasperreports.engine.xml.JRXmlLoader;
import net.sf.jasperreports.engine.JasperCompileManager;
import net.sf.jasperreports.engine.JasperFillManager;
import net.sf.jasperreports.engine.JasperPrint;
import net.sf.jasperreports.engine.design.JasperDesign;
import net.sf.jasperreports.engine.JasperReport;
import net.sf.jasperreports.engine.export.JRHtmlExporter;
import net.sf.jasperreports.engine.JRExporterParameter;

import org.apache.commons.fileupload.FileUpload;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileItemFactory;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;

/**
 * Servlet program to connect to a database and to view a jasper report (.jrxml)
 * @author Oguzhan Topsakal
 * @since 28 March 2006
 *
 * Required jar files to run this class:
 * 1. jasperreports-1.2.0.jar
 * 2. classes12.jar (for Oracle JDBC connection)
 * 3. commons-beanutils-1.5.jar
 * 4. commons-collections-2.1.jar
 * 5. commons-digester-1.7.jar
 * 6. commons-logging-1.0.2.jar
 * 7. commons-fileupload-1.1.jar
 * 8. commons-io-1.2.jar
 * 9. servlet-api.jar
 *
 */

public class ReportServlet extends HttpServlet {

public void init(ServletConfig config) throws ServletException {
        super.init(config);
}
    
    /** Destroys the servlet.
     */

public void destroy() {
}

public void doPost(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
        processRequest(request, response);
    }

public void doGet(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
        processRequest(request, response);
    }


public void processRequest(HttpServletRequest req,HttpServletResponse res)
{

/*
try{
}catch(Exception e){
	System.out.println("error res.getWriter()");
}
*/


try{

// Check that we have a file upload request
boolean isMultipart = FileUpload.isMultipartContent(req);

if (isMultipart)
{
	// Create a factory for disk-based file items
	FileItemFactory factory = new DiskFileItemFactory();

	// Create a new file upload handler
	ServletFileUpload upload = new ServletFileUpload(factory);

	// Parse the request
	List /* FileItem */ items = upload.parseRequest(req);

	// Process the uploaded items
	Iterator iter = items.iterator();
	while (iter.hasNext()) {
	    FileItem item = (FileItem) iter.next();
		
	    String databaseName = "";
	    String userName = "";
	    String password = "";
	
	    if (item.isFormField()) {
		    String name = item.getFieldName();
		    String value = item.getString();
		    if (name.equals("databaseName")){
			databaseName = value;
		    }else if (name.equals("userName")){
			userName = value;
		    }else if (name.equals("password")){
			password = value;
		    }

//		    out.println("Form field:" + name + " " + value);

	    } else {

/* 		   
		    String fieldName = item.getFieldName();
		    String fileName = item.getName();
		    String contentType = item.getContentType();
		    boolean isInMemory = item.isInMemory();
		    long sizeInBytes = item.getSize();
*/

		    InputStream uploadedStream = item.getInputStream();
		   
/*
		    out.println("Fiel field - fieldName" + ": " + fieldName);
		    out.println("- fileName" + ": " + fileName);
		    out.println("- contentType" + ": " + contentType);
		    out.println("- sizeInBytes" + ": " + sizeInBytes);
*/

		    JasperPrint jasperPrint = returnReportPrint(databaseName,userName,password,uploadedStream);

//		    res.setContentType("text/html");
		    PrintWriter out = res.getWriter();

                    JRHtmlExporter exporter = new JRHtmlExporter();
                    exporter.setParameter(JRExporterParameter.JASPER_PRINT, jasperPrint);
                    exporter.setParameter(JRExporterParameter.OUTPUT_WRITER,out);


		    exporter.exportReport();

		    out.close();
	    }
	}
}
else{
	System.out.println("No Multipart ");
}



}catch(Exception e){
	System.out.println("Error " + e.getMessage());
}


}

    /**
     * Takes 4 parameters: databaseName, userName, password, inputstream
     * and connects to the database and prepares the report.
     * @param databaseName holds database name,
     * @param userName holds user name
     * @param password holds password to connect the database,
     * @param inputstream holds the stream of the Jasper Report file (.jrxml)
     * @return jasperReport holds the jasperReport variable that will be used to export an HTML report
     */
    public JasperPrint returnReportPrint(String databaseName, String userName, String password, InputStream inputStream) {
	JasperPrint jasperPrint = null;
        try{
            JasperDesign jasperDesign = JRXmlLoader.load(inputStream);
            JasperReport jasperReport = JasperCompileManager.compileReport(jasperDesign);
            Connection jdbcConnection = connectDB(databaseName, userName, password);
            jasperPrint = JasperFillManager.fillReport(jasperReport, null, jdbcConnection);
        }catch(Exception ex) {
            String connectMsg = "Could not create the report stream " + ex.getMessage() + " " + ex.getLocalizedMessage();
            System.out.println(connectMsg);
        }
        return jasperPrint;
    }


    /**
     * Takes 3 parameters: databaseName, userName, password
     * and connects to the database.
     * @param databaseName holds database name,
     * @param userName holds user name
     * @param password holds password to connect the database,
     * @return Returns the JDBC connection to the database
     */
    public Connection connectDB(String databaseName, String userName, String password) {
        Connection jdbcConnection = null;
        try{
            Class.forName("oracle.jdbc.driver.OracleDriver");
            jdbcConnection = DriverManager.getConnection(databaseName,userName,password);
        }catch(Exception ex) {
            String connectMsg = "Could not connect to the database: " + ex.getMessage() + " " + ex.getLocalizedMessage();
            System.out.println(connectMsg);
        }
        return jdbcConnection;
    }

}