dbdsreportservlet.java

iReport 和 Jasperreport整合开发web报表3

package net.ensode.jasperbook;

import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
import java.util.HashMap;

import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import net.sf.jasperreports.engine.JRResultSetDataSource;
import net.sf.jasperreports.engine.JasperRunManager;

public class DbDSReportServlet extends HttpServlet
{

  protected void doGet(HttpServletRequest request, HttpServletResponse response)
      throws ServletException, IOException
  {
    Connection connection;
    Statement statement;
    ResultSet resultSet;
    
    ServletOutputStream servletOutputStream = response.getOutputStream();
    InputStream reportStream = getServletConfig().getServletContext()
        .getResourceAsStream("/reports/DbReportDS.jasper");

    try
    {
      String query = "select a.tail_num, a.aircraft_serial, " 
        + "am.model as aircraft_model, ae.model as engine_model from aircraft a, "
        + "aircraft_models am, aircraft_engines ae where a.aircraft_engine_code in ("
        + "select aircraft_engine_code from aircraft_engines "
        + "where horsepower >= 1000) and am.aircraft_model_code = a.aircraft_model_code "
        + "and ae.aircraft_engine_code = a.aircraft_engine_code";
      
      Class.forName("com.mysql.jdbc.Driver");

      connection = DriverManager
          .getConnection("jdbc:mysql://localhost:3306/flightstats?user=dbuser&password=secret");
      statement = connection.createStatement();
      resultSet = statement.executeQuery(query);
      
      JRResultSetDataSource resultSetDataSource = new JRResultSetDataSource(resultSet);

      JasperRunManager.runReportToPdfStream(reportStream, servletOutputStream,
          new HashMap(), resultSetDataSource);
      
      resultSet.close();
      statement.close();
      connection.close();
      
      response.setContentType("application/pdf");
      servletOutputStream.flush();
      servletOutputStream.close();
    }
    catch (Exception e)
    {
      // display stack trace in the browser
      StringWriter stringWriter = new StringWriter();
      PrintWriter printWriter = new PrintWriter(stringWriter);
      e.printStackTrace(printWriter);
      response.setContentType("text/plain");
      response.getOutputStream().print(stringWriter.toString());
    }
  }
}