4.JasperReports学习笔记4-查询数据库生成动态的报表（WEB）

2 import java.io.IOException;
3 import java.io.InputStream;
4 import java.sql.Connection;
5 import java.sql.DriverManager;
6 import java.sql.ResultSet;
7 import java.sql.SQLException;
8 import java.sql.Statement;
9 import java.util.HashMap;
10
11 import javax.servlet.ServletException;
12 import javax.servlet.ServletOutputStream;
13 import javax.servlet.http.HttpServlet;
14 import javax.servlet.http.HttpServletRequest;
15 import javax.servlet.http.HttpServletResponse;
16
17 import net.sf.jasperreports.engine.JRException;
18 import net.sf.jasperreports.engine.JRResultSetDataSource;
19 import net.sf.jasperreports.engine.JasperRunManager;
20
21 public class DynamicCreateReportWithServletDateSource extends HttpServlet {
22
23     private static final long serialVersionUID = 1L;
24
25     public void doGet(HttpServletRequest request, HttpServletResponse response)
26             throws ServletException, IOException {
27         Connection connection = null;
28         Statement statument = null;
29         ResultSet resultSet = null;
30         String sql = "select tb.name as name,tb.age as age,tbs.marks as marks from jaspertb tb join jaspertbs tbs";
31         ServletOutputStream servletOutputStream = response.getOutputStream();
32         InputStream is = getServletConfig().getServletContext().getResourceAsStream("report\\JasperReportSQLResult.jasper");
33         try {
34             Class.forName("com.mysql.jdbc.Driver");
35             connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/jasperreportdb","root", "root");
36             statument = connection.createStatement();
37             resultSet = statument.executeQuery(sql);
38             //这里把ResultSet封装到JRResultSetDataSource对象里面了
39             JasperRunManager.runReportToPdfStream(is,servletOutputStream,new HashMap(), new JRResultSetDataSource(resultSet));
40             response.setContentType("application/pdf");
41             servletOutputStream.flush();
42             servletOutputStream.close();43             connection.close();44         } catch (ClassNotFoundException e) {45             e.printStackTrace();46         } catch (SQLException e) {47             e.printStackTrace();48         } catch (JRException e) {49             e.printStackTrace();50         }51     }52 53     public void doPost(HttpServletRequest request, HttpServletResponse response)54             throws ServletException, IOException {55         this.doGet(request, response);56     }57 58 }