第一种方式：
sql语句中定义查询条件，报表中定义接收参数
第二种方式：
JRXML文件里面不用写SQL语句，而是将结果集查询出来经过JRResultSetDataSource转换
1
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 }
注意：JRXML文件里面数据库的字段都是用$F{marks},而parameter是用$P{xxxx}表示的
，而parameter的值都是传过去的那个HashMap里面设置的