JasperReport学习笔记4-查询数据库生成动态的报表（WEB）

分两种方法
第一种
1.模版

<?xmlversion="1.0"encoding="UTF-8"?>
<!DOCTYPE jasperReport PUBLIC "//JasperReports//DTD Report Design//EN"
"http://jasperreports.sourceforge.net/dtds/jasperreport.dtd">
<jasperReportname="DBReport">
<parametername="hp"class="java.lang.Integer"></parameter>
<queryString>
<![CDATA[
 select tb.name as name,tb.age as age,tbs.marks as marks from jaspertb tb join jaspertbs tbs on(tb.id = tbs.tbid) where tb.id > $P{hp}
 ]]>
</queryString>
<fieldname="marks"class="java.lang.Integer"></field>
<fieldname="name"class="java.lang.String"></field>
<fieldname="age"class="java.lang.Integer"></field>
<pageHeader>
<bandheight="30">
<staticText>
<reportElementx="0"y="0"width="69"height="24"/>
<text><![CDATA[marks:]]></text>
</staticText>

<staticText>
<reportElementx="140"y="0"width="79"height="24"/>
<text><![CDATA[name:]]></text>
</staticText>

<staticText>
<reportElementx="280"y="0"width="69"height="24"/>
<text><![CDATA[age:]]></text>
</staticText>

<staticText>
<reportElementx="420"y="0"width="69"height="24"/>
<text><![CDATA[you don't see this]]></text>
</staticText>
</band>
</pageHeader>

<detail>
<bandheight="30">
<textField>
<reportElementx="0"y="0"width="69"height="24"/>
<textFieldExpressionclass="java.lang.Integer">
<![CDATA[$F{marks}]]>
</textFieldExpression>
</textField>
<textField>
<reportElementx="140"y="0"width="69"height="24"/>
<textFieldExpressionclass="java.lang.String">
<![CDATA[$F{name}]]>
</textFieldExpression>
</textField>
<textField>
<reportElementx="280"y="0"width="69"height="24"/>
<textFieldExpressionclass="java.lang.Integer">
<![CDATA[$F{age}]]>
</textFieldExpression>
</textField>
<staticText>
<reportElementx="420"y="0"width="69"height="24"/>
<text><![CDATA[If you don't see this, it didn't work]]></text>
</staticText>
</band>
</detail>
</jasperReport>

2.把上面的JRXML文件生成JASPER文件，方便在WEB里面的调用（可以用下面的方法先生成好，放到你知道的文件夹下面）

JasperCompileManager.compileReportToFile("WebRoot\\report\\JasperReportSQL.xml","WebRoot\\report\\JasperReportSQL.jasper");

3.写Servlet调用

import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
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.JRException;
import net.sf.jasperreports.engine.JasperRunManager;

publicclass DynamicCreateReportWithServlet extends HttpServlet {

privatestaticfinallong serialVersionUID = 1L;

publicvoid doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
 Connection connection = null;
//获得输出流
 ServletOutputStream servletOutputStream = response.getOutputStream();
//获得JASPER文件的输入流,一定要知道你的文件的地方
 InputStream is = getServletConfig().getServletContext().getResourceAsStream("report\\JasperReportSQL.jasper");
//生成Map对象传数据
 HashMap hm = new HashMap();
 hm.put("hp", new Integer(3));
try {
//连结JDBC
 Class.forName("com.mysql.jdbc.Driver");
 connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/jasperreportdb","root", "root");
//生成相于的PDF输入流,这个JasperRunManager对象还有很多种方法的,这只是一种
 JasperRunManager.runReportToPdfStream(is,servletOutputStream,hm, connection);
//设置格式
 response.setContentType("application/pdf");
 servletOutputStream.flush();
 servletOutputStream.close();
 connection.close();
 } catch (ClassNotFoundException e) {
 e.printStackTrace();
 } catch (SQLException e) {
 e.printStackTrace();
 } catch (JRException e) {
 e.printStackTrace();
 }
 }

publicvoid doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
this.doGet(request, response);
 }

}

第二种方法
1.这种方法JRXML文件里面不用写SQL

<?xmlversion="1.0"encoding="UTF-8"?>
<!DOCTYPE jasperReport PUBLIC "//JasperReports//DTD Report Design//EN"
"http://jasperreports.sourceforge.net/dtds/jasperreport.dtd">
<jasperReportname="DBReport">
<fieldname="id"class="java.lang.Integer"></field>
<fieldname="name"class="java.lang.String"></field>
<fieldname="marks"class="java.lang.Integer"></field>

<pageHeader>
<bandheight="30">
<staticText>
<reportElementx="0"y="0"width="69"height="24"/>
<text><![CDATA[id:]]></text>
</staticText>

<staticText>
<reportElementx="140"y="0"width="79"height="24"/>
<text><![CDATA[name:]]></text>
</staticText>

<staticText>
<reportElementx="280"y="0"width="69"height="24"/>
<text><![CDATA[marks:]]></text>
</staticText>

<staticText>
<reportElementx="420"y="0"width="69"height="24"/>
<text><![CDATA[you don't see this]]></text>
</staticText>
</band>
</pageHeader>

<detail>
<bandheight="30">
<textField>
<reportElementx="0"y="0"width="69"height="24"/>
<textFieldExpressionclass="java.lang.Integer">
<![CDATA[$F{id}]]>
</textFieldExpression>
</textField>
<textField>
<reportElementx="140"y="0"width="69"height="24"/>
<textFieldExpressionclass="java.lang.String">
<![CDATA[$F{name}]]>
</textFieldExpression>
</textField>
<textField>
<reportElementx="280"y="0"width="69"height="24"/>
<textFieldExpressionclass="java.lang.Integer">
<![CDATA[$F{marks}]]>
</textFieldExpression>
</textField>
<staticText>
<reportElementx="420"y="0"width="69"height="24"/>
<text><![CDATA[If you don't see this, it didn't work]]></text>
</staticText>
</band>
</detail>
</jasperReport>

2.同样是用下面的方法生成JASPER文件

JasperCompileManager.compileReportToFile("WebRoot\\report\\JasperReportSQLResult.xml","WebRoot\\report\\JasperReportSQLResult.jasper");

3.写出Servlet

import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
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.JRException;
import net.sf.jasperreports.engine.JRResultSetDataSource;
import net.sf.jasperreports.engine.JasperRunManager;

publicclass DynamicCreateReportWithServletDateSource extends HttpServlet {

privatestaticfinallong serialVersionUID = 1L;

publicvoid doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
 Connection connection = null;
 Statement statument = null;
 ResultSet resultSet = null;
 String sql = "select tb.name as name,tb.age as age,tbs.marks as marks from jaspertb tb join jaspertbs tbs";
 ServletOutputStream servletOutputStream = response.getOutputStream();
 InputStream is = getServletConfig().getServletContext().getResourceAsStream("report\\JasperReportSQLResult.jasper");
try {
 Class.forName("com.mysql.jdbc.Driver");
 connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/jasperreportdb","root", "root");
 statument = connection.createStatement();
 resultSet = statument.executeQuery(sql);
//这里把ResultSet封装到JRResultSetDataSource对象里面了
 JasperRunManager.runReportToPdfStream(is,servletOutputStream,new HashMap(), new JRResultSetDataSource(resultSet));
 response.setContentType("application/pdf");
 servletOutputStream.flush();
 servletOutputStream.close();
 connection.close();
 } catch (ClassNotFoundException e) {
 e.printStackTrace();
 } catch (SQLException e) {
 e.printStackTrace();
 } catch (JRException e) {
 e.printStackTrace();
 }
 }

publicvoid doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
this.doGet(request, response);
 }

}

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