前言
上一篇我们使用了JRResultSetDataSource数据源来与数据库进行交互，今天我们来介绍下如何使用Map类型的数据源。
正题
跟之前的一样，我们要生成报表需要以下几个步骤：
1.引入jar包，请看《静态文本报表》。
2.新建报表模版：
由于我们这次是使用的Map数据源，其实就是报表的数据来自于这个Map对象，所以我们的报表跟前面的一样：
<?xmlversion="1.0" encoding="UTF-8"?>
<jasperReportxmlns="http://jasperreports.sourceforge.net/jasperreports"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://jasperreports.sourceforge.net/jasperreportshttp://jasperreports.sourceforge.net/xsd/jasperreport.xsd"
name="AircraftReport">
<fieldname="ID" class="java.lang.String" />
<fieldname="NAME" class="java.lang.String" />
<fieldname="SEX" class="java.lang.String" />
<pageHeader>
<bandheight="30">
<staticText>
<reportElementx="0" y="0" width="69" height="24"/>
<textElementverticalAlignment="Bottom"/>
<text>Id</text>
</staticText>
<staticText>
<reportElementx="140" y="0" width="79" height="24"/>
<text>Name</text>
</staticText>
<staticText>
<reportElementx="280" y="0" width="69" height="24"/>
<text>Sex</text>
</staticText>
</band>
</pageHeader>
<detail>
<bandheight="40">
<textField>
<reportElementx="0" y="0" width="69" height="24"/>
<textFieldExpressionclass="java.lang.String">
$F{ID}
</textFieldExpression>
</textField>
<textField>
<reportElementx="140" y="0" width="69" height="24"/>
<textFieldExpressionclass="java.lang.String">
$F{NAME}
</textFieldExpression>
</textField>
<textField>
<reportElementx="280" y="0" width="69" height="24"/>
<textFieldExpressionclass="java.lang.String">
$F{SEX}
</textFieldExpression>
</textField>
</band>
</detail>
</jasperReport>
3.编译报表模版，请看《静态文本报表》。
4.编写servlet:
由于Map对象分为两种JRMapArrayDataSource和JRMapCollectionDataSource，下面将这两种形式都写出来：
1）JRMapArrayDataSource:
packagecom.dan.servlet;
importjava.io.IOException;
importjava.io.InputStream;
importjava.io.PrintWriter;
importjava.io.StringWriter;
importjava.sql.Connection;
importjava.sql.DriverManager;
importjava.sql.ResultSet;
importjava.sql.Statement;
importjava.util.HashMap;
importjava.util.Map;
importjavax.servlet.ServletException;
importjavax.servlet.ServletOutputStream;
importjavax.servlet.http.HttpServlet;
importjavax.servlet.http.HttpServletRequest;
importjavax.servlet.http.HttpServletResponse;
importnet.sf.jasperreports.engine.JRDataSource;
importnet.sf.jasperreports.engine.JRResultSetDataSource;
importnet.sf.jasperreports.engine.JasperRunManager;
importnet.sf.jasperreports.engine.data.JRMapArrayDataSource;
/**
* 使用Map作为数据源
* @author zdd
*
*/
publicclass MapArrayDSReportServlet extends HttpServlet {
privateJRDataSource createReportDataSource(){
JRMapArrayDataSourcedataSource;
Map[]resportRows = initializeMapArray();
dataSource= new JRMapArrayDataSource(resportRows);
returndataSource;
}
privateMap[] initializeMapArray(){
HashMap[]reportRows = new HashMap[4];
HashMaprow1Map = new HashMap();
HashMaprow2Map = new HashMap();
HashMaprow3Map = new HashMap();
HashMaprow4Map = new HashMap();
row1Map.put("ID","1");
row1Map.put("NAME","zhaodd");
row1Map.put("SEX","female");
row2Map.put("ID","2");
row2Map.put("NAME","zhaodd2");
row2Map.put("SEX","female");
row3Map.put("ID","3");
row3Map.put("NAME","zhaodd3");
row3Map.put("SEX","female");
row4Map.put("ID","4");
row4Map.put("NAME","zhaodd4");
row4Map.put("SEX","female");
reportRows[0]= row1Map;
reportRows[1]= row2Map;
reportRows[2]= row3Map;
reportRows[3]= row4Map;
returnreportRows;
}
@Override
protectedvoid doGet(HttpServletRequest req, HttpServletResponse resp)
throwsServletException, IOException {
ServletOutputStreamservletOutputStream = resp.getOutputStream();
InputStreamreportStream =getServletConfig().getServletContext().getResourceAsStream("/WEB-INF/classes/reports/AircraftReport.jasper");
try{
JRDataSourcedataSource = createReportDataSource();
JasperRunManager.runReportToPdfStream(reportStream,servletOutputStream,newHashMap(),dataSource );
resp.setContentType("application/pdf");
servletOutputStream.flush();
servletOutputStream.close();
}catch(Exceptione){
StringWriterstringWriter = new StringWriter();
PrintWriterprintWriter = new PrintWriter(stringWriter);
e.printStackTrace(printWriter);
resp.setContentType("text/plain");
resp.getOutputStream().print(stringWriter.toString());
}
}
}
2）JRMapCollectionDataSource:
packagecom.dan.servlet;
importjava.io.IOException;
importjava.io.InputStream;
importjava.io.PrintWriter;
importjava.io.StringWriter;
importjava.util.ArrayList;
importjava.util.Collection;
importjava.util.HashMap;
importjavax.servlet.ServletException;
importjavax.servlet.ServletOutputStream;
importjavax.servlet.http.HttpServlet;
importjavax.servlet.http.HttpServletRequest;
importjavax.servlet.http.HttpServletResponse;
importnet.sf.jasperreports.engine.JRDataSource;
importnet.sf.jasperreports.engine.JasperRunManager;
importnet.sf.jasperreports.engine.data.JRMapCollectionDataSource;
/**
* 使用Map作为数据源
* @author zdd
*
*/
publicclass MapCollectionDSReportServlet extends HttpServlet {
privateJRDataSource createReportDataSource(){
JRMapCollectionDataSourcedataSource;
CollectionresportRows = initializeMapArray();
dataSource= new JRMapCollectionDataSource(resportRows);
returndataSource;
}
privateCollection initializeMapArray(){
ArrayListreportRows = new ArrayList();
HashMaprow1Map = new HashMap();
HashMaprow2Map = new HashMap();
HashMaprow3Map = new HashMap();
HashMaprow4Map = new HashMap();
row1Map.put("ID","1");
row1Map.put("NAME","zhaodd");
row1Map.put("SEX","female");
row2Map.put("ID","2");
row2Map.put("NAME","zhaodd2");
row2Map.put("SEX","female");
row3Map.put("ID","3");
row3Map.put("NAME","zhaodd3");
row3Map.put("SEX","female");
row4Map.put("ID","4");
row4Map.put("NAME","zhaodd4");
row4Map.put("SEX","female");
reportRows.add(row1Map);
reportRows.add(row2Map);
reportRows.add(row3Map);
reportRows.add(row4Map);
returnreportRows;
}
@Override
protectedvoid doGet(HttpServletRequest req, HttpServletResponse resp)
throwsServletException, IOException {
ServletOutputStreamservletOutputStream = resp.getOutputStream();
InputStreamreportStream =getServletConfig().getServletContext().getResourceAsStream("/WEB-INF/classes/reports/AircraftReport.jasper");
try{
JRDataSourcedataSource = createReportDataSource();
JasperRunManager.runReportToPdfStream(reportStream,servletOutputStream,newHashMap(),dataSource );
resp.setContentType("application/pdf");
servletOutputStream.flush();
servletOutputStream.close();
}catch(Exceptione){
StringWriterstringWriter = new StringWriter();
PrintWriterprintWriter = new PrintWriter(stringWriter);
e.printStackTrace(printWriter);
resp.setContentType("text/plain");
resp.getOutputStream().print(stringWriter.toString());
}
}
}
5.配置web.xml，就是配置servlet。
6.运行项目
看一下我的运行结果：
1）JRMapArrayDataSource：
2）JRMapCollectionDataSource：
小结：
其实大家都知道一般有Array形式就会有Collection的形式，这个也不例外，所以Map对象有JRMapArrayDataSource和JRMapCollectionDataSource这两种形式，接下来还会介绍其他形式的数据源例如实体对象的，xml形式的，cvs形式的等等。