单个或者多个jasper文件生成PDF文件

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;


import net.sf.jasperreports.engine.JREmptyDataSource;
import net.sf.jasperreports.engine.JRException;
import net.sf.jasperreports.engine.JRExporterParameter;
import net.sf.jasperreports.engine.JasperFillManager;
import net.sf.jasperreports.engine.JasperPrint;
import net.sf.jasperreports.engine.JasperReport;
import net.sf.jasperreports.engine.JasperRunManager;
import net.sf.jasperreports.engine.data.JRBeanCollectionDataSource;
import net.sf.jasperreports.engine.export.JRPdfExporter;
import net.sf.jasperreports.engine.util.JRLoader;








public class TestUtils {
 
public static void main(String[] args) throws JRException {
getFirst();
getPa();
}


private static void getFirst() throws JRException {
// 第一步：装载jasper文件
File jasperFileName = new File("c://test2.jasper");
// 第二步：设置参数值
/* 设置参数 */
HashMap<String, Object> params = new HashMap<String, Object>();// 建立参数表
params.put("name","我们的产品"); // 设置参数值
// 第三步：利用JasperRunManager生成PDF文件
JasperRunManager.runReportToPdfFile(jasperFileName.getPath(),
params, new JREmptyDataSource());
}

private static void getPa() throws JRException{
JRPdfExporter jrpdf = new JRPdfExporter();
JasperReport report1 = (JasperReport) JRLoader.loadObject(new File("c://test.jasper"));
JasperReport report2 = (JasperReport) JRLoader.loadObject(new File("c://test2.jasper"));
List<String> list = new ArrayList<String>();
list.add("测试数据");
JRBeanCollectionDataSource ds1 = new JRBeanCollectionDataSource(list);
JRBeanCollectionDataSource ds2 = new JRBeanCollectionDataSource(list);
HashMap<String, Object> params = new HashMap<String, Object>();// 建立参数表
params.put("name", "我们的产品"); // 设置参数值

JasperPrint jasperPrint = JasperFillManager.fillReport(report1,params,ds1);
JasperPrint jasperPrint2 = JasperFillManager.fillReport(report2,params,ds2);
List jasperPrintList = new ArrayList();
jasperPrintList.add(jasperPrint);
jasperPrintList.add(jasperPrint2);

File file = new File("c://Test.pdf");

ByteArrayOutputStream baos = new ByteArrayOutputStream();
JRPdfExporter exporter = new JRPdfExporter();
exporter.setParameter(JRExporterParameter.JASPER_PRINT_LIST, jasperPrintList);
exporter.setParameter(JRExporterParameter.OUTPUT_STREAM, baos);
exporter.exportReport();
byte[] bytes = baos.toByteArray();
// 确定写出文件的位置
try {
// 建立输出字节流
FileOutputStream fos = new FileOutputStream(file);
// 用FileOutputStream 的write方法写入字节数组
fos.write(bytes);
System.out.println("写入成功");
// 为了节省IO流的开销，需要关闭
fos.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}



}