我已经用ireport工具生成了jasper文件，并且利用ireport已经可以成功预览并生成pdf文件，但是现在需要在java web工程中，利用jasper文件生成相应的pdf文件，自己测视了好久，在网上也搜了好久，没有找到解决办法，现在把相应代码及错误贴出来，希望会做的朋友帮忙改正一下！
主要的servlet文件，在web.xml中都已将其配置好了
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.HashMap;
import java.util.Map;
import util.JDBCConnection;
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.export.JRHtmlExporter;
import net.sf.jasperreports.engine.export.JRHtmlExporterParameter;
import net.sf.jasperreports.engine.export.JRPdfExporter;
import net.sf.jasperreports.engine.export.JRXlsExporter;
import net.sf.jasperreports.engine.export.JRXlsExporterParameter;
import net.sf.jasperreports.engine.util.JRLoader;
public class JRHTMLServlet extends HttpServlet {
private Connection conn = JDBCConnection.getConnection(); //这个是连接mysql数据库
public JRHTMLServlet() {
super();
}
public void destroy() {
super.destroy(); // Just puts "destroy" string in log
// Put your code here
}
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String type = request.getParameter("type");
try
{
ServletContext servletContext = this.getServletContext();
File reportFile = new File(servletContext.getRealPath("/")+"/WEB-INF/report/Untitled_report_1.jasper");
Map parameters = new HashMap();
if("pdf".equals(type)){
byte[] bytes = JasperRunManager.runReportToPdf(reportFile.getPath(), parameters, conn);
response.setContentType("application/pdf");
response.addHeader("Content-Disposition", "attachment; filename=report.pdf");
response.setContentLength(bytes.length);
ServletOutputStream ouputStream = response.getOutputStream();
ouputStream.write(bytes, 0, bytes.length);
ouputStream.flush();
ouputStream.close();
} else if ("excel".equals(type)){
JRXlsExporter exporter = new JRXlsExporter();
ByteArrayOutputStream oStream = new ByteArrayOutputStream();
JasperPrint jasperPrint = JasperFillManager.fillReport(reportFile.getPath(), parameters, conn);
exporter.setParameter(JRExporterParameter.JASPER_PRINT, jasperPrint);
exporter.setParameter(JRExporterParameter.OUTPUT_STREAM, oStream);
exporter.setParameter(JRXlsExporterParameter.IS_REMOVE_EMPTY_SPACE_BETWEEN_ROWS, Boolean.TRUE);
exporter.setParameter(JRXlsExporterParameter.IS_ONE_PAGE_PER_SHEET, Boolean.FALSE);
exporter.setParameter(JRXlsExporterParameter.IS_WHITE_PAGE_BACKGROUND, Boolean.FALSE);
exporter.exportReport();
byte[] bytes = oStream.toByteArray();
response.setContentType("application/vnd.ms-excel");
response.addHeader("Content-Disposition", "attachment; filename=report.xls");
response.setContentLength(bytes.length);
ServletOutputStream ouputStream = response.getOutputStream();
ouputStream.write(bytes, 0, bytes.length);
ouputStream.flush();
ouputStream.close();
} else
{
JRHtmlExporter exporter = new JRHtmlExporter();
ByteArrayOutputStream oStream = new ByteArrayOutputStream();
JasperPrint jasperPrint = JasperFillManager.fillReport(reportFile.getPath(), parameters, conn);
exporter.setParameter(JRHtmlExporterParameter.IS_USING_IMAGES_TO_ALIGN, Boolean.FALSE);
exporter.setParameter(JRHtmlExporterParameter.JASPER_PRINT, jasperPrint);
exporter.setParameter(JRHtmlExporterParameter.CHARACTER_ENCODING, "utf-8");
exporter.setParameter(JRHtmlExporterParameter.OUTPUT_STREAM, oStream);
exporter.exportReport();
byte[] bytes = oStream.toByteArray();
response.setContentType("text/html");
response.setContentLength(bytes.length);
response.setCharacterEncoding("utf-8");
ServletOutputStream ouputStream = response.getOutputStream();
ouputStream.write(bytes, 0, bytes.length);
ouputStream.flush();
ouputStream.close();
}
}
catch (JRException jre)
{
System.out.println("JRException:" + jre.getMessage());
}
catch (Exception e)
{
System.out.println("Exception:" + e.getMessage());
}
finally{
try
{
conn.close();
}
catch (SQLException ex)
{
// TODO Auto-generated catch block
ex.printStackTrace();
}
}
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
this.doGet(request, response);
}
}
在jsp文件中的主要代码：
Servlet中生成pdf
Servlet中生成excel
Servlet中生成html
然后编译都没有问题，在执行时，如果点击了“Servlet中生成pdf”超链接，就会提示错误：
JRException:Error evaluating expression :
Source text : new java.lang.Integer(1)
若点击“Servlet中生成excel”超链接，就会提示错误：
严重: Servlet.service() for servlet JRHTMLServlet threw exception
java.lang.ClassNotFoundException: org.apache.poi.ss.usermodel.Sheet
若点击“Servlet中生成html”超链接，就会提示错误：
JRException:Error preparing statement for executing the report query :
SELECT
customer.ID AS customer_ID,
customer.USERNAME AS customer_USERNAME,
customer.PASSWORD AS customer_PASSWORD,
customer.REALNAME AS customer_REALNAME,
customer.ADDRESS AS customer_ADDRESS,
customer.MOBILE AS customer_MOBILE,
customer.IDCARD_ID AS customer_IDCARD_ID
FROMcustomer customer
以上三种都试了，执行时，页面都可以跳转，但是跳转之后，都没有显示，直接出错了，我尝试了好久好久，确实不知道是什么问题，还请各位帮忙看看啊，在这里先谢谢你们啦
附：数据库的连接：
String url = "jdbc:mysql://localhost/test";
String userName = "root";
String password = "123456";
Class.forName("com.mysql.jdbc.Driver");
Connection connection = DriverManager.getConnection(url, userName,password);
数据库表里面有中文，应该没有影响，现在只要求可以在web工程中导出pdf就可以了
