java - 使用 jasper 和 servlet 创建 pdf 报告

Question

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已关闭 10 年前。

我想使用 servlet、.jasper 文件创建 pdf 格式的报告，但有一个异常(exception):

HTTP Status 500 - Servlet execution threw an exception

--------------------------------------------------------------------------------

type Exception report

message Servlet execution threw an exception

description The server encountered an internal error that prevented it from fulfilling     this request.

exception 

javax.servlet.ServletException: Servlet execution threw an exception

root cause

java.lang.NoClassDefFoundError: net/sf/jasperreports/engine/JasperRunManager one.Patient.doGet(Patient.java:46) javax.servlet.http.HttpServlet.service(HttpServlet.java:621) javax.servlet.http.HttpServlet.service(HttpServlet.java:728)

note The full stack trace of the root cause is available in the Apache Tomcat/7.0.34 logs.

---

servlet 代码是:

package one;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.sql.Connection;
import java.util.HashMap;

import javax.servlet.Servlet;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
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;

/**
 * Servlet implementation class Patient
 */
@WebServlet("/Patient")
public class Patient extends HttpServlet implements Servlet {
    private static final long serialVersionUID = 1L;

    /**
     * @see HttpServlet#HttpServlet()
     */
    public Patient() {
        super();
        // TODO Auto-generated constructor stub
    }

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
        Connection con=DBCon.getConnection();
        InputStream inS=getServletContext().getResourceAsStream("/report-src/ganeshaji.jashper");

        OutputStream outS=response.getOutputStream();
        response.setContentType("application/pdf");

        try {
            JasperRunManager.runReportToPdfStream(inS, outS, new HashMap<String, Object>(),con);
            outS.flush();
            con.close();
        } catch (Exception e) {
            // TODO Auto-generated catch block
            response.setContentType("text/html");
            e.printStackTrace();
        }   
        }

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
    }

}

请。给我解决方案

Answer 1

通过调查根本原因

java.lang.NoClassDefFoundError: net/sf/jasperreports/engine/JasperRunManager 

看来您要么错过了 jasper jar，要么使用了不支持 JasperRunManager 的错误版本。

在类路径中包含正确的 jar 将解决您的问题。

请下载这些 jar :

itext-4.2.0.jar 

itextpdf-5.3.4.jar 

jasperreports-4.0.1.jar 

jasperreports-fonts-4.0.0.jar 

并编写如下代码:

try { 
FileInputStream fis = new FileInputStream(YOURREPORTPATH.jasper"); 
BufferedInputStream bufferedInputStream = new BufferedInputStream(fis); 
jasperReport = (JasperReport) JRLoader.loadObject(bufferedInputStream); 
} catch (Exception e2) {
 e2.printStackTrace(); 
}

然后在填写参数和数据源后创建 pdf，如下所示:

JasperExportManager.exportReportToPdfFile(jasperPrint, OUTPUTFILENAME+".pdf");

谢谢...

777先生