使用JasperReport+iReport进行WEB开发

新建一 web 项目 Test2。将 iReport 目录 lib 下的所有 jar 包导入。在 servlet 程序中把从数据库得到的数据传入 *.jrxml 文件得到 *.jrprint 文件（这才是我们想要的东西），并把这个对象写入 Stream流，以返还给请求客户端。源码：

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package com.defonds.test;

import java.io.File;

import java.io.IOException;

import java.io.ObjectOutputStream;

import javax.servlet.RequestDispatcher;

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.sql.Connection;

import java.sql.DriverManager;

import java.sql.ResultSet;

import java.sql.SQLException;

import java.sql.Statement;

import java.util.Calendar;

import java.util.HashMap;

import java.util.Map;

import net.sf.jasperreports.engine.JRResultSetDataSource;

import net.sf.jasperreports.engine.JasperCompileManager;

import net.sf.jasperreports.engine.JasperExportManager;

import net.sf.jasperreports.engine.JasperFillManager;

import net.sf.jasperreports.engine.JasperPrint;

import net.sf.jasperreports.engine.JasperReport;

import net.sf.jasperreports.engine.JasperRunManager;

/**

* 建立数据库链接

* 由 sql 语法取出资料，准备好传入的 parameters

* 将 parameters 及取出的资料传入 Jasper 中。会由 .jasper 文档生出 .jrprint 文档

* 再由 .jrprint 文档生出 .pdf 目的文档给调用页面下载

* @author Defonds

*

*/

public class TestServlet3 extends HttpServlet {

private static final String CONTENTTYPE = "application/octet-stream";

/**

* Constructor of the object.

*/

public TestServlet3() {

super();

}

/**

* Destruction of the servlet. <br>

*/

public void destroy() {

super.destroy(); // Just puts "destroy" string in log

// Put your code here

}

/**

* The doGet method of the servlet. <br>

*

* This method is called when a form has its tag value method equals to get.

*

* @param request the request send by the client to the server

* @param response the response send by the server to the client

* @throws ServletException if an error occurred

* @throws IOException if an error occurred

*/

public void doGet(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

String fileName = "";

String sql = "";

Map parameters = new HashMap();

//parameters.put("rptToday", strDate);//传入的 prameters 引数

sql = "select * from tab_channel_car_basic t";

Connection conn = this.createConnection();//建立连接

try {

Statement stmt = conn.createStatement();

ResultSet rs = stmt.executeQuery(sql);

response.setContentType(CONTENTTYPE);

ServletOutputStream ouputStream = response.getOutputStream();

fileName="D://iReport//iReport-0.4.0//Work//carBasic3.jrxml";

JasperReport jrt = JasperCompileManager.compileReport(fileName);//编译报表格式

JasperPrint jpt = JasperFillManager.fillReport(jrt, parameters, new JRResultSetDataSource(rs));//匹配数据源，生成JasperPrint

ObjectOutputStream oos = new ObjectOutputStream(ouputStream);

oos.writeObject(jpt);

oos.flush();

oos.close();

}catch(Exception e) {

System.out.println("Error:" + e.toString());

e.printStackTrace();

}finally {

CloseConnect(conn);

conn = null;

}

}

/**

* 建立连接方法

* @return Connection

*/

public Connection createConnection() {

Connection conn;

try {

String driver = "oracle.jdbc.driver.OracleDriver";

String url = "jdbc:oracle:thin:@localhost:1521:CUC";

Class.forName(driver);

conn = DriverManager.getConnection(url,"sybj","sybj");

conn.setAutoCommit(false);

return conn;

}catch(SQLException e1) {

System.out.println("建立连接错误 = " + e1.toString());

e1.printStackTrace();

}catch(ClassNotFoundException e2) {

System.out.println("建立连接错误 = " + e2.toString());

e2.printStackTrace();

}

return null;

}

/**

* 关闭连接方法

* @param conn

*/

public void CloseConnect(Connection conn) {

try {

conn.commit();

conn.setAutoCommit(true);

conn.close();

}catch(Exception e) {

System.out.println("关闭连接错误 = " + e.toString());

}

}

}

PS:这里，关于 carBasic3.jrxml 文件的提取，笔者采用的是物理路径，读者可以把 *.jrxml 文件放到项目根目录下，然后采用其他方式提取。

如果输入http://localhost:9999/Test2/testServlet3 就弹出来一个下载窗口，证明这个
servlet 已经 ok（笔者 tomcat 端口号设置的是 9999，在 Test2 项目中进行测试）。

7、applet 请求服务器 servlet 得到 JasperPrint 对象并打印。源码：

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package com.defonds.test;

import java.applet.Applet;

import java.io.PrintWriter;

import java.io.StringWriter;

import java.net.URL;

import javax.swing.JOptionPane;

import net.sf.jasperreports.engine.JasperPrint;

import net.sf.jasperreports.engine.JasperPrintManager;

import net.sf.jasperreports.engine.util.JRLoader;

public class JRPrinterApplet extends javax.swing.JApplet

{

/**

*

*/

private URL url = null;

private JasperPrint jasperPrint = null;

/** Creates new form AppletViewer */

public JRPrinterApplet()

{

}

/**

*

*/

public void init()

{

// String strUrl = getParameter("REPORT_URL");

String strUrl = "http://localhost:9999/Test2/testServlet3";

if (strUrl != null)

{

try

{

//url = new URL(getCodeBase(), strUrl);

URL urll = new URL("http://localhost:9999/Test2/testServlet3");

url = urll;

System.out.println("url="+urll);

}

catch (Exception e)

{

StringWriter swriter = new StringWriter();

PrintWriter pwriter = new PrintWriter(swriter);

e.printStackTrace(pwriter);

JOptionPane.showMessageDialog(this, swriter.toString());

}

}

else

{

JOptionPane.showMessageDialog(this, "init():Source URL not specified");

}

}

public void start() {

if (url != null)

{

if (jasperPrint == null)

{

try

{

System.out.println("进入start方法，即将下载pdf文件");

jasperPrint = (JasperPrint)JRLoader.loadObject(url);

System.out.println("进入start方法，下载pdf文件完毕");

}

catch (Exception e)

{

StringWriter swriter = new StringWriter();

PrintWriter pwriter = new PrintWriter(swriter);

e.printStackTrace(pwriter);

JOptionPane.showMessageDialog(this, swriter.toString());

}

}

if (jasperPrint != null)

{

final JasperPrint print = jasperPrint;

Thread thread = new Thread

(

new Runnable()

{

public void run()

{

try

{

System.out.println("进入start方法，即将打印pdf文件");

JasperPrintManager.printReport(print, true);

}

catch (Exception e)

{

StringWriter swriter = new StringWriter();

PrintWriter pwriter = new PrintWriter(swriter);

e.printStackTrace(pwriter);

JOptionPane.showMessageDialog(null, swriter.toString());

}

}

}

);

thread.start();

}

else

{

JOptionPane.showMessageDialog(this, "Empty report.");

}

}

else

{

JOptionPane.showMessageDialog(this, "start():Source URL not specified");

}

}

}

右键单击 JRPrinterApplet.java，选择 “Run as Java Applet”，弹出打印对话框，确认后打印机正常打印，证明 applet 已经编写成功。

8、jsp 页面嵌入 applet源码：

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<%@ page language="java" import="java.util.*" pageEncoding="GBK"%>

<%

String path = request.getContextPath();

String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";

%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>

<head>

<base href="<%=basePath%>">

<title>My JSP 'index.jsp' starting page</title>

<meta http-equiv="pragma" content="no-cache">

<meta http-equiv="cache-control" content="no-cache">

<meta http-equiv="expires" content="0">

<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">

<meta http-equiv="description" content="This is my page">

<!--

<link rel="stylesheet" type="text/css" href="styles.css" mce_href="styles.css">

-->

</head>

<mce:script language="javascript"><!--

function openApp()

{

var url = "/JRPrintServlet";

document.write('<APPLET ID="JrPrt" CODE="com.defonds.test.JRPrinterApplet.class" CODEBASE = "./" ARCHIVE = "reportprint.jar" WIDTH = "0" HEIGHT = "0">');

document.write('<PARAM NAME = "type" VALUE="application/x-java-applet;version=1.2.2">');

document.write('<PARAM NAME = "scriptable" VALUE="false">');

document.write('<PARAM NAME = "REPORT_URL" VALUE ="'+url+'">');

document.write('</APPLET>');

}

// --></mce:script>

<body bgcolor="#FFFFFF">

<input type="button" value="测试打印" onclick="openApp();">

</body>

</html>