iReport+jasperReport 之scriptlet

标签： parameters报表stringencodingreport联想

2010-04-08 23:40 901人阅读 评论(0)收藏 举报

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iReport+jasperReport 之scriptlet

提起scriptlet就不能不联想到它的强大功能，jasperReport也是支持scriptlet的哦，先分析一下JasperReport的 API吧！
在填充报表时scriplet是一个非常有力的工具，JRAbstractScriptlet.Java位于 net.sf.jasperreports.engine包下是一个抽象
类


beforeReportInit() ，afterReportInit() ，beforePageInit()，afterPageInit(), beforeColumnInit(), afterColumnInit() ,beforeGroupInit(String groupName),afterGroupInit(String groupName) 
看看这些名字就知道你能完成那些功能，这几个方法是要求我们实现的，jasperReport给我们提供了一个实现类 JRDefaultScriptlet.java，默认的空实现了上面几个方法，它只是很便利的为我们提供了所需的八个方法的空实现。我们写自己的 scriptlet时需要继承JRDefaultScriptlet.java这个类实现自己的相应的功能即可。
 先来看一个简单的例子：
先看看模板文件的处理：
新建时填写的这个类是下面我们要介绍的继承自JRDefaultScriptlet.java类，也就是在模板文件中我们要加上如下代码

scriptletClass="org.bulktree.ireport.scriptlet.ScriptletReportDemo"

完整的模板文件如下：scriptletDemo.jrxml

<? xml version="1.0" encoding="UTF-8"  ?>
<!--  Created with iReport - A designer for JasperReports -->
<! DOCTYPE jasperReport PUBLIC "//JasperReports//DTD Report Design//EN" "http://jasperreports.sourceforge.net/dtds/jasperreport.dtd">
< jasperReport
         name ="scriptletDemo"
         columnCount="1"
         printOrder="Vertical"
         orientation="Portrait"
         pageWidth="595"
         pageHeight="842"
         columnWidth="535"
         columnSpacing="0"
         leftMargin="30"
         rightMargin="30"
         topMargin="20"
         bottomMargin="20"
         whenNoDataType="NoPages"
         scriptletClass="org.bulktree.ireport.scriptlet.ScriptletReportDemo"
         isTitleNewPage="false"
         isSummaryNewPage="false" >
    < property name ="ireport.scriptlethandling" value ="2"  />
    < property name ="ireport.encoding" value ="UTF-8"  />
    < import value ="java.util.*"  />
    < import value ="net.sf.jasperreports.engine.*"  />
    < import value ="net.sf.jasperreports.engine.data.*"  />

    < parameter name ="ReportTitle" isForPrompting ="true"  class ="java.lang.String" />

        < background>
            < band height ="0"  isSplitAllowed ="true"   >
            </ band>
        </ background>
        < title>
            < band height ="20"  isSplitAllowed ="true"   >
                < textField isStretchWithOverflow ="false"  isBlankWhenNull ="false"  evaluationTime ="Now"  hyperlinkType ="None"   hyperlinkTarget ="Self"   >
                    < reportElement
                        mode ="Opaque"
                        x="193"
                        y="0"
                        width="134"
                        height="18"
                        backcolor="#FFCC33"
                        key="textField" />
                    < box></ box>
                    < textElement textAlignment ="Center"  verticalAlignment ="Middle" >
                        < font pdfFontName ="Helvetica-Bold"  size ="12"  isBold ="true" />
                    </ textElement>
                < textFieldExpression   class ="java.lang.String"> <![CDATA[$P{ReportTitle} ]]> </ textFieldExpression >
                </ textField>
            </ band>
        </ title>
        < pageHeader>
            < band height ="0"  isSplitAllowed ="true"   >
            </ band>
        </ pageHeader>
        < columnHeader>
            < band height ="0"  isSplitAllowed ="true"   >
            </ band>
        </ columnHeader>
        < detail>
            < band height ="264"  isSplitAllowed ="true"   >
                < textField isStretchWithOverflow ="false"  isBlankWhenNull ="false"  evaluationTime ="Now"  hyperlinkType ="None"   hyperlinkTarget ="Self"   >
                    < reportElement
                        x ="85"
                        y="20"
                        width="329"
                        height="61"
                        forecolor="#FF0099"
                        key="textField-1" />
                    < box></ box>
                    < textElement textAlignment ="Center"  verticalAlignment ="Middle" >
                        < font pdfFontName ="Helvetica-Bold"  size ="20"  isBold ="true" />
                    </ textElement>
                < textFieldExpression   class ="java.lang.String"> <![CDATA[$P{REPORT_SCRIPTLET}.showInfor() ]]> </ textFieldExpression >
                </ textField>
            </ band>
        </ detail>
        < columnFooter>
            < band height ="0"  isSplitAllowed ="true"   >
            </ band>
        </ columnFooter>
        < pageFooter>
            < band height ="0"  isSplitAllowed ="true"   >
            </ band>
        </ pageFooter>
        < summary>
            < band height ="50"  isSplitAllowed ="true"   >
            </ band>
        </ summary>
</ jasperReport>

下来看看怎么实现我们自己的scriplet

ScriptletReportDemo.java

package  org.bulktree.ireport.scriptlet;

import  net.sf.jasperreports.engine.JRDefaultScriptlet;
import  net.sf.jasperreports.engine.JRScriptletException;

/** */ /**
 * 
 * @author  bulktree Email: [e-mail]
 * @Nov 26, 2008
 */
public   class  ScriptletReportDemo  extends  JRDefaultScriptlet  {

    @Override
    public   void  afterColumnInit()  throws  JRScriptletException  {
        System.out.println( " **************************************afterColumnInit()************************************** " );
    }

    @Override
    public   void  afterDetailEval()  throws  JRScriptletException  {
        System.out.println( " **************************************afterDetailEval()************************************** " );
    }

    @Override
    public   void  afterGroupInit(String groupName)  throws  JRScriptletException  {
        System.out.println( " **************************************afterDetailEval()************************************** " );
    }

    @Override
    public   void  afterPageInit()  throws  JRScriptletException  {
        System.out.println( " **************************************afterPageInit()************************************** " );
    }

    @Override
    public   void  afterReportInit()  throws  JRScriptletException  {
        System.out.println( " **************************************afterReportInit() begin************************************** " );
        
        String str  =  (String) this .getParameterValue( " ReportTitle " );
        System.out.println( " report title=====>>>> " + str);
        
        str  +=  str.subSequence( 0 , str.length() - 2 );
        this .setParameterValue( " ReportTitle " , str);
        System.out.println( " **************************************afterReportInit() end************************************** " );
    }

    @Override
    public   void  beforeColumnInit()  throws  JRScriptletException  {
        System.out.println( " **************************************beforeColumnInit()************************************** " );
    }

    @Override
    public   void  beforeDetailEval()  throws  JRScriptletException  {
        System.out.println( " **************************************beforeDetailEval()************************************** " );
    }

    @Override
    public   void  beforeGroupInit(String groupName)  throws  JRScriptletException  {
        System.out.println( " **************************************beforeGroupInit()************************************** " );
    }

    @Override
    public   void  beforePageInit()  throws  JRScriptletException  {
        System.out.println( " **************************************beforePageInit()************************************** " );
    }

    @Override
    public   void  beforeReportInit()  throws  JRScriptletException  {
        System.out.println( " **************************************beforeReportInit()************************************** " );
    }

    public  String showInfor()  throws  JRScriptletException  {
        return   " the is scriptlet scriptlet scriptlet the,sscriptlet report the is ascriptlet report this is a scriptlet report this is a scriptlet report " ;
    }
    
}

这段代码最后一个方法是我们自己的加的，用来在报表上显示一段文本。我们知道对于一个Field、Parameter、 Variable，JasperReport分别采 用$F{FieldName}、$P{Parametername}、$V{VariableName}来引用，而如果要引用 ScriptletReportDemo.java类的showInfor()返回字符串显示在报表上，看看这个就知道了

在afterReportInit方法中我们把parameter字段取出来前后添上五个*号再set进去
    下来写一个test类测试一下：

package  org.bulktree.ireport.scriptlet;

import  java.io.File;
import  java.io.FileInputStream;
import  java.io.InputStream;
import  java.util.HashMap;

import  net.sf.jasperreports.engine.JREmptyDataSource;
import  net.sf.jasperreports.engine.JasperCompileManager;
import  net.sf.jasperreports.engine.JasperFillManager;
import  net.sf.jasperreports.engine.JasperPrint;
import  net.sf.jasperreports.engine.JasperReport;
import  net.sf.jasperreports.view.JasperViewer;

/** */ /**
 * 
 * @author  bulktree Email: [e-mail]
 * @Nov 27, 2008
 */
public   class  ScriptletTestMain  {

    public   static   void  main(String[] args)  {
        String path  =   " D:/workspace/scriptletDemo.jrxml " ;

        File file  =  new  File(path);
        InputStream in;
        try   {

            HashMap parameters  =  new  HashMap();
            parameters.put( " ReportTitle " ,  " LAOSHULIN " );
            in  =  new  FileInputStream(file);
            JasperReport jasperReport  =  JasperCompileManager.compileReport(in);
            JasperPrint jasperPrint  =  JasperFillManager.fillReport(jasperReport,
                    parameters, new  JREmptyDataSource());
            JasperViewer viewer  =  new  JasperViewer(jasperPrint);
            viewer.setVisible(true );

        }  catch  (Exception e)  {
            //  TODO Auto-generated catch block
            e.printStackTrace();
        }

    }
}

效果不错吧：

 

 

http://www.blogjava.NET/bulktree/archive/2008/12/17/246786.html