无法使用Jasper报告库生成Excel工作表报告
我尝试使用以下代码生成Excel报告。
I tried to generate Excel report, using the below code.
import java.util.*;
import net.sf.jasperreports.engine.*;
import net.sf.jasperreports.engine.export.JRXlsExporter;
import net.sf.jasperreports.export.OutputStreamExporterOutput;
import net.sf.jasperreports.export.SimpleExporterInput;
import net.sf.jasperreports.export.SimpleOutputStreamExporterOutput;
import net.sf.jasperreports.export.SimpleXlsReportConfiguration;
public class FirstReport
{
public static void main(String[] args)
{
try
{
JRXlsExporter exporter = new JRXlsExporter();
exporter.setExporterInput(new SimpleExporterInput("FirstReport.jrxml"));
exporter.setExporterOutput(new SimpleOutputStreamExporterOutput("C://sample_report.xls"));
SimpleXlsReportConfiguration configuration = new SimpleXlsReportConfiguration();
configuration.setOnePagePerSheet(true);
configuration.setDetectCellType(true);
configuration.setCollapseRowSpan(false);
exporter.setConfiguration(configuration);
exporter.exportReport();
}
catch (Exception e)
{
e.printStackTrace();
}
}
}
此程序正在生成以下异常
This program is generating following exception
net.sf.jasperreports.engine.JRRuntimeException：net.sf.jasperreports.engine.JRException：从文件加载对象时出错：FirstReport.jrxml
at net.sf.jasperreports.export.SimpleExporterInput。（SimpleExporterInput.java:157）
在FirstReport.main（FirstReport.java:33）
引起：net.sf.jasperreports.engine。 JRException：从文件加载对象时出错：net.sf.jasperreports.engine.util.JRLoader.loadObject中的FirstReport.jrxml
（JRLoader.java:131）net.sf.jasperreports.engine.util上的
.JRLoader.loadObject（JRLoader.java:103）
at net.sf.jasperreports.engine.util.JRLoader.loadObjectFromFile（JRLoader.java:94）
at net.sf.jasperreports.export.SimpleExporterInput 。 （SimpleExporterInput.java:153）
... 1更多
引起：java.io.StreamCorruptedException：无效的流标题：java.io.ObjectInputStream.readStreamHeader（未知来源）中的3C3F786D
at java.io.ObjectInputStream。（Unknown Source）
at net.sf.jasperreports.engine.util.ContextClassLoaderObjectInputStream。 （ContextClassLoaderObjectInputStream.java:57）
at net.sf.jasperreports.engine.util.JRLoader.loadObject（JRLoader.java:126)
... 4 more
net.sf.jasperreports.engine.JRRuntimeException: net.sf.jasperreports.engine.JRException: Error loading object from file : FirstReport.jrxml at net.sf.jasperreports.export.SimpleExporterInput.(SimpleExporterInput.java:157) at FirstReport.main(FirstReport.java:33) Caused by: net.sf.jasperreports.engine.JRException: Error loading object from file : FirstReport.jrxml at net.sf.jasperreports.engine.util.JRLoader.loadObject(JRLoader.java:131) at net.sf.jasperreports.engine.util.JRLoader.loadObject(JRLoader.java:103) at net.sf.jasperreports.engine.util.JRLoader.loadObjectFromFile(JRLoader.java:94) at net.sf.jasperreports.export.SimpleExporterInput. (SimpleExporterInput.java:153) ... 1 more Caused by: java.io.StreamCorruptedException: invalid stream header: 3C3F786D at java.io.ObjectInputStream.readStreamHeader(Unknown Source) at java.io.ObjectInputStream.(Unknown Source) at net.sf.jasperreports.engine.util.ContextClassLoaderObjectInputStream. (ContextClassLoaderObjectInputStream.java:57) at net.sf.jasperreports.engine.util.JRLoader.loadObject(JRLoader.java:126) ... 4 more
exporter.setExporterInput（）的参数必须基于JasperPrint对象（不是jrxml文件）。
Parameter of exporter.setExporterInput() must be based on JasperPrint object (not jrxml file).
您可以在 net.sf.jasperreports.export.SimpleExporterInput 类中看到它。此类中的一些代码：
You can see it at net.sf.jasperreports.export.SimpleExporterInput class. Some code from this class:
/**
* Creates an {@link ExporterInput} object with a single item wrapping the {@link JasperPrint} object that will be exported.
* If you already have a JasperPrint object, you can pass it to the exporter using this type of input.
*/
public SimpleExporterInput(JasperPrint jasperPrint)
{
if (jasperPrint != null)
{
this.items = new ArrayList<ExporterInputItem>();
items.add(new SimpleExporterInputItem(jasperPrint));
}
}
/**
* Creates an {@link ExporterInput} object with a single {@link JasperPrint} item read from the provided input stream.
* If you want to read the JasperPrint object from an input stream (like a web location), you can pass the stream to this constructor.
*/
public SimpleExporterInput(InputStream inputStream)
{
if (inputStream != null)
{
JasperPrint jasperPrint = null;
try
{
jasperPrint = (JasperPrint)JRLoader.loadObject(inputStream);
}
catch (JRException e)
{
throw new JRRuntimeException(e);
}
this.items = new ArrayList<ExporterInputItem>();
items.add(new SimpleExporterInputItem(jasperPrint));
}
}
JasperPrint对象是执行方法fillReport的结果。例如：
JasperPrint object is result of execution method fillReport. For example:
JasperPrint jasperPrint = JasperFillManager.fillReport(jasperReportFile, reportParameters, dataSource);
在此代码中，jasperReportFile是与编译的报告文件（不是jrxml）对应的对象。在你的情况下FirstReport.jasper
In this code jasperReportFile is object which corresponds with compiled report file (not jrxml). In your case FirstReport.jasper
一些代码来自 net.sf.jasperreports.engine.JasperFillManager ：
/**
* @see #fill(String, Map, JRDataSource)
*/
public static JasperPrint fillReport(
String sourceFileName,
Map<String,Object> params,
JRDataSource dataSource
) throws JRException
{
return getDefaultInstance().fill(sourceFileName, params, dataSource);
}
....
/**
* Fills the compiled report design loaded from the specified file and returns
* the generated report object.
*
* @param sourceFileName source file containing the compile report design
* @param params report parameters map
* @param dataSource data source object
* @return generated report object
*/
public JasperPrint fill(
String sourceFileName,
Map<String,Object> params,
JRDataSource dataSource
) throws JRException
{
File sourceFile = new File(sourceFileName);
JasperReport jasperReport = (JasperReport)JRLoader.loadObject(sourceFile);
JasperReportsContext lcJrCtx = getLocalJasperReportsContext(sourceFile);
return JRFiller.fill(lcJrCtx, jasperReport, params, dataSource);
}
HTH