我正在尝试开发一个用于报告的Web应用程序，并且已经构建了一个包含EJB3 + primefaces的站点。现在，我正在努力将Jasperreport整合到主要方面...我没有找到关于这个主题的指导或讨论，我想这是不可能的？或者实际上这不是一种正确的方法吗？我实际上是开发JavaEE6的新手，不打算使用像spring和seam这样的框架。
模型
@Stateless
@LocalBean
public class BookEJB {
// @Override
public void printReport() throws ClassNotFoundException, IOException, JRException, SQLException {
Connection connection;
Map parameterMap = new HashMap();
FacesContext ctx = FacesContext.getCurrentInstance();
HttpServletResponse response = (HttpServletResponse) ctx
.getExternalContext().getResponse();
InputStream reportStream = ctx.getExternalContext()
.getResourceAsStream("reports/report1.jasper");
ServletOutputStream servletOutputStream = response.getOutputStream();
Class.forName("com.mysql.jdbc.Driver");
connection = DriverManager.getConnection("jdbc:mysql://localhost/bookdb?user=root&password=******");
ctx.responseComplete();
response.setContentType("application/pdf");
JasperRunManager.runReportToPdfStream(reportStream, servletOutputStream, parameterMap, connection);
connection.close();
servletOutputStream.flush();
servletOutputStream.close();
}
}
控制器
@ManagedBean(name = "bookCtrl")
@RequestScoped
public class BookController {
@EJB
private BookEJB bookEJB;
public void doPrintReport() throws ClassNotFoundException, IOException, JRException, SQLException {
bookEJB.printReport();
}
}
查看（JSF）
<body>
<f:view>
<h:outputText value="Click on the link below to generate the report." />
<h:form>
<h:commandButton action="#{bookCtrl.doPrintReport}" value="Generate Report" />
</h:form>
</f:view>
</body>
碧玉
<?xml version="1.0" encoding="UTF-8"?>
<!-- Created with Jaspersoft Studio -->
<jasperReport xmlns="http://jasperreports.sourceforge.net/jasperreports" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://jasperreports.sourceforge.net/jasperreports http://jasperreports.sourceforge.net/xsd/jasperreport.xsd" name="report1" language="groovy" pageWidth="595" pageHeight="842" columnWidth="555" leftMargin="20" rightMargin="20" topMargin="20" bottomMargin="20">
<property name="ireport.zoom" value="1.0"/>
<property name="ireport.x" value="0"/>
<property name="ireport.y" value="0"/>
<queryString language="SQL">
<![CDATA[SELECT
*
FROM
`book` book]]>
</queryString>
<field name="Id" class="java.lang.Integer"/>
<field name="title" class="java.lang.String"/>
<field name="price" class="java.lang.String"/>
<background>
<band splitType="Stretch"/>
</background>
<title>
<band height="45" splitType="Stretch"/>
</title>
<pageHeader>
<band height="35" splitType="Stretch"/>
</pageHeader>
<columnHeader>
<band height="21" splitType="Stretch">
<staticText>
<reportElement x="0" y="0" width="100" height="20"/>
<textElement/>
<text><![CDATA[Id]]></text>
</staticText>
<staticText>
<reportElement x="100" y="0" width="100" height="20"/>
<textElement/>
<text><![CDATA[title]]></text>
</staticText>
<staticText>
<reportElement x="200" y="0" width="100" height="20"/>
<textElement/>
<text><![CDATA[price]]></text>
</staticText>
</band>
</columnHeader>
<detail>
<band height="24" splitType="Stretch">
<textField>
<reportElement x="0" y="0" width="100" height="20"/>
<textElement/>
<textFieldExpression class="java.lang.Integer"><![CDATA[$F{Id}]]></textFieldExpression>
</textField>
<textField>
<reportElement x="100" y="0" width="100" height="20"/>
<textElement/>
<textFieldExpression class="java.lang.String"><![CDATA[$F{title}]]></textFieldExpression>
</textField>
<textField>
<reportElement x="200" y="0" width="100" height="20"/>
<textElement/>
<textFieldExpression class="java.lang.String"><![CDATA[$F{price}]]></textFieldExpression>
</textField>
</band>
</detail>
<columnFooter>
<band height="45" splitType="Stretch"/>
</columnFooter>
<pageFooter>
<band height="54" splitType="Stretch"/>
</pageFooter>
<summary>
<band height="42" splitType="Stretch"/>
</summary>
</jasperReport>
单击JSF按钮时发生错误，下面的日志来自glassfish
WARNING: A system exception occurred during an invocation on EJB BookEJB method public void blah.BookEJB.printReport() throws java.lang.ClassNotFoundException,java.io.IOException,net.sf.jasperreports.engine.JRException,java.sql.SQLException
javax.ejb.EJBException.....
SEVERE: javax.ejb.EJBException
javax.faces.el.EvaluationException: javax.ejb.EJBException
at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:102)
WARNING: #{bookCtrl.doPrintReport}: javax.ejb.EJBException
javax.faces.FacesException: #{bookCtrl.doPrintReport}: javax.ejb.EJBException...
Caused by: javax.faces.el.EvaluationException: javax.ejb.EJBException...
SEVERE: javax.faces.FacesException: #{bookCtrl.doPrintReport}: javax.ejb.EJBException...
Caused by: javax.faces.FacesException: #{bookCtrl.doPrintReport}: javax.ejb.EJBException...
Caused by: javax.faces.el.EvaluationException: javax.ejb.EJBException...
Caused by: javax.ejb.EJBException...
Caused by: java.lang.NullPointerException...
WARNING: StandardWrapperValve[Faces Servlet]: PWC1406: Servlet.service() for servlet Faces Servlet threw exception
java.lang.IllegalStateException: PWC3991: getOutputStream() has already been called for this response.....
WARNING: StandardWrapperValve[Faces Servlet]: PWC1406: Servlet.service() for servlet Faces Servlet threw exception
java.lang.IllegalStateException: PWC3991: getOutputStream() has already been called for this response.....
WARNING: StandardWrapperValve[Faces Servlet]: PWC1406: Servlet.service() for servlet Faces Servlet threw exception
java.lang.IllegalStateException: PWC3991: getOutputStream() has already been called for this response.....
答案 0 :(得分：4)
您是否尝试在commandLink中使用p：fileDownload组件？
请参阅： http://www.primefaces.org/showcase/ui/fileDownload.jsf
这样，您只需要另一个控制器/托管bean方法来返回StreamedContent（primefaces类）的实例，而不是乱用responseComplete或者必须创建一个单独的servlet。
答案 1 :(得分：1)
您正在修改“responseComplete（）”之后的响应。调用“responseComplete（）”应该是你做的最后一件事。
答案 2 :(得分：1)
处理jasper方法的最佳方法是在commandButton / commandLink中禁用ajax。这就是如何保持贾斯珀转换。
<p:commandButton title="EK Preview" icon="fa fa-file-pdf-o" actionListener="#{ctrlFiDoc.doReport_PC}" ajax="false"/>
如果没有必要，则无需严格遵守p:fileDownload - 元素。
答案 3 :(得分：0)
这条线可能导致了这个问题：
InputStream reportStream = ctx.getExternalContext（） .getResourceAsStream（ “报告/ report1.jasper”）;