我正在使用 GWT 构建一个网站,并且我想使用JasperReports在网站中合并一个报告生成器。报告绘制的所有数据都存储在云中的数据库中,因此我使用实例和云 sql 连接到数据库并检索/存储数据(基本上是用户表)。用户应该使用一些凭据登录,然后按“下载”按钮,他们应该能够以 pdf 格式获取生成的报告。我已经使用 RPC 进程实现了这一点。
问题是当JasperFillManager.fillReport
调用该方法以填充报告时,我得到以下异常
SEVERE: javax.servlet.ServletContext log: Exception while dispatching incoming RPC call
com.google.gwt.user.server.rpc.UnexpectedException: Service method 'public abstract java.lang.String com.MyProject.website.client.ReportService.createReport(java.lang.String,java.lang.String)' threw an unexpected exception: java.lang.NoClassDefFoundError: java.awt.Font is a restricted class. Please see the Google App Engine developer's guide for more details.
at com.google.gwt.user.server.rpc.RPC.encodeResponseForFailure(RPC.java:389)
at com.google.gwt.user.server.rpc.RPC.invokeAndEncodeResponse(RPC.java:579)
at com.google.gwt.user.server.rpc.RemoteServiceServlet.processCall(RemoteServiceServlet.java:208)
at com.google.gwt.user.server.rpc.RemoteServiceServlet.processPost(RemoteServiceServlet.java:248)
at com.google.gwt.user.server.rpc.AbstractRemoteServiceServlet.doPost(AbstractRemoteServiceServlet.java:62)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166)
at com.google.appengine.api.socket.dev.DevSocketFilter.doFilter(DevSocketFilter.java:74)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.appengine.tools.development.ResponseRewriterFilter.doFilter(ResponseRewriterFilter.java:123)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.appengine.tools.development.HeaderVerificationFilter.doFilter(HeaderVerificationFilter.java:34)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.appengine.api.blobstore.dev.ServeBlobFilter.doFilter(ServeBlobFilter.java:61)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.apphosting.utils.servlet.TransactionCleanupFilter.doFilter(TransactionCleanupFilter.java:43)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.appengine.tools.development.StaticFileFilter.doFilter(StaticFileFilter.java:125)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.appengine.tools.development.BackendServersFilter.doFilter(BackendServersFilter.java:97)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388)
at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418)
at com.google.appengine.tools.development.DevAppEngineWebAppContext.handle(DevAppEngineWebAppContext.java:94)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at com.google.appengine.tools.development.JettyContainerService$ApiProxyHandler.handle(JettyContainerService.java:383)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at org.mortbay.jetty.Server.handle(Server.java:326)
at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
at org.mortbay.jetty.HttpConnection$RequestHandler.content(HttpConnection.java:938)
at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:755)
at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:218)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:409)
at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)
Caused by: java.lang.NoClassDefFoundError: java.awt.Font is a restricted class. Please see the Google App Engine developer's guide for more details.
at com.google.appengine.tools.development.agent.runtime.Runtime.reject(Runtime.java:51)
at net.sf.jasperreports.engine.fonts.SimpleFontFace.<init>(SimpleFontFace.java:100)
at net.sf.jasperreports.engine.fonts.SimpleFontFace.<init>(SimpleFontFace.java:128)
at net.sf.jasperreports.engine.fonts.SimpleFontFace.getInstance(SimpleFontFace.java:67)
at net.sf.jasperreports.engine.fonts.SimpleFontFamily.setNormal(SimpleFontFamily.java:99)
at net.sf.jasperreports.engine.fonts.SimpleFontExtensionHelper.parseFontFamily(SimpleFontExtensionHelper.java:261)
at net.sf.jasperreports.engine.fonts.SimpleFontExtensionHelper.parseFontFamilies(SimpleFontExtensionHelper.java:232)
at net.sf.jasperreports.engine.fonts.SimpleFontExtensionHelper.loadFontFamilies(SimpleFontExtensionHelper.java:193)
at net.sf.jasperreports.engine.fonts.SimpleFontExtensionHelper.loadFontFamilies(SimpleFontExtensionHelper.java:162)
at net.sf.jasperreports.engine.fonts.FontExtensionsRegistry.getExtensions(FontExtensionsRegistry.java:56)
at net.sf.jasperreports.extensions.DefaultExtensionsRegistry.getExtensions(DefaultExtensionsRegistry.java:110)
at net.sf.jasperreports.engine.util.JRStyledTextParser.<clinit>(JRStyledTextParser.java:83)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Unknown Source)
at com.google.appengine.tools.development.agent.runtime.RuntimeHelper.checkRestricted(RuntimeHelper.java:70)
at com.google.appengine.tools.development.agent.runtime.Runtime.checkRestricted(Runtime.java:64)
at net.sf.jasperreports.engine.fill.JRBaseFiller.<init>(JRBaseFiller.java:121)
at net.sf.jasperreports.engine.fill.JRVerticalFiller.<init>(JRVerticalFiller.java:88)
at net.sf.jasperreports.engine.fill.JRVerticalFiller.<init>(JRVerticalFiller.java:103)
at net.sf.jasperreports.engine.fill.JRVerticalFiller.<init>(JRVerticalFiller.java:61)
at net.sf.jasperreports.engine.fill.JRFiller.createFiller(JRFiller.java:153)
at net.sf.jasperreports.engine.fill.JRFiller.fill(JRFiller.java:55)
at net.sf.jasperreports.engine.JasperFillManager.fill(JasperFillManager.java:446)
at net.sf.jasperreports.engine.JasperFillManager.fill(JasperFillManager.java:276)
at net.sf.jasperreports.engine.JasperFillManager.fillReport(JasperFillManager.java:745)
at com.MyProject.website.server.ReportServiceImpl.createReport(ReportServiceImpl.java:65)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.google.appengine.tools.development.agent.runtime.Runtime.invoke(Runtime.java:115)
at com.google.gwt.user.server.rpc.RPC.invokeAndEncodeResponse(RPC.java:561)
... 38 more
Could not generate the report
如果我再次按下下载按钮(没有更改任何内容),我会得到一个稍微不同的异常
SEVERE: javax.servlet.ServletContext log: Exception while dispatching incoming RPC call
com.google.gwt.user.server.rpc.UnexpectedException: Service method 'public abstract java.lang.String com.MyProject.website.client.ReportService.createReport(java.lang.String,java.lang.String)' threw an unexpected exception: java.lang.NoClassDefFoundError: Could not initialize class net.sf.jasperreports.engine.util.JRStyledTextParser
at com.google.gwt.user.server.rpc.RPC.encodeResponseForFailure(RPC.java:389)
at com.google.gwt.user.server.rpc.RPC.invokeAndEncodeResponse(RPC.java:579)
at com.google.gwt.user.server.rpc.RemoteServiceServlet.processCall(RemoteServiceServlet.java:208)
at com.google.gwt.user.server.rpc.RemoteServiceServlet.processPost(RemoteServiceServlet.java:248)
at com.google.gwt.user.server.rpc.AbstractRemoteServiceServlet.doPost(AbstractRemoteServiceServlet.java:62)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166)
at com.google.appengine.api.socket.dev.DevSocketFilter.doFilter(DevSocketFilter.java:74)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.appengine.tools.development.ResponseRewriterFilter.doFilter(ResponseRewriterFilter.java:123)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.appengine.tools.development.HeaderVerificationFilter.doFilter(HeaderVerificationFilter.java:34)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.appengine.api.blobstore.dev.ServeBlobFilter.doFilter(ServeBlobFilter.java:61)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.apphosting.utils.servlet.TransactionCleanupFilter.doFilter(TransactionCleanupFilter.java:43)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.appengine.tools.development.StaticFileFilter.doFilter(StaticFileFilter.java:125)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.appengine.tools.development.BackendServersFilter.doFilter(BackendServersFilter.java:97)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388)
at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418)
at com.google.appengine.tools.development.DevAppEngineWebAppContext.handle(DevAppEngineWebAppContext.java:94)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at com.google.appengine.tools.development.JettyContainerService$ApiProxyHandler.handle(JettyContainerService.java:383)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at org.mortbay.jetty.Server.handle(Server.java:326)
at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
at org.mortbay.jetty.HttpConnection$RequestHandler.content(HttpConnection.java:938)
at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:755)
at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:218)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:409)
at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)
Caused by: java.lang.NoClassDefFoundError: Could not initialize class net.sf.jasperreports.engine.util.JRStyledTextParser
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Unknown Source)
at com.google.appengine.tools.development.agent.runtime.RuntimeHelper.checkRestricted(RuntimeHelper.java:70)
at com.google.appengine.tools.development.agent.runtime.Runtime.checkRestricted(Runtime.java:64)
at net.sf.jasperreports.engine.fill.JRBaseFiller.<init>(JRBaseFiller.java:121)
at net.sf.jasperreports.engine.fill.JRVerticalFiller.<init>(JRVerticalFiller.java:88)
at net.sf.jasperreports.engine.fill.JRVerticalFiller.<init>(JRVerticalFiller.java:103)
at net.sf.jasperreports.engine.fill.JRVerticalFiller.<init>(JRVerticalFiller.java:61)
at net.sf.jasperreports.engine.fill.JRFiller.createFiller(JRFiller.java:153)
at net.sf.jasperreports.engine.fill.JRFiller.fill(JRFiller.java:55)
at net.sf.jasperreports.engine.JasperFillManager.fill(JasperFillManager.java:446)
at net.sf.jasperreports.engine.JasperFillManager.fill(JasperFillManager.java:276)
at net.sf.jasperreports.engine.JasperFillManager.fillReport(JasperFillManager.java:745)
at com.MyProject.website.server.ReportServiceImpl.createReport(ReportServiceImpl.java:65)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.google.appengine.tools.development.agent.runtime.Runtime.invoke(Runtime.java:115)
at com.google.gwt.user.server.rpc.RPC.invokeAndEncodeResponse(RPC.java:561)
... 38 more
Could not generate the report
在互联网上寻找了一段时间后,我在 SO 上读到这可能是一个缺少库的问题,所以我从 JasperReports 发行版中添加了一些额外的库到我项目的类路径中。现在类路径中的文件(来自 JR 发行版)是:
- commons-beanutils-1.8.0.jar
- commons-collections-2.1.1.jar
- commons-digester-2.1.jar
- commons-javaflow-20060411.jar
- commons-logging-1.1.1.jar
- iText-2.1.7.js1.jar
- jasperreports-5.0.0.jar
- jasperreports-fonts-5.0.0.jar
- jasperreports-javaflow-5.0.0.jar
然而,我仍然抛出同样的异常......
我应该在哪里寻找问题的任何提示?
我在这里发布了 downloadReport 函数的代码以及 RPC 方法的代码
下载报告方法
void downloadReport(String username, String password){
// create the report and get it
ReportService.Util.getInstance().createReport(username, password, new AsyncCallback<String>(){
@Override
public void onSuccess(String result){ // the URL of the created report file is returned
text1.setText(result);
}
@Override
public void onFailure(Throwable caught){
System.out.println("Could not generate the report");
}
});
}
报告服务.java
package com.MyProject.website.client;
import com.google.gwt.core.client.GWT;
import com.google.gwt.user.client.rpc.RemoteService;
import com.google.gwt.user.client.rpc.RemoteServiceRelativePath;
@RemoteServiceRelativePath("ReportService")
public interface ReportService extends RemoteService {
public static class Util {
private static ReportServiceAsync instance;
public static ReportServiceAsync getInstance() {
if (instance == null) {
instance = GWT.create(ReportService.class);
}
return instance;
}
}
String createReport(String name, String password);
}
ReportServiceImpl.java
package com.MyProject.website.server;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import com.google.appengine.api.rdbms.AppEngineDriver;
import com.google.gwt.user.server.rpc.RemoteServiceServlet;
import com.MyProject.website.client.ReportService;
import java.io.File;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.HashMap;
import java.util.Map;
import net.sf.jasperreports.engine.JasperFillManager;
import net.sf.jasperreports.engine.JRException;
import net.sf.jasperreports.engine.JRRuntimeException;
import net.sf.jasperreports.engine.JasperExportManager;
import net.sf.jasperreports.engine.JasperFillManager;
import net.sf.jasperreports.engine.JasperPrint;
import net.sf.jasperreports.engine.util.*;
import net.sf.jasperreports.j2ee.servlets.BaseHttpServlet;
@SuppressWarnings("serial")
public class ReportServiceImpl extends RemoteServiceServlet implements ReportService{
@Override
public String createReport(String name, String password) {
String temp = null;
Connection c = null;
Map<String, Object> rParamet = new HashMap<String, Object>();
try {
DriverManager.registerDriver(new AppEngineDriver());
c = DriverManager.getConnection("jdbc:google:rdbms://MyProject:dbutest/DBtest");
rParamet.put("email", name);
rParamet.put("password", password);
rParamet.put("ReportTitle", "Test Report");
String sourceFile = this.getServletContext().getRealPath("WEB-INF") + "/testReport.jasper";
try {
JasperPrint reportPrint = JasperFillManager.fillReport(sourceFile, rParamet, c);
JasperExportManager.exportReportToPdfFile(reportPrint, "ReportTest");
} catch (JRException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
} catch (SQLException e) {
e.printStackTrace();
} finally {
if (c != null)
try {
c.close();
} catch (SQLException ignore) {
}
}
// More code to be added here for getting the report URL
return temp;
}
}
提前致谢!