java - 填写 JasperReports 报告时出现意外异常 - 无法初始化 net.sf.jasperreports.engine.util.JRStyledTextParser (GWT)

Question

我正在使用 GWT 构建一个网站，我想使用 JasperReports 在网站中加入一个报告生成器。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“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 流程实现了这一点。

问题是当调用 JasperFillManager.fillReport 方法来填充报告时，出现以下异常

    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(没有做任何更改)，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

在互联网上搜索了一段时间后，我了解到这可能是一个缺少库的问题，所以我从 JasperReports 分发版中添加了一些额外的库到我的项目的类路径中。现在类路径中的文件(来自 JR 发行版)是:

1. commons-beanutils-1.8.0.jar
2. commons-collections-2.1.1.jar
3. commons-digester-2.1.jar
4. commons-javaflow-20060411.jar
5. commons-logging-1.1.1.jar
6. iText-2.1.7.js1.jar
7. jasperreports-5.0.0.jar
8. jasperreports-fonts-5.0.0.jar
9. jasperreports-javaflow-5.0.0.jar

但是，我仍然抛出相同的异常...

关于我应该在哪里查找问题的任何提示？

我在这里发布了 downloadReport 函数的代码以及 RPC 方法的代码

下载报表方法

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");
        }
    }); 
}

ReportService.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!

Answer 1

从第一个堆栈跟踪:java.lang.NoClassDefFoundError:java.awt.Font 是一个受限类。有关详细信息，请参阅 Google App Engine 开发人员指南。

它所指的指南是https://developers.google.com/appengine/docs/java/jrewhitelist

所以:

• 要么你想在将部署到 AppEngine 的应用程序中制作报告，要么你必须找到另一个库，因为 JasperReports 不能在那个环境中工作
• 或者您不打算在 AppEngine 上运行并且错误配置了您的项目