适用于 Android 的 FOP? [英] FOP for Android?

问题描述

我最近使用 FOP 编译了一个 Android 应用程序，因为我想将一些 XML 转换为 PDF 文件.但是我不认为 FOP JAR 文件不能在 Android 上运行.是否有适用于 Android 的任何版本的 FOP?或者我可以在我的应用程序中使用的任何其他 XML 到 PDF 转换器，而不是连接到互联网上启用 FOP 的服务器?

I recently compiled an Android app using FOP as I want to convert some XML into a PDF file. However I don't think the FOP JAR files are mean't to work on Android. Are there any versions of FOP available for Android? Or any other XML to PDF converter I could use within my app instead of connecting to a FOP enabled server on the Internet?

我尝试包含 fop.jar 和 xmlgraphics.jar，但即使将它们添加到我的项目中，对 FopFactory.newInstance() 的调用也失败了.

I've tried including fop.jar and the xmlgraphics.jar but even with those added to my project, the call to FopFactory.newInstance() fails.

这是调用 FOP 的按钮点击的代码片段:

Here's my code snippet for the button click that calls FOP:

// Add button listener
btnCreatePDF.setOnClickListener(new OnClickListener()
        {
            @Override
            public void onClick(View v)
            {   
                FopFactory fopFactory = FopFactory.newInstance();
                OutputStream out = new BufferedOutputStream(new FileOutputStream(new File("/sdcard/test.pdf")));
                Fop fop = fopFactory.newFop(MimeConstants.MIME_PDF, out);
                TransformerFactory factory = TransformerFactory.newInstance();
                Transformer transformer = factory.newTransformer();
                Source src = new StreamSource(new File("/sdcard/test.fo"));
                Result res = new SAXResult(fop.getDefaultHandler());

                transformer.transform(src, res);

                out.close();
            }
        });

编译器还给我一堆Dxwarning: Ignoring InnerClasses attribute... 错误.这是我单击按钮创建 PDF 时的错误:

The compiler is also giving a me a bunch of Dxwarning: Ignoring InnerClasses attribute... errors. Here's the error when I click the button to create the PDF:

02-22 14:16:23.641: WARN/System.err(5590): java.lang.UnsupportedOperationException: Don't know how to handle "application/pdf" as an output format. Neither an FOEventHandler, nor a Renderer could be found for this output format.
02-22 14:16:23.641: WARN/System.err(5590):     at org.apache.fop.render.RendererFactory.createFOEventHandler(RendererFactory.java:361)
02-22 14:16:23.641: WARN/System.err(5590):     at org.apache.fop.fo.FOTreeBuilder.(FOTreeBuilder.java:105)
02-22 14:16:23.641: WARN/System.err(5590):     at org.apache.fop.apps.Fop.createDefaultHandler(Fop.java:101)
02-22 14:16:23.641: WARN/System.err(5590):     at org.apache.fop.apps.Fop.(Fop.java:79)
02-22 14:16:23.641: WARN/System.err(5590):     at org.apache.fop.apps.FopFactory.newFop(FopFactory.java:271)
02-22 14:16:23.641: WARN/System.err(5590):     at org.apache.fop.apps.FopFactory.newFop(FopFactory.java:248)
02-22 14:16:23.641: WARN/System.err(5590):     at com.zebdor.signal88.ProposalCalculator$3.onClick(ProposalCalculator.java:158)
02-22 14:16:23.641: WARN/System.err(5590):     at android.view.View.performClick(View.java:2501)
02-22 14:16:23.641: WARN/System.err(5590):     at android.view.View$PerformClick.run(View.java:9107)
02-22 14:16:23.641: WARN/System.err(5590):     at android.os.Handler.handleCallback(Handler.java:587)
02-22 14:16:23.641: WARN/System.err(5590):     at android.os.Handler.dispatchMessage(Handler.java:92)
02-22 14:16:23.641: WARN/System.err(5590):     at android.os.Looper.loop(Looper.java:123)
02-22 14:16:23.641: WARN/System.err(5590):     at android.app.ActivityThread.main(ActivityThread.java:3812)
02-22 14:16:23.641: WARN/System.err(5590):     at java.lang.reflect.Method.invokeNative(Native Method)
02-22 14:16:23.641: WARN/System.err(5590):     at java.lang.reflect.Method.invoke(Method.java:507)
02-22 14:16:23.641: WARN/System.err(5590):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:841)
02-22 14:16:23.641: WARN/System.err(5590):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:599)
02-22 14:16:23.641: WARN/System.err(5590):     at dalvik.system.NativeStart.main(Native Method)

推荐答案

对于 Android，您不能仅仅从 Java 库中获取 .jar 文件并在 Android 应用程序中使用它.Android 使用 Dalvik JVM (http://en.wikipedia.org/wiki/Dalvik_(software))，它与来自 Java SE API 的完整 API 不是 100% 兼容，而是仅支持 API 的一个子集.出于这个原因，您可能会使用的许多 Java 库(如 FOP)与 Android 原样不兼容，并且需要专门化才能使此类库在 Android 设备上正常运行.祝你好运.

With Android, you can't just take a .jar from a Java library and use it in an Android application. Android uses the Dalvik JVM (http://en.wikipedia.org/wiki/Dalvik_(software)) which is not 100% compatible with the full API from the Java SE API, and instead only supports a subset of the API. For this reason, many of the Java libraries you might be use to, like FOP, are not Android compatible as-is and require specialization before such libraries will function properly on an Android device. Good luck.

这篇关于适用于 Android 的 FOP?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！