使用itext从带有图像和css的Html字符串生成Pdf for android答案

【问题标题】：Generate Pdf from Html string with image and css for android using itext使用itext从带有图像和css的Html字符串生成Pdf for android
【发布时间】：2016-10-30 12:03:27
【问题描述】：

我正在使用 itext-5.3.4.jar 和 xmlworker-1.2.1.jar 库从 html 字符串生成 pdf，html 包含图像徽标和内联 css。

我的 html 文件和图像位于 Asset 文件夹中，使用此库成功生成了我的 pdf，但没有图像显示和 css 样式排序。如果任何其他库或任何其他从 html 生成 pdf 的选项会有所帮助，任何人都有建议我应该怎么做来解决这个问题。

我正在使用这些函数来生成 pdf：

    public static void generatePdfFromHtlm(String fileName, String htmlString){


    try {
        File mediaStorageDir = new File(Environment.getExternalStorageDirectory(), AppConfig.getContext().getPackageName() + "/" + "Pdf");

        if (!mediaStorageDir.exists()) {
            mediaStorageDir.mkdirs();
        }

        File fileWithinMyDir = new File(mediaStorageDir, fileName);

        FontFactory.registerDirectories();
        Document document = new Document(PageSize.A4);
        PdfWriter writer = PdfWriter.getInstance(document,
                new FileOutputStream(fileWithinMyDir));
        document.open();
        HtmlPipelineContext htmlContext = new HtmlPipelineContext(null);
        htmlContext.setTagFactory(Tags.getHtmlTagProcessorFactory());
        htmlContext.setImageProvider(new AbstractImageProvider() {
            public String getImageRootPath() {

                Uri uri = Uri.parse("file:///android_asset/");

                String newPath = uri.toString();

                return newPath;
            }
        });


        CSSResolver cssResolver =
                XMLWorkerHelper.getInstance().getDefaultCssResolver(false);
        /*Pipeline<?> pipeline =
                new CssResolverPipeline(cssResolver,
                        new HtmlPipeline(htmlContext,
                                new PdfWriterPipeline(document, writer)));*/

        // Pipelines
        PdfWriterPipeline pdf = new PdfWriterPipeline(document, writer);
        HtmlPipeline html = new HtmlPipeline(htmlContext, pdf);
        CssResolverPipeline css = new CssResolverPipeline(cssResolver, html);

        XMLWorker worker = new XMLWorker(css, true);

        XMLParser p = new XMLParser(worker);
        InputStream is = new ByteArrayInputStream(htmlString.getBytes());
        p.parse(is);

        document.close();


    } catch (Exception e) {
        e.printStackTrace();
    }
}

我的 html 文件是

<!DOCTYPE html>
<!--[if IE 8]> <html lang="en" class="ie8"> <![endif]-->
<!--[if IE 9]> <html lang="en" class="ie9"> <![endif]-->
<!--[if !IE]><!-->
<html lang="en"> <!--<![endif]-->

<!-- BEGIN HEAD -->
<head>
  <meta charset="utf-8" />
  
  <title>WeighInsheet</title> 
  
  
  <style type="text/css">
  
  body { font-family:Arial; }
      .Wrapper { border:1px solid #cccccc; height:auto; margin:0px 65px;}
      .header { height:105px; margin:5px; float:left;}
      .logo { width:100px; height:100px; float:left; }
  .heading { width:600px;}
  h2{ margin:40px 0px 0px 0px;font-size: 22px; font-weight:bold;}
  h3{ margin:0px; font-weight:normal;font-size: 16px;}
  table { border-collapse: collapse; border-spacing: 0;  width:100%; }
  table td { font-family: arial; font-size: 14px; padding: 10px 5px; border: 1px solid #ddd; }  
  table th { background-color:#000000; color:#ffffff; font-family: arial; font-size: 16px; font-weight: bold;
             border: 1px solid #ddd; }  
  
  </style>


</head>

<!-- END HEAD -->

<!-- BEGIN BODY -->

<body>  
  
<div class="Wrapper">

<div class="header">

<div class="logo"><img src="logo.jpg" class="logo"/></div>

<div class="heading" align="center">
<h2>Description</h2>
<h3>Title Meta</h3>
</div>

</div>
<table>

<thead>
 ##CHANGEHEADER##
</thead>

<tbody>
  ##CHANGEBODY##
</tbody>

</table>

</div>  

</body>

<!-- END BODY -->

</html>

我的图片文件“logo.jpg”在资产文件夹中。

【问题讨论】：

你为什么不用安卓端口，iTextG？为什么不使用当前版本 5.5.9？
java.lang.NoSuchMethodError：Lcom/itextpdf/text/pdf/PdfPTable 类中没有虚拟方法 addCell(Lcom/itextpdf/text/pdf/PdfPCell;)V；或其超类（“com.itextpdf.text.pdf.PdfPTable”的声明出现在 /data/app/com.test.pdfgenerate-1/base.apk 中）
更新 itext 5.5.9 后会出现此错误
它为我工作的好问题

标签： android html css pdf-generation itext

【解决方案1】：

我已经修复了 Xml Worker 类的 Pdf 生成问题。

为了克服 CSS 问题，我创建了外部 css 文件并将其与 html 一起应用。

例如

InputStream is = new ByteArrayInputStream(aHtmlString.getBytes());
                            InputStream css = new ByteArrayInputStream(cssString.getBytes());

                            XMLWorkerHelper.getInstance().parseXHtml(writer, document, is, css);

对于图像显示问题，将您的图像从资产文件夹复制到手机内部文件夹。

将你的 img 标签添加到该文件夹图像路径。

例如

<img src="/storage/emulated/0/MyApp/Images/my_logo.jpg"/>

使用此方法将文件从资产复制到文件夹。

 public static void listAssetFiles(String path,Context ctx,String folderPath) {

    String [] list;
    try {
        list = ctx.getAssets().list(path);
        if (list.length > 0) {
            // This is a folder
            for (String file : list) {

                copyIntoFolder(file,ctx,path+"/",folderPath);
            }
        }
    } catch (IOException e) {

    }



}

public static void copyIntoFolder(String fileName, Context ctx, String filePath, String folderPath){
    AssetManager assetManager = ctx.getAssets();
    InputStream in = null;
    OutputStream out = null;
    try {
        in = assetManager.open(filePath+fileName);
        File outFile = new File(folderPath , fileName);
        out = new FileOutputStream(outFile);
        Utility.copyFile(in, out);
        in.close();
        // in = null;
        out.flush();
        out.close();
        //out = null;
    } catch(IOException e) {
        Log.e("IOException", "copyIntoFolder: ",e );

    }
}

Itext 不支持所有 css 属性以下是支持的 css 属性列表，请根据此支持的 css 属性创建您的 html。

Css Support

【讨论】：

您是否从 html 文件中删除了 css 部分？我的 html 文件在其标题中包含 css 并且无法应用它！

【解决方案2】：

iText Sharp 不支持所有 css 属性。您可以在 webview 中加载 html 并使用此代码生成 pdf。

private void createWebPrintJob(WebView webView) {

        try {
            PrintDocumentAdapter printAdapter;
            String jobName = getString(R.string.app_name) + " Document";
            PrintAttributes attributes = new PrintAttributes.Builder()
                    .setMediaSize(PrintAttributes.MediaSize.ISO_A4)
                    .setResolution(new PrintAttributes.Resolution("pdf", "pdf", 600, 600))
                    .setMinMargins(PrintAttributes.Margins.NO_MARGINS).build();
            File path = new File(Environment.getExternalStorageDirectory()
                    .getAbsolutePath() + "/AamirPDF/");


            path.mkdirs();
            PdfPrint pdfPrint = new PdfPrint(attributes);
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
                printAdapter = webView.createPrintDocumentAdapter(jobName);
            } else {
                printAdapter = webView.createPrintDocumentAdapter();
            }


            pdfPrint.printNew(printAdapter, path, "output_" + System.currentTimeMillis() + ".pdf", getActivity().getCacheDir().getPath());
        } catch (Exception e) {
            e.printStackTrace();
        }

    }

用于生成 PDF 的 PdfPrint 类。

package com.example.nisarg.invoice;

import android.os.Bundle;
import android.os.CancellationSignal;
import android.os.ParcelFileDescriptor;
import android.print.PageRange;
import android.print.PrintAttributes;
import android.print.PrintDocumentAdapter;
import android.util.Log;

import com.example.nisarg.invoice.android.print.ProxyBuilder;

import java.io.File;
import java.io.IOException;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;

import static com.example.nisarg.invoice.Database.appglobal.context;

public class PdfPrint {

    public static final String TAG = PdfPrint.class.getSimpleName();
    public static PrintAttributes printAttributes;
    File cacheFolder;


    public PdfPrint(PrintAttributes printAttributes) {
        this.printAttributes = printAttributes;
        cacheFolder = new File(context.getFilesDir() + "/etemp/");
    }

    public static PrintDocumentAdapter.WriteResultCallback getWriteResultCallback(InvocationHandler invocationHandler,
                                                                                  File dexCacheDir) throws IOException {
        return ProxyBuilder.forClass(PrintDocumentAdapter.WriteResultCallback.class)
                .dexCache(dexCacheDir)
                .handler(invocationHandler)
                .build();
    }

    public static PrintDocumentAdapter.LayoutResultCallback getLayoutResultCallback(InvocationHandler invocationHandler,
                                                                                    File dexCacheDir) throws IOException {
        return ProxyBuilder.forClass(PrintDocumentAdapter.LayoutResultCallback.class)
                .dexCache(dexCacheDir)
                .handler(invocationHandler)
                .build();
    }

  /*  public void print(final PrintDocumentAdapter printAdapter, final File path, final String fileName) {
        printAdapter.onLayout(null, printAttributes, null, new PrintDocumentAdapter.LayoutResultCallback() {
            @Override
            public void onLayoutFinished(PrintDocumentInfo info, boolean changed) {


                try {
                    PrintDocumentAdapter.WriteResultCallback callback = getWriteResultCallback(new InvocationHandler() {
                        @Override
                        public Object invoke(Object o, Method method, Object[] objects) throws Throwable {
                            if (method.getName().equals("onWriteFinished")) {
                                //                            pdfCallback.onPdfCreated();
                            } else {
                                Log.e(TAG, "Layout failed");
                                //                            pdfCallback.onPdfFailed();
                            }
                            return null;
                        }
                    }, null);

                    printAdapter.onWrite(new PageRange[]{PageRange.ALL_PAGES}, getOutputFile(path, fileName), new CancellationSignal(), callback);
                } catch (IOException e) {
                    e.printStackTrace();
                }


            }
        }, null);
    }*/

    public void printNew(final PrintDocumentAdapter printAdapter, final File path, final String fileName, final String fileNamenew) {

        try {

            printAdapter.onStart();
            printAdapter.onLayout(null, printAttributes, new CancellationSignal(), getLayoutResultCallback(new InvocationHandler() {
                @Override
                public Object invoke(Object o, Method method, Object[] objects) throws Throwable {

                    if (method.getName().equals("onLayoutFinished")) {
                        onLayoutSuccess(printAdapter, path, fileName, fileNamenew);
                    } else {
                        Log.e(TAG, "Layout failed");

                    }
                    return null;
                }
            }, new File(fileNamenew)), new Bundle());


        } catch (Exception e) {
            e.printStackTrace();

        }
    }

    private void onLayoutSuccess(PrintDocumentAdapter printAdapter, File path, String fileName, String filenamenew) throws IOException {
        PrintDocumentAdapter.WriteResultCallback callback = getWriteResultCallback(new InvocationHandler() {
            @Override
            public Object invoke(Object o, Method method, Object[] objects) throws Throwable {
                if (method.getName().equals("onWriteFinished")) {

                    System.out.print("hello");

                } else {
                    Log.e(TAG, "Layout failed");

                }
                return null;
            }
        }, new File(filenamenew));
        printAdapter.onWrite(new PageRange[]{PageRange.ALL_PAGES}, getOutputFile(path, fileName), new CancellationSignal(), callback);
    }

    private ParcelFileDescriptor getOutputFile(File path, String fileName) {
        if (!path.exists()) {
            path.mkdirs();
        }
        File file = new File(path, fileName);
        try {
            file.createNewFile();
            return ParcelFileDescriptor.open(file, ParcelFileDescriptor.MODE_READ_WRITE);
        } catch (Exception e) {
            Log.e(TAG, "Failed to open ParcelFileDescriptor", e);
        }
        return null;
    }
}

生成类的代理。[https://gist.github.com/brettwold/838c092329c486b6112c8ebe94c8007e]

对于代理生成器类中使用的依赖，在 gradle 中添加这一行。

 compile 'com.linkedin.dexmaker:dexmaker-mockito:2.2.0'

【讨论】：