HTML embedded images in PDF

问题

I created a report using BIRT and some dynamic fields are HTML values, which come from backend systems, but when I try to generate a PDF report with HTML embedded image - then it shows: "The resource of this report item is not reachable." instead of image.

Is there any solution to render embedded image in PDF? It works fine in HTML.

回答1:

I found a solution, how to render images in PDF, which are embedded in HTML content. The problem was with BIRT library ResourceLocatorWrapper class. I changed method:

public byte[] findResource(ModuleHandle design, String fileName, int fileType, Map appContext);

Now it successfully shows embedded images and rest HTML content in PDF. It is not needed to add this in BIRT jar library, you could add this class in your project under org.eclipse.birt.report.engine.util package, as I did, and it should work fine.

package org.eclipse.birt.report.engine.util;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.util.HashMap;
import java.util.Map;
import java.util.logging.Level;
import java.util.logging.Logger;

import org.eclipse.birt.report.engine.i18n.MessageConstants;
import org.eclipse.birt.report.model.api.ModuleHandle;

import com.lowagie.text.ExceptionConverter;
import com.lowagie.text.pdf.codec.Base64;

public class ResourceLocatorWrapper {

    private HashMap<URL, byte[]> cache;
    private static final byte[] DUMMY_BYTES = new byte[0];
    private static final String RESOURCE_BUNDLE = "org.eclipse.birt.report.engine.i18n.Messages";
    protected static Logger logger = Logger.getLogger(ResourceLocatorWrapper.class.getName(), RESOURCE_BUNDLE);

    public ResourceLocatorWrapper() {
        cache = new HashMap<URL, byte[]>();
    }

    public void dispose() {
        synchronized (cache) {
            cache.clear();
            cache = null;
        }
    }

    /**
     * 
     * @param fileName
     * @param fileType
     * @param appContext
     * @return
     */
    public byte[] findResource(ModuleHandle design, String fileName, int fileType, Map appContext) {

        if (fileName.startsWith("data:")) {
            final String base64Data = fileName.substring(fileName.indexOf(",") + 1);
            try {
                return Base64.decode(base64Data);
            } catch (Exception e) {
                throw new ExceptionConverter(e);
            }
        } else {
            URL url = design.findResource(fileName, fileType, appContext);
            if (url == null) {
                logger.log(Level.WARNING, MessageConstants.RESOURCE_NOT_ACCESSIBLE, fileName);
                return DUMMY_BYTES;
            }
            return findResource(url);
        }
    }

    /**
     * Finds a resource from the given URL. If the URL is not accessible, it
     * will return a 0-size byte array.
     */
    public byte[] findResource(URL url) {
        System.out.println("findResource(URL url)");
        if (url == null) {
            return DUMMY_BYTES;
        }
        synchronized (cache) {
            if (cache == null) {
                return DUMMY_BYTES;
            }
            byte[] inBytes = cache.get(url);
            if (inBytes == null) {
                try {
                    InputStream in = url.openStream();
                    inBytes = getByteArrayFromInputStream(in);
                    in.close();
                    cache.put(url, inBytes);
                } catch (IOException e) {
                    logger.log(Level.WARNING, MessageConstants.RESOURCE_NOT_ACCESSIBLE, url.toExternalForm());
                    cache.put(url, DUMMY_BYTES);
                    return DUMMY_BYTES;
                }
            }
            return inBytes;
        }
    }

    private byte[] getByteArrayFromInputStream(InputStream in) throws IOException {
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        byte[] buffer = new byte[1024];
        int size = in.read(buffer);
        while (size != -1) {
            out.write(buffer, 0, size);
            size = in.read(buffer);
        }
        buffer = out.toByteArray();
        out.close();
        return buffer;
    }

}

回答2:

Simply put this line in the onCreate element of an Dynamic Image

importPackage(Packages.javax.imageio);
importPackage(Packages.java.io);
importPackage(Packages.sun.misc);
decoder = new BASE64Decoder();
decodedBytes = decoder.decodeBuffer(this.getRowData().getColumnValue("YOUR_DATA_BS64"));
this.data =decodedBytes;
bais = new ByteArrayInputStream( decodedBytes);
bufimg = ImageIO.read(bais);
this.setHeight(bufimg.getHeight() +"px");
this.setWidth(bufimg.getWidth() +"px");

来源：https://stackoverflow.com/questions/32116995/html-embedded-images-in-pdf