simplify API for creating PDF: now user needs to write less code to g…

…enerate PDF from HTML

This commits adds 2 new apis:
1. class Html2Pdf   (a single method for generating PDF from HTML)
2. renderer.createPDF(doc, os)   (instead of old sequence `setDocument`, `layout`, `createPDF`)

flying-saucer-core/src/main/java/org/xhtmlrenderer/resource/XMLResource.java

@@ -48,8 +48,10 @@
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.Reader;
+import java.io.StringReader;
 import java.lang.ref.Reference;
 import java.lang.ref.SoftReference;
+import java.net.URL;
 import java.util.Queue;
 import java.util.concurrent.ArrayBlockingQueue;
 import java.util.logging.Level;
@@ -77,6 +79,10 @@ private XMLResource(InputSource source) {
         super(source);
     }
 
+    public static XMLResource load(URL source) {
+        return load(new InputSource(source.toString()));
+    }
+
     public static XMLResource load(InputStream stream) {
         return XML_RESOURCE_BUILDER.createXMLResource(new XMLResource(stream));
     }
@@ -89,6 +95,10 @@ public static XMLResource load(Reader reader) {
         return XML_RESOURCE_BUILDER.createXMLResource(new XMLResource(new InputSource(reader)));
     }
 
+    public static XMLResource load(String xml) {
+        return load(new StringReader(xml));
+    }
+
     public static XMLResource load(Source source) {
         return XML_RESOURCE_BUILDER.createXMLResource(source);
     }

flying-saucer-examples/src/main/java/FontGlyphTableRender.java

@@ -339,16 +339,16 @@ private void renderPDF(Document doc) {
         String msgToUser;
         try (FileOutputStream fos = new FileOutputStream(f)) {
             BufferedOutputStream bos = new BufferedOutputStream(fos);
-            renderer.setDocument(doc, null, new XhtmlNamespaceHandler());
+
             ITextFontResolver resolver = renderer.getFontResolver();
             // TODO: encoding is hard-coded as IDENTITY_H; maybe give user option to override
             resolver.addFont(
                     fontPathTF.getText(),
                     BaseFont.IDENTITY_H,
                     BaseFont.EMBEDDED
             );
-            renderer.layout();
-            renderer.createPDF(bos);
+            renderer.getSharedContext().setNamespaceHandler(new XhtmlNamespaceHandler());
+            renderer.createPDF(doc, bos);
 
             msgToUser = "Rendered PDF: " + f.getCanonicalPath();
         } catch (DocumentException | IOException e) {

flying-saucer-examples/src/main/java/PDFRender.java

@@ -59,9 +59,7 @@ public static void createPDF(String url, String pdf) throws IOException, Documen
 
             Document doc = XMLResource.load(new InputSource(url)).getDocument();
 
-            renderer.setDocument(doc, url);
-            renderer.layout();
-            renderer.createPDF(os);
+            renderer.createPDF(doc, os);
         }
     }
 

flying-saucer-examples/src/main/java/org/xhtmlrenderer/demo/browser/BrowserPanel.java

@@ -289,35 +289,31 @@ public void loadPage(final String url_text) {
         }
     }
 
-    public void exportToPdf( String path )
-    {
-       if (manager.getBaseURL() != null) {
-           setStatus( "Exporting to " + path + "..." );
-           try (OutputStream os = Files.newOutputStream(Paths.get(path))) {
-               try {
-               ITextRenderer renderer = new ITextRenderer();
-
-               DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
-               DocumentBuilder db = dbf.newDocumentBuilder();
-               Document doc =  db.parse(manager.getBaseURL());
-
-               PDFCreationListener pdfCreationListener = new XHtmlMetaToPdfInfoAdapter( doc );
-               renderer.setListener( pdfCreationListener );
-
-               renderer.setDocument(manager.getBaseURL());
-               renderer.layout();
-
-               renderer.createPDF(os);
-               setStatus( "Done export." );
+    public void exportToPdf(String path) {
+        if (manager.getBaseURL() != null) {
+            setStatus("Exporting to " + path + "...");
+            try (OutputStream os = Files.newOutputStream(Paths.get(path))) {
+                try {
+                    ITextRenderer renderer = new ITextRenderer();
+
+                    DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
+                    DocumentBuilder db = dbf.newDocumentBuilder();
+                    Document doc = db.parse(manager.getBaseURL());
+
+                    PDFCreationListener pdfCreationListener = new XHtmlMetaToPdfInfoAdapter(doc);
+                    renderer.setListener(pdfCreationListener);
+
+                    renderer.createPDF(doc, os);
+                    setStatus("Done export.");
+                } catch (Exception e) {
+                    XRLog.general(Level.SEVERE, "Could not export PDF.", e);
+                    e.printStackTrace();
+                    setStatus("Error exporting to PDF.");
+                }
             } catch (Exception e) {
-                XRLog.general(Level.SEVERE, "Could not export PDF.", e);
                 e.printStackTrace();
-                setStatus( "Error exporting to PDF." );
-               }
-           } catch (Exception e) {
-               e.printStackTrace();
-           }
-       }
+            }
+        }
     }
 
     private void handlePageLoadFailed(String url_text, XRRuntimeException ex) {

flying-saucer-examples/src/test/java/org/xhtmlrenderer/pdf/ConcurrentPdfGenerationTest.java

@@ -1,26 +1,18 @@
 package org.xhtmlrenderer.pdf;
 
 import com.codeborne.pdftest.PDF;
-import com.lowagie.text.DocumentException;
 import org.junit.jupiter.api.Test;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
-import org.w3c.dom.Document;
-import org.xhtmlrenderer.resource.FSEntityResolver;
-import org.xml.sax.SAXException;
 
-import javax.xml.parsers.DocumentBuilder;
-import javax.xml.parsers.DocumentBuilderFactory;
-import javax.xml.parsers.ParserConfigurationException;
-import java.io.ByteArrayOutputStream;
-import java.io.IOException;
 import java.net.URL;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.ScheduledExecutorService;
 
 import static com.codeborne.pdftest.assertj.Assertions.assertThat;
+import static java.lang.Thread.currentThread;
 import static java.util.Objects.requireNonNull;
 import static java.util.concurrent.Executors.newFixedThreadPool;
 import static java.util.concurrent.Executors.newScheduledThreadPool;
@@ -73,29 +65,9 @@ private void verifyPdf(byte[] pdfBytes) {
     }
 
     private byte[] generatePdf(String htmlPath) {
-        ITextRenderer renderer = new ITextRenderer();
-        renderer.getSharedContext().setMedia("pdf");
-        renderer.getSharedContext().setInteractive(false);
-        renderer.getSharedContext().getTextRenderer().setSmoothingThreshold(0);
-
-        URL htmlUrl = requireNonNull(Thread.currentThread().getContextClassLoader().getResource(htmlPath), () -> "Test resource not found: " + htmlPath);
-
-        try {
-            DocumentBuilder builder = DocumentBuilderFactory.newInstance().newDocumentBuilder();
-            builder.setEntityResolver(FSEntityResolver.instance());
-
-            Document doc = builder.parse(htmlUrl.openStream());
-
-            renderer.setDocument(doc, htmlUrl.toString());
-            renderer.layout();
-
-            ByteArrayOutputStream bos = new ByteArrayOutputStream();
-            renderer.createPDF(bos);
-            return bos.toByteArray();
-        }
-        catch (DocumentException | IOException | SAXException | ParserConfigurationException e) {
-            throw new IllegalArgumentException(e);
-        }
+        URL htmlUrl = requireNonNull(currentThread().getContextClassLoader().getResource(htmlPath), 
+                () -> "Test resource not found: " + htmlPath);
+        return Html2Pdf.fromUrl(htmlUrl);
     }
 
 }

flying-saucer-examples/src/test/java/org/xhtmlrenderer/pdf/PDFRenderTest.java

@@ -7,7 +7,6 @@
 import org.slf4j.LoggerFactory;
 import org.w3c.dom.Document;
 import org.xhtmlrenderer.resource.XMLResource;
-import org.xml.sax.InputSource;
 
 import javax.annotation.ParametersAreNonnullByDefault;
 import java.io.File;
@@ -51,16 +50,13 @@ public void convertComplexHtmlToPdf() throws IOException, DocumentException {
     }
 
     private static PDF generatePDF(URL source, File output) throws IOException, DocumentException {
+        Document doc = XMLResource.load(source).getDocument();
+
         try (OutputStream os = newOutputStream(output.toPath())) {
             ITextRenderer renderer = new ITextRenderer();
             ResourceLoaderUserAgent callback = new ResourceLoaderUserAgent(renderer.getOutputDevice(), renderer.getSharedContext().getDotsPerPixel());
             renderer.getSharedContext().setUserAgentCallback(callback);
-
-            Document doc = XMLResource.load(new InputSource(source.toString())).getDocument();
-
-            renderer.setDocument(doc, source.toString());
-            renderer.layout();
-            renderer.createPDF(os);
+            renderer.createPDF(doc, os);
         }
         log.info("Rendered {}{}  to PDF: {}", source, lineSeparator(), output.toURI());
         return new PDF(output);

flying-saucer-examples/src/test/java/org/xhtmlrenderer/pdf/SimpleHtmlTest.java

@@ -2,16 +2,16 @@
 
 import com.codeborne.pdftest.PDF;
 import com.lowagie.text.DocumentException;
-import org.apache.pdfbox.io.IOUtils;
 import org.junit.jupiter.api.Test;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import org.w3c.dom.Document;
+import org.xhtmlrenderer.resource.XMLResource;
 
-import java.io.ByteArrayInputStream;
-import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.io.FileOutputStream;
 import java.io.IOException;
+import java.io.StringReader;
 
 import static com.codeborne.pdftest.assertj.Assertions.assertThat;
 
@@ -20,20 +20,13 @@ public class SimpleHtmlTest {
 
     @Test
     public void simplePdf() throws DocumentException, IOException {
-        ITextRenderer renderer = new ITextRenderer();
-
         String htmlContent = "<!DOCTYPE html><html><body><h1>My First Heading</h1><p>My first paragraph.</p></body></html>";
 
-        renderer.setDocumentFromString(htmlContent);
-
-        ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
-        renderer.layout();
-        renderer.createPDF(outputStream);
-        renderer.finishPDF();
-
         File file = new File("target/simple.pdf");
         try (FileOutputStream o = new FileOutputStream(file)) {
-            IOUtils.copy(new ByteArrayInputStream(outputStream.toByteArray()), o);
+            ITextRenderer renderer = new ITextRenderer();
+            Document source = XMLResource.load(new StringReader(htmlContent)).getDocument();
+            renderer.createPDF(source, o);
         }
         log.info("Generated PDF: {}", file.getAbsolutePath());
 

flying-saucer-pdf/src/main/java/org/xhtmlrenderer/pdf/Html2Pdf.java

@@ -0,0 +1,40 @@
+package org.xhtmlrenderer.pdf;
+
+import com.lowagie.text.DocumentException;
+import org.w3c.dom.Document;
+import org.xhtmlrenderer.resource.FSEntityResolver;
+import org.xml.sax.SAXException;
+
+import javax.xml.parsers.DocumentBuilder;
+import javax.xml.parsers.DocumentBuilderFactory;
+import javax.xml.parsers.ParserConfigurationException;
+import java.io.IOException;
+import java.net.URL;
+
+import static java.util.Objects.requireNonNull;
+
+public class Html2Pdf {
+    public static byte[] fromClasspathResource(String fileName) {
+        URL htmlUrl = requireNonNull(Thread.currentThread().getContextClassLoader().getResource(fileName), 
+                () -> "Resource not found in classpath: " + fileName);
+        return fromUrl(htmlUrl);
+    }
+
+    public static byte[] fromUrl(URL html) {
+        ITextRenderer renderer = new ITextRenderer();
+        renderer.getSharedContext().setMedia("pdf");
+        renderer.getSharedContext().setInteractive(false);
+        renderer.getSharedContext().getTextRenderer().setSmoothingThreshold(0);
+
+        try {
+            DocumentBuilder builder = DocumentBuilderFactory.newInstance().newDocumentBuilder();
+            builder.setEntityResolver(FSEntityResolver.instance());
+
+            Document doc = builder.parse(html.toString());
+            return renderer.createPDF(doc);
+        }
+        catch (DocumentException | IOException | SAXException | ParserConfigurationException e) {
+            throw new IllegalArgumentException(e);
+        }
+    }
+}

flying-saucer-pdf/src/main/java/org/xhtmlrenderer/pdf/ITextRenderer.java

@@ -53,6 +53,7 @@
 import javax.xml.transform.stream.StreamResult;
 import java.awt.*;
 import java.io.BufferedReader;
+import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.io.IOException;
 import java.io.OutputStream;
@@ -180,8 +181,8 @@ public void setDocument(Document doc, String url) {
         setDocument(doc, url, new XhtmlNamespaceHandler());
     }
 
+    @Deprecated
     public void setDocument(File file) throws IOException {
-
         File parent = file.getAbsoluteFile().getParentFile();
         setDocument(loadDocument(file.toURI().toURL().toExternalForm()), (parent == null ? "" : parent.toURI().toURL().toExternalForm()));
     }
@@ -197,6 +198,7 @@ public void setDocumentFromString(String content, String baseUrl) {
         setDocument(dom, baseUrl);
     }
 
+    @Deprecated
     public void setDocument(Document doc, String url, NamespaceHandler nsh) {
         _doc = doc;
 
@@ -245,7 +247,6 @@ public int getPDFXConformance(){
         return _pdfXConformance == null ? '0' : _pdfXConformance;
     }
 
-
     public void layout() {
         LayoutContext c = newLayoutContext();
         BlockBox root = BoxBuilder.createRootBox(c, _doc);
@@ -285,6 +286,23 @@ private LayoutContext newLayoutContext() {
         return result;
     }
 
+    public byte[] createPDF(Document source) throws DocumentException {
+        setDocument(source, source.getDocumentURI());
+        layout();
+
+        ByteArrayOutputStream bos = new ByteArrayOutputStream();
+        createPDF(bos);
+        finishPDF();
+        return bos.toByteArray();
+    }
+
+    public void createPDF(Document source, OutputStream os) throws DocumentException {
+        setDocument(source, source.getDocumentURI());
+        layout();
+        createPDF(os);
+        finishPDF();
+    }
+
     public void createPDF(OutputStream os) throws DocumentException {
         createPDF(os, true, 0);
     }