Java programming converts HTML files into PDF files

There are several ways to convert HTML files into PDF files on the Internet, but some have strict requirements on the HTML file format. If you are a little wrong, you cannot generate the PDF file we want. Here I recommend one

Pd4ml, which can solve the problem of incorrect HTML file format. It can generate a good PDF file, which is fast in processing and highly compatible with CSS files. Below is the most basic pd4ml programming:

package samples;import java.awt.Insets;import java.io.File;import java.io.IOException;import java.net.MalformedURLException;import java.net.URL;import java.security.InvalidParameterException;import org.zefer.pd4ml.PD4Constants;import org.zefer.pd4ml.PD4ML;public class GettingStarted1 {protected int topValue = 10;protected int leftValue = 20;protected int rightValue = 10;protected int bottomValue = 10;protected int userSpaceWidth = 1300;public static void main(String[] args) {try {GettingStarted1 jt = new GettingStarted1();jt.doConversion("http://pd4ml.com/sample.htm", "c:/pd4ml.pdf");} catch (Exception e) {e.printStackTrace();}}public void doConversion( String url, String outputPath ) throws InvalidParameterException, MalformedURLException, IOException {File output = new File(outputPath);java.io.FileOutputStream fos = new java.io.FileOutputStream(output);PD4ML pd4ml = new PD4ML();pd4ml.setHtmlWidth(userSpaceWidth); // set frame width of "virtual web browser" // choose target paper format and "rotate" it to landscape orientationpd4ml.setPageSize(pd4ml.changePageOrientation(PD4Constants.A4)); // define PDF page marginspd4ml.setPageInsetsMM(new Insets(topValue, leftValue, bottomValue, rightValue)); // source HTML document also may have margins, could be suppressed this way // (PD4ML *Pro* feature):pd4ml.addStyle("BODY {margin: 0}", true);// If built-in basic PDF fonts are not sufficient or // if you need to output non-Latin texts,// TTF embedding feature should help (PD4ML *Pro*)pd4ml.useTTF("c:/windows/fonts", true);pd4ml.render(new URL(url), fos); // actual document conversion from URL to filefos.close();System.out.println( outputPath + "\ndone." );}}

The following Java class slightly changes the above example. Now it pre-reads source HTML to a string and passes it to render () method
Wrapped to stringreader. First it writes PDF bytes to bytearrayoutputstream,
Which makes possible to measure size of the resulting document.

A disadvantage of the method is a bigger ram utilization.

package samples;import java.awt.Insets;;import java.io.BufferedInputStream;import java.io.ByteArrayOutputStream;import java.io.File;import java.io.FileInputStream;import java.io.FileOutputStream;import java.io.IOException;import java.io.StringReader;import java.net.MalformedURLException;import java.net.URL;import java.security.InvalidParameterException;import org.zefer.pd4ml.PD4Constants;import org.zefer.pd4ml.PD4ML;public class GettingStarted2 {protected int topValue = 10;protected int leftValue = 20;protected int rightValue = 10;protected int bottomValue = 10;protected int userSpaceWidth = 1300;public static void main(String[] args) {try {GettingStarted2 jt = new GettingStarted2();String html = readFile("c:/sample.htm", "UTF-8");jt.doConversion2(html, "c:/pd4ml.pdf");} catch (Exception e) {e.printStackTrace();}}public void doConversion2( String htmlDocument, String outputPath ) throws InvalidParameterException, MalformedURLException, IOException {PD4ML pd4ml = new PD4ML();pd4ml.setHtmlWidth(userSpaceWidth); // set frame width of "virtual web browser" // choose target paper formatpd4ml.setPageSize(pd4ml.changePageOrientation(PD4Constants.A4)); // define PDF page marginspd4ml.setPageInsetsMM(new Insets(topValue, leftValue, bottomValue, rightValue)); // source HTML document also may have margins, could be suppressed this way // (PD4ML *Pro* feature):pd4ml.addStyle("BODY {margin: 0}", true);// If built-in basic PDF fonts are not sufficient or // if you need to output non-Latin texts, TTF embedding feature should help // (PD4ML *Pro*)pd4ml.useTTF("c:/windows/fonts", true);ByteArrayOutputStream baos = new ByteArrayOutputStream();// actual document conversion from HTML string to byte arraypd4ml.render(new StringReader(htmlDocument), baos); // if the HTML has relative references to images etc, // use render() method with baseDirectory parameter insteadbaos.close();System.out.println( "resulting PDF size: " + baos.size() + " bytes" );// in Web scenarios it is a good idea to send the size with // "Content-length" HTTP headerFile output = new File(outputPath);java.io.FileOutputStream fos = new java.io.FileOutputStream(output);fos.write( baos.toByteArray() );fos.close();System.out.println( outputPath + "\ndone." );}private final static String readFile( String path, String encoding ) throws IOException {File f = new File( path );FileInputStream is = new FileInputStream(f);BufferedInputStream bis = new BufferedInputStream(is);ByteArrayOutputStream fos = new ByteArrayOutputStream();byte buffer[] = new byte[2048];int read;do {read = is.read(buffer, 0, buffer.length);if (read > 0) { fos.write(buffer, 0, read); }} while (read > -1);fos.close();bis.close();is.close();return fos.toString(encoding);}}