java编程将HTML文件转换成PDF文件

网上有好几种方法可以将将HTML文件转换成PDF文件但是有些对HTML文件格式要求比较严格，稍微错了一些就不能生成我们所要的PDF文件，这里我推荐一个

PD4ML，它可以解决HTML文件格式不正确的问题，可以生成一个比较好的PDF文件，其处理速度快，而且对CSS文件兼容的非常好。下面是最基本的

PD4ML编程：

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 orientation                pd4ml.setPageSize(pd4ml.changePageOrientation(PD4Constants.A4));                                     // define PDF page margins                pd4ml.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 file                fos.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 format                pd4ml.setPageSize(pd4ml.changePageOrientation(PD4Constants.A4));                                     // define PDF page margins                pd4ml.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 array                pd4ml.render(new StringReader(htmlDocument), baos);                 // if the HTML has relative references to images etc,                 // use render() method with baseDirectory parameter instead                baos.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 header                        File 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);            }        }