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);    }}