/**
* 使用pdfbox提取pdf文档的文字和图片内容
* pdfbox官网：https://pdfbox.apache.org/
* maven依赖如下：
* <dependency>
* <groupId>org.apache.pdfbox</groupId>
* <artifactId>fontbox</artifactId>
* <version>2.0.1</version>
* </dependency>
* <dependency>
* <groupId>org.apache.pdfbox</groupId>
* <artifactId>pdfbox</artifactId>
* <version>2.0.1</version>
* </dependency>
* <dependency>
* <groupId>com.itextpdf</groupId>
* <artifactId>itextpdf</artifactId>
* <version>5.5.13</version>
* </dependency>
* <dependency>
* <groupId>net.coobird</groupId>
* <artifactId>thumbnailator</artifactId>
* <version>0.4.8</version>
* </dependency>
*/
public class PdfTest {
public static final String DATE_FORMAT = "yyyy-MM-dd HH:mm:ss";

/**
*
*
* @param pdfFilePath
* @throws Exception
*/
public static void extractText(String pdfFilePath) throws Exception{
try (PDDocument document = PDDocument.load(new File(pdfFilePath)))
{
AccessPermission ap = document.getCurrentAccessPermission();
if (!ap.canExtractContent())
{
throw new IOException("You do not have permission to extract text");
}
PDFTextStripper stripper = new PDFTextStripper();
stripper.setSortByPosition(true);

for (int p = 1; p <= document.getNumberOfPages(); ++p)
{
// 这里分为一页一页的提取，如果不设置，默认会把所有页的内容一次性提取出来，根据需要选择
stripper.setStartPage(p);
stripper.setEndPage(p);

//提取内容就这一行代码
//提取内容很彻底，包括了页眉页脚的内容也都会被提出来
String text = stripper.getText(document);

String pageStr = String.format("page %d:", p);
System.out.println(pageStr);
//为了打印出来更美观
for (int i = 0; i < pageStr.length(); ++i)
{
System.out.print("-");
}
System.out.println();
System.out.println(text.trim());
System.out.println();
}
}
}

public static void pdfParse(String pdfPath) throws Exception {
InputStream input = null;
PDDocument document = null;
try {
document = PDDocument.load(new File(pdfPath));

/** 文档属性信息 **/
PDDocumentInformation info = document.getDocumentInformation();
System.out.println("标题:" + info.getTitle());
System.out.println("主题:" + info.getSubject());
System.out.println("作者:" + info.getAuthor());
System.out.println("关键字:" + info.getKeywords());

System.out.println("应用程序:" + info.getCreator());
System.out.println("pdf 制作程序:" + info.getProducer());

System.out.println("作者:" + info.getTrapped());

System.out.println("创建时间:" + dateFormat(info.getCreationDate()));
System.out.println("修改时间:" + dateFormat(info.getModificationDate()));


//获取内容信息
PDFTextStripper pts = new PDFTextStripper();
String content = pts.getText(document);
System.out.println("内容:" + content);

/** 文档页面信息 **/
PDDocumentCatalog cata = document.getDocumentCatalog();
int count = 1;
for (int i = 0; i < document.getNumberOfPages(); i++) {
PDPage page = document.getPage(i);
if (null != page) {
//获取到所有rescourse信息
PDResources res = page.getResources();
Iterable<COSName> xit = res.getXObjectNames();
Iterator<COSName> iterator = xit.iterator();
while (iterator.hasNext()){
COSName cosName = iterator.next();
System.out.println(cosName.getName());
//判断是否图片资源，这个提取图片也很彻底，包括页眉页脚的图片也会被获取到
if(res.isImageXObject(cosName)){
PDImageXObject pdImageXObject = (PDImageXObject)res.getXObject(cosName);
//这里保存图片我用了谷歌的thumbnailator框架，也可以用自己的方法去保存BufferedImage对象到本地图片
Thumbnails.of(pdImageXObject.getImage()).scale(0.9).toFile(new File("D:\\pdf\\"+System.currentTimeMillis()+".jpg"));
}
}
}
}
} catch (Exception e) {
throw e;
} finally {
if (null != input)
input.close();
if (null != document)
document.close();
}
}

/***
* PDF文件转PNG图片，全部页数
*
* @param PdfFilePath pdf完整路径
* @param dpi dpi越大转换后越清晰，相对转换速度越慢
* @return
*/
private static boolean pdf2Image(String PdfFilePath, String dstImgFolder, int dpi) {
File file = new File(PdfFilePath);
PDDocument pdDocument;
try {
String imgPDFPath = file.getParent();
int dot = file.getName().lastIndexOf('.');
String imagePDFName = file.getName().substring(0, dot); // 获取图片文件名
String imgFolderPath = null;
if (dstImgFolder.equals("")) {
imgFolderPath = imgPDFPath + File.separator + imagePDFName;// 获取图片存放的文件夹路径
} else {
imgFolderPath = dstImgFolder + File.separator + imagePDFName;
}

if (createDirectory(imgFolderPath)) {

pdDocument = PDDocument.load(file);
PDFRenderer renderer = new PDFRenderer(pdDocument);
/* dpi越大转换后越清晰，相对转换速度越慢 */
PdfReader reader = new PdfReader(PdfFilePath);
int pages = reader.getNumberOfPages();
StringBuffer imgFilePath = null;
for (int i = 0; i < pages; i++) {
String imgFilePathPrefix = imgFolderPath + File.separator + imagePDFName;
imgFilePath = new StringBuffer();
imgFilePath.append(imgFilePathPrefix);
imgFilePath.append("_");
imgFilePath.append(String.valueOf(formatNumber(i+1)));
imgFilePath.append(".jpg");
File dstFile = new File(imgFilePath.toString());
BufferedImage image = renderer.renderImageWithDPI(i, dpi);


ImageWriter writer = ImageIO.getImageWritersByFormatName("jpg").next();
writer.setOutput(ImageIO.createImageOutputStream(dstFile));
ImageWriteParam param = writer.getDefaultWriteParam();
param.setCompressionMode(ImageWriteParam.MODE_EXPLICIT);
param.setCompressionQuality(0.3f);
writer.write(null, new IIOImage(image, null, null), param);

// ImageIO.write(image, "jpg", dstFile);
}
System.out.println("PDF文档转图片成功！"+dstImgFolder);
return true;
} else {
System.out.println("PDF文档转图片失败：" + "创建" + imgFolderPath + "失败");
}

} catch (IOException e) {
e.printStackTrace();
}
return false;
}

private static String formatNumber(int i){
if(i<10){
return "00"+i;
}else if(i<100){
return "0"+i;
}else{
return i+"";
}
}

private static boolean createDirectory(String folder) {
File dir = new File(folder);
if (dir.exists()) {
return true;
} else {
return dir.mkdirs();
}
}

public static String dateFormat(Calendar calendar) throws Exception {
if (null == calendar)
return null;
String date = null;
try {
String pattern = DATE_FORMAT;
SimpleDateFormat format = new SimpleDateFormat(pattern);
date = format.format(calendar.getTime());
} catch (Exception e) {
throw e;
}
return date == null ? "" : date;
}

}