使用itextpdf提取pdf内容

 package test;

 import java.io.FileInputStream;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.regex.Pattern;

 import org.apache.pdfbox.cos.COSDocument;
 import org.apache.pdfbox.pdfparser.PDFParser;
 import org.apache.pdfbox.util.PDFTextStripper;

 import com.itextpdf.text.pdf.PdfReader;
 import com.itextpdf.text.pdf.parser.PdfTextExtractor;

 public class UploadUtils {

     private final static Pattern pattern = Pattern.compile("\\d+");
     private final static int stateParaOverFlag = 800;
     private final static int thankParaOverFlag = 800;

     /**
      * 读取pdf参考文献内容
      *
      * @param s
      * @return
      */
     public String readPdf(String filePath) {
         StringBuilder buffer = new StringBuilder();
         FileInputStream fis = null;
         PdfReader pdfReader = null;
         COSDocument cosDocument = null;
         String[] paragraphs = null;
         PDFParser p;
         boolean addBool = true;
         boolean judgeState = false;
         boolean judgeThank = false;
         StringBuilder tempSb = new StringBuilder();
         try {
             fis = new FileInputStream(filePath);
             p = new PDFParser(fis);
             p.parse();
             cosDocument = p.getDocument();
             // 加密文档判断
             if (cosDocument.isEncrypted()) {
                 StringBuilder tempContent = new StringBuilder();
                 pdfReader = new PdfReader(filePath);
                 int i = pdfReader.getNumberOfPages();
                 for (int j = 1; j <= i; j++) {
                     tempContent.append(PdfTextExtractor.getTextFromPage(pdfReader, j));
                 }
                 paragraphs = tempContent.toString().split("\n");
             } else {
                 PDFTextStripper ts = new PDFTextStripper();
                 paragraphs = ts.getText(p.getPDDocument()).split("\n");
             }
             boolean mark = false;
             List<Integer> errornum = new ArrayList<Integer>();
             int flag = 0;
             int endRange = paragraphs.length * 70 / 100;
             int rangeFlag = 0;
             for (String lineContent : paragraphs) {
                 if (judgeState) {
                     tempSb.append(lineContent);
                     if (tempSb.length() >= stateParaOverFlag) {
                         judgeState = false;
                         addBool = true;
                         tempSb.delete(0, tempSb.length() - 1);
                     }
                 }
                 if (judgeThank) {
                     tempSb.append(lineContent);
                     if (tempSb.length() >= thankParaOverFlag) {
                         judgeThank = false;
                         addBool = true;
                         tempSb.delete(0, tempSb.length() - 1);
                     }
                 }
                 if (addBool) {
                     buffer.append(lineContent);
                 }
                 if (mark && rangeFlag >= endRange) {
                     if (lineContent.length() < 5) {
                         errornum.add(++flag);
                         rangeFlag++;
                         continue;
                     }
                     if (pattern.matcher(lineContent.substring(0, 5)).find()) {
                         if (flag != 0) {
                             flag = 0;
                             errornum.clear();
                         }
                     } else {
                         errornum.add(++flag);
                     }
                     if (errornum.size() > 2) {
                         mark = false;
                     }
                 }
                 rangeFlag++;
             }
         } catch (Exception e) {
             e.printStackTrace();
         } finally {
             if (fis != null) {
                 try {
                     fis.close();
                 } catch (IOException e) {
                     e.printStackTrace();
                 } finally {
                     fis = null;
                 }
             }
             if (pdfReader != null) {
                 pdfReader.close();
             }
             if (cosDocument != null) {
                 try {
                     cosDocument.close();
                 } catch (IOException e) {
                     e.printStackTrace();
                 } finally {
                     cosDocument = null;
                 }
             }
         }
         return buffer.toString();
     }

     public static boolean isBlank(CharSequence cs) {
         int strLen;
         if (cs == null || (strLen = cs.length()) == 0) {
             return true;
         }
         for (int i = 0; i < strLen; i++) {
             if (Character.isWhitespace(cs.charAt(i)) == false) {
                 return false;
             }
         }
         return true;
     }

     public static void main(String[] args) {
         // System.err.println(new UploadUtils()
         // .readPdf("/opt/fileCache/2014/125/13/shuangping_D7037870CF4FC5C421A3E5359DCF8BBE.pdf"));
         System.err.println(new UploadUtils().readPdf("E:\\MyWork\\guyezhai\\pdf提取\\路径依赖视角下高校新专业建设的策略创新(1).pdf"));

     }

 }

其中用到的jar包：

bcpkix-jdk15on-1.47.jar
bcprov-jdk15on-1.49.jar
commons-logging-1.1..jar
fontbox-1.8..jar
icu4j-4.0..jar
itextpdf-5.4..jar
jempbox-1.8..jar
pdfbox-1.8..jar