如何使用 pentaho 从 pdf 中提取文本？

Question

如何使用 pentaho 从 PDF 文件中读取文本？

是否有仅使用内置 java 库的解决方案？

Answer 1

只需使用以下代码添加步骤JavaScript Modified Values ：

var reader = new com.lowagie.text.pdf.PdfReader("c:\\temp\\mypdf.pdf") // OR JUST PUT THE COLUMN NAME IN THE FLOW;
var pdfTE = new com.lowagie.text.pdf.parser.PdfTextExtractor(reader);
var noOfPages = reader.getNumberOfPages();
var textPDF = "";
for (var i = 1; i <= noOfPages; i++) {
    textPDF += pdfTE.getTextFromPage(i);
}

Answer 2

我遵循了以下步骤：

1. 把jar文件itextpdf-5.5.9.jar放在~\pdi-ce-9.4.0.0-343\data-integration\lib
2. 配置用户自定义Java Class如下：

2.a. Class代码

            import java.io.IOException;
            
            import com.itextpdf.text.pdf.PdfReader;
            import com.itextpdf.text.pdf.parser.PdfTextExtractor;
            
            
            //String firstnameField;
            //String lastnameField;
            String nameField;
            
            //https://www.w3schools.blog/itext-read-pdf-file-in-java
            
            public boolean processRow(StepMetaInterface smi, StepDataInterface sdi) throws KettleException
            {
                // First, get a row from the default input hop
                //
                Object[] r = getRow();
            
                // If the row object is null, we are done processing.
                //
                if (r == null) {
                    setOutputDone();
                    return false;
                }
            
                if (first) {
                    //firstnameField = getParameter("FIRSTNAME_FIELD");
                    //lastnameField = getParameter("LASTNAME_FIELD");
                    nameField = getParameter("NAME_FIELD");
                    first=false;
                }
            
                // It is always safest to call createOutputRow() to ensure that your output row's Object[] is large
                // enough to handle any new fields you are creating in this step.
                //
                Object[] outputRow = createOutputRow(r, data.outputRowMeta.size());
            
                //String firstname = get(Fields.In, firstnameField).getString(r);
                //String lastname = get(Fields.In, lastnameField).getString(r);
            
            
                String pageContent = "";
            
                try {
                    //Create PdfReader instance.
                    String path = "C:\\Users\\myusername\\Downloads\\myPDF.pdf";
                    path = path.replace("\\", "/");        
                    PdfReader pdfReader = new PdfReader(path);
            
                    //Get the number of pages in pdf.
                    int pages = pdfReader.getNumberOfPages();
            
                    //Iterate the pdf through pages.
                    for(int i=1; i<=pages; i++) {
                        //Extract the page content using PdfTextExtractor.
                        pageContent =
                        PdfTextExtractor.getTextFromPage(pdfReader, i);
            
                        //Print the page content on console.
                        System.out.println("Content on Page "
                            + i + ": " + pageContent);
                    }
            
                    //Close the PdfReader.
                    pdfReader.close();
            
                // OR JUST PUT THE COLUMN NAME IN THE FLOW;
                } catch (Exception e) {
                    e.printStackTrace();
                }
            
                
                // Set the value in the output field
                //
                get(Fields.Out, nameField).setValue(outputRow, pageContent);
                
                // putRow will send the row on to the default output hop.
                //
                putRow(data.outputRowMeta, outputRow);
            
                return true;
            }

2.b. 领域

2.c。 参数

PDF 内容将在结果字段pageContent中

我的环境：

• Windows 10
• Java 8
• Pentaho 数据集成 9.4
• itextpdf 5.5.9（从https://repo1.maven.org/maven2/com/itextpdf/itextpdf/5.5.9/itextpdf-5.5.9.jar下载）