Android™ Requires Chilkat v11.7.0+

Extract Text from a Two-Column PDF

See more PDF Text Extraction Examples

Demonstrates how multi-column pages are read. By default the columns are detected and each column is read top to bottom before the next ("columns": "auto"); "columns": "none" reads the full page width line by line, which interleaves the columns. The quality report tells how many columns were found. Android™

// Important: Don't forget to include the call to System.loadLibrary
// as shown at the bottom of this code sample.
package com.test;

import android.app.Activity;
import com.chilkatsoft.*;

import android.widget.TextView;
import android.os.Bundle;

public class SimpleActivity extends Activity {

  private static final String TAG = "Chilkat";

  // Called when the activity is first created.
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    boolean success = false;

    //  This example requires the Chilkat API to have been previously unlocked.
    //  See Global Unlock Sample for sample code.

    //  The two-column PDF used in this example is available at two_column_article.pdf

    CkPdf pdf = new CkPdf();
    success = pdf.LoadFile("qa_data/pdf/two_column_article.pdf");
    if (success == false) {
        Log.i(TAG, pdf.lastErrorText());
        return;
        }

    CkJsonObject json = new CkJsonObject();
    CkJsonObject jsonOut = new CkJsonObject();

    //  With the default options the columns are detected, and the text of the left column
    //  comes before the text of the right column.
    success = pdf.ExtractText("text",json,jsonOut);
    if (success == false) {
        Log.i(TAG, pdf.lastErrorText());
        return;
        }

    Log.i(TAG, "Columns detected: " + String.valueOf(jsonOut.IntOf("quality.pages[0].columns")));
    Log.i(TAG, "Reading order: " + jsonOut.stringOf("quality.pages[0].readingOrderSource"));
    Log.i(TAG, jsonOut.stringOf("text"));

    //  "none" switches column detection off: the page is read across its full width, line by line,
    //  so each output line holds a line of the left column followed by a line of the right column.
    //  This is rarely wanted, but it shows what the detection does.
    json.UpdateString("columns","none");
    json.UpdateString("layout","lines");
    success = pdf.ExtractText("text",json,jsonOut);
    if (success == false) {
        Log.i(TAG, pdf.lastErrorText());
        return;
        }

    Log.i(TAG, "---- columns: none ----");
    Log.i(TAG, jsonOut.stringOf("text"));

    //  Sample output (abbreviated):

    //  Columns detected: 2
    //  Reading order: visual
    //  The Harbor Lighthouse, Season Two
    //  
    //  The harbor lighthouse was built in 1874 to mark the entrance to the inner channel. It operated continuously until 1968, ...
    //  
    //  The restoration society took ownership in 2021 with three goals: ...
    //  ...
    //  The lantern room frame was stripped, primed and repainted in the original dark green. ...
    //  ...
    //  ---- columns: none ----
    //  The Harbor Lighthouse, Season Two
    //  The harbor lighthouse was built in 1874 to The lantern room frame was stripped, primed
    //  mark the entrance to the inner channel. It and repainted in the original dark green. New
    //  ...

  }

  static {
      System.loadLibrary("chilkat");

      // Note: If the incorrect library name is passed to System.loadLibrary,
      // then you will see the following error message at application startup:
      //"The application <your-application-name> has stopped unexpectedly. Please try again."
  }
}