In the Split Pdf file tutorial, I showed you how to split a Pdf file into multiple Pdf files using iTextG library. Sometimes, you wish to merge multiple Pdf files into a sing Pdf file. In iTextG, merging Pdf files can be done simply as splitting a Pdf file.
To achieve the goal, first you need to have a list of paths of the source Pdf files. Then you use the PdfReader to read all pages of every source Pdf file and add the pages to a PdfCopy object. In the example application below, you can merge two Pdf files into one Pdf file called meragedresult.pdf. The user is able to select the Pdf files from his/her device by clicking the browser button (...) next to the text boxes. In your phone, you need to install a File Explorer app so that you will be able to choose a Pdf file once you press the browse buttons.


<TableLayout xmlns:android= "http://schemas.android.com/apk/res/android"
   xmlns:tools= "http://schemas.android.com/tools"
   android:layout_width= "match_parent"
   android:layout_height= "wrap_content"
   android:stretchColumns="*"
   android:layout_gravity= "center_vertical"
   android:background="#3f18c1d2"
   >

   <TableRow>
      <EditText
        android:id="@+id/txtfirstpdf"
        android:text="Pdf file"
        android:padding="5dip"

        android:layout_span="4" />
      <Button
        android:id="@+id/bt1"
        android:text="..."
        android:tag="fbt"
        android:maxWidth="30dp"
        android:padding="5dip"

        />

   </TableRow>

   <TableRow>
      <EditText
        android:id="@+id/txtsecondpdf"
        android:text="Pdf file"
        android:padding="5dip"
        android:layout_span="4" />
      <Button
        android:id="@+id/bt2"
        android:text="..."
        android:tag="sbt"
        android:padding="5dip"

        />

   </TableRow>

   <TableRow>

      <Button
        android:id="@+id/btmerge"
        android:layout_span="5"
        android:text="Merge"
        android:padding="5dip"
        android:onClick="mergePdfFiles"

        />

   </TableRow>

</TableLayout>

import android.content.Intent;
import android.net.Uri;
import android.os.Environment;
import android.os.Handler;
import android.support.v4.app.FragmentActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.Gravity;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import java.io.FileOutputStream;
import com.itextpdf.text.Document;
import com.itextpdf.text.pdf.PdfCopy;
import com.itextpdf.text.pdf.PdfReader;

public class MainActivity extends FragmentActivity {
   private EditText txt1,txt2;
   private Button bt1,bt2;
   private Handler handler;
   private final int PICKFILE_RESULT_CODE=10;
   private String btTag="";
   @Override
   protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
      txt1=(EditText)findViewById(R.id.txtfirstpdf);
      txt2=(EditText)findViewById(R.id.txtsecondpdf);
      bt1=(Button)findViewById(R.id.bt1);
      bt2=(Button)findViewById(R.id.bt2);
      bt1.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
              btTag=((Button)v).getTag().toString();
              showFileChooser();
             
        }
      });
      bt2.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
              btTag=((Button)v).getTag().toString();
              showFileChooser();
              
        }
      });


   public void mergePdfFiles(View view){
      try {
        String[] srcs = {txt1.getText().toString(), txt2.getText().toString()};
        mergePdf(srcs);
      }catch (Exception e){e.printStackTrace();}
   }

   public void mergePdf(String[] srcs){
      try{
        // Create document object
        Document document = new Document();
        // Create pdf copy object to copy current document to the output mergedresult file
        PdfCopy copy = new PdfCopy(document, new FileOutputStream(Environment.getExternalStorageDirectory()+"/mergedresult.pdf"));
        // Open the document
        document.open();
        PdfReader pr;
        int n;
        for (int i = 0; i < srcs.length; i++) {
           // Create pdf reader object to read each input pdf file
           pr = new PdfReader(srcs[i].toString());
           // Get the number of pages of the pdf file
           n = pr.getNumberOfPages();
           for (int page = 1; page <=n;page++) {
              // Import all pages from the file to PdfCopy
              copy.addPage( copy.getImportedPage(pr,page));
           }
        }
        document.close(); // close the document

      }catch(Exception e){e.printStackTrace();}
   }


   @Override
   // Save tag of the clicked button
   // It is used to identify the button has been pressed
   public void onSaveInstanceState( Bundle outState) {
      super.onSaveInstanceState(outState);
      outState.putString("savText", btTag);
      

   }

   @Override
   // Restore the tag
   protected void onRestoreInstanceState( Bundle savedInstanceState) {
      super.onRestoreInstanceState( savedInstanceState);
      btTag=savedInstanceState.getString( "savText");
      
   }

   private void showFileChooser(){
      Log.e("AA","bttag="+btTag);
      String folderPath = Environment. getExternalStorageDirectory()+"/";
      Intent intent = new Intent();
      intent.setAction( Intent.ACTION_GET_CONTENT);
      Uri myUri = Uri.parse(folderPath);
      intent.setDataAndType( myUri ,"file/*");
      Intent intentChooser = Intent.createChooser(intent, "Select a file");
      startActivityForResult(intentChooser, PICKFILE_RESULT_CODE);
   }

   protected void onActivityResult(int requestCode, int resultCode, Intent data) {

      if (data != null) {
        if (requestCode == PICKFILE_RESULT_CODE) {
           if (resultCode == RESULT_OK) {
              String FilePath = data.getData().getPath();
              if(bt1.getTag().toString().equals(btTag))
                txt1.setText(FilePath);
              else
                txt2.setText(FilePath);

           }
        }
      }
   }  
   
}

Posted by: Dara | post date: 03-05-2015 | Subject: Android Apps Development