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Update or edit existing Excel files in Java using Apache POI

Requirement -Programatically update an Excel spreadsheet in Java.

Solutions – Here an example of Apache POI to update a XLS workbook. Apache POI is a very good API , that can be handy in manipulating Excel documents.This tutorial focuses on XLS documents (Office 97 – 2003).

The existing excel file like below –

sdsdsdsdsdsdsd

Below is code to update the excel file

import java.io.*;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.ss.usermodel.*;
import java.util.Iterator;
public class updateExcels {  

        public static void main(String[] args) throws Exception{
                
                FileInputStream fsIP= new FileInputStream(new File("C:\\TechartifactExcel.xls")); //Read the spreadsheet that needs to be updated
                 
                HSSFWorkbook wb = new HSSFWorkbook(fsIP); //Access the workbook
                 
                HSSFSheet worksheet = wb.getSheetAt(0); //Access the worksheet, so that we can update / modify it.
                 
                Cell cell = null; // declare a Cell object
               
                cell = worksheet.getRow(2).getCell(2);   // Access the second cell in second row to update the value
                 
                cell.setCellValue("OverRide Last Name");  // Get current cell value value and overwrite the value
                 
                fsIP.close(); //Close the InputStream
                
                FileOutputStream output_file =new FileOutputStream(new File("C:\\TechartifactExcel.xls"));  //Open FileOutputStream to write updates
                 
                wb.write(output_file); //write changes
                 
                output_file.close();  //close the stream    
        }
}

after updating excel file would look like below –

1updateexcel2

happy coding with Vinay in techartifact ….

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Converting java.lang.String to oracle.jbo.domain.Date

Requirement- to convert date as a string to oracle.jbo.domain.Date.

Solutions-

/**
*Converts a String to oracle.jbo.domain.Date
* @param String
* @return oracle.jbo.domain.Date
*/
public oracle.jbo.domain.Date castToJBODate(String aDate){
          DateFormat formatter;
          java.util.Date date; 

          if(aDate!=null){

            try {

              formatter = new SimpleDateFormat("dd/MMM/yyyy");
              date = formatter.parse(aDate);
              java.sql.Date sqlDate = new java.sql.Date(date.getTime());
              oracle.jbo.domain.Date jboDate = new oracle.jbo.domain.Date(sqlDate);

                return jboDate;
               } catch (ParseException e) {

                        e.printStackTrace();
                }

         }

         return null;
}

Another scenario –Convert oracle.jbo.domain.Date to String

Use this code-

 public String convertJbodateToString(oracle.jbo.domain.Date domainDate){
        
        SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.S");  
        Date date = null;
        
        try {
            date = formatter.parse(domainDate.toString().substring(0, 21));
        } catch (ParseException e) {
        }
        
                
        SimpleDateFormat FORMATTER = new SimpleDateFormat("MM/dd/yyyy HH:mm:ss");
        System.out.println("NewDate-->" + FORMATTER.format(date));
        
        return FORMATTER.format(date);
    }

Happing coding with Vinay in techartifact

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Set value in attribute in binding in Oracle ADF

Requirement – how to set value of attribute value in binding…

Solutions – you can use this expression –

JsfUtils.setExpressionValue("#{ManagedBean.empName}", "Vinay");

You have to add this method in JsfUtils class.

Note to call the getters and setters via your EL expression, you don’t include the get/set prefix.

 public static void setExpressionValue(String expression, Object newValue) {
    FacesContext facesContext = getFacesContext();
    Application app = facesContext.getApplication();
    ExpressionFactory elFactory = app.getExpressionFactory();
    ELContext elContext = facesContext.getELContext();
    ValueExpression valueExp = elFactory.createValueExpression(elContext, expression, Object.class);

    //Check that the input newValue can be cast to the property type
    //expected by the managed bean.
    //If the managed Bean expects a primitive we rely on Auto-Unboxing
    //I could do a more comprehensive check and conversion from the object
    //to the equivilent primitive but life is too short
    Class bindClass = valueExp.getType(elContext);
    if (bindClass.isPrimitive() || bindClass.isInstance(newValue)) {
      valueExp.setValue(elContext, newValue);
    }
  }

Happy coding in Techartifact with Vinay…