Hi to all,
i am newbie in java. I have created a program to read data from excel files with APACHE POI and show them in my console. I am using Eclipse as editor. Now I an trying to import these data in database so I can store them. The purpose for that is i would like to be able to access them from different locations. I am using JDBC connection!
Can someone help me of how I would do this? How i will connect these two? When i ran tha first code i get this: Exception in thread "main" java.lang.NullPointerException
at NewExcel2DB.main(NewExcel2DB.java:40)
How I will solve this?
**Here is my code for import data from Eclipse console to DATABASE: **
import java.io.*;
import java.sql.DriverManager;
import java.sql.SQLException;
import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.poifs.filesystem.POIFSFileSystem;
import org.apache.poi.ss.usermodel.*;
import java.util.*;
import java.sql.*;
import com.mysql.jdbc.Connection;
import com.mysql.jdbc.PreparedStatement;
public class NewExcel2DB {
public static void main(String[] args) throws Exception{
try {
Class.forName ("oracle.jdbc.OracleDriver");
Connection con = (Connection)
DriverManager.getConnection("jdbc:mysql://localhost:3306", "root", "root");
PreparedStatement sql_statement = null;
String jdbc_insert_sql = "INSERT INTO XLS_POI"
+ "(ID, Name, Salary) VALUES"
+ "(?,?,?)";
sql_statement = (PreparedStatement) con.prepareStatement(jdbc_insert_sql);
FileInputStream input = new FileInputStream
("C:\\Users\\Efi\\Documents\\test5.xls");
POIFSFileSystem fs = new POIFSFileSystem (input);
HSSFWorkbook wb = new HSSFWorkbook(fs);
HSSFSheet sheet = wb.getSheetAt(0);
Iterator rows = sheet.rowIterator();
for(int i=1; i<=sheet.getLastRowNum(); i++){
HSSFRow HSSFRow = sheet.getRow(i);
HSSFRow row=null;
int id = (int) row.getCell(0).getNumericCellValue();
String name = row.getCell(1).getStringCellValue();
String salary = row.getCell(2).getStringCellValue();
String sql = "INSERT INTO tablename VALUES('"+id+"','"+name+"','"+salary+"')";
PreparedStatement pstm = (PreparedStatement)con.prepareStatement(sql);
System.out.println("Import rows "+i);
}
while(rows.hasNext()) {
HSSFRow row = (HSSFRow) rows.next();
Iterator cells = row.cellIterator();
while(cells.hasNext()) {
HSSFCell cell = (HSSFCell) cells.next();
switch(cell.getCellType()) {
case Cell.CELL_TYPE_STRING: //handle string columns
sql_statement.setString(1,
cell.getStringCellValue());
break;
case Cell.CELL_TYPE_NUMERIC: //handle double data
sql_statement.setDouble(2,cell.getNumericCellValue() );
break;
}
}
}
sql_statement.executeUpdate(); //we can execute the statement before
con.commit();
con.close();
input.close();
System.out.println("Success import excel to mysql table");
}catch (ClassNotFoundException e){
System.out.println (e);
}catch (SQLException ex){
System.out.println(ex);
}catch (IOException ioe){
System.out.println(ioe);
}
}
}
And here is my code to read excel file using APACHE POI:
import java.io.FileInputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.Cell;
public class ExcelRead{
public static void main(String[] args) throws Exception {
//
// An excel file name. You can create a file name with a full
// path information.
//
String filename = "C:\\Users\\Efi\\Documents\\test5.xls";
//
// Create an ArrayList to store the data read from excel sheet.
//
List sheetData = new ArrayList();
FileInputStream fis = null;
try {
//
// Create a FileInputStream that will be use to read the
// excel file.
//
fis = new FileInputStream(filename);
//
// Create an excel workbook from the file system.
//
HSSFWorkbook workbook = new HSSFWorkbook(fis);
//
// Get the first sheet on the workbook.
//
HSSFSheet sheet = workbook.getSheetAt(0);
//
// When we have a sheet object in hand we can iterator on
// each sheet's rows and on each row's cells. We store the
// data read on an ArrayList so that we can printed the
// content of the excel to the console.
//
Iterator rows = sheet.rowIterator();
while (rows.hasNext()) {
HSSFRow row = (HSSFRow) rows.next();
Iterator cells = row.cellIterator();
List data = new ArrayList();
while (cells.hasNext()) {
HSSFCell cell = (HSSFCell) cells.next();
data.add(cell);
}
sheetData.add(data);
}
} catch (IOException e) {
e.printStackTrace();
} finally {
if (fis != null) {
fis.close();
}
}
showExelData(sheetData);
}
private static void showExelData(List sheetData) {
//
// Iterates the data and print it out to the console.
//
for (int i = 0; i < sheetData.size(); i++) {
List list = (List) sheetData.get(i);
for (int j = 0; j < list.size(); j++) {
Cell cell = (Cell) list.get(j);
if (cell.getCellType() == Cell.CELL_TYPE_NUMERIC) {
System.out.print(cell.getNumericCellValue());
} else if (cell.getCellType() == Cell.CELL_TYPE_STRING) {
System.out.print(cell.getRichStringCellValue());
} else if (cell.getCellType() == Cell.CELL_TYPE_BOOLEAN) {
System.out.print(cell.getBooleanCellValue());
}
if (j < list.size() - 1) {
System.out.print(", ");
}
}
System.out.println("");
}
}
}
Thank you in advance!
