How to export data from postgresql to excel using java?

Question

can you give me a simple code with a simple table. thank you.

Answer 1

import java.io.*;
import org.apache.poi.hssf.*;
import org.apache.poi.ss.usermodel.Cell;
import java.io.FileOutputStream;
import java.sql.*;
public class ReadPostgresandExcel{
static String [] array = new String[3];
public static void main(String[] args){
readPostgres();
writeExcelData();
}
public static void writeExcelData(){
//create blank workbook
HSSFWorkbook workbook = new HSSFWorkbook();
HSSFSheet spreadsheet = workbook.createSheet("Sheet1");
try{
HSSFRow row = spreadsheet.createRow(0);
Cell cell = row.createCell(0);
String result = array[0] + " " + array[1] + " " + array[2];
cell.setCellValue(result);
FileOutputStream out = new FileOutputStream(new File("C:\\Users\\XXX\\Documents\\CreateWorkbook.xls"));
workbook.write(out);
out.close();
}catch(Exception e){
System.out.println("Error: " + e);
}
System.out.println("createworkbook.xls created!");
}
public static void readPostgres(){
try{
Class.forName("org.postgresql.Driver");
}catch(ClassNotFoundException e){
System.out.println("Where psql JDBC jar?"
+ "include library path!");
e.printStackTrace();
return;
}
System.out.println("psql driver success!");
Connection connection = null;
Statement stmt = null;
try{
connection = DriverManager.getConnection("jdbc:postgresql://127.0.0.1:5432/postgres", "postgres", "password");
stmt = connection.createStatement();
String sql = "select employe_id, firstname, lastname from employe";
ResultSet rs = stmt.executeQuery(sql);
while(rs.next()){
int id = rs.getInt("employe_id");
String first = rs.getString("firstname");
String last = rs.getString("lastname");
array[0] = "" + id;
array[1] = first;
array[2] = last;
}
}catch(SQLException e){
println("");
}
if(connection != null){
println("db Success!");
}else{
println("Failed sql connection!");
}
}
}
// I shorted a little with import, println...
// Sorry for typos!

Answer 2

I wonder why do you need to use java to export data to excel when you can simply do copy and paste?

Answer 3

this for my practice. i want to make a report of the data to excel.

Answer 4

thank you intro.