java - Apache POI 和文件删除类

Question

我的类(class)获取一个数据库并复制它。然后运行 ​​Apache POI 并将值提取到 Excel 电子表格中。然后它删除复制的文件。我将这两个类作为独立的类，但现在我已将它们缝合在一起，我收到一个错误，并且它似乎不喜欢 public class public class ExportToExcel { 之后的大括号。

代码:

import java.io.File;
import java.io.IOException;
import javax.swing.JOptionPane;
import org.apache.commons.io.FileUtils;
import java.io.File;
import java.io.FileOutputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
import java.sql.SQLException;
import org.apache.poi.xssf.usermodel.XSSFCell;
import org.apache.poi.xssf.usermodel.XSSFRow;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

public class ExportToExcel {
{

   public static void main(String args[]) throws IOException {
       {
           String source = "C:/Test/DATABASE.db";
           String target ="C:/Test/COPY_";


           File sourceFile = new File(source);
           String name = sourceFile.getName();

           File targetFile = new File(target+name);
           System.out.println("Copying file : " + sourceFile.getName());


           FileUtils.copyFile(sourceFile, targetFile);

           System.out.println("copying of file:"+ sourceFile.getName() +"is completed");

            Connection connection = null;
            //@Override
            //public Connection getConection() throws SQLException {


                try {
                    Class.forName("org.sqlite.JDBC");


                    connection = DriverManager.getConnection("jdbc:sqlite:" + "C:/Test/DATABASE.db"); 
                } catch (SQLException e) {
                    throw new SQLException(e.getMessage());
                } catch (Exception e) {
                    throw new SQLException(e.getCause());
                }

          Statement statement = connection.createStatement();
          ResultSet resultSet = statement
          .executeQuery("select * from MAIN_TABLE");
          XSSFWorkbook workbook = new XSSFWorkbook(); 
          XSSFSheet spreadsheet = workbook
          .createSheet("EXPORTED DB");
          XSSFRow row=spreadsheet.createRow(1);// should start at 0 not one.. But this is ok for testing..
          XSSFCell cell;
          cell=row.createCell(1);// should start at 0 not one.. But this is ok for testing..
          cell.setCellValue("Number");
          cell=row.createCell(2);
          cell.setCellValue("First Name");
          cell=row.createCell(3);
          cell.setCellValue("Last Name");
          cell=row.createCell(4);
          cell.setCellValue("Origin");
          cell=row.createCell(5);
          cell.setCellValue("Destination");
          cell=row.createCell(6);
          //
          cell.setCellValue("Arrival");
          cell=row.createCell(7);
          cell.setCellValue("Departure");     
          cell=row.createCell(8);
          cell.setCellValue("Status");
          cell=row.createCell(9);
          cell.setCellValue("Created");    
          cell=row.createCell(10);
          cell.setCellValue("Updated");   
          cell=row.createCell(11);
          cell.setCellValue("Message"); 
          cell=row.createCell(12);
          cell.setCellValue("Active");    
          //
          int i=2;
          while(resultSet.next())
          {
             row=spreadsheet.createRow(i);
             cell=row.createCell(1);
             cell.setCellValue(resultSet.getInt("number"));
             cell=row.createCell(2);
             cell.setCellValue(resultSet.getString("first_name"));
             cell=row.createCell(3);
             cell.setCellValue(resultSet.getString("last_name"));
             cell=row.createCell(4);
             cell.setCellValue(resultSet.getString("origin"));
             cell=row.createCell(5);
             cell.setCellValue(resultSet.getString("destination"));
             //
             cell=row.createCell(6);
             cell.setCellValue(resultSet.getString("arrival"));
             cell=row.createCell(7);
             cell.setCellValue(resultSet.getString("departure")); 
             cell=row.createCell(8);
             cell.setCellValue(resultSet.getString("status"));
             cell=row.createCell(9);
             cell.setCellValue(resultSet.getString("created"));
             cell=row.createCell(10);
             cell.setCellValue(resultSet.getString("updated"));
             cell=row.createCell(11);
             cell.setCellValue(resultSet.getString("message"));
             cell=row.createCell(12);
             cell.setCellValue(resultSet.getString("active"));
             //
             i++;
          }
          FileOutputStream out = new FileOutputStream(
          new File("exceldatabase.xlsx"));
          workbook.write(out);
          out.close();
         // workbook.close();
          System.out.println(
          "exceldatabase.xlsx written successfully");

       {    
    try{

        File filetodelete = new File("C:/Test/COPY_DATABASE.db");

        if(filetodelete.delete()){
            System.out.println(filetodelete.getName() + " is deleted!");
        }else{
            System.out.println("Delete has failed.");

        }

    }catch(Exception e){

        e.printStackTrace();
    }
       }
   }
}
}

错误:

Exception in thread "main" java.lang.Error: Unresolved compilation problem: 

at ExportToExcel.main(ExportToExcel.java:20)

Answer 1

查看评论:

public class ExportToExcel {
    //{  remove this

    public static void main(String args[]) throws IOException {
        //{ remove this
        String source = "C:/Test/DATABASE.db";
        String target ="C:/Test/COPY_";


        File sourceFile = new File(source);
        String name = sourceFile.getName();

        File targetFile = new File(target+name);
        System.out.println("Copying file : " + sourceFile.getName());


        FileUtils.copyFile(sourceFile, targetFile);

        System.out.println("copying of file:"+ sourceFile.getName() +"is completed");

        Connection connection = null;
        //@Override
        //public Connection getConection() throws SQLException {


        try {
            Class.forName("org.sqlite.JDBC");


            connection = DriverManager.getConnection("jdbc:sqlite:" + "C:/Test/DATABASE.db"); 
        } catch (SQLException e) {
            throw new SQLException(e.getMessage());
        } catch (Exception e) {
            throw new SQLException(e.getCause());
        }

        Statement statement = connection.createStatement();
        ResultSet resultSet = statement
                .executeQuery("select * from MAIN_TABLE");
        XSSFWorkbook workbook = new XSSFWorkbook(); 
        XSSFSheet spreadsheet = workbook
                .createSheet("EXPORTED DB");
        XSSFRow row=spreadsheet.createRow(1);// should start at 0 not one.. But this is ok for testing..
        XSSFCell cell;
        cell=row.createCell(1);// should start at 0 not one.. But this is ok for testing..
        cell.setCellValue("Number");
        cell=row.createCell(2);
        cell.setCellValue("First Name");
        cell=row.createCell(3);
        cell.setCellValue("Last Name");
        cell=row.createCell(4);
        cell.setCellValue("Origin");
        cell=row.createCell(5);
        cell.setCellValue("Destination");
        cell=row.createCell(6);
        //
        cell.setCellValue("Arrival");
        cell=row.createCell(7);
        cell.setCellValue("Departure");     
        cell=row.createCell(8);
        cell.setCellValue("Status");
        cell=row.createCell(9);
        cell.setCellValue("Created");    
        cell=row.createCell(10);
        cell.setCellValue("Updated");   
        cell=row.createCell(11);
        cell.setCellValue("Message"); 
        cell=row.createCell(12);
        cell.setCellValue("Active");    
        //
        int i=2;
        while(resultSet.next())
        {
            row=spreadsheet.createRow(i);
            cell=row.createCell(1);
            cell.setCellValue(resultSet.getInt("number"));
            cell=row.createCell(2);
            cell.setCellValue(resultSet.getString("first_name"));
            cell=row.createCell(3);
            cell.setCellValue(resultSet.getString("last_name"));
            cell=row.createCell(4);
            cell.setCellValue(resultSet.getString("origin"));
            cell=row.createCell(5);
            cell.setCellValue(resultSet.getString("destination"));
            //
            cell=row.createCell(6);
            cell.setCellValue(resultSet.getString("arrival"));
            cell=row.createCell(7);
            cell.setCellValue(resultSet.getString("departure")); 
            cell=row.createCell(8);
            cell.setCellValue(resultSet.getString("status"));
            cell=row.createCell(9);
            cell.setCellValue(resultSet.getString("created"));
            cell=row.createCell(10);
            cell.setCellValue(resultSet.getString("updated"));
            cell=row.createCell(11);
            cell.setCellValue(resultSet.getString("message"));
            cell=row.createCell(12);
            cell.setCellValue(resultSet.getString("active"));
            //
            i++;
        }
        FileOutputStream out = new FileOutputStream(
                new File("exceldatabase.xlsx"));
        workbook.write(out);
        out.close();
        // workbook.close();
        System.out.println(
                "exceldatabase.xlsx written successfully");

        {    
            try{

                File filetodelete = new File("C:/Test/COPY_DATABASE.db");

                if(filetodelete.delete()){
                    System.out.println(filetodelete.getName() + " is deleted!");
                }else{
                    System.out.println("Delete has failed.");

                }

            }catch(Exception e){

                e.printStackTrace();
            }
        }
    }
}
//} remove this