Apache POI和文件删除类
我的课程需要一个数据库并复制一份。 然后运行Apache POI并将值提取到Excel表格中。 然后删除复制的文件。 我有这两个作为独立的类，但现在，我把它们缝在一起我得到一个错误，它似乎不喜欢公共类public class ExportToExcel { 。
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)
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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