java实现查询某个表的数据导出excel

可以使用Apache POI库来实现将数据库中的数据导出成Excel文件。以下是一个简单的示例代码：

import java.io.FileOutputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

public class ExportToExcel {
   
    public static void main(String[] args) {
   
        String url = "jdbc:mysql://localhost:3306/database_name";
        String user = "username";
        String password = "password";
        String query = "SELECT * FROM table_name";

        try (Connection conn = DriverManager.getConnection(url, user, password);
             Statement stmt = conn.createStatement();
             ResultSet rs = stmt.executeQuery(query)) {
   

            Workbook workbook = new XSSFWorkbook();
            Sheet sheet = workbook.createSheet("Data");

            int rowNum = 0;
            Row headerRow = sheet.createRow(rowNum++);

            ResultSetMetaData metaData = rs.getMetaData();
            int columnCount = metaData.getColumnCount();

            for (int i = 1; i <= columnCount; i++) {
   
                Cell cell = headerRow.createCell(i - 1);
                cell.setCellValue(metaData.getColumnName(i));
            }

            while (rs.next()) {
   
                Row dataRow = sheet.createRow(rowNum++);

                for (int i = 1; i <= columnCount; i++) {
   
                    Cell cell = dataRow.createCell(i - 1);
                    cell.setCellValue(rs.getString(i));
                }
            }

            FileOutputStream outputStream = new FileOutputStream("data.xlsx");
            workbook.write(outputStream);
            workbook.close();

            System.out.println("Data exported successfully.");
        } catch (Exception e) {
   
            e.printStackTrace();
        }
    }
}

请替换url，user，password，query，database_name，table_name和输出文件名data.xlsx为你自己的数据库连接信息和表信息。

运行这段代码将会将指定表的数据导出成名为data.xlsx的Excel文件。