import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
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;

public class writeDataToExcel {
	public static void main(String[] args) {
		writerExcel(getListUser());
	}

	public static void writerExcel(List<User> listUser) {
		// POI操作Excle 所有的类都以HSSF作为前缀
		// 创建文档对象
		HSSFWorkbook workBook = new HSSFWorkbook();
		// 创建工作单元
		HSSFSheet sheet = workBook.createSheet("用户信息");
		// 创建行
		HSSFRow row = sheet.createRow(0);
		// 创建单元格
		HSSFCell cl0 = row.createCell(0);
		HSSFCell cl1 = row.createCell(1);
		HSSFCell cl2 = row.createCell(2);

		// 往单元格中放数据
		cl0.setCellValue("学号");
		cl1.setCellValue("姓名");
		cl2.setCellValue("密码");

		// 循环users集合 给每个UserInfo创建新行 并赋值；
		for (int i = 1; i <= listUser.size(); i++) {
			HSSFRow newRow = sheet.createRow(i);
			HSSFCell cl_1 = newRow.createCell(1);
			User usInfo = listUser.get(i - 1);
			cl_1.setCellValue(usInfo.getName());
		}

		FileOutputStream output = null;
		// 输出流
		try {
			output = new FileOutputStream(new File("c:\\user.xls"));
			// 将文档对象写入输出流
			workBook.write(output);
			// 刷新缓冲区
			output.flush();
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		} finally {
			if (null != output) {
				try {
					output.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
		}
	}

	public static List<User> getListUser() {
		Connection conn = null;
		String url = "jdbc:oracle:thin:@localhost:1521:orcl";
		String user = "system";
		String password = "orcl";
		String sql = "select * from scott.emp";
		ResultSet rs = null;
		Statement sm = null;
		List<User> listUser = new ArrayList<User>();
		try {
			Class.forName("oracle.jdbc.driver.OracleDriver");
			conn = DriverManager.getConnection(url, user, password);
			sm = conn.createStatement();
			rs = sm.executeQuery(sql);
			while (rs.next()) {
				User userClass = new User();
				userClass.setName(rs.getString("ENAME"));
				listUser.add(userClass);
			}
		} catch (ClassNotFoundException e) {
			e.printStackTrace();
		} catch (SQLException e) {
			e.printStackTrace();
		} finally {
			try {
				if (rs != null) {
					rs.close();
				}
			} catch (SQLException e) {
				e.printStackTrace();
			}
			try {
				if (conn != null) {
					conn.close();
				}
			} catch (SQLException e) {
				e.printStackTrace();
			}
		}
		return listUser;
	}
}

class User {
	private String name;

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}
}

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