jsp+servlet+poi導出數據庫中的數據

時間 2019-12-18

標籤 jsp+servlet+poi jsp servlet poi 導出數據庫數據欄目 JSP 简体版

原文原文鏈接

index.jsp:html

<a href="POIout">簡單導出數據</a>java

<a href="POIoutTemplate">根據模板導出數據</a>mysql

package com.wp.poi;

import java.sql.Connection;
import java.sql.DriverManager;
//鏈接數據庫類
public class DbUtil {

    private String dbUrl = "jdbc:mysql://localhost:3306/db_easyui";
    private String dbUserName = "root";
    private String dbPassword = "root";
    private String jdbcName = "com.mysql.jdbc.Driver";

    public Connection getCon() throws Exception {
        Class.forName(jdbcName);
        Connection con = DriverManager.getConnection(dbUrl, dbUserName,
                dbPassword);
        return con;
    }

    public void closeCon(Connection con) throws Exception {
        if (con != null) {
            con.close();
        }
    }
}

package com.wp.poi;

import java.io.IOException;
import java.io.OutputStream;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;

/**
 * 普通導出數據
 * 
 * @author admin
 * 
 */
public class POIout extends HttpServlet {

    public POIout() {
        super();
    }

    public void init() throws ServletException {
    }

    public void destroy() {
        super.destroy();
    }

    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        doPost(request, response);
    }

    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        response.setContentType("text/html;charset=utf-8");
        DbUtil dbUtil = new DbUtil();
        Connection conn = null;
        try {
            conn = dbUtil.getCon();// 得到數據庫鏈接
            Workbook wb = new HSSFWorkbook();
            String headers[] = { "編號", "姓名", "電話", "Email", "QQ" };// 標題
            ResultSet rs = userList(conn);// 獲得結果集
            fillExcelData(rs, wb, headers);
            export(response, wb, "導出數據.xls");
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                dbUtil.closeCon(conn);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

    /**
     * 查詢數據庫
     * 
     * @param con
     * @return ResultSet 返回結果集
     * @throws Exception
     */
    public ResultSet userList(Connection con) throws Exception {
        StringBuffer sb = new StringBuffer("select * from t_user");
        PreparedStatement pstmt = con.prepareStatement(sb.toString());
        return pstmt.executeQuery();
    }

    /**
     * 導出用戶
     * 
     * @throws Exception
     */
    public void fillExcelData(ResultSet rs, Workbook wb, String[] headers)
            throws Exception {
        int rowIndex = 0; // 第一行
        Sheet sheet = wb.createSheet(); // 建立sheet頁
        Row row = sheet.createRow(rowIndex++);
        // 建立標題
        for (int i = 0; i < headers.length; i++) {
            row.createCell(i).setCellValue(headers[i]);
        }
        // 導出數據庫中的數據
        while (rs.next()) {
            row = sheet.createRow(rowIndex++);
            for (int i = 0; i < headers.length; i++) {
                row.createCell(i).setCellValue(rs.getObject(i + 1).toString());
                //rs.getObject(i + 1)獲得一個對象，即數據庫中一行的結果，每一列就是屬性湊成一行變成對象。由於id是從1開始，因此要+1。
            }
        }
    }

    /**
     * 把數據放入到.xls文件中並下載到本地
     * 
     * @param response
     * @param wb
     * @param fileName
     * @throws Exception
     */
    public void export(HttpServletResponse response, Workbook wb,
            String fileName) throws Exception {
        response.setHeader("Content-Disposition", "attachment;filename="
                + new String(fileName.getBytes("utf-8"), "iso8859-1"));// 設置頭信息
        response.setContentType("application/ynd.ms-excel;charset=UTF-8");
        OutputStream out = response.getOutputStream();
        wb.write(out);// 進行輸出，下載到本地
        out.flush();
        out.close();
    }
}

package com.wp.poi;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.poifs.filesystem.POIFSFileSystem;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;

/**
 * 利用模板導出數據
 * 
 * @author admin
 * 
 */
public class POIoutTemplate extends HttpServlet {

    public POIoutTemplate() {
        super();
    }

    public void init() throws ServletException {
    }

    public void destroy() {
        super.destroy();
    }

    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        doPost(request, response);
    }

    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        response.setContentType("text/html;charset=utf-8");
        DbUtil dbUtil = new DbUtil();
        Connection conn = null;
        try {
            conn = dbUtil.getCon();
            Workbook wb = fillExcelDataWithTemplate(userList(conn),
                    "Template.xls");
            export(response, wb, "利用模板導出的數據.xls");
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                dbUtil.closeCon(conn);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

    /**
     * 查詢數據庫
     * 
     * @param con
     * @return
     * @throws Exception
     */
    public ResultSet userList(Connection con) throws Exception {
        StringBuffer sb = new StringBuffer("select * from t_user");
        PreparedStatement pstmt = con.prepareStatement(sb.toString());
        return pstmt.executeQuery();
    }

    /**
     * 根據模板導出用戶
     * 
     * @throws Exception
     */
    public Workbook fillExcelDataWithTemplate(ResultSet rs,
            String templateFileName) throws Exception {
        InputStream in = POIoutTemplate.class
                .getResourceAsStream("/com/wp/poi/" + templateFileName);
        POIFSFileSystem fs = new POIFSFileSystem(in);// 解析Excel文件
        Workbook wb = new HSSFWorkbook(fs);// 以解析的excel文件格式進行建立
        Sheet sheet = wb.getSheetAt(0);
        // 獲取列數
        int cellNums = sheet.getRow(0).getLastCellNum();

        int rowIndex = 1;// 從1開始的緣由，模板的第一行固定了，因此從下一行開始
        while (rs.next()) {
            Row row = sheet.createRow(rowIndex++);
            for (int i = 0; i < cellNums; i++) {
                row.createCell(i).setCellValue(rs.getObject(i + 1).toString());
            }
        }
        return wb;
    }

    /**
     * 導出
     * 
     * @param response
     * @param wb
     * @param fileName
     * @throws Exception
     */
    public static void export(HttpServletResponse response, Workbook wb,
            String fileName) throws Exception {
        response.setHeader("Content-Disposition", "attachment;filename="
                + new String(fileName.getBytes("utf-8"), "iso8859-1"));
        response.setContentType("application/ynd.ms-excel;charset=UTF-8");
        OutputStream out = response.getOutputStream();
        wb.write(out);
        out.flush();
        out.close();
    }
}