基于springBoot实现Excel的读写(基于模板，自定义样式的，基于注解的)

依赖

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.poi.eg</groupId>
    <artifactId>java-poi</artifactId>
    <version>1.0-SNAPSHOT</version>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.5.RELEASE</version>
        <relativePath/>
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
        <fastjson.version>1.2.47</fastjson.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-logging</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>${fastjson.version}</version>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.16.16</version>
        </dependency>
<!--    poi依赖-->
    <dependency>
        <groupId>org.apache.poi</groupId>
        <artifactId>poi</artifactId>
        <version>4.0.1</version>
    </dependency>
<!--    poi对于excel 2007的支持依赖-->
    <dependency>
        <groupId>org.apache.poi</groupId>
        <artifactId>poi-ooxml</artifactId>
        <version>4.0.1</version>
    </dependency>
    <!--    poi对于excel 2007的支持依赖-->
    <dependency>
        <groupId>org.apache.poi</groupId>
        <artifactId>poi-ooxml-schemas</artifactId>
        <version>4.0.1</version>
    </dependency>

</dependencies>
    <build>
        <plugins>
            <!--编译插件-->
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.1</version>
                <configuration>
                    <source>${java.version}</source>
                    <target>${java.version}</target>
                </configuration>
            </plugin>

            <!--单元测试插件-->
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-surefire-plugin</artifactId>
                <version>2.12.4</version>
                <configuration>
                    <skipTests>true</skipTests>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

Controller

package com.zhao.web;

import com.zhao.common.util.DownloadUtils;
import com.zhao.common.util.ExcelExportUtil;
import com.zhao.common.util.ExcelImportUtil;
import com.zhao.domain.User;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.Resource;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.http.HttpServletResponse;
import java.io.ByteArrayOutputStream;
import java.io.FileInputStream;
import java.io.IOException;
import java.time.LocalDate;
import java.util.ArrayList;
import java.util.List;

@RestController
public class controller {

    /**
     * 使用抽取的Excel的工具类进行导入 基于模板
     */
    @PostMapping("ExcelUtilImport")
    public void  ExcelUtilImport(@RequestParam(name = "file") MultipartFile file) throws Exception {
        List<User> list = new ExcelImportUtil(User.class).readExcel(file.getInputStream(), 1, 2);
        System.out.println(list);
    }




    /**
     * 使用抽取的Excel的工具类进行导出 基于模板
     */
    @GetMapping("ExcelUtilExport")
    public void  ExcelUtilExport(HttpServletResponse response) throws Exception {
        //1.获取数据
        //人为构造的数据，实际是要从数据库中查的
        List<User> users=new ArrayList<>();
        User user= new User();
        for (int i = 0; i <3 ; i++) {
            user.setName("洪真英");
            user.setPassword(123456);
            users.add(user);
        }

        //2.加载模板
        Resource resource = new ClassPathResource("template-Excel/exceltUtilTemplate.xlsx");
        FileInputStream fis = new FileInputStream(resource.getFile());

        //3.通过 工具类下载文件
        //因为内容样式和要写的内容都在下标2也就时excel中的第三行
        new ExcelExportUtil(User.class,2,2)
                /**
                 * 参数 1：HttpServletResponse
                 *      2：文件输入流
                 *      3：封装好的对象
                 *      4：文件名
                 */
        .export(response,fis,users,"反射的形式导出.xlsx");

    }



    /**
     * 采用 提前制作好的excel模板导出 数据
     */
    @GetMapping("exportTemplate")
    public void  exportTemplate(HttpServletResponse response) throws IOException {
        //1.获取数据
        //人为构造的数据，实际是要从数据库中查的
        List<User> users=new ArrayList<>();
        User user= new User();
        for (int i = 0; i <3 ; i++) {
            user.setName("洪真英");
            user.setPassword(123456);
            users.add(user);
        }

        //2.加载模板
        Resource resource = new ClassPathResource("template-Excel/exceltTemplate.xlsx");
        FileInputStream fis = new FileInputStream(resource.getFile());

        //3.根据模板创建工作簿
        Workbook wb = new XSSFWorkbook(fis);
        //4.读取工作表
        Sheet sheet = wb.getSheetAt(0);
        //5.抽取公共样式 , 因为前2行 为标题 第三行是数据 下标为2
        Row row = sheet.getRow(2);
        CellStyle styles[] = new CellStyle[row.getLastCellNum()];
        Cell cell = null;
        for (int i = 0; i < row.getLastCellNum(); i++) {
            cell = row.getCell(i);
            styles[i] = cell.getCellStyle();
        }
        //6.构造单元格
        int rowIndex=2;
        int indexNumber=1;
        for (User user1:users) {
            //创建每一行，同excel的第二行开始
            row=sheet.createRow(rowIndex++);
            //第一列
            cell = row.createCell(0);
            //设置单元格样式
            cell.setCellStyle(styles[0]);
            //写入数据 序号
            cell.setCellValue(indexNumber++);
            //第2列
            cell = row.createCell(1);
            cell.setCellStyle(styles[1]);
            cell.setCellValue(user1.getName());
            //第3列
            cell = row.createCell(2);
            cell.setCellStyle(styles[2]);
            cell.setCellValue(user1.getPassword());
            //第4列 自己乱加的一列时间 user对象中没有
            cell = row.createCell(3);
            cell.setCellStyle(styles[3]);
            cell.setCellValue(LocalDate.now().toString());
        }
        //7.下载
        ByteArrayOutputStream os=new ByteArrayOutputStream();
        wb.write(os);
        new DownloadUtils().download(os,response,"webExcel模板导出.xlsx");
    }
    /**
     * Excel 报表导出
     */
    @GetMapping("export")
    public void  export(HttpServletResponse response) throws IOException {
        //1.创建workbook工作簿
        Workbook wb = new XSSFWorkbook();
        //2.创建表单Sheet
        Sheet sheet = wb.createSheet("web");
        String[] title="序号，名字，密码".split("，"); //怎么创建数组都行
        //3.创建行对象，从0开始 ,创建标题
        Row row = sheet.createRow(0);
        //4.创建单元格，从0开始
        Cell cell = null;
       //标题
        /**   标题的第二种实现
         *    for (int i = 0; i < title.length; i++) {
         *             //4.创建单元格，从0开始
         *             row.createCell(i);
         *             //5.单元格写入数据
         *             cell.setCellValue(title[i]);
         *         }
         */
        int indexTitle=0;
        for (String s : title) {
            //4.创建单元格，从0开始
            cell = row.createCell(indexTitle++);
            //5.单元格写入数据
            cell.setCellValue(s);
        }

        //人为构造的数据，实际是要从数据库中查的
        List<User> users=new ArrayList<>();
         User user= new User();
        for (int i = 0; i <3 ; i++) {
            user.setName("洪真英");
            user.setPassword(123456);
            users.add(user);
        }

        int indexContext=1;
        int index=1;
        //内容
        for (User user1:users) {
            //创建每一行，同excel的第二行开始
            row=sheet.createRow(indexContext++);
            //第一列
            cell = row.createCell(0);
            //写入数据 序号
            cell.setCellValue(index++);
            //第2列
            cell = row.createCell(1);
            cell.setCellValue(user1.getName());
            //第2列
            cell = row.createCell(2);
            cell.setCellValue(user1.getPassword());
        }
        ByteArrayOutputStream os=new ByteArrayOutputStream();
        wb.write(os);
        new DownloadUtils().download(os,response,"webExcel导出.xlsx");

    }



    /**
     * excel 文件上传
     * postman 上传文件 操作指南https://jingyan.baidu.com/article/425e69e614f472be14fc166f.html
     */
    @PostMapping("upload")
    public String upload(@RequestParam(name = "file") MultipartFile file) throws IOException {
        //1.解析Excel
        //1.1.根据Excel文件创建工作簿
        Workbook wb = new XSSFWorkbook(file.getInputStream());
        //1.2.获取Sheet
        Sheet sheet = wb.getSheetAt(0);//参数：索引
        //1.3.获取Sheet中的每一行，和每一个单元格
        //2.获取用户数据列表
        List<User> list = new ArrayList<>();
        System.out.println("最后一行的下标 :" + sheet.getLastRowNum());
        for (int rowNum = 1; rowNum <= sheet.getLastRowNum(); rowNum++) {
            Row row = sheet.getRow(rowNum);//根据索引获取每一个行
//            System.out.println("列数"+row.getLastCellNum());
            Object[] values = new Object[row.getLastCellNum()];
            for (int cellNum = 1; cellNum < row.getLastCellNum(); cellNum++) {
                Cell cell = row.getCell(cellNum);
                Object value = getCellValue(cell);
                values[cellNum] = value;
            }
            User user = new User(values);
            list.add(user);
        }
        //3.批量保存用户
//        userService.saveAll(list,companyId,companyName);

        return "SUCCESS";
    }

    public static Object getCellValue(Cell cell) {
        //1.获取到单元格的属性类型
        CellType cellType = cell.getCellType();
        //2.根据单元格数据类型获取数据
        Object value = null;
        switch (cellType) {
            case STRING:
                value = cell.getStringCellValue();
                break;
            case BOOLEAN:
                value = cell.getBooleanCellValue();
                break;
            case NUMERIC:
                if (DateUtil.isCellDateFormatted(cell)) {
                    //日期格式
                    value = cell.getDateCellValue();
                } else {
                    //数字
                    value = cell.getNumericCellValue();
                }
                break;
            case FORMULA: //公式
                value = cell.getCellFormula();
                break;
            default:
                break;
        }
        return value;
    }
}

实体类

package com.zhao.domain;

import com.zhao.common.util.ExcelAttribute;
import com.zhao.common.util.ExcelImportAnnotation;
import lombok.Data;
import lombok.NoArgsConstructor;

import java.text.DecimalFormat;

@Data
@NoArgsConstructor
public class User {
    @ExcelAttribute(sort = 0)
    @ExcelImportAnnotation(sort = 2)
    private  String name;
    @ExcelAttribute(sort = 1)
    @ExcelImportAnnotation(sort = 3)
    private  Integer password;

    public User(Object[] args){
        /** DecimalFormat 用法
         * https://www.jianshu.com/p/b3699d73142e
         * Integer.valueOf 返回的时包装类  Integer.parseInt() 返回的是int
         */
        //因为传进来的args 的赋值是从1开始的
        this.name=args[1].toString();   //new DecimalFormat("#").format(args[2]).toString();
        //因为从Excel中读取的数字是double类型的 所以不能用 Integer.valueOf
        this.password=new Double(args[2].toString()).intValue();
    }

}

下载工具类

package com.zhao.common.util;


import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.ByteArrayOutputStream;
import java.io.IOException;

/**
 * 用于 Excel下载的工具类
 */
public class DownloadUtils {
    /**
     *
     * @param byteArrayOutputStream 输出字节流
     * @param response
     * @param returnName 输出到客户端的文件名
     * @throws IOException
     */
    public   void download(ByteArrayOutputStream byteArrayOutputStream, HttpServletResponse response, String returnName) throws IOException {
        response.setContentType("application/octet-stream");
        returnName = response.encodeURL(new String(returnName.getBytes(),"iso8859-1"));            //保存的文件名,必须和页面编码一致,否则乱码
//        response.addHeader("Content-Disposition","attachment;filename=total.xls");
        response.addHeader("Content-Disposition","attachment;filename="+returnName);
        response.setContentLength(byteArrayOutputStream.size());
        response.addHeader("Content-Length", "" + byteArrayOutputStream.size());
        ServletOutputStream outputStream = response.getOutputStream();    //取得输出流
        byteArrayOutputStream.writeTo(outputStream);                    //写到输出流
        byteArrayOutputStream.close();                                    //关闭
        outputStream.flush();                                            //刷数据
    }
}

导出注解

package com.zhao.common.util;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

/**
 * 定义到 对象中的属性的 标致它导出Excel'时的列位置
 */
//运行时注解
@Retention(RetentionPolicy.RUNTIME)
//属性注解
@Target(ElementType.FIELD)
public @interface ExcelAttribute {
    /** 对应的列名称 */
    String name() default "";

    /** 列序号
     * 属性 上short=0  在excel导出时他就是第一列
     * */
    int sort();

    /** 字段类型对应的格式 */
    String format() default "";

}

导入注解

package com.zhao.common.util;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

/**
 * 定义到 对象中的属性的 标致它导入Excel'时的列位置
 */
//运行时注解
@Retention(RetentionPolicy.RUNTIME)
//属性注解
@Target(ElementType.FIELD)
public @interface ExcelImportAnnotation {
    /** 对应的列名称 */
    String name() default "";

    /** 列序号
     * 属性 上short=0  在excel导入时他就是第一列
     * */
    int sort();

    /** 字段类型对应的格式 */
    String format() default "";

}

导出工具类

package com.zhao.common.util;


import lombok.Getter;
import lombok.Setter;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import javax.servlet.http.HttpServletResponse;
import java.io.InputStream;
import java.lang.reflect.Field;
import java.net.URLEncoder;
import java.util.List;
import java.util.concurrent.atomic.AtomicInteger;

/**
 * 导出Excel工具类
 *      基于模板打印的方式导出：
 */
@Getter
@Setter
public class ExcelExportUtil<T> {

    private int rowIndex;       //写入数据的起始行
    private int styleIndex;     //需要提取的样式所在的行号
    private Class clazz;        //对象的字节码
    private Field fields[];     //对象中的所有属性

    public ExcelExportUtil(Class clazz,int rowIndex,int styleIndex) {
        this.clazz = clazz;
        this.rowIndex = rowIndex;
        this.styleIndex = styleIndex;
        fields = clazz.getDeclaredFields();
    }

    /**
     * 基于注解导出
             参数：
                response：
                InputStream:模板的输入流
                objs：数据
                fileName：生成的文件名
     *
     */
    public void export(HttpServletResponse response,InputStream is, List<T> objs,String fileName) throws Exception {

        //1.根据模板创建工作簿
        XSSFWorkbook workbook = new XSSFWorkbook(is);
        //2.读取工作表
        Sheet sheet = workbook.getSheetAt(0);
        //3.提取公共的样式
        CellStyle[] styles = getTemplateStyles(sheet.getRow(styleIndex));
        //4.根据数据创建每一行和每一个单元格的数据2
        AtomicInteger datasAi = new AtomicInteger(rowIndex); //数字
        for (T t : objs) {
            //datasAi.getAndIncrement()  ：获取数字，并++    i++
            Row row = sheet.createRow(datasAi.getAndIncrement());
            for(int i=0;i<styles.length;i++) {
                Cell cell = row.createCell(i);
                cell.setCellStyle(styles[i]);
                for (Field field : fields) {
                    if(field.isAnnotationPresent(ExcelAttribute.class)){
                        field.setAccessible(true);
                        ExcelAttribute ea = field.getAnnotation(ExcelAttribute.class);
                        //如果当前i的值和 属性上注解的 sort值一致就反射调用它的get方法,也就时 当 i=0时就会找属性上注解为0的属性值写入其值
                        if(i == ea.sort()) {
                            if(field.get(t) != null) {
                                cell.setCellValue(field.get(t).toString());
                            }
                        }
                    }
                }

            }
        }
        fileName = URLEncoder.encode(fileName, "UTF-8");
        response.setContentType("application/octet-stream");
        response.setHeader("content-disposition", "attachment;filename=" + new String(fileName.getBytes("ISO8859-1")));
        response.setHeader("filename", fileName);
        workbook.write(response.getOutputStream());
    }

    public CellStyle[] getTemplateStyles(Row row) {
        CellStyle [] styles = new CellStyle[row.getLastCellNum()];
        for(int i=0;i<row.getLastCellNum();i++) {
            styles[i] = row.getCell(i).getCellStyle();
        }
        return styles;
    }
}

导入工具类

package com.zhao.common.util;

import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.DateUtil;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import java.io.InputStream;
import java.lang.reflect.Field;
import java.math.BigDecimal;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;

/**
 *  Excel 的导入工具类
 *  ExcelImportAnnotation 导入注解
 * @param <T>
 */
public class ExcelImportUtil<T> {
 
    private Class clazz;
    private  Field fields[];
    /** 传入你希望构建的队象*/
    public ExcelImportUtil(Class clazz) {
        this.clazz = clazz;
        fields = clazz.getDeclaredFields();
    }

    /**
     * 基于注解读取excel
     * @param is  文件上传的流信息
     * @param rowIndex  读取数据的起始行
     * @param cellIndex   读取数据的起始单元格位置
     * @return
     */
    public List<T> readExcel(InputStream is, int rowIndex,int cellIndex) {
        List<T> list = new ArrayList<T>();
        T entity = null;
        try {
            XSSFWorkbook workbook = new XSSFWorkbook(is);
            Sheet sheet = workbook.getSheetAt(0);
            // 不准确
            int rowLength = sheet.getLastRowNum();

            System.out.println("一共 "+(sheet.getLastRowNum()+1)+" 行");
            for (int rowNum = rowIndex; rowNum <= sheet.getLastRowNum(); rowNum++) {
                Row row = sheet.getRow(rowNum);
                entity = (T) clazz.newInstance();
                System.out.println("一共 "+row.getLastCellNum()+" 列");
                for (int j = cellIndex; j < row.getLastCellNum(); j++) {
                    Cell cell = row.getCell(j);
                    for (Field field : fields) {
                        if(field.isAnnotationPresent(ExcelImportAnnotation.class)){
                            field.setAccessible(true);
                            ExcelImportAnnotation ea = field.getAnnotation(ExcelImportAnnotation.class);
                            if(j == ea.sort()) {
                                field.set(entity, covertAttrType(field, cell));
                            }
                        }
                    }
                }
                list.add(entity);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return list;
    }
 

    /**
     * 类型转换 将cell 单元格格式转为 字段类型
     */
    private Object covertAttrType(Field field, Cell cell) throws Exception {
//        System.out.println(field.getType());
        String fieldType = field.getType().getSimpleName();
        if ("String".equals(fieldType)) {
            return getValue(cell);
        }else if ("Date".equals(fieldType)) {
            return new SimpleDateFormat("yyyy-MM-dd hh:mm:ss").parse(getValue(cell)) ;
        }else if ("int".equals(fieldType) || "Integer".equals(fieldType)) {
            return Integer.parseInt(getValue(cell));
        }else if ("double".equals(fieldType) || "Double".equals(fieldType)) {
            return Double.parseDouble(getValue(cell));
        }else {
            return null;
        }
    }
 
 
    /**
     * 格式转为String
     * @param cell
     * @return
     */
    public String getValue(Cell cell) {
        if (cell == null) {
            return "";
        }
        switch (cell.getCellType()) {
            case STRING:
                return cell.getRichStringCellValue().getString().trim();
            case NUMERIC:
                if (DateUtil.isCellDateFormatted(cell)) {
                    Date dt = DateUtil.getJavaDate(cell.getNumericCellValue());
                    return new SimpleDateFormat("yyyy-MM-dd hh:mm:ss").format(dt);
                } else {
                    // 防止数值变成科学计数法
                    String strCell = "";
                    Double num = cell.getNumericCellValue();
                    BigDecimal bd = new BigDecimal(num.toString());
                    if (bd != null) {
                        strCell = bd.toPlainString();
                    }
                    // 去除 浮点型 自动加的 .0
                    if (strCell.endsWith(".0")) {
                        strCell = strCell.substring(0, strCell.indexOf("."));
                    }
                    return strCell;
                }
            case BOOLEAN:
                return String.valueOf(cell.getBooleanCellValue());
            default:
                return "";
        }
    }
}

 项目地址：https://gitee.com/richOne/java_poi_operation_example