JAVA实现前台,后台,及复杂格式的excel导出功能

先附上大佬链接:https://blog.csdn.net/jiankang66/article/details/89040742
简单的单行表头可通过注解导出:
依赖

	<dependency>
			<groupId>org.apache.poi</groupId>
			<artifactId>poi</artifactId>
			<version>3.15-beta2</version>
		</dependency>
		<dependency>
			<groupId>org.apache.poi</groupId>
			<artifactId>poi-ooxml</artifactId>
			<version>3.15-beta2</version>
		</dependency>
		<dependency>
			<groupId>org.apache.poi</groupId>
			<artifactId>poi-ooxml-schemas</artifactId>
			<version>3.15-beta2</version>
		</dependency>

工具类(直接复制就行):

package com.utils.excel;

import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.Collections;
import java.util.Comparator;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.servlet.http.HttpServletResponse;

import org.apache.commons.lang3.StringUtils;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.CellStyle;
import org.apache.poi.ss.usermodel.Comment;
import org.apache.poi.ss.usermodel.DataFormat;
import org.apache.poi.ss.usermodel.Font;
import org.apache.poi.ss.usermodel.IndexedColors;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.ss.util.CellRangeAddress;
import org.apache.poi.xssf.streaming.SXSSFSheet;
import org.apache.poi.xssf.streaming.SXSSFWorkbook;
import org.apache.poi.xssf.usermodel.XSSFClientAnchor;
import org.apache.poi.xssf.usermodel.XSSFRichTextString;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.common.collect.Lists;

public class ExportExcel {

    private static Logger log = LoggerFactory.getLogger(ExportExcel.class);

    /**
     * 工作薄对象
     */
    private SXSSFWorkbook wb;

    /**
     * 工作表对象
     */
    private SXSSFSheet  sheet;

    /**
     * 样式列表
     */
    private Map<String, CellStyle> styles;

    /**
     * 当前行号
     */
    private int rownum;

    /**
     * 注解列表（Object[]{ ExcelField, Field/Method }）
     */
    List<Object[]> annotationList = Lists.newArrayList();

    /**
     * 构造函数
     * @param title 表格标题，传“空值”，表示无标题
     * @param cls 实体对象，通过annotation.ExportField获取标题
     */
    public ExportExcel(String title, Class<?> cls){
        this(title, cls, 1);
    }

    /**
     * 构造函数
     * @param title 表格标题，传“空值”，表示无标题
     * @param cls 实体对象，通过annotation.ExportField获取标题
     * @param type 导出类型（1:导出模板；2：导出数据）
     * @param groups 导入分组
     */
    public ExportExcel(String title, Class<?> cls, int type, int... groups){
        // Get annotation field
        Field[] fs = cls.getDeclaredFields();
        for (Field f : fs){
            //获取字段上加的@Excel注解
            ExcelField ef = f.getAnnotation(ExcelField.class);
            if (ef != null && (ef.type()==0 || ef.type()==type)){
                //根据字段注解中配置的groups进行分组
                if (groups!=null && groups.length>0){
                    boolean inGroup = false;
                    for (int g : groups){
                        if (inGroup){
                            break;
                        }
                        for (int efg : ef.groups()){
                            if (g == efg){
                                inGroup = true;
                                annotationList.add(new Object[]{ef, f});
                                break;
                            }
                        }
                    }
                }else{
                    //若无group属性，则直接将字段和对应的注解加入到一个全局的注解链表中，用于之后进行统一的排序
                    annotationList.add(new Object[]{ef, f});
                }
            }
        }
        // Get annotation method
        Method[] ms = cls.getDeclaredMethods();
        for (Method m : ms){
            //获取方法上的注解
            ExcelField ef = m.getAnnotation(ExcelField.class);
            if (ef != null && (ef.type()==0 || ef.type()==type)){
                if (groups!=null && groups.length>0){
                    boolean inGroup = false;
                    for (int g : groups){
                        if (inGroup){
                            break;
                        }
                        for (int efg : ef.groups()){
                            if (g == efg){
                                inGroup = true;
                                annotationList.add(new Object[]{ef, m});
                                break;
                            }
                        }
                    }
                }else{
                    annotationList.add(new Object[]{ef, m});
                }
            }
        }
        // 对字段进行排序 Field sorting
        Collections.sort(annotationList, new Comparator<Object[]>() {
            public int compare(Object[] o1, Object[] o2) {
                return new Integer(((ExcelField)o1[0]).sort()).compareTo(
                        new Integer(((ExcelField)o2[0]).sort()));
            };
        });
        // Initialize
        List<String> headerList = Lists.newArrayList();
        for (Object[] os : annotationList){
            //获取注解title属性值
            String t = ((ExcelField)os[0]).title();
            // 如果是导出，则去掉注释
            if (type==1){
                String[] ss = StringUtils.split(t, "**", 2);
                if (ss.length==2){
                    t = ss[0];
                }
            }
            //将字段名称保存在一个list中，交给初始化方法使用
            headerList.add(t);
        }
        initialize(title, headerList);
    }

    /**
     * 构造函数
     * @param title 表格标题，传“空值”，表示无标题
     * @param headers 表头数组
     */
    public ExportExcel(String title, String[] headers) {
        initialize(title, Lists.newArrayList(headers));
    }

    /**
     * 构造函数
     * @param title 表格标题，传“空值”，表示无标题
     * @param headerList 表头列表
     */
    public ExportExcel(String title, List<String> headerList) {
        initialize(title, headerList);
    }

    /**
     * 初始化函数
     * @param title 表格标题，传“空值”，表示无标题
     * @param headerList 表头列表
     */
    private void initialize(String title, List<String> headerList) {
        this.wb = new SXSSFWorkbook(500);
        this.sheet = wb.createSheet("Export");
        this.styles = createStyles(wb);
        this.sheet.trackAllColumnsForAutoSizing();
        // Create title
        if (StringUtils.isNotBlank(title)){
            Row titleRow = sheet.createRow(rownum++);
            titleRow.setHeightInPoints(30);
            Cell titleCell = titleRow.createCell(0);
            titleCell.setCellStyle(styles.get("title"));
            titleCell.setCellValue(title);
            sheet.addMergedRegion(new CellRangeAddress(titleRow.getRowNum(),
                    titleRow.getRowNum(), titleRow.getRowNum(), headerList.size()-1));
        }
        // Create header
        if (headerList == null){
            throw new RuntimeException("headerList not null!");
        }
        Row headerRow = sheet.createRow(rownum++);
        headerRow.setHeightInPoints(16);
        for (int i = 0; i < headerList.size(); i++) {
            Cell cell = headerRow.createCell(i);
            cell.setCellStyle(styles.get("header"));
            String[] ss = StringUtils.split(headerList.get(i), "**", 2);
            if (ss.length==2){
                cell.setCellValue(ss[0]);
                Comment comment = this.sheet.createDrawingPatriarch().createCellComment(
                        new XSSFClientAnchor(0, 0, 0, 0, (short) 3, 3, (short) 5, 6));
                comment.setString(new XSSFRichTextString(ss[1]));
                cell.setCellComment(comment);
            }else{
                cell.setCellValue(headerList.get(i));
            }
            sheet.autoSizeColumn(i);
        }
        for (int i = 0; i < headerList.size(); i++) {
            int colWidth = sheet.getColumnWidth(i)*2;
            sheet.setColumnWidth(i, colWidth < 3000 ? 3000 : colWidth);
        }
        log.debug("Initialize success.");
    }

    /**
     * 创建表格样式
     * @param wb 工作薄对象
     * @return 样式列表
     */
    private Map<String, CellStyle> createStyles(Workbook wb) {
        Map<String, CellStyle> styles = new HashMap<String, CellStyle>();

        CellStyle style = wb.createCellStyle();
        style.setAlignment(CellStyle.ALIGN_CENTER);
        style.setVerticalAlignment(CellStyle.VERTICAL_CENTER);
        Font titleFont = wb.createFont();
        titleFont.setFontName("Arial");
        titleFont.setFontHeightInPoints((short) 16);
        titleFont.setBoldweight(Font.BOLDWEIGHT_BOLD);
        style.setFont(titleFont);
        styles.put("title", style);

        style = wb.createCellStyle();
        style.setVerticalAlignment(CellStyle.VERTICAL_CENTER);
        style.setBorderRight(CellStyle.BORDER_THIN);
        style.setRightBorderColor(IndexedColors.GREY_50_PERCENT.getIndex());
        style.setBorderLeft(CellStyle.BORDER_THIN);
        style.setLeftBorderColor(IndexedColors.GREY_50_PERCENT.getIndex());
        style.setBorderTop(CellStyle.BORDER_THIN);
        style.setTopBorderColor(IndexedColors.GREY_50_PERCENT.getIndex());
        style.setBorderBottom(CellStyle.BORDER_THIN);
        style.setBottomBorderColor(IndexedColors.GREY_50_PERCENT.getIndex());
        Font dataFont = wb.createFont();
        dataFont.setFontName("Arial");
        dataFont.setFontHeightInPoints((short) 10);
        style.setFont(dataFont);
        styles.put("data", style);

        style = wb.createCellStyle();
        style.cloneStyleFrom(styles.get("data"));
        style.setAlignment(CellStyle.ALIGN_LEFT);
        styles.put("data1", style);

        style = wb.createCellStyle();
        style.cloneStyleFrom(styles.get("data"));
        style.setAlignment(CellStyle.ALIGN_CENTER);
        styles.put("data2", style);

        style = wb.createCellStyle();
        style.cloneStyleFrom(styles.get("data"));
        style.setAlignment(CellStyle.ALIGN_RIGHT);
        styles.put("data3", style);

        style = wb.createCellStyle();
        style.cloneStyleFrom(styles.get("data"));
//		style.setWrapText(true);
        style.setAlignment(CellStyle.ALIGN_CENTER);
        style.setFillForegroundColor(IndexedColors.GREY_50_PERCENT.getIndex());
        style.setFillPattern(CellStyle.SOLID_FOREGROUND);
        Font headerFont = wb.createFont();
        headerFont.setFontName("Arial");
        headerFont.setFontHeightInPoints((short) 10);
        headerFont.setBoldweight(Font.BOLDWEIGHT_BOLD);
        headerFont.setColor(IndexedColors.WHITE.getIndex());
        style.setFont(headerFont);
        styles.put("header", style);

        return styles;
    }

    /**
     * 添加一行
     * @return 行对象
     */
    public Row addRow(){
        return sheet.createRow(rownum++);
    }


    /**
     * 添加一个单元格
     * @param row 添加的行
     * @param column 添加列号
     * @param val 添加值
     * @return 单元格对象
     */
    public Cell addCell(Row row, int column, Object val){
        return this.addCell(row, column, val, 0, Class.class);
    }

    /**
     * 添加一个单元格
     * @param row 添加的行
     * @param column 添加列号
     * @param val 添加值
     * @param align 对齐方式（1：靠左；2：居中；3：靠右）
     * @return 单元格对象
     */
    public Cell addCell(Row row, int column, Object val, int align, Class<?> fieldType){
        Cell cell = row.createCell(column);
        CellStyle style = styles.get("data"+(align>=1&&align<=3?align:""));
        try {
            if (val == null){
                cell.setCellValue("");
            } else if (val instanceof String) {
                cell.setCellValue((String) val);
            } else if (val instanceof Integer) {
                cell.setCellValue((Integer) val);
            } else if (val instanceof Long) {
                cell.setCellValue((Long) val);
            } else if (val instanceof Double) {
                cell.setCellValue((Double) val);
            } else if (val instanceof Float) {
                cell.setCellValue((Float) val);
            } else if (val instanceof Date) {
                DataFormat format = wb.createDataFormat();
                style.setDataFormat(format.getFormat("yyyy-MM-dd"));
                cell.setCellValue((Date) val);
            } else {
                if (fieldType != Class.class){
                    cell.setCellValue((String)fieldType.getMethod("setValue", Object.class).invoke(null, val));
                }else{
                    cell.setCellValue((String)Class.forName(this.getClass().getName().replaceAll(this.getClass().getSimpleName(),
                            "fieldtype."+val.getClass().getSimpleName()+"Type")).getMethod("setValue", Object.class).invoke(null, val));
                }
            }
        } catch (Exception ex) {
            log.info("Set cell value ["+row.getRowNum()+","+column+"] error: " + ex.toString());
            cell.setCellValue(val.toString());
        }
        cell.setCellStyle(style);
        return cell;
    }

    /**
     * 添加数据（通过annotation.ExportField添加数据）
     * @return list 数据列表
     */
    public <E> ExportExcel setDataList(List<E> list){
        for (E e : list){
            int colunm = 0;
            Row row = this.addRow();
            StringBuilder sb = new StringBuilder();
            for (Object[] os : annotationList){
                ExcelField ef = (ExcelField)os[0];
                Object val = null;
                // Get entity value
                try{
                    if (StringUtils.isNotBlank(ef.value())){
                        val = Reflections.invokeGetter(e, ef.value());
                    }else{
                        if (os[1] instanceof Field){
                            val = Reflections.invokeGetter(e, ((Field)os[1]).getName());
                        }else if (os[1] instanceof Method){
                            val = Reflections.invokeMethod(e, ((Method)os[1]).getName(), new Class[] {}, new Object[] {});
                        }
                    }
                }catch(Exception ex) {
                    // Failure to ignore
                    log.info(ex.toString());
                    val = "";
                }
                this.addCell(row, colunm++, val, ef.align(), ef.fieldType());
                sb.append(val + ", ");
            }
            log.debug("Write success: ["+row.getRowNum()+"] "+sb.toString());
        }
        return this;
    }

    /**
     * 输出数据流
     * @param os 输出数据流
     */
    public ExportExcel write(OutputStream os) throws IOException{
        wb.write(os);
        return this;
    }

    /**
     * 输出到客户端
     * @param fileName 输出文件名
     */
    public ExportExcel write(HttpServletResponse response, String fileName) throws IOException{
        response.reset();
        response.setContentType("application/octet-stream; charset=utf-8");
        response.setHeader("Content-Disposition", "attachment; filename="+Encodes.urlEncode(fileName));
        write(response.getOutputStream());
        return this;
    }

    /**
     * 输出到文件
     * @param name 输出文件名
     */
    public ExportExcel writeFile(String name) throws FileNotFoundException, IOException{
        FileOutputStream os = new FileOutputStream(name);
        this.write(os);
        return this;
    }

    /**
     * 清理临时文件
     */
    public ExportExcel dispose(){
        wb.dispose();
        return this;
    }
}

定义注解的工具类,直接复制就行

package com.utils.excel;


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

/**
 * Excel注解定义
 */
@Target({ElementType.FIELD,ElementType.TYPE,ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
public @interface ExcelField {

    /**
     * 导出字段名（默认调用当前字段的“get”方法，如指定导出字段为对象，请填写“对象名.对象属性”，例：“area.name”、“office.name”）
     */
    String value() default "";

    /**
     * 导出字段标题（需要添加批注请用“**”分隔，标题**批注，仅对导出模板有效）
     */
    String title();

    /**
     * 字段类型（0：导出导入；1：仅导出；2：仅导入）
     */
    int type() default 0;

    /**
     * 导出字段对齐方式（0：自动；1：靠左；2：居中；3：靠右）
     */
    int align() default 0;

    /**
     * 导出字段字段排序（升序）
     */
    int sort() default 0;

    /**
     * 如果是字典类型，请设置字典的type值
     */
    String dictType() default "";

    /**
     * 反射类型
     */
    Class<?> fieldType() default Class.class;

    /**
     * 字段归属组（根据分组导出导入）
     */
    int[] groups() default {};
}

注解的使用,在实体类上加注解就行:

public class User{
    //主键
    private String id ;
    //姓名
    @ExcelField(title = "姓名", groups = 1, sort = 1)
    private String name ;
    //年龄
    @ExcelField(title = "年龄", groups = 1, sort = 2)
    private String  age;

	//  setter,getter... 必须要
	//  注解中 title是列名,sort是第几列
	}

Controller中调用:

    @RequestMapping("/user/exportExcel")
    @ResponseBody
    public void meanExportExcel(HttpServletResponse response, @RequestParam Map<String, Object> params) {
        List<User> users = userService.getUserAll;
        try {
            new ExportExcel("导出所有用户", User.class, 2).setDataList(users).write(response, "所有用户结果.xlsx").dispose();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }