Java基于注解的Excel导出方式
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Java注解的Excel导出
依赖：
<dependency>
<groupId>cn.afterturn</groupId>
<artifactId>easypoi-base</artifactId>
<version>4.1.2</version>
</dependency>
<dependency>
<groupId>cn.afterturn</groupId>
<artifactId>easypoi-web</artifactId>
<version>4.1.2</version>
</dependency>
<dependency>
<groupId>cn.afterturn</groupId>
<artifactId>easypoi-annotation</artifactId>
<version>4.1.2</version>
</dependency>注解配合工具类做了个小工具如下:
第一步：自定义注解:（读者请直接复制）
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.FIELD)
public @interface Excel {
public String name();
public String dateFormat() default "";
public String readConverterExp() default "";
public double height() default 14;
public double width() default 20;
public String suffix() default "";
public String defaultValue() default "";
public String prompt() default "";
public String[] combo() default {};
public boolean isExport() default true;
}第二步：实体类:（为每个需要的字段打上@Excel注解）
import java.time.LocalDateTime;
import com.ciih.authcenter.client.util.excel.Excel;
import io.swagger.annotations.ApiModelProperty;
import lombok.Data;
import lombok.EqualsAndHashCode;
@SuppressWarnings("serial")
@EqualsAndHashCode(callSuper = true)
@Data
public class User {
@Excel(name = "编号")
@ApiModelProperty(value = "主键")
private String id;
@Excel(name = "账号")
@ApiModelProperty(value = "账号")
private String loginName;
@Excel(name = "用户名")
@ApiModelProperty(value = "用户名")
private String userName;
@ApiModelProperty(value = "用户名拼音")
private String namePinyin;
@Excel(name = "性别", readConverterExp = "1=男,0=女")
@ApiModelProperty(value = "性别")
private String gender;
@Excel(name = "证件类型",readConverterExp="1=居民身份证,2=香港居民来往内地通行证,3=澳门居民来往内地通行证,4=台湾居民来往大陆通行证,6=护照")
@ApiModelProperty(value = "证件类型")
private String credType;
@Excel(name = "证件号码")
@ApiModelProperty(value = "证件号码")
private String credNum;
@ApiModelProperty(value = "机构id")
private String orgId;
@Excel(name = "机构名称")
@ApiModelProperty(value = "机构名称")
private String orgName;
@Excel(name = "电话")
@ApiModelProperty(value = "电话")
private String phone;
@Excel(name = "邮箱")
@ApiModelProperty(value = "邮箱")
private String email;
@Excel(name = "人员类型",readConverterExp = "student=学生,teacher=教师,parent=家长,system=系统人员,developers=开发者,manager=管理员")
@ApiModelProperty(value = "人员类型")
private String personType;
@Excel(name = "应用系统角色编码")
@ApiModelProperty(value = "应用系统角色编码")
private String appRoleCode;
@ApiModelProperty(value = "创建时间")
private LocalDateTime createTime;
@ApiModelProperty(value = "更新时间")
private LocalDateTime updateTime;
}第三步：解析工具类:（读者请直接复制）
import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.Field;
import java.net.URLEncoder;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.lang3.StringUtils;
import org.apache.poi.hssf.usermodel.DVConstraint;
import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFCellStyle;
import org.apache.poi.hssf.usermodel.HSSFDataValidation;
import org.apache.poi.hssf.usermodel.HSSFFont;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.CellType;
import org.apache.poi.ss.usermodel.HorizontalAlignment;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.VerticalAlignment;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.ss.usermodel.WorkbookFactory;
import org.apache.poi.ss.util.CellRangeAddressList;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class ExcelUtil<T> {
private static final Logger log = LoggerFactory.getLogger(ExcelUtil.class);
private Class<T> clazz;
public ExcelUtil(Class<T> clazz) {
this.clazz = clazz;
}
public List<T> importExcel(InputStream input) throws Exception {
return importExcel(StringUtils.EMPTY, input);
}
public List<T> importExcel(String sheetName, InputStream input) throws Exception {
List<T> list = new ArrayList<T>();
Workbook workbook = WorkbookFactory.create(input);
Sheet sheet = null;
if (StringUtils.isNotEmpty(sheetName)) {
// 如果指定sheet名,则取指定sheet中的内容.
sheet = workbook.getSheet(sheetName);
} else {
// 如果传入的sheet名不存在则默认指向第1个sheet.
sheet = workbook.getSheetAt(0);
}
if (sheet == null) {
throw new IOException("文件sheet不存在");
}
int rows = sheet.getPhysicalNumberOfRows();
if (rows > 0) {
// 默认序号
// int serialNum = 0;
// 有数据时才处理 得到类的所有field.
Field[] allFields = clazz.getDeclaredFields();
// 定义一个map用于存放列的序号和field.
Map<Integer, Field> fieldsMap = new HashMap<Integer, Field>();
//定义一个name到Excel表的index的映射Map
HashMap<String, Integer> name2index = new HashMap<>();
//默认第一行是表头
Row r = sheet.getRow(0);
for (int i = 0; i < allFields.length; i++) {
Cell cell = r.getCell(i);
if (cell == null) {
continue;
} else {
// 先设置Cell的类型，然后就可以把纯数字作为String类型读进来了
r.getCell(i).setCellType(CellType.STRING);
cell = r.getCell(i);
String c = cell.getStringCellValue();
if (StringUtils.isEmpty(c)) {
continue;
}
name2index.put(c, i);
}
}
for (int col = 0; col < allFields.length; col++) {
Field field = allFields[col];
// 将有注解的field存放到map中.
if (field.isAnnotationPresent(Excel.class)) {
Excel excel = field.getAnnotation(Excel.class);
String name = excel.name();
Integer index = name2index.get(name);
if (index != null) {
field.setAccessible(true);
fieldsMap.put(index, field);
}
}
}
//下面这个是按序号一一对应的。不太友好，还是按照表头名称来对应
// for (int col = 0; col < allFields.length; col++) {
// Field field = allFields[col];
// // 将有注解的field存放到map中.
// if (field.isAnnotationPresent(Excel.class)) {
// // 设置类的私有字段属性可访问.
// field.setAccessible(true);
// fieldsMap.put(++serialNum, field);
// }
// }
for (int i = 1; i < rows; i++) {
// 从第2行开始取数据,默认第一行是表头.
Row row = sheet.getRow(i);
int cellNum = allFields.length;
T entity = null;
for (int j = 0; j < cellNum; j++) {
Cell cell = row.getCell(j);
if (cell == null) {
continue;
} else {
// 先设置Cell的类型，然后就可以把纯数字作为String类型读进来了
row.getCell(j).setCellType(CellType.STRING);
cell = row.getCell(j);
}
String c = cell.getStringCellValue();
if (StringUtils.isEmpty(c)) {
continue;
}
// 如果不存在实例则新建.
entity = (entity == null ? clazz.newInstance() : entity);
// 从map中得到对应列的field.
Field field = fieldsMap.get(j);
// 取得类型,并根据对象类型设置值.
Class<?> fieldType = field.getType();
if (String.class == fieldType) {
field.set(entity, String.valueOf(c));
} else if ((Integer.TYPE == fieldType) || (Integer.class == fieldType)) {
field.set(entity, Integer.parseInt(c));
} else if ((Long.TYPE == fieldType) || (Long.class == fieldType)) {
field.set(entity, Long.valueOf(c));
} else if ((Float.TYPE == fieldType) || (Float.class == fieldType)) {
field.set(entity, Float.valueOf(c));
} else if ((Short.TYPE == fieldType) || (Short.class == fieldType)) {
field.set(entity, Short.valueOf(c));
} else if ((Double.TYPE == fieldType) || (Double.class == fieldType)) {
field.set(entity, Double.valueOf(c));
} else if (Character.TYPE == fieldType) {
if ((c != null) && (c.length() > 0)) {
field.set(entity, Character.valueOf(c.charAt(0)));
}
} else if (Date.class == fieldType) {
//对字符串解析成日期
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
String s = cell.getStringCellValue()
.replaceAll("/", "-")
.replaceAll("上午", "")
.replaceAll("下午", "")
.replaceAll(" ", " ");
System.out.println("----------------------------:" + s);
Date parse = sdf.parse(s);
field.set(entity, parse);
// if (cell.getCellTypeEnum() == CellType.NUMERIC) {
// SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
// cell.setCellValue(sdf.format(cell.getNumericCellValue()));
// c = sdf.format(cell.getNumericCellValue());
// } else {
// c = cell.getStringCellValue();
// }
} else if (java.math.BigDecimal.class == fieldType) {
c = cell.getStringCellValue();
}
}
if (entity != null) {
list.add(entity);
}
}
}
return list;
}
public static void exportMapExcel(List<Map> list, String[] title, String sheetName, HttpServletResponse response) {
if (null == list || list.size() == 0) {
return;
}
HSSFWorkbook workbook = null;
try {
// 产生工作薄对象
workbook = new HSSFWorkbook();
// excel2003中每个sheet中最多有65536行
int sheetSize = 65536;
// 取出一共有多少个sheet.
double sheetNo = Math.ceil(list.size() / sheetSize);
for (int index = 0; index <= sheetNo; index++) {
// 产生工作表对象
HSSFSheet sheet = workbook.createSheet();
if (sheetNo == 0) {
workbook.setSheetName(index, sheetName);
} else {
// 设置工作表的名称.
workbook.setSheetName(index, sheetName + index);
}
HSSFRow row;
HSSFCell cell; // 产生单元格
// 产生第一行，写入标题
row = sheet.createRow(0);
if (null == title || title.length == 0) {
throw new RuntimeException("导出错误");
}
for (int i = 0; i < title.length; i++) {
cell = row.createCell(i);
cell.setCellType(CellType.STRING);
cell.setCellValue(title[i]);
}
int cell_idx = 0;
int startNo = index * sheetSize;
int endNo = Math.min(startNo + sheetSize, list.size());
// 写入各条记录,每条记录对应excel表中的一行
for (int i = startNo; i < endNo; i++) {
row = sheet.createRow(i + 1 - startNo);
// 得到导出对象.
Map map = list.get(i);
Set keySet = map.keySet();
Iterator values = keySet.iterator();
cell_idx = 0;
while (values.hasNext()) {
Object value = map.get(values.next());
cell = row.createCell(cell_idx);
cell.setCellValue(value.toString());
cell_idx++;
}
}
}
//String filename = encodingFilename(sheetName);
response.setHeader("content-Type", "application/vnd.ms-excel");
response.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(sheetName, "UTF-8"));
// response.setContentType("application/octet-stream");
// response.setHeader("Content-disposition", "attachment;filename=" + URLEncoder.encode(filename, "UTF-8"));
response.flushBuffer();
workbook.write(response.getOutputStream());
//return filename;
} catch (Exception e) {
log.error("导出Excel异常{}", e.getMessage());
throw new RuntimeException("导出Excel失败，请联系网站管理员！");
} finally {
if (workbook != null) {
try {
workbook.close();
} catch (IOException e1) {
e1.printStackTrace();
}
}
}
}
public void exportExcel(List<?> list, String sheetName, HttpServletResponse response) {
HSSFWorkbook workbook = null;
try {
// 得到所有定义字段
Field[] allFields = clazz.getDeclaredFields();
List<Field> fields = new ArrayList<Field>();
// 得到所有field并存放到一个list中.
for (Field field : allFields) {
if (field.isAnnotationPresent(Excel.class)) {
fields.add(field);
}
}
// 产生工作薄对象
workbook = new HSSFWorkbook();
// excel2003中每个sheet中最多有65536行
int sheetSize = 65536;
// 取出一共有多少个sheet.
double sheetNo = Math.ceil(list.size() / sheetSize);
for (int index = 0; index <= sheetNo; index++) {
// 产生工作表对象
HSSFSheet sheet = workbook.createSheet();
if (sheetNo == 0) {
workbook.setSheetName(index, sheetName);
} else {
// 设置工作表的名称.
workbook.setSheetName(index, sheetName + index);
}
HSSFRow row;
HSSFCell cell; // 产生单元格
// 产生一行
row = sheet.createRow(0);
// 写入各个字段的列头名称
for (int i = 0; i < fields.size(); i++) {
Field field = fields.get(i);
Excel attr = field.getAnnotation(Excel.class);
// 创建列
cell = row.createCell(i);
// 设置列中写入内容为String类型
cell.setCellType(CellType.STRING);
HSSFCellStyle cellStyle = workbook.createCellStyle();
cellStyle.setAlignment(HorizontalAlignment.CENTER);
cellStyle.setVerticalAlignment(VerticalAlignment.CENTER);
if (attr.name().indexOf("注：") >= 0) {
HSSFFont font = workbook.createFont();
font.setColor(HSSFFont.COLOR_RED);
// cellStyle.setFont(font);
//设置颜色
// cellStyle.setFillForegroundColor(HSSFColor.HSSFColorPredefined.YELLOW.getIndex());
sheet.setColumnWidth(i, 6000);
} else {
HSSFFont font = workbook.createFont();
// 粗体显示
font.setBold(true);
// 选择需要用到的字体格式
// cellStyle.setFont(font);
//设置颜色
// cellStyle.setFillForegroundColor(HSSFColor.HSSFColorPredefined.LIGHT_YELLOW.getIndex());
// 设置列宽
sheet.setColumnWidth(i, (int) ((attr.width() + 0.72) * 256));
row.setHeight((short) (attr.height() * 20));
}
// cellStyle.setFillPattern(FillPatternType.SOLID_FOREGROUND);
// cellStyle.setWrapText(true);
cell.setCellStyle(cellStyle);
// 写入列名
cell.setCellValue(attr.name());
// 如果设置了提示信息则鼠标放上去提示.
if (StringUtils.isNotEmpty(attr.prompt())) {
// 这里默认设了2-101列提示.
setHSSFPrompt(sheet, "", attr.prompt(), 1, 100, i, i);
}
// 如果设置了combo属性则本列只能选择不能输入
if (attr.combo().length > 0) {
// 这里默认设了2-101列只能选择不能输入.
setHSSFValidation(sheet, attr.combo(), 1, 100, i, i);
}
}
int startNo = index * sheetSize;
int endNo = Math.min(startNo + sheetSize, list.size());
// 写入各条记录,每条记录对应excel表中的一行
HSSFCellStyle cs = workbook.createCellStyle();
cs.setAlignment(HorizontalAlignment.CENTER);
cs.setVerticalAlignment(VerticalAlignment.CENTER);
for (int i = startNo; i < endNo; i++) {
row = sheet.createRow(i + 1 - startNo);
// 得到导出对象.
T vo = (T) list.get(i);
for (int j = 0; j < fields.size(); j++) {
// 获得field.
Field field = fields.get(j);
// 设置实体类私有属性可访问
field.setAccessible(true);
Excel attr = field.getAnnotation(Excel.class);
try {
// 设置行高
row.setHeight((short) (attr.height() * 20));
// 根据Excel中设置情况决定是否导出,有些情况需要保持为空,希望用户填写这一列.
if (attr.isExport()) {
// 创建cell
cell = row.createCell(j);
cell.setCellStyle(cs);
if (vo == null) {
// 如果数据存在就填入,不存在填入空格.
cell.setCellValue("");
continue;
}
String dateFormat = attr.dateFormat();
String readConverterExp = attr.readConverterExp();
if (StringUtils.isNotEmpty(dateFormat)) {
cell.setCellValue(new SimpleDateFormat(dateFormat).format((Date) field.get(vo)));
} else if (StringUtils.isNotEmpty(readConverterExp)) {
cell.setCellValue(convertByExp(String.valueOf(field.get(vo)), readConverterExp));
} else {
cell.setCellType(CellType.STRING);
// 如果数据存在就填入,不存在填入空格.
cell.setCellValue(field.get(vo) == null ? attr.defaultValue() : field.get(vo) + attr.suffix());
}
}
} catch (Exception e) {
log.error("导出Excel失败{}", e.getMessage());
}
}
}
}
//String filename = encodingFilename(sheetName);
response.setContentType("application/octet-stream");
response.setHeader("Content-disposition", "attachment;filename=" + URLEncoder.encode(sheetName, "UTF-8"));
response.flushBuffer();
workbook.write(response.getOutputStream());
} catch (Exception e) {
log.error("导出Excel异常{}", e.getMessage());
throw new RuntimeException("导出Excel失败，请联系网站管理员！");
} finally {
if (workbook != null) {
try {
workbook.close();
} catch (IOException e1) {
e1.printStackTrace();
}
}
}
}
private static HSSFSheet setHSSFPrompt(HSSFSheet sheet, String promptTitle, String promptContent, int firstRow,
int endRow, int firstCol, int endCol) {
// 构造constraint对象
DVConstraint constraint = DVConstraint.createCustomFormulaConstraint("DD1");
// 四个参数分别是：起始行、终止行、起始列、终止列
CellRangeAddressList regions = new CellRangeAddressList(firstRow, endRow, firstCol, endCol);
// 数据有效性对象
HSSFDataValidation dataValidationView = new HSSFDataValidation(regions, constraint);
dataValidationView.createPromptBox(promptTitle, promptContent);
sheet.addValidationData(dataValidationView);
return sheet;
}
private static HSSFSheet setHSSFValidation(HSSFSheet sheet, String[] textlist, int firstRow, int endRow,
int firstCol, int endCol) {
// 加载下拉列表内容
DVConstraint constraint = DVConstraint.createExplicitListConstraint(textlist);
// 设置数据有效性加载在哪个单元格上,四个参数分别是：起始行、终止行、起始列、终止列
CellRangeAddressList regions = new CellRangeAddressList(firstRow, endRow, firstCol, endCol);
// 数据有效性对象
HSSFDataValidation dataValidationList = new HSSFDataValidation(regions, constraint);
sheet.addValidationData(dataValidationList);
return sheet;
}
private static String convertByExp(String propertyValue, String converterExp) throws Exception {
try {
String[] convertSource = converterExp.split(",");
for (String item : convertSource) {
String[] itemArray = item.split("=");
if (itemArray[0].equals(propertyValue)) {
return itemArray[1];
}
}
} catch (Exception e) {
throw e;
}
return propertyValue;
}
}第四步：无论导入导出，Excel表格的第一行都是跟实体类上@Excel注解的name属性进行映射对应的。
以下是示例:导出Excel表（该方法最好是返回void或者返回null），否则后台会报错（不影响运行）。
@PostMapping("/export")
@ResponseBody
public void export()
{
ExcelUtil<User> excelUtil = new ExcelUtil<>(User.class);
//要导出的数据集
List<User> list = getList();
excelUtil.exportExcel(list, "userInformation.xlsx", ServletUtils.getResponse());
}附件：前端代码：
exportExcel() {
let link = document.createElement('a');
link.style.display = 'none'
axios({
url: 'http://test.cih.net/user/pageExport',
methods: "get",
data: {},
headers: {
token: 'eyJ0eXB1234bklkIjoie1wiZWnm7jwkJtbvdcnqo'
}
}).then((res) => {
let blob = new Blob([res.data], {
type: "application/vnd.ms-excel"
}); // 2.获取请求返回的response对象中的blob 设置文件类型，这里以excel为例
let url = window.URL.createObjectURL(blob); // 3.创建一个临时的url指向blob对象
// 4.创建url之后可以模拟对此文件对象的一系列操作，例如：预览、下载
let a = document.createElement("a");
a.href = url;
a.download = "导出表格.xlsx";
a.click();
// 5.释放这个临时的对象url
window.URL.revokeObjectURL(url);
})
}java简单的导出excel
1.pom 引入poi
<!-- poi -->
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi</artifactId>
</dependency>
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi-ooxml</artifactId>
</dependency>2.创建excel导出工具类
@Slf4j
public class ExportExcelUtils {
public static <T> void export(String excelName, List<T> list, Class<T> c, HttpServletResponse response) {
// 设置日期格式
SimpleDateFormat df = new SimpleDateFormat("yyyyMMddHHmmss");
// 设置默认文件名为当前时间：年月日时分秒
if (excelName == null || excelName == "") {
excelName = df.format(new Date());
} else {
excelName = excelName + df.format(new Date());
}
try {
//创建一个WorkBook,对应一个Excel文件
HSSFWorkbook wb = new HSSFWorkbook();
//在Workbook中，创建一个sheet，对应Excel中的工作薄（sheet）
HSSFSheet sheet = wb.createSheet(excelName);
//设置 边距、页眉、页脚
HSSFPrintSetup printSetup = sheet.getPrintSetup();
//打印方向，true：横向，false：纵向(默认)
printSetup.setLandscape(true);
printSetup.setHeaderMargin(0.2);
printSetup.setFooterMargin(0.2);
//设置打印缩放为88%
///printSetup.setScale((short) 55);
printSetup.setFitHeight((short) 0);
printSetup.setFitWidth((short) 1);
//列从左向右显示②
/// printSetup.setLeftToRight(true);
// 纸张
printSetup.setPaperSize(HSSFPrintSetup.A4_PAPERSIZE);
// 页边距（下）
sheet.setMargin(HSSFSheet.BottomMargin, 0.8);
// 页边距（左）
sheet.setMargin(HSSFSheet.LeftMargin, 0);
// 页边距（右）
sheet.setMargin(HSSFSheet.RightMargin, 0);
// 页边距（上）
sheet.setMargin(HSSFSheet.TopMargin, 0.8);
//设置打印页面为水平居中
sheet.setHorizontallyCenter(true);
sheet.setVerticallyCenter(true);
sheet.setAutobreaks(false);
sheet.setFitToPage(false);
Footer footer = sheet.getFooter();
//设置页数
footer.setCenter("第" + HeaderFooter.page() + "页，共 " + HeaderFooter.numPages() + "页");
Header header = sheet.getHeader();
//自定义页眉,并设置页眉 左中右显示信息
//居中
///header.setCenter("Center Header");
//靠左
header.setLeft(HSSFHeader.font("宋体", "") +
HSSFHeader.fontSize((short) 16) + excelName + ".xlsx");
//靠右
///header.setRight(HSSFHeader.font("Stencil-Normal", "Italic") +
///HSSFHeader.fontSize((short) 16) + "Right w/ Stencil-Normal Italic font and size 16");
//创建单元格，并设置值表头 设置表头居中
HSSFCellStyle style = wb.createCellStyle();
//设置边框
//下边框
style.setBorderBottom(HSSFCellStyle.BORDER_THIN);
//左边框
style.setBorderLeft(HSSFCellStyle.BORDER_THIN);
//上边框
style.setBorderTop(HSSFCellStyle.BORDER_THIN);
//右边框
style.setBorderRight(HSSFCellStyle.BORDER_THIN);
//自动换行
///style.setWrapText(true);
//创建一个居中格式
style.setAlignment(HSSFCellStyle.ALIGN_CENTER);
//上下居中
style.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER);
//设置字体
HSSFFont font = wb.createFont();
font.setFontName("宋体");
style.setFont(font);
// 填充工作表
//获取需要转出的excel表头的map字段
LinkedHashMap<String, String> fieldMap = new LinkedHashMap<>();
//循环注解里面的值 填入Link集合
Field[] declaredFields = c.getDeclaredFields();
//获取属性对应的枚举类
LinkedHashMap<String, Class> converterMap = new LinkedHashMap<>();
for (Field declaredField : declaredFields) {
//获取注解对象
ExportEntityMap declaredAnnotation = declaredField.getDeclaredAnnotation(ExportEntityMap.class);
ExportProperty converterAnnotation = declaredField.getDeclaredAnnotation(ExportProperty.class);
if (declaredAnnotation != null) {
fieldMap.put(declaredAnnotation.EnName(), declaredAnnotation.CnName());
if (converterAnnotation != null) {
converterMap.put(declaredAnnotation.EnName(), converterAnnotation.Converter());
}
}
}
fillSheet(sheet, list, fieldMap, style, converterMap);
// 设置response头信息
response.reset();
try {
log.info("excelName:{}", excelName);
String fileName = URLEncoder.encode(excelName + ".xlsx", "UTF-8");
response.setHeader("Content-disposition", "attachment; filename=" + fileName);
} catch (UnsupportedEncodingException e1) {
log.error("导出excel失败，异常：", e1);
}
//将文件输出
OutputStream outputStream = new BufferedOutputStream(response.getOutputStream());
response.setContentType("application/octet-stream");
response.flushBuffer();
wb.write(outputStream);
outputStream.flush();
outputStream.close();
} catch (Exception e) {
log.error("导出Excel失败，异常：", e);
}
}
public static Field getFieldByName(String fieldName, Class<?> clazz) {
// 拿到本类的所有字段
Field[] selfFields = clazz.getDeclaredFields();
// 如果本类中存在该字段，则返回
for (Field field : selfFields) {
//如果本类中存在该字段，则返回
if (field.getName().equals(fieldName)) {
return field;
}
}
// 否则，查看父类中是否存在此字段，如果有则返回
Class<?> superClazz = clazz.getSuperclass();
if (superClazz != null && superClazz != Object.class) {
//递归
return getFieldByName(fieldName, superClazz);
}
// 如果本类和父类都没有，则返回空
return null;
}
public static String getFieldValueByName(String fieldName, Object o)
throws Exception {
String fieldValue = null;
//根据字段名得到字段对象
Field field = getFieldByName(fieldName, o.getClass());
//如果该字段存在，则取出该字段的值
if (field != null) {
//类中的成员变量为private,在类外边使用属性值，故必须进行此操作
field.setAccessible(true);
//获取当前对象中当前Field的value
fieldValue = field.get(o) == null ? "" : field.get(o).toString();
String fieldType = field.getGenericType().toString();
if ("class java.math.BigDecimal".equals(fieldType) || "class java.lang.Double".equals(fieldType)) {
fieldValue = new BigDecimal(fieldValue).setScale(2, BigDecimal.ROUND_HALF_UP).toString();
} else if ("class java.time.LocalDateTime".equals(fieldType) || "class java.time.LocalDate".equals(fieldType)) {
fieldValue = fieldValue.replace("T", " ");
}
} else {
throw new Exception(o.getClass().getSimpleName() + "类不存在字段名 "
+ fieldName);
}
return fieldValue;
}
public static String getFieldValueByNameSequence(String fieldNameSequence,
Object o) throws Exception {
String value = null;
// 将fieldNameSequence进行拆分
String[] attributes = fieldNameSequence.split("\\.");
if (attributes.length == 1) {
value = getFieldValueByName(fieldNameSequence, o);
} else {
// 根据数组中第一个连接属性名获取连接属性对象，如student.department.name
Object fieldObj = getFieldValueByName(attributes[0], o);
//截取除第一个属性名之后的路径
String subFieldNameSequence = fieldNameSequence
.substring(fieldNameSequence.indexOf(".") + 1);
//递归得到最终的属性对象的值
value = getFieldValueByNameSequence(subFieldNameSequence, fieldObj);
}
return value;
}
public static <T> void fillSheet(HSSFSheet sheet, List<T> list,
LinkedHashMap<String, String> fieldMap, HSSFCellStyle style, LinkedHashMap<String, Class> converterMap) throws Exception {
// 定义存放英文字段名和中文字段名的数组
String[] enFields = new String[fieldMap.size()];
String[] cnFields = new String[fieldMap.size()];
// 填充数组
int count = 0;
for (Map.Entry<String, String> entry : fieldMap.entrySet()) {
enFields[count] = entry.getKey();
cnFields[count] = entry.getValue();
count++;
}
//存储最大列宽
Map<Integer, Integer> maxWidth = new HashMap<>(16);
HSSFRow row = sheet.createRow(0);
HSSFCell cell = null;
// 填充表头
for (int i = 0; i < cnFields.length; i++) {
cell = row.createCell(i);
cell.setCellValue(cnFields[i]);
cell.setCellStyle(style);
sheet.autoSizeColumn(i);
//设置自适应宽高
maxWidth.put(i, cell.getStringCellValue().getBytes().length * 256 + 200);
}
// 填充内容
for (int index = 0; index < list.size(); index++) {
row = sheet.createRow(index + 1);
// 获取单个对象
T item = list.get(index);
int j = 0;
for (int i = 0; i < enFields.length; i++) {
HSSFCell createCell = row.createCell(j);
String objValue = getFieldValueByNameSequence(enFields[i], item);
//获取属性对应的枚举类
Class<Enum> converterClazz = converterMap.get(enFields[i]);
objValue = convertFieldValue(objValue, converterClazz);
String fieldValue = objValue == null ? "" : objValue;
cell = row.createCell(i);
createCell.setCellValue(fieldValue);
int length = createCell.getStringCellValue().getBytes().length * 256 + 200;
//这里把宽度最大限制到15000
if (length > 15000) {
length = 15000;
}
maxWidth.put(j, Math.max(length, maxWidth.get(j)));
j++;
createCell.setCellStyle(style);
}
}
// 列宽自适应
for (int i = 0; i < cnFields.length; i++) {
sheet.setColumnWidth(i, maxWidth.get(i));
}
}
private static <T> String convertFieldValue(String objValue, Class<Enum> converterClazz) throws Exception {
if (ObjectUtil.isNotNull(converterClazz)) {
//获取所有枚举实例
Enum[] enumConstants = converterClazz.getEnumConstants();
//根据方法名获取方法
Method valueMethod = converterClazz.getMethod("getValue");
if (ObjectUtil.isNull(valueMethod)) {
throw new Exception(converterClazz.getSimpleName() + "类找不到getValue()方法");
}
Method descMethod = converterClazz.getMethod("getDescription");
if (ObjectUtil.isNull(descMethod)) {
throw new Exception(converterClazz.getSimpleName() + "类找不到getDescription()方法");
}
for (Enum enumFiled : enumConstants) {
//执行枚举方法获得枚举实例对应的值
Object value = valueMethod.invoke(enumFiled);
Object description = descMethod.invoke(enumFiled);
if (ObjectUtil.equal(objValue, value.toString())) {
objValue = description.toString();
}
}
}
return objValue;
}
}3.自定义标签Export标签
@Target({ElementType.FIELD})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface ExportEntityMap {
String EnName() default "实体属性名称";
String CnName() default "excel标题名称";
}
@Target({ElementType.FIELD})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface ExportProperty {
Class<? extends Enum> Converter();
}枚举
public enum SexEnum {
MALE(1, "MALE", "男"),
FEMALE(2, "FEMALE", "女");
private int value;
private String code;
private String description;
SexEnum(int value, String code, String description) {
this.value = value;
this.code = code;
this.description = description;
}
public int getValue() {
return value;
}
public String getDescription() {
return description;
}
public String getCode() {
return code;
}
}4. 实体类引入@ExportEntityMap标签
@ExportEntityMap(CnName = "性别", EnName = "sex")
//通过@ExportProperty来转换枚举字段
@ExportProperty(Converter = SexEnum.class)
private Integer sex;
@ExportEntityMap(CnName = "年龄", EnName = "age")
private Integer age;5.在Controller层中调用ExportExcelUtils方法即可
@ApiOperation("xxxx")
@PostMapping(value = "/xxxx")
public void getExport(HttpServletResponse response, @RequestBody ListRo ro) {
//导出数据
ExportExcelUtils.export("name", list, EntityClass.class, response);
}总结
以上为个人经验，希望能给大家一个参考，也希望大家多多支持编程网。
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