POI官方文档
引入依赖
<!--POI-->
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi</artifactId>
<version>4.1.2</version>
</dependency>
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi-ooxml</artifactId>
<version>4.1.2</version>
</dependency>
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi-ooxml-schemas</artifactId>
<version>4.1.2</version>
</dependency>定义注解
我们结合自定义注解，让导出使用起来更方便简洁且更容易扩展。
@ExcelField
@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
public @interface ExcelField {
/**
* 字段名
*/
String name() default "";
/**
* 字段顺序
*/
int order() default 1;
/**
* 单元格宽度
*/
int width() default 100;
/**
* 日期格式
*/
String dateFormat() default "yyyy-MM-dd HH:mm:ss";
}@ExcelHeader
@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
public @interface ExcelHeader {
/**
* 文件名称
* @return
*/
String fileName() default "导出文件";
/**
* sheet页名称
* @return
*/
String sheetName() default "sheet1";
/**
* 表头是否加粗
* @return
*/
boolean headBold() default false;
/**
* 表头颜色
* @return
*/
IndexedColors headColor() default IndexedColors.GREEN;
}编写POI导出工具类
public class ExcelExportUtil {
/*
* @description: 导出 <br>
* @create: 2023/9/12 16:28 <br>
* @param response
* @param data
* @param clazz
* @return void
*/
public static<T> void export(HttpServletResponse response, List<T> data, Class<T> clazz){
if(ObjectUtils.isEmpty(response) || ObjectUtils.isEmpty(data)){
return;
}
//解析表头
ExcelHeader excelHeader = getExcelHeader(clazz);
if(ObjectUtils.isEmpty(excelHeader)){
return;
}
//解析字段
List<String> keyList = new ArrayList<>();
List<ExcelField> excelFieldList = new ArrayList<>();
getExcelFields(clazz, keyList, excelFieldList);
if(ObjectUtils.isEmpty(keyList)){
return;
}
//创建workbook，SXSSFWorkbook支持大数据量导出
Workbook workbook = new SXSSFWorkbook();
//创建sheet
Sheet sheet = workbook.createSheet(excelHeader.sheetName());
//创建表头
Row row = createHeader(workbook, sheet, excelHeader, excelFieldList);
//写入数据
setData(data, sheet, keyList, excelFieldList);
//输出文件
try {
String fileName = URLEncoder.encode(excelHeader.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());
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}finally {
try {
workbook.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
/*
* @description: 设置数据 <br>
* @create: 2023/9/13 9:33 <br>
* @param data
* @param sheet
* @param keyList
* @return void
*/
private static<T> void setData(List<T> data, Sheet sheet, List<String> keyList, List<ExcelField> excelFieldList){
List<Map<String, Object>> dataList = convertDataToJson(data);
Map<String, Object> rowData;
String dataKey;
Object value;
ExcelField excelField;
for (int i = 0; i < dataList.size(); i++) {
Row row = sheet.createRow(i+1);
rowData = dataList.get(i);
for (int j = 0; j < keyList.size(); j++) {
dataKey = keyList.get(j);
value = rowData.get(dataKey);
if(ObjectUtils.isEmpty(value)){
continue;
}
Cell cell = row.createCell(j);
cell.setCellValue(value.toString());
}
}
}
/*
* @description: 创建表头 <br>
* @create: 2023/9/12 17:28 <br>
* @param workbook
* @param sheet
* @param excelFieldList
* @return org.apache.poi.ss.usermodel.Row
*/
private static Row createHeader(Workbook workbook, Sheet sheet, ExcelHeader excelHeader,List<ExcelField> excelFieldList){
//创建行
Row row = sheet.createRow(0);
//创建行样式
CellStyle cellStyle = workbook.createCellStyle();
//单元格颜色
cellStyle.setFillForegroundColor(excelHeader.headColor().getIndex());
cellStyle.setFillPattern(FillPatternType.SOLID_FOREGROUND);
//水平居中
cellStyle.setAlignment(HorizontalAlignment.CENTER);
//字体
Font font = workbook.createFont();
font.setBold(excelHeader.headBold());
font.setFontName("宋体");
cellStyle.setFont(font);
for (int i = 0; i < excelFieldList.size(); i++) {
ExcelField excelField = excelFieldList.get(i);
Cell cell = row.createCell(i);
cell.setCellValue(excelField.name());
cell.setCellStyle(cellStyle);
sheet.setColumnWidth(i+1, excelField.width() * 10 );
}
return row;
}
/*
* @description: 获取excel头注解信息 <br>
* @create: 2023/9/12 10:28 <br>
* @param clazz
* @return com.springboot.demo.base.annotation.ExcelHeader
*/
private static<T> ExcelHeader getExcelHeader(Class<T> clazz){
ExcelHeader excelHeader = clazz.getAnnotation(ExcelHeader.class);
return excelHeader;
}
/*
* @description: 获取excel字段注解信息 <br>
* @create: 2023/9/12 10:31 <br>
* @param clazz
* @return java.util.List<com.springboot.demo.base.annotation.ExcelField>
*/
private static<T> void getExcelFields(Class<T> clazz, List<String> keyList, List<ExcelField> excelFieldList){
Field[] fields = clazz.getDeclaredFields();
if(ObjectUtils.isEmpty(fields)){
return;
}
Map<String, String> keyMap = new HashMap<>();
for(Field field : fields){
ExcelField excelField = field.getAnnotation(ExcelField.class);
if(ObjectUtils.isNotEmpty(excelField)){
keyMap.put(excelField.name(), field.getName());
excelFieldList.add(excelField);
}
}
if(ObjectUtils.isNotEmpty(excelFieldList)){
excelFieldList = excelFieldList.stream().sorted(Comparator.comparing(ExcelField::order)).collect(
Collectors.toList());
}
for (ExcelField excelField : excelFieldList) {
keyList.add(keyMap.get(excelField.name()));
}
}
/*
* @description: 将数据转未json <br>
* @create: 2023/9/13 10:00 <br>
* @param data
* @return java.util.List<java.util.Map<java.lang.String,java.lang.Object>>
*/
private static<T> List<Map<String, Object>> convertDataToJson(List<T> data){
ObjectMapper objectMapper = new ObjectMapper();
//日期格式
objectMapper.setDateFormat(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"));
//设置时区
objectMapper.setTimeZone(TimeZone.getTimeZone("Asia/Shanghai"));
//序列化-忽略null值的属性
objectMapper.setSerializationInclusion(Include.NON_NULL);
//序列化-允许序列化空对象
objectMapper.disable(SerializationFeature.FAIL_ON_EMPTY_BEANS);
List<Map<String, Object>> dataList = objectMapper.convertValue(data, List.class);
return dataList;
}
}
测试
Test.java
@Data
@ExcelHeader(fileName = "导出文件.xlsx")
public class Test {
@ExcelField(name = "字段1", width = 500, order = 1)
private String field1 = "撒大声地撒分都是";
@ExcelField(name = "字段2", width = 400, order = 2)
private Integer field2 = 11;
@ExcelField(name = "字段3", width = 300, order = 5)
private Double field3;
@ExcelField(name = "字段4", width = 700, order = 10)
private BigDecimal field4 = new BigDecimal("12312312312.222");
@ExcelField(name = "字段5", width = 600, order = 3)
private Date field5 = new Date();
}TestController.java
@Api(tags = "测试")
@RestController
@RequestMapping("/test")
public class TestController {
@ApiOperation("test")
@PostMapping("/test")
public void test(HttpServletResponse response){
Test test = new Test();
List<Test> list = new ArrayList<>();
for (int i = 0; i < 10000; i++) {
list.add(test);
}
ExcelExportUtil.export(response, list, Test.class);
}
}输出结果
