<!--POI-->
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi</artifactId>
<version>4.0.1</version>
</dependency>
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi-ooxml</artifactId>
<version>4.0.1</version>
</dependency>
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi-ooxml-schemas</artifactId>
<version>4.0.1</version>
</dependency>
/**
* 自定义注解
*/
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.FIELD)
public @interface ExcelAttribute {
//对应的列名称
String name() default ""; // default java8新特性
//列序号
int sort();
//字段类型对应的格式
String format() default "";
}
/**
* 导出
*/
@Getter
@Setter
public class ExcelExportUtil<T> {
private int rowIndex;
private int styleIndex;
private String templatePath;
private Class clazz;
private Field fields[];
public ExcelExportUtil(Class clazz,int rowIndex,int styleIndex) {
this.clazz = clazz;
this.rowIndex = rowIndex;
this.styleIndex = styleIndex;
fields = clazz.getDeclaredFields();//获取声明字段
}
/**
* 基于注解导出
*/
public void export(HttpServletResponse response,InputStream is, List<T> objs,String fileName) throws Exception {
XSSFWorkbook workbook = new XSSFWorkbook(is);
Sheet sheet = workbook.getSheetAt(0);
CellStyle[] styles = getTemplateStyles(sheet.getRow(styleIndex));
AtomicInteger datasAi = new AtomicInteger(rowIndex);
for (T t : objs) {
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);
if(i == ea.sort()) { //列序号
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;
}
}
public class ExcelImportUtil<T> {
private Class clazz;
private Field fields[];
public ExcelImportUtil(Class clazz) {
this.clazz = clazz;
fields = clazz.getDeclaredFields();
}
/**
* 基于注解读取excel
*/
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(sheet.getLastRowNum());
for (int rowNum = rowIndex; rowNum <= sheet.getLastRowNum(); rowNum++) {
Row row = sheet.getRow(rowNum);
entity = (T) clazz.newInstance();
System.out.println(row.getLastCellNum());
for (int j = cellIndex; j < row.getLastCellNum(); j++) {
Cell cell = row.getCell(j);
for (Field field : fields) {
if(field.isAnnotationPresent(ExcelAttribute.class)){
field.setAccessible(true);
ExcelAttribute ea = field.getAnnotation(ExcelAttribute.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 {
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 "";
}
}
}
@ExcelAttribute(sort = 0)
private String userId;
@ExcelAttribute(sort = 1)
private String username;
//加载模板流数据
Resource resource = new ClassPathResource("excel-template/hr-demo.xlsx");
FileInputStream fis = new FileInputStream(resource.getFile());
new ExcelExportUtil(PoiEmployeeReportResult.class,2,2).export(response,fis,list,"报表.xlsx");
List list = new ExcelImportUtil(User.class).readExcel(file.getInputStream(), 1, 0);