基于注解的Excel 导入导出
在做后台管理系统时，经常遇到Excel的导入导出，基本都是使用poi的api。虽然都封装了一些工具类，但是重复性代码还是很多。特别是导入时，基本导入一个Excel就要写一个导入方法，很麻烦。最近研究了一下注解，可以利用注解加反射很简单的进行导入导出。
1：依赖
junit
junit
4.9
org.springframework
spring-test
4.1.2.RELEASE
log4j
log4j
1.2.14
org.slf4j
slf4j-api
1.7.5
org.slf4j
slf4j-nop
1.7.8
commons-lang
commons-lang
2.6
org.apache.poi
poi
3.9
org.apache.poi
poi-ooxml
3.9
2：自定义注解
package com.mpp.easypoi.anon;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
/**
* @des Excel 注解
* @author mapp 2018/2/10.
*/
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.FIELD)
public @interface ExceVo {
/** 对应的列名称 */
String name() default "";
/** 列序号 */
int sort();
/** 字段类型对应的格式 */
String format() default "";
/** 是否需要校验 */
boolean isCheck() default false;
/** 校验字段长度 */
int fieldLength() default 50;
/** 校验是否可以为空 */
boolean isEmpty() default true;
}
3：导出工具类
/**
* @des Excel 导出 工具类
* @author mapp 2018/2/10.
*/
public class ExcelExportUtil {
private Class claze;
public ExcelExportUtil(Class claze) {
this.claze = claze;
}
/**
* 基于模板导出
* @param fileName 模板名称
* @param objs 导出实体集合
* @param rowIndex excel第几行开始导出
*/
public void export(String fileName, List objs, int rowIndex) {
POIFSFileSystem fs = null;
FileOutputStream os = null;
try {
fs = new POIFSFileSystem(Thread.currentThread().getContextClassLoader().getResourceAsStream(fileName));
} catch (IOException e) {
e.printStackTrace();
}
try {
HSSFWorkbook workbook = new HSSFWorkbook(fs);
HSSFCellStyle style = setCellStyle(workbook);
HSSFSheet sheet = workbook.getSheetAt(0);
for (int i = 0; i < objs.size(); i++) {
HSSFRow row = sheet.createRow(i + rowIndex - 1);
for (int j = 0; j < objs.get(i).length; j++) {
HSSFCell cell = row.createCell(j);
cell.setCellStyle(style);
cell.setCellValue(objs.get(i)[j].toString());
}
}
os = new FileOutputStream(new File("D:\\8888.xls"));
workbook.write(os);
} catch (IOException e) {
e.printStackTrace();
}finally {
if (os != null) {
try {
os.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
/**
* 基于注解导出
* 不需要自己封装每列的值
* @param fileName 模板名称
* @param objs 导出实体集合
* @param rowIndex excel第几行开始导出
*/
public void export1(String fileName, List objs, int rowIndex) {
POIFSFileSystem fs = null;
FileOutputStream os = null;
try {
// classpath 下的模板excel文件
fs = new POIFSFileSystem(Thread.currentThread().getContextClassLoader().getResourceAsStream(fileName));
} catch (IOException e) {
e.printStackTrace();
}
try {
// 带注解并排序好的字段
List fieldList = getFieldList();
HSSFWorkbook workbook = new HSSFWorkbook(fs);
HSSFCellStyle style = setCellStyle(workbook);
HSSFSheet sheet = workbook.getSheetAt(0);
for (int i = 0; i < objs.size(); i++) {
HSSFRow row = sheet.createRow(i + rowIndex - 1);
for (int j = 0; j < fieldList.size(); j++) {
HSSFCell cell = row.createCell(j);
cell.setCellStyle(style);
Field field = fieldList.get(j);
String fieldValue = covertAttrType(field, objs.get(i));
cell.setCellValue(fieldValue);
}
}
os = new FileOutputStream(new File("D:\\8888.xls"));
workbook.write(os);
} catch (Exception e) {
throw new ExcelException("导出失败", e);
} finally {
if (os != null) {
try {
os.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
/**
* 设置样式
* @param workbook
*/
private HSSFCellStyle setCellStyle(HSSFWorkbook workbook) {
HSSFCellStyle style = workbook.createCellStyle();
HSSFFont font = workbook.createFont();
font.setFontHeightInPoints((short) 12);
style.setFont(font);
style.setAlignment(HSSFCellStyle.ALIGN_CENTER);
style.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER);
return style;
}
/**
* 获取带注解的字段 并且排序
* @return
*/
private List getFieldList() {
Field[] fields = this.claze.getDeclaredFields();
// 无序
List fieldList = new ArrayList();
// 排序后的字段
List fieldSortList = new LinkedList();
int length = fields.length;
int sort = 0;
Field field = null;
// 获取带注解的字段
for (int i = 0; i < length; i++) {
field = fields[i];
if (field.isAnnotationPresent(ExceVo.class)) {
fieldList.add(field);
}
}
Assert.assertNotNull("未获取到需要导出的字段", fieldList);
length = fieldList.size();
for (int i = 1; i <= length; i++) {
for (int j = 0; j < length; j++) {
field = fieldList.get(j);
ExceVo exceVo = field.getAnnotation(ExceVo.class);
field.setAccessible(true);
sort = exceVo.sort();
if (sort == i) {
fieldSortList.add(field);
continue;
}
}
}
return fieldSortList;
}
/**
* 类型转换 转为String
*/
private String covertAttrType(Field field, T obj) throws IllegalAccessException {
if (field.get(obj) == null) {
return "";
}
ExceVo exceVo = field.getAnnotation(ExceVo.class);
String type = field.getType().getSimpleName();
String format = exceVo.format();
if ("Date".equals(type)) {
return DateFormatUtils.format((Date)field.get(obj), "yyyy-MM-dd");
}else {
return field.get(obj).toString();
}
}
} 4：导入工具类
/**
* @des Excel 导入 工具类
* @author mapp 2018/2/10.
*/
public class ExcelReadUtil {
private Class claze;
public ExcelReadUtil(Class claze) {
this.claze = claze;
}
/**
* 基于注解读取excel
* @param filePath 文件地址
* @param rowIndex 从第几行开始读取数据
* @return List List 集合
*/
public List readExcel(String filePath, int rowIndex) {
POIFSFileSystem fs = null;
List list = new ArrayList();
T entity = null;
try {
// 带注解并排序好的字段
List fieldList = getFieldList();
int size = fieldList.size();
Field field = null;
fs = new POIFSFileSystem(new FileInputStream(filePath));
HSSFWorkbook workbook = new HSSFWorkbook(fs);
HSSFSheet sheet = workbook.getSheetAt(0);
// 不准确
int rowLength = sheet.getLastRowNum();
for (int i = 0; i <= 3 - rowIndex; i++) {
HSSFRow row = sheet.getRow(i + rowIndex - 1);
entity = (T) claze.newInstance();
for (int j = 0; j < size; j++) {
HSSFCell cell = row.getCell(j);
field = fieldList.get(j);
field.set(entity, covertAttrType(field, cell));
}
list.add(entity);
}
} catch (Exception e) {
e.printStackTrace();
}
return list;
}
/**
* 获取带注解的字段 并且排序
* @return
*/
private List getFieldList() {
Field[] fields = this.claze.getDeclaredFields();
// 无序
List fieldList = new ArrayList();
// 排序后的字段
List fieldSortList = new LinkedList();
int length = fields.length;
int sort = 0;
Field field = null;
// 获取带注解的字段
for (int i = 0; i < length; i++) {
field = fields[i];
if (field.isAnnotationPresent(ExceVo.class)) {
fieldList.add(field);
}
}
Assert.assertNotNull("未获取到需要导出的字段", fieldList);
length = fieldList.size();
for (int i = 1; i <= length; i++) {
for (int j = 0; j < length; j++) {
field = fieldList.get(j);
ExceVo exceVo = field.getAnnotation(ExceVo.class);
field.setAccessible(true);
sort = exceVo.sort();
if (sort == i) {
fieldSortList.add(field);
continue;
}
}
}
return fieldSortList;
}
/**
* 类型转换 将cell 单元格格式转为 字段类型
*/
private Object covertAttrType(Field field, HSSFCell cell) {
int type = cell.getCellType();
if (type == Cell.CELL_TYPE_BLANK) {
return null;
}
ExceVo exceVo = field.getAnnotation(ExceVo.class);
// 字段类型
String fieldType = field.getType().getSimpleName();
try {
if ("String".equals(fieldType)) {
return getValue(cell);
}else if ("Date".equals(fieldType)) {
return DateUtils.parseDate(getValue(cell), new String[]{"yyyy-MM-dd"});
}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));
}
}catch (Exception e) {
if (e instanceof ParseException) {
throw new ExcelException("时间格式转换失败", e);
}else {
e.printStackTrace();
throw new ExcelException("格式转换失败");
}
}
throw new ExcelException("excel 单元格 格式暂不支持");
}
/**
* 格式转为String
* @param cell
* @return
*/
public String getValue(Cell cell) {
if (cell == null) {
return "";
}
switch (cell.getCellType()) {
case HSSFCell.CELL_TYPE_STRING:
return cell.getRichStringCellValue().getString().trim();
case HSSFCell.CELL_TYPE_NUMERIC:
if (HSSFDateUtil.isCellDateFormatted(cell)) {
Date dt = HSSFDateUtil.getJavaDate(cell.getNumericCellValue());
return DateFormatUtils.format(dt, "yyyy-MM-dd");
} 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 HSSFCell.CELL_TYPE_BOOLEAN:
return String.valueOf(cell.getBooleanCellValue());
case HSSFCell.CELL_TYPE_FORMULA:
return cell.getCellFormula();
case HSSFCell.CELL_TYPE_BLANK:
return "";
default:
return "";
}
}
} 5：导出导入实体
/**
* 导入实体
* @author mapp 2018/2/10.
*/
public class Student {
@ExceVo(sort = 1)
private String name;
@ExceVo(sort = 3)
private String sex;
@ExceVo(sort = 8, format = "yyyy-MM-dd")
private Date birthDay;
@ExceVo(sort = 4)
private String className;
@ExceVo(sort = 6)
private String address;
@ExceVo(sort = 5)
private String phone;
@ExceVo(sort = 7)
private String love;
@ExceVo(sort = 2)
private int age;
}/**
* 导出实体
* @author mapp 2018/2/10.
*/
public class User {
private String id;
@ExceVo(name = "姓名",sort = 1)
private String name;
@ExceVo(name = "性别",sort = 2)
private String sex;
@ExceVo(name = "生日",sort = 3)
private Date birthDay;
public Date getBirthDay() {
return birthDay;
}
public User() {
}
}6：测试方法
/**
* 测试
*/
public class TestExport {
public static void main(String[] args) throws ParseException {
User user1 = new User("1", "盖伦", "男", DateUtils.parseDate("2018-2-11", new String[]{"yyyy-MM-dd"}));
User user2 = new User("2", "德邦", "男", DateUtils.parseDate("2018-2-11", new String[]{"yyyy-MM-dd"}));
User user3 = new User("3", "拉克丝", "女", DateUtils.parseDate("2018-2-11", new String[]{"yyyy-MM-dd"}));
User user4 = new User("4", "寒冰", "女", DateUtils.parseDate("2018-2-11", new String[]{"yyyy-MM-dd"}));
List users = new ArrayList();
users.add(user1);
users.add(user2);
users.add(user3);
users.add(user4);
Object[] objs = null;
List list = new ArrayList();
for (int i = 0; i < users.size(); i++) {
objs = new Object[3];
objs[0] = users.get(i).getId();
objs[1] = users.get(i).getName();
objs[2] = users.get(i).getSex();
list.add(objs);
}
ExcelExportUtil excelUtil = new ExcelExportUtil(User.class);
// 原始方式导出
// excelUtil.export("test.xls", list, 2);
// 基于注解导出
excelUtil.export1("test.xls", users, 2);
}
}
/**
* 测试导入
*/
public class TestReadExcel {
public static void main(String[] args) throws ParseException {
ExcelReadUtil excelReadUtil = new ExcelReadUtil(Student.class);
List students = excelReadUtil.readExcel("D:\\student.xls", 2);
for (Student student : students) {
System.out.println(student);
}
}
}