170313、poi:采用自定义注解的方式导入、导出excel（这种方式比较好扩展）
步骤一、自定义注解
步骤二、写Excel泛型工具类
步骤三、在需要导出excel的类属相上加上自定义注解，并设置
步骤四、写service，controller
步骤一：自定义注解
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
@Retention(RetentionPolicy.RUNTIME)
@Target({java.lang.annotation.ElementType.FIELD})
public @interface ExcelField {
/**
* 导出到Excel中的名字.
*/
public abstract String name();
/**
* 配置列的名称,对应A,B,C,D....
*/
public abstract String column();
/**
* 提示信息
*/
public abstract String prompt() default "";
/**
* 设置只能选择不能输入的列内容.
*/
public abstract String[] combo() default {};
/**
* 是否导出数据
*/
public abstract boolean isExport() default true;
}
步骤二、excel泛型工具类
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
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.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.hssf.util.HSSFColor;
import org.apache.poi.ss.util.CellRangeAddressList;
/**
* 导出excel的工具类
* 全部采用string类型，如果需要加入其它类型需要修改工具方法
*/
public class ExcelUtil<T> {
Class<T> clazz;
public ExcelUtil(Class<T> clazz) {
this.clazz = clazz;
}
/**
* 批量导入
* 这里的批量导入指的是一个excel文件中有多个相同类型的sheet页
*/
public List<T> importBatch(InputStream input) throws Exception {
List<T> newList = new ArrayList<T>();
HSSFWorkbook workbook=new HSSFWorkbook(input);
if(null != workbook){
int sheets = workbook.getNumberOfSheets();
if(sheets>0){
for(int i=0;i<sheets;i++){
HSSFSheet sheet = workbook.getSheetAt(i);
if(null != sheet){
List<T> importProcessor = importProcessor(sheet);
newList.addAll(importProcessor);
}
}
}
}
return newList;
}
/**
* 指定sheet页导入，如果不指定默认会选第一个sheet
*/
public List<T> importExcel(String sheetName, InputStream input) throws Exception {
HSSFWorkbook workbook = new HSSFWorkbook(input);
HSSFSheet sheet = workbook.getSheet(sheetName);
if (!sheetName.trim().equals("")) {
sheet = workbook.getSheet(sheetName);// 如果指定sheet名,则取指定sheet中的内容.
}
if (sheet == null) {
sheet = workbook.getSheetAt(0); // 如果传入的sheet名不存在则默认指向第1个sheet.
}
return importProcessor(sheet);
}
/**
* 具体处理导入
*/
private List<T> importProcessor(HSSFSheet sheet) throws Exception {
int maxCol = 0;
List<T> list = new ArrayList<T>();
int rows = sheet.getPhysicalNumberOfRows();
if (rows > 0) {// 有数据时才处理
// Field[] allFields = clazz.getDeclaredFields();// 得到类的所有field.
List<Field> allFields = getMappedFiled(clazz, null);
Map<Integer, Field> fieldsMap = new HashMap<Integer, Field>();// 定义一个map用于存放列的序号和field.
for (Field field : allFields) {
// 将有注解的field存放到map中.
if (field.isAnnotationPresent(ExcelField.class)) {
ExcelField attr = field
.getAnnotation(ExcelField.class);
int col = getExcelCol(attr.column());// 获得列号
maxCol = Math.max(col, maxCol);
// System.out.println(col + "====" + field.getName());
field.setAccessible(true);// 设置类的私有字段属性可访问.
fieldsMap.put(col, 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.
HSSFRow row = sheet.getRow(i);
// int cellNum = row.getPhysicalNumberOfCells();
// int cellNum = row.getLastCellNum();
int cellNum = maxCol;
T entity = null;
for (int j = 0; j <= cellNum; j++) {
HSSFCell cell = row.getCell(j);
if (cell == null) {
continue;
}
int cellType = cell.getCellType();
String c = "";
if (cellType == HSSFCell.CELL_TYPE_NUMERIC) {
c = String.valueOf(cell.getNumericCellValue());
} else if (cellType == HSSFCell.CELL_TYPE_BOOLEAN) {
c = String.valueOf(cell.getBooleanCellValue());
} else {
c = cell.getStringCellValue();
}
if (c == null || c.equals("")) {
continue;
}
entity = (entity == null ? clazz.newInstance() : entity);// 如果不存在实例则新建.
// System.out.println(cells[j].getContents());
Field field = fieldsMap.get(j);// 从map中得到对应列的field.
if (field==null) {
continue;
}
// 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)));
}
}
}
if (entity != null) {
list.add(entity);
}
}
}
return list;
}
/**
* 对list数据源将其里面的数据导出到excel表单
*/
public boolean exportExcel(List<T> lists[], String sheetNames[], OutputStream output) {
if (lists.length != sheetNames.length) {
return false;
}
HSSFWorkbook workbook = new HSSFWorkbook();// 产生工作薄对象
for (int ii = 0; ii < lists.length; ii++) {
List<T> list = lists[ii];
String sheetName = sheetNames[ii];
List<Field> fields = getMappedFiled(clazz, null);
HSSFSheet sheet = workbook.createSheet();// 产生工作表对象
workbook.setSheetName(ii, sheetName);
HSSFRow row;
HSSFCell cell;// 产生单元格
HSSFCellStyle style = workbook.createCellStyle();
style.setFillForegroundColor(HSSFColor.SKY_BLUE.index);
style.setFillBackgroundColor(HSSFColor.GREY_40_PERCENT.index);
row = sheet.createRow(0);// 产生一行
for (int i = 0; i < fields.size(); i++) {
Field field = fields.get(i);
ExcelField attr = field.getAnnotation(ExcelField.class);
int col = getExcelCol(attr.column());// 获得列号
cell = row.createCell(col);// 创建列
cell.setCellType(HSSFCell.CELL_TYPE_STRING);// 设置列中写入内容为String类型
cell.setCellValue(attr.name());// 写入列名
if (!attr.prompt().trim().equals("")) {
setHSSFPrompt(sheet, "", attr.prompt(), 1, 100, col, col);// 这里默认设了2-101列提示.
}
if (attr.combo().length > 0) {
setHSSFValidation(sheet, attr.combo(), 1, 100, col, col);// 这里默认设了2-101列只能选择不能输入.
}
cell.setCellStyle(style);
}
int startNo = 0;
int endNo = list.size();
for (int i = startNo; i < endNo; i++) {
row = sheet.createRow(i + 1 - startNo);
T vo = (T) list.get(i);
for (int j = 0; j < fields.size(); j++) {
Field field = fields.get(j);
field.setAccessible(true);
ExcelField attr = field.getAnnotation(ExcelField.class);
try {
if (attr.isExport()) {
cell = row.createCell(getExcelCol(attr.column()));
cell.setCellType(HSSFCell.CELL_TYPE_STRING);
cell.setCellValue(field.get(vo) == null ? ""
: String.valueOf(field.get(vo)));
}
} catch (IllegalArgumentException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
}
}
}
}
try {
output.flush();
workbook.write(output);
output.close();
return true;
} catch (IOException e) {
e.printStackTrace();
return false;
}
}
/**
* 对list数据源将其里面的数据导出到excel表单
*/
@SuppressWarnings("unchecked")
public boolean exportExcel(List<T> list, String sheetName,
OutputStream output) {
//此处 对类型进行转换
List<T> ilist = new ArrayList<>();
for (T t : list) {
ilist.add(t);
}
List<T>[] lists = new ArrayList[1];
lists[0] = ilist;
String[] sheetNames = new String[1];
sheetNames[0] = sheetName;
return exportExcel(lists, sheetNames, output);
}
/**
* 将EXCEL中A,B,C,D,E列映射成0,1,2,3,4
* @param col
*/
public static int getExcelCol(String col) {
col = col.toUpperCase();
// 从-1开始计算,字母重1开始运算。这种总数下来算数正好相同。
int count = -1;
char[] cs = col.toCharArray();
for (int i = 0; i < cs.length; i++) {
count += (cs[i] - 64) * Math.pow(26, cs.length - 1 - i);
}
return count;
}
/**
* 设置单元格上提示
*/
public static HSSFSheet setHSSFPrompt(HSSFSheet sheet, String promptTitle,
String promptContent, int firstRow, int endRow, int firstCol,
int endCol) {
DVConstraint constraint = DVConstraint
.createCustomFormulaConstraint("DD1");
CellRangeAddressList regions = new CellRangeAddressList(firstRow,
endRow, firstCol, endCol);
HSSFDataValidation data_validation_view = new HSSFDataValidation(
regions, constraint);
data_validation_view.createPromptBox(promptTitle, promptContent);
sheet.addValidationData(data_validation_view);
return sheet;
}
/**
* 设置某些列的值只能输入预制的数据,显示下拉框.
*/
public static HSSFSheet setHSSFValidation(HSSFSheet sheet,
String[] textlist, int firstRow, int endRow, int firstCol,
int endCol) {
DVConstraint constraint = DVConstraint
.createExplicitListConstraint(textlist);
CellRangeAddressList regions = new CellRangeAddressList(firstRow,
endRow, firstCol, endCol);
HSSFDataValidation data_validation_list = new HSSFDataValidation(
regions, constraint);
sheet.addValidationData(data_validation_list);
return sheet;
}
/**
* 得到实体类所有通过注解映射了数据表的字段
* 递归调用
*/
private List<Field> getMappedFiled(Class clazz, List<Field> fields) {
if (fields == null) {
fields = new ArrayList<Field>();
}
Field[] allFields = clazz.getDeclaredFields();// 得到所有定义字段
for (Field field : allFields) {
if (field.isAnnotationPresent(ExcelField.class)) {
fields.add(field);
}
}
if (clazz.getSuperclass() != null
&& !clazz.getSuperclass().equals(Object.class)) {
getMappedFiled(clazz.getSuperclass(), fields);
}
return fields;
}
}
步骤三、需要导出的java类属性上加上自定义注解
/**
* 退款excel导出
*/
public class ExcelPackageRefund {
@ExcelField(name="订单",column="A")
private String orderSn;//订单
@ExcelField(name="包裹",column="B")
private String packageSn;//包裹
//setter/getter
}
四、service和cotroller（字数限制，只保留了核心）
response.setHeader("Content-Disposition", "attachment;filename="+new String(filename.getBytes("utf-8"),"iso8859-1"));
response.setContentType("application/ynd.ms-excel;charset=UTF-8");
List<ExcelPackageRefund> packageReturn = excelExportService.exportPackageRefund(bean);
ExcelUtil<ExcelPackageRefund> prbs = new ExcelUtil<ExcelPackageRefund>(ExcelPackageRefund.class);
boolean result = prbs.exportExcel(packageReturn, sheetName,response.getOutputStream());
