java反射技术应用--灵活导出excel

业务需求如下：

根据开始和结束时间查询，时间段内的工资明细，并导出Excel表格(根据选中的字段导出该列数据)

Excel共3列数据 

|  年       |  月            | 具体工资明细项     如：绩效，岗位补贴等 

|  year     | month      |   value

实体类如下

public class Salary implements Serializable{

/**
*
*/
private static final long serialVersionUID = 1L;
private String deptCode="";
private String deptName=""
private String pay="";
.
.
.此处省略多个字段

     public String getDeptCode() {
         return deptCode;
    }
    public void setDeptCode(String deptCode) {
        this.deptCode = deptCode;
    };
public String getDeptName() {
        return deptName;
    }
    public void setDeptName(String deptName) {
        this.deptName = deptName;
    }
public String getPay() {
        return pay;
    }
    public void setPay(String pay) {
        this.pay = pay;
    }

}

@Controller
@RequestMapping("/salary")
public class SalaryController {

/**
*
* @param session
* @param startDate 起始时间
* @param endDate 结束时间
* @param model
* @param type 导出工资明细类型
* @return
*/
@RequestMapping(value = "/exportDataWithType", method = RequestMethod.GET)
public ModelAndView exportDataWithType(HttpSession session,
@RequestParam(required=false) Date startDate,@RequestParam(required=false) Date endDate,
ModelMap model,@RequestParam(required=false)String type) {

BaseUsers user = (BaseUsers)session.getAttribute(WebConstants.CURRENT_USER);
//设置查询条件
Criteria criteria = new Criteria();
if(StringUtils.isNotBlank(user.getUserCode())){
criteria.put("staffCode", user.getUserCode());
}
if(startDate != null){
criteria.put("startDate", startDate);
}
if(endDate != null){
criteria.put("endDate", endDate);
}
//经过筛选后的数据
List<Salary> newList = new ArrayList<Salary>();
try {
//查询所有数据
List<Salary> list = salaryService.queryListGerenForPage(criteria);
for(Salary li:list){
Salary salary = new Salary();
salary.setYear(li.getYear());
salary.setMonth(li.getMonth());
//根据选择的明细  对第三列的值进行设置   setTing方法
 setThing(salary,type,getGetMethod(li,type));
newList.add(salary);
}
} catch (Exception e) {
e.printStackTrace();
}
ViewExcel2 viewExcel = new ViewExcel2();

model.put("data", newList);
return new ModelAndView(viewExcel, model);
}

/**
* 根据属性名获取get方法，并获取对应值
* @param obj  实体类
* @param filed  属性名
* @return 返回该属性对应的值
*/
public  static Object getGetMethod(Object obj, String filed) {
Object o = null;
try {
Class clazz = obj.getClass();
PropertyDescriptor pd = new PropertyDescriptor(filed, clazz);
Method getMethod = pd.getReadMethod();//获得get方法
if (pd != null) {
o = getMethod.invoke(obj);//执行get方法返回一个Object
}
}catch(Exception e) {
e.printStackTrace();
}
return o;

}

/**
* 获取对应set方法 并将值赋进去
* @param obj 实体类
* @param type 传入工资明细类型 pay
* @param s 需要设置的参数值  "1000.0"
*/
public static void setThing(Object obj,String type,Object s){
Field field = null;
try {
field = obj.getClass().getDeclaredField(type);
} catch (NoSuchFieldException e) {
e.printStackTrace();
} catch (SecurityException e) {
e.printStackTrace();
}
field.setAccessible(true);
try {
field.set((Object) obj, s);
} catch (IllegalArgumentException e1) {
e1.printStackTrace();
} catch (IllegalAccessException e1) {
e1.printStackTrace();
}
}

//内部类 生成Excel表格
class ViewExcel2 extends AbstractExcelView {
@Override
protected void buildExcelDocument(Map<String, Object> model,
HSSFWorkbook workbook, HttpServletRequest request,
HttpServletResponse response) throws Exception {
response.setContentType("application/vnd.ms-excel");
response.setHeader("Content-disposition", "attachment;filename="+ new String("个人工资表.xls".getBytes(), "iso8859-1"));
List<Salary> data = (List<Salary>) model.get("data");
int rowNum = 1;
HSSFRow row = null;
HSSFSheet sheet = workbook.createSheet("新生列表");
// 设置样式
HSSFFont cnFont = workbook.createFont();
cnFont.setFontHeightInPoints((short) 10);
cnFont.setFontName("宋体");
HSSFCellStyle cnStyle = workbook.createCellStyle();
cnStyle.setFont(cnFont);
String password = null;
// 设置首行信息
HSSFRow headerRow = sheet.createRow(0);
this.setExcelHeader(headerRow, data);
if (data != null) {
for (Salary s : data) {
row = sheet.createRow(rowNum++);
//设置年份
 createNewCell(row, cnStyle, 0, s.getYear());
//设置月份
 createNewCell(row, cnStyle, 1, s.getMonth());

Field[] fields = s.getClass().getDeclaredFields();
String[]   name   =   new   String[fields.length];
//获取实体类 所有private 属性
Object[]   value   =   new  Object[fields.length];
try{
Field.setAccessible(fields,   true);
for   (int i = 0;i < name.length; i++)   {
//属性名
name[i]   =   fields[i].getName();
//属性值
value[i]   =   fields[i].get(s);
if(fields[i].get(s)!=null && fields[i].get(s)!=""){
//本业务逻辑
if(!(name[i].equals("year")) && !(name[i].equals("month")) &&! (name[i].equals("serialVersionUID")) ){
//往  Excel 中第三列赋值    | year | month  |fields[i].get(s).toString()   共三列
createNewCell(row, cnStyle, 2,fields[i].get(s).toString());
}
}
}
}
catch(Exception   e){
e.printStackTrace();
}

}
}
// 设置首行信息
OutputStream ouputStream = response.getOutputStream();
workbook.write(ouputStream);
ouputStream.flush();
ouputStream.close();
}

/**
* 按顺序设置表头
* 工资由多个不同项组成  根据需要导出的类型不同 设置表头信息
* @return
*/
private void setExcelHeader(HSSFRow headerRow,List<Salary> data) {
headerRow.createCell(0).setCellValue("年份");
headerRow.createCell(1).setCellValue("月份");

if(StringUtils.isNotBlank(data.get(0).getWages())){
headerRow.createCell(2).setCellValue("应发额");
}else if(StringUtils.isNotBlank(data.get(0).getPostWage())){
headerRow.createCell(2).setCellValue("岗资");
}else if(StringUtils.isNotBlank(data.get(0).getPay())){
headerRow.createCell(2).setCellValue("薪资");
}
.
.此处省略多个情况判断
.

else if(StringUtils.isNotBlank(data.get(0).getMeritPay())){
headerRow.createCell(2).setCellValue("绩效");
}else if(StringUtils.isNotBlank(data.get(0).getTask())){
headerRow.createCell(2).setCellValue("岗位津贴");
}

}

/**
* 生成单元格
*
* @param row
* @param style
* @param columnIndex
* @param value
*/
private void createNewCell(HSSFRow row, HSSFCellStyle style,
int columnIndex, String value) {
if (row != null) {
HSSFCell cell = row.createCell(columnIndex);
cell.setCellStyle(style);
if (value != null) {
cell.setCellValue(value);
}
}
}

}

}