框架：springboot, poi, freemarker, jquery
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.10.RELEASE</version>
</parent>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-freemarker</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<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>
</dependencies>
前端代碼：
customer-export.ftl
<a id="btnExport" class="easyui-linkbutton" data-options="iconCls:'icon-save'" style="width:120px;border:none;">Export</a>
customer-export.js
$("#btnExport").click(downloadReport);
function downloadReport(){
var queryParams = function(){...};
if(!queryParams) return;
// failed to open excel file when using ajax to request, so here i use XMLHttpRequest
var xhr = new XMLHttpRequest();
xhr.open('GET', '/customer/download' + stringifyParams(queryParams,true), true);
xhr.responseType = 'blob';
xhr.onload = function(){
var content = xhr.response;
var el = document.createElement('a');
el.download = 'reports.xls';
el.style.display = 'none';
var blob = new Blob([content]);
el.href = URL.createObjectURL(blob);
document.body.appendChild(el);
el.click();
document.body.removeChild(el);
};
xhr.send();
}
// format params into url parameter format
function stringifyParams (data, isPrefix) {
var prefix = isPrefix ? '?' : '',
result = [];
for (var key in data) {
var value = data[key];
if (['', undefined, null].includes(value)) {
continue;
}
if (value.constructor === Array) {
value.forEach(function(val, key){
result.push(encodeURIComponent(key) + '[]=' + encodeURIComponent(val));
});
} else {
result.push(encodeURIComponent(key) + '=' + encodeURIComponent(value))
}}
return result.length ? prefix + result.join('&') : '';
}
// besides, we can use form to request the download, code as follow:
/*
function downloadReport(){
var queryParams = getQueryParams();
if(!queryParams) return;
var downloadForm = $("<form method='get'></form>");
downloadForm.attr("action","/customer/download");
$(document.body).append(downloadForm);
downloadForm.submit();
}
*/
後端代碼：
@RestController
@RequestMapping("/customer")
public class CustomerController {
@Autowired
private ExcelUtil<Customer> excelUtil;
@GetMapping("/download")
public void download(QueryCriteria criteria, HttpServletResponse response) {
response.setContentType("application/octet-stream");
response.setHeader("Content-Disposition", "attachment;filename=reports.xls");
List<String> titles = ...;
List<String> fields = ...;
List<Customer> customers = customerService.find(criteria);
Workbook workbook = excelUtil.write(titles,fields,customers);
try (OutputStream os = response.getOutputStream()) {
workbook.write(os);
} catch (IOException e) {
//...}}}
/**
excel handler type
*/
@Component
public class ExcelUtil<T> {
/**
* write out excel file
* @param titles title of every column
* @param fields field name of type T
* @param data list data to be written in Workbook object
* @return an instance of Workbook
*/
public Workbook write(List<String> titles, List<String> fields, List<T> data) {
if (null == titles || null == fields || null == data)
return null;
Workbook wb = new HSSFWorkbook();
Sheet s1 = wb.createSheet();
// create title row
Row row = s1.createRow(0);
for (int i = 0; i < titles.size(); i++) {
Cell cell = row.createCell(i);
String title = titles.get(i);
cell.setCellValue(title);
}
int index = 1;
for (T t : data){
row = s1.createRow(index);
for (int i=0;i<fields.size();i++){
try {
Field field = t.getClass().getDeclaredField(fields.get(i));
field.setAccessible(true);
setCell(row.createCell(i), field.get(t));
} catch (NoSuchFieldException | IllegalAccessException e) {
throw new RuntimeException(e);
}
}
index++;
}
return wb;
}
private void setCell(Cell c, Object val) {
SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
if (val instanceof Double) {
c.setCellValue((Double) val);
} else if (val instanceof Date) {
String time = simpleDateFormat.format((Date) val);
c.setCellValue(time);
} else if (val instanceof Calendar) {
Calendar calendar = (Calendar) val;
String time = simpleDateFormat.format(calendar.getTime());
c.setCellValue(time);
} else if (val instanceof Boolean) {
c.setCellValue((Boolean) val);
} else {
if (val != null) {
c.setCellValue(String.valueOf(val));
}}}}