内容简介
本文主要内容为使用java把内容写入文本文件，并实现下载/导出的功能。
实现步骤
1. controller层
@ResponseBody
@RequestMapping(value = "/exportLand2ndClassIndex", method = RequestMethod.GET)
public ResponseEntity<byte[]> exportLand2ndClassIndex(){
return extractTifService.exportLand2ndClassIndex();
}
2. 服务实现层，请自行定义服务接口，这里不展示了
/**
* 导出
* @return CallbackBody
*/
@Override
public ResponseEntity<byte[]> exportLand2ndClassIndex(){
//查询表数据
List<TswatLuc2ndClassIndex> list = tswatLuc2ndClassIndexDao.queryAllClassIndex();
if (list == null || list.size() <= 0){
return null;
}
List txtContentList = new ArrayList();
txtContentList.add("\"value\",\"name\"");
for(TswatLuc2ndClassIndex classIndex : list){
String value = classIndex.getLevel2Code();
String name = classIndex.getSwat();
txtContentList.add(value + "," + name);
}
//导出的文件存储目录
String fileSavePath = GisPathConfigurationUtil.getSwatLuc2ndClassIndexTxtFileSavePath();
//保存文本文件
writeToTxt(txtContentList, fileSavePath);
//获取文本文件的ResponseEntity
try{
ResponseEntity<byte[]> fileByte = buildResponseEntity(new File(fileSavePath));
return fileByte;
}catch (Exception e){
e.printStackTrace();
return null;
}
} /**
* 将数据写入文本文件
* @param list
* @param path
*/
private void writeToTxt(List list,String path) { String dir = path.substring(0,path.lastIndexOf("\\"));
File parent = new File(dir);
if (parent != null && !parent.exists()) {
parent.mkdirs();
}
FileOutputStream outSTr = null;
BufferedOutputStream Buff = null;
String enter = "\r\n";
StringBuffer write ;
try {
outSTr = new FileOutputStream(new File(path));
Buff = new BufferedOutputStream(outSTr);
for (int i = 0; i < list.size(); i++) {
write = new StringBuffer();
write.append(list.get(i));
write.append(enter);
Buff.write(write.toString().getBytes("UTF-8"));
}
Buff.flush();
Buff.close();
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
Buff.close();
outSTr.close();
} catch (Exception e) {
e.printStackTrace();
}
}
} //读取文件
private ResponseEntity<byte[]> buildResponseEntity(File file) throws IOException {
byte[] body = null;
//获取文件
InputStream is = new FileInputStream(file);
body = new byte[is.available()];
is.read(body);
HttpHeaders headers = new HttpHeaders();
//设置文件类型
headers.add("Content-Disposition", "attchement;filename=" + file.getName());
//设置Http状态码
HttpStatus statusCode = HttpStatus.OK;
//返回数据
ResponseEntity<byte[]> entity = new ResponseEntity<byte[]>(body, headers, statusCode);
return entity;
}