java 文件上传到读取文件内容的实例

public String uploadFile() throws Exception {
logger.info("开始导入规则文件：" + fileInputFileName);
InputStream is = new FileInputStream(fileInput);
String uploadPath = ServletActionContext.getServletContext()
.getRealPath("/upload");
System.out.println(uploadPath);
File targetFile = new File(uploadPath, this.getFileInputFileName());
OutputStream os = new FileOutputStream(targetFile);
byte[] buffer = new byte[1024];
int length = 0;
while ((length = is.read(buffer)) > 0) {
os.write(buffer, 0, length);
}
is.close();
os.close();
Map<String, Object> map = personalKPIMonitorManualRuleService
.importRules(targetFile);
HttpServletResponse response = ServletActionContext.getResponse();
response.setContentType("text/html;charset=utf-8");
PrintWriter out = response.getWriter();
out.println(JSONObject.fromObject(map));
// if(flag==true){
// logger.info("规则文件导入成功："+fileInputFileName);
// out.println("规则文件导入成功："+fileInputFileName);
// }else{
// logger.info("规则文件导入失败："+fileInputFileName);
// out.println("规则文件导入失败，详见日志："+fileInputFileName);
// }
out.flush();
out.close();
return null;
}