@ResponseBody
@RequestMapping(value="/kjhjdh" ,produces = {"application/text;charset=UTF-8"})//加此中文乱码解除
public String returnAudit(AssignCaseForm assignCaseForm,HttpServletRequest request,HttpServletResponse response) throws IOException{
request.setCharacterEncoding("utf-8");  
response.setContentType("text/html;charset=utf-8");
HandleInfo handleInfo=assignCaseForm.getHandleInfo();
handleInfo=(HandleInfo) applyRegisterService.getRetHandleInfo(handleInfo.getAppNo());//更新总局业务信息，保存发送机关
assignCaseForm.setHandleInfo(handleInfo);
String str=handleInfo.getHandleOpinion();

return str;

}

前台页面用此接收时出现中文乱码

	 $.ajax({  type:'post',      url: "<%=request.getContextPath()%>/cases/assign/returnAudit", data:$("#assignCaseForm").serialize(),  success:function(data){ alert(data); }  });