Jsonp解决跨域调用问题实战

‍核心：‍前端通过jsonp跨域调用后端接口，接口返回的json必须支持callback回调函数

代码如下：

1、前端jquery

var searchUrl ="${some_url}/tieba/queryTiebaThread4Admin.action";
$.ajax(searchUrl, {
	data: {'tiebaId': tiebaId,'threadId': threadId},
	dataType: 'jsonp',
	type : "get",
	jsonpCallback:"callback",
	jsonp: "callback",
	cache : false,
	crossDomain: true,
	success: function(result) {
		if(result && result.resultCode == 0){
			$("#first_post_id").val(result.data.firstPost);
			$("#title").val(result.data.title);
			showTips('数据搜索有结果',"success");
		}else{
			$("#first_post_id").val('');
			$("#title").val('');
			showTips('未抓取主题帖数据,请检查主题和帖吧ID是否正确',"error");
		}
	},
	error:function(e){
		$("#first_post_id").val('');
		$("#title").val('');
		showTips('未抓取主题帖数据,请稍后重试',"error");
	}
});

2、后端controller

 public Render queryTiebaThread4Admin(@Read(key = "tiebaId") Long tiebaId, @Read(key = "threadId") Long threadId, @Read(key = "callback") String callback) {
        TiebaResult<Map<String,Object>> result = new TiebaResult<Map<String,Object>>();
        Map<String,Object> dataMap = new HashMap<String, Object>();
        try {
            AnchorTieba  tiebaInfo = tiebaQueryManager.getTieba(tiebaId);
            AnchorTiebaThread tiebaThread = threadQueryManager.queryThread(tiebaId, threadId);

            if(tiebaInfo != null && tiebaThread != null){
                dataMap.put("tiebaId",tiebaId);
                dataMap.put("threadId",threadId);
                dataMap.put("tiebaName",tiebaInfo.getName());
                dataMap.put("firstPost",tiebaThread.getFirstPost());
                dataMap.put("title",tiebaThread.getTitle());
                result.setData(dataMap);
            }else{
                result.setResultCode(ErrorCode.NOT_FOUND);
            }
        } catch (Exception e) {
            result.setResultCode(ErrorCode.NOT_FOUND);
            logger.info("queryTiebaThread4Admin:", e);
        }

        StringBuilder resultBuilder = new StringBuilder(JSONObject.fromObject(result).toString());
        if(StringUtils.isNotBlank(callback)){
            resultBuilder.insert(0, '(').insert(0,callback).append(')');
        }
        return new Render(RenderType.TEXT, resultBuilder.toString());
    }