说一下我的项目中遇到的一个问题,后台生成一个json字符串,然后在freemarker模板中,将json字符串转成json对象保存到localstorage中,刚开始不知道freemarker默认是输出做了转义的,导致输出的JSON字符串被转义,从而导致JSON.parse无法转成json对象.后面看了一个官方文档然后使用no_esc内置函数就把问题解决了
服务端代码
@GetMapping("/test")
public String test(RedirectAttributes redirectAttributes) throws JsonProcessingException {
redirectAttributes.addFlashAttribute(CeHuiConstant.FLASH_USER_KEY, objectMapper.writeValueAsString(new User()));
return "redirect:/index";
}
@GetMapping
public String index(Model model) {
return "index";
}
页面代码
<#if flash_user??>
var user = JSON.parse('${flash_user}');
store.set("user", user, new Date().getTime() + 30 * 60 *1000);
</#if>
输出的内容
<script type="text/javascript">
var user = JSON.parse('{"id":null,"phone":"","username":"","openid":"","nickname":"","sex":"UNKNOWN","province":"","city":"","country":"","headimgurl":"","unionid":"","status":"PERMIT","bindPhone":"NO_BIND"}');
store.set("user", user, new Date().getTime() + 30 * 60 *1000);
</script>
使用no_esc解决此问题
将页面中的代码修改
<script type="text/javascript">
<#if flash_user??>
var user = JSON.parse('${flash_user?no_esc}');
store.set("user", user, new Date().getTime() + 30 * 60 *1000);
</#if>
</script>
输出的内容
<script type="text/javascript">
var user = JSON.parse('{"id":null,"phone":"","username":"","openid":"","nickname":"","sex":"UNKNOWN","province":"","city":"","country":"","headimgurl":"","unionid":"","status":"PERMIT","bindPhone":"NO_BIND"}');
store.set("user", user, new Date().getTime() + 30 * 60 *1000);
</script>
使用no_esc就可以禁止"被转义了.
freemarker在springmvc框架中因为主要是用来做页面模板引擎的,所以为了网站的安全字符串输出默认是使用html转义的,但是如果输入的内容不希望freemarker转义怎么搞呢.那就是no_esc了,注意freemarker版本,此功能是freemarker 2.3.24引入的新内置函数.
看一个官方文档的例子
no_esc
Note:
This built-in is available since FreeMarker 2.3.24.
Prevents the auto-escaping of a value. For example:
TEMPLATE
<#ftl output_format="HTML">
<#assign s = "<b>Test</b>">
{s?no_esc}
OUTPUT
<b>Test</b>
<b>Test</b>
