json - 连接 JSONArray 会向 groovy 中的字符串添加双引号

Question

我有 grails 应用程序可以进行 REST 调用。如果发生错误，则返回包含错误消息的 JSON 数组。我需要将这些字符串组合成一个字符串。但是，当我这样做时，双引号会添加到字符串的前面和末尾。我写了一个简单的测试 Controller 来说明问题:

import net.sf.json.*
class MyController {

    def test = {

        String msg = "'fred' is not a valid LDAP distinguished name."
        JSONArray messages = new JSONArray()
        messages.add(msg)
        def renderStr = messages.join('<br/>')

        render(renderStr)
    }
}

输出如下所示:

"'fred' is not a valid LDAP distinguished name."

Answer 1

问题是 join 函数返回 JSON-spec 字符串...根据他们的文档: http://grails.org/doc/1.0.3/api/org/codehaus/groovy/grails/web/json/JSONArray.html

 The texts produced by the toString methods strictly conform to JSON syntax rules. The constructors are more forgiving in the texts they will accept:

    An extra , (comma) may appear just before the closing bracket.
    The null value will be inserted when there is , (comma) elision.
    Strings may be quoted with ' (single quote).
    Strings do not need to be quoted at all if they do not begin with a quote or single quote, and if they do not contain leading or trailing spaces, and if they do not contain any of these characters: { } [ ] / \ : , = ; # and if they do not look like numbers and if they are not the reserved words true, false, or null.
    Values can be separated by ; (semicolon) as well as by , (comma).
    Numbers may have the 0- (octal) or 0x- (hex) prefix.
    Comments written in the slashshlash, slashstar, and hash conventions will be ignored.

请注意，“如果字符串不以引号或单引号开头，则根本不需要加引号”这一规则就是所发生的情况。您的字符串以引号开头，因此如果输出时不带引号，JSON 解析器将假定字符串以第二个单引号结束，之后的文本将是无法解析的垃圾。