Question

尝试使用JSON格式将请求数据从JavaScript转换为Java。 JavaScript中的请求正文如下所示：

{
    "id": "3",
    "name": "Chicken pasta",
    "description": "Lets make chicken pasta",
    "category": "Unassigned",
    "favorite": true,
    "prepTime": "",
    "cookTime": "",
    "ingredients": [
        {}
    ],
    "steps": [],
    "user": {
        "id": "2",
        "username": "user2"
    }
}

但是在服务器端（在我的Java控制器中）它是：

%7B%0A%09%22id%22%3A+%223%22%2C%0A%09%22name%22%3A+%22Chicken+pasta%22%2C%0A%09%22description%22%3A+%22Lets+make+chicken+pasta%22%2C%0A%09%22category%22%3A+%22Unassigned%22%2C%0A%09%22favorite%22%3A+true%2C%0A%09%22prepTime%22%3A+%22%22%2C%0A%09%22cookTime%22%3A+%22%22%2C%0A%09%22ingredients%22%3A+%5B%0A%09%09%7B%7D%0A%09%5D%2C%0A%09%22steps%22%3A+%5B%5D%2C%0A%09%22user%22%3A+%7B%0A%09%09%22id%22%3A+%222%22%2C%0A%09%09%22username%22%3A+%22user2%22%0A%09%7D%0A%7D=

所以我得到了JSON解析异常。怎么编码呢？

Answer 1

您在服务器上收到的字符串是URL编码的。您需要对URL进行URL解码，然后才能将其解析为JSON。有关java中的URL解码，请参阅this SO question。

Answer 2

是的，托马斯，你说对了，我已经发现了。但是没有使用过URLDecoder.decode，只写了我自己的几行代码：）

   public static String toDecimal (String hexStr) {
        char[] hex = hexStr.toCharArray();
        char current;
        String result = "";
        for (int i=0;i<hex.length;i++) {
            if (hex[i] == '%') {
                current = (char) ((toDecimal(hex[i+1]) * 16) + toDecimal(hex[i+2]));
                i+=2;
            } else {
                if (hex[i] == '+') {
                    current = ' ';
                } else {
                    current = hex[i];
                }
            }
            result += current;
        }
        while (!(result.endsWith("}") || result.endsWith("]"))) {
            result = result.substring(0, result.length()-1);
        }
        return result;
    }

    private static int toDecimal (char hex) {
        switch (hex) {
            case '0': return 0;
            case '1': return 1;
            case '2': return 2;
            case '3': return 3;
            case '4': return 4;
            case '5': return 5;
            case '6': return 6;
            case '7': return 7;
            case '8': return 8;
            case '9': return 9;
            case 'A': return 10;
            case 'B': return 11;
            case 'C': return 12;
            case 'D': return 13;
            case 'E': return 14;
            case 'F': return 15;
        }
        return -1;
    }

与前面提到的URLDecoder.decode方法相同的结果，但是我的函数也从末尾删除所有字符而没有找到Json（'}'或']'的结尾），我不知道为什么，但我得到了字符串来自JS以'='符号结尾。

char设置有什么问题？

2 个答案: