配置Jackson以反序列化单引号(无效)JSON

Question

我是使用杰克逊图书馆的新手.

我试图这样做[见下文],它正在抛出错误.

String x="{'candidateId':'k','candEducationId':1,'activitiesSocieties':'Activities for cand1'}";
ObjectMapper mapper = new ObjectMapper();

try {
    JsonNode df=mapper.readValue(x,JsonNode.class);
    int i=0;
} catch .....

例外:

org.codehaus.jackson.JsonParseException: Unexpected character (''' (code 39)): was expecting double-quote to start field name
at [Source: java.io.StringReader@1afd1810; line: 1, column: 3]
  at org.codehaus.jackson.JsonParser._constructError(JsonParser.java:1291)

如果我用双引号(")替换单引号('),同样的事情也有效.

Answer 1

这不是有效的JSON,但你可以告诉杰克逊允许它.这是如何做.

String x = "{'candidateId':'k','candEducationId':1,'activitiesSocieties':'Activities for cand1'}";
ObjectMapper mapper = new ObjectMapper();
mapper.configure(JsonParser.Feature.ALLOW_SINGLE_QUOTES, true);
JsonNode df = mapper.readValue(x, JsonNode.class);
System.out.println(df.toString());
// output: {"candidateId":"k","candEducationId":1,"activitiesSocieties":"Activities for cand1"}

Answer 2

JSON中的字符串只能使用双引号(")而不是单引号(')来指定,这就是出错的原因; 使用双引号.

这是指定有效JSON字符串的管道图(注意它们只能用双引号封装!)

有效的JSON字符串管道图http://www.json.org/string.gif

(有关JSON的完整规范,请参阅json.org.)