用jackson输出标准的json字符串

public class JacksonObjectMapperExample {

    public static String formatJson(String jsonStr) throws IOException {
        ObjectMapper objectMapper = new ObjectMapper();
        // 允许没有引号的字段名（非标准）
        objectMapper.configure(JsonParser.Feature.ALLOW_UNQUOTED_FIELD_NAMES, true);
        // 允许单引号（非标准）
        objectMapper.configure(JsonParser.Feature.ALLOW_SINGLE_QUOTES, true);
        Object json = objectMapper.readValue(jsonStr, Object.class);
        //美化
        //System.out.println(objectMapper.writerWithDefaultPrettyPrinter().writeValueAsString(json));
        //objectMapper.configure(SerializationFeature.INDENT_OUTPUT, true);
        //不美化
        objectMapper.configure(SerializationFeature.INDENT_OUTPUT, false);

        return objectMapper.writeValueAsString(json);
    }

    public static void main(String[] args) throws IOException {
        String test = "{age:29,messages:["msg 1","msg 2","msg 3"],"name":"mkyong"}";
        System.out.println(formatJson(test));
    }
}