签名算法

签名规则:

    第一步:将⾮空输入参数按照参数名(key)进行升序排序(排序规则:ASCII码从小到⼤排序-字典序排序。例如：
           排序前   api_method,api_version,app_key,access_token,timestamp,nonce_str,api_data                      排序后      access_token,api_data,api_method,api_version,app_key,nonce_str,timestamp
       第二步:按照url键值对的形式（key=value&key=value）拼接参数名与参数值。形成字符串。
           示例:access_token=xxx&api_data=xxx&api_method=xxx&api_version=xxx&app_key=xxx&nonce_str=xxx&timestamp=xxx
    第三步: 在字符串末尾，拼接加入”app_secret“的值(不含app_secret的键)
           示例:access_token=xxx&api_data=xxx&api_method=xxx&api_version=xxx&app_key=xxx&nonce_str=xxx×tamp=xxxapp_secret的值


    第四步: 对字符串进行Md5运算(运算方式:32位小写),得到签名参数“signature"的值
           示例:string signature= Md5(拼接后的字符串)

签名示例:

1.假设现在有如下输入参数

{
         "api_method":"u-city-list",
         "api_version":"1.0",
         "app_key":"wxd930ea5d5a258f4f",
         "access_token":"xxxx",
         "nonce_str":"ibuaiVcKdpRxkhJA",
         "timestamp":"1559096649",
         "signature":"xxxx",
         "api_data":{              "city_id":1002,
              "order_vehicle_id":402,
              "vehicle_std":["双排座"],
              "spec_req":[2,5],
              "city_info_revision":296,
              "order_time":1568895707,
              "addr_info":[{
                    "name":"维也纳国际酒店(深圳北站店)",
                    "addr":"深圳市⻰华区致远中路2号",
                    "city_id":1002,
                    "city_name":"深圳",
                    "district_name":"宝安区",
                    "house_number":"20层2003号房",
                    "contacts_name":"刘⽣",
                    "contacts_phone_no":"136999969966",
                    "lat_lon":{
                         "lon":114.02309914676592,
                         "lat":22.609618527821251
                    }
               },
               {
                    "name":"⻓城开发⾼层公寓",
                    "addr":"皇岗路5000号",
                    "city_id":1002,
                    "city_name":"深圳",
                    "district_name":"福⽥区",
                    "house_number":"",
                    "contacts_name":"",
                    "contacts_phone_no":"",
                    "lat_lon":{
                         "lon":114.06548381551384,
                         "lat":22.569156830453188
                    }
                }]
            }
}

2.先对输入参数中非空值参数按照(ascii字典序)进行升序排序,排序结果如下

{
    "access_token":"xxxx",
    "api_data":{
        "city_id":1002,
        "order_vehicle_id":402,
        "vehicle_std":["双排座"],
        "spec_req":[2,5],
        "city_info_revision":296,
        "order_time":1568895707,
        "addr_info":[{
                "name":"维也纳国际酒店(深圳北站店)",
                "addr":"深圳市⻰华区致远中路2号",
                "city_id":1002,
                "city_name":"深圳",
                "district_name":"宝安区",
                "house_number":"20层2003号房",
                "contacts_name":"刘⽣",
                "contacts_phone_no":"136999969966",
                "lat_lon":{
                    "lon":114.02309914676592,
                    "lat":22.609618527821251
                }
            },
            {
                "name":"⻓城开发⾼层公寓",
                "addr":"皇岗路5000号",
                "city_id":1002,
                "city_name":"深圳",
                "district_name":"福⽥区",
                "house_number":"",
                "contacts_name":"",
                "contacts_phone_no":"",
                "lat_lon":{
                    "lon":114.06548381551384,
                    "lat":22.569156830453188
                }
            }
        ]
    },
    "api_method":"u-city-list",
    "api_version":"1.0",
    "app_key":"wxd930ea5d5a258f4f",
    "nonce_str":"ibuaiVcKdpRxkhJA",
    "timestamp":"1559096649"
}

3.按照key=value&key=value的格式形成键值对,并使用&符号拼接各个键值对,示例如下:

"access_token=xxxxx&
 api_data={
        "city_id":1002,
        "order_vehicle_id":402,
        "vehicle_std":["双排座"],
        "spec_req":[2,5],
        "city_info_revision":296,
        "order_time":1568895707,
        "addr_info":[{
                "name":"维也纳国际酒店(深圳北站店)",
                "addr":"深圳市⻰华区致远中路2号",
                "city_id":1002,
                "city_name":"深圳",
                "district_name":"宝安区",
                "house_number":"20层2003号房",
                "contacts_name":"刘⽣",
                "contacts_phone_no":"136999969966",
                "lat_lon":{
                    "lon":114.02309914676592,
                    "lat":22.609618527821251
                }
            },
            {
                "name":"⻓城开发⾼层公寓",
                "addr":"皇岗路5000号",
                "city_id":1002,
                "city_name":"深圳",
                "district_name":"福⽥区",
                "house_number":"",
                "contacts_name":"",
                "contacts_phone_no":"",
                "lat_lon":{
                    "lon":114.06548381551384,
                    "lat":22.569156830453188
                }
            }
        ]
 }&
 api_method=xxx&
 api_version=xxx&
 app_key=xxx&
 nonce_str=xxx&
 timestamp=xxx
"

4.尾部加入app_secret的值,假设app_secret=192006250b4c09247ec02edce69f6a2d,示例如下：

"access_token=xxxxx&
 api_data={
        "city_id":1002,
        "order_vehicle_id":402,
        "vehicle_std":["双排座"],
        "spec_req":[2,5],
        "city_info_revision":296,
        "order_time":1568895707,
        "addr_info":[{
                "name":"维也纳国际酒店(深圳北站店)",
                "addr":"深圳市⻰华区致远中路2号",
                "city_id":1002,
                "city_name":"深圳",
                "district_name":"宝安区",
                "house_number":"20层2003号房",
                "contacts_name":"刘⽣",
                "contacts_phone_no":"136999969966",
                "lat_lon":{
                    "lon":114.02309914676592,
                    "lat":22.609618527821251
                }
            },
            {
                "name":"⻓城开发⾼层公寓",
                "addr":"皇岗路5000号",
                "city_id":1002,
                "city_name":"深圳",
                "district_name":"福⽥区",
                "house_number":"",
                "contacts_name":"",
                "contacts_phone_no":"",
                "lat_lon":{
                    "lon":114.06548381551384,
                    "lat":22.569156830453188
                }
            }
        ]

 }&
 api_method=xxx&
 api_version=xxx&
 app_key=xxx&
 nonce_str=xxx&
 timestamp=xxx
 app_secret的值"

5. 对最终形成的字符串进行md5运算（32位小写）,示例如下,运算结果就是签名值signature
```
String signature=Md5(str); 
```