Retrofit2使用初探

首先需要导入这样两个包

 compile 'com.squareup.retrofit2:retrofit:2.0.0-beta4'
 compile 'com.squareup.retrofit2:converter-gson:2.0.0-beta4'

写model，这里参照的是淘宝ip库，地址类似这种，http://ip.taobao.com/service/getIpInfo.php?xxx.xxx.xxx.xxx，最后xxx为你要查询的ip

json有了，写model，可以在JSON字符串转换成Java实体类(POJO)这个网站中将json转成java实体类，对于这个json，实体类转化出来是这个样子

IPModel.java

 public class IPModel {
     private int code;

     private IPDataModel data;

     public void setCode(int code){
         this.code = code;
     }
     public int getCode(){
         return this.code;
     }
     public void setData(IPDataModel data){
         this.data = data;
     }
     public IPDataModel getData(){
         return this.data;
     }

 }

IPDataModel.java

 public class IPDataModel {
     private String country;

     private String country_id;

     private String area;

     private String area_id;

     private String region;

     private String region_id;

     private String city;

     private String city_id;

     private String county;

     private String county_id;

     private String isp;

     private String isp_id;

     private String ip;

     public void setCountry(String country){
         this.country = country;
     }
     public String getCountry(){
         return this.country;
     }
     public void setCountry_id(String country_id){
         this.country_id = country_id;
     }
     public String getCountry_id(){
         return this.country_id;
     }
     public void setArea(String area){
         this.area = area;
     }
     public String getArea(){
         return this.area;
     }
     public void setArea_id(String area_id){
         this.area_id = area_id;
     }
     public String getArea_id(){
         return this.area_id;
     }
     public void setRegion(String region){
         this.region = region;
     }
     public String getRegion(){
         return this.region;
     }
     public void setRegion_id(String region_id){
         this.region_id = region_id;
     }
     public String getRegion_id(){
         return this.region_id;
     }
     public void setCity(String city){
         this.city = city;
     }
     public String getCity(){
         return this.city;
     }
     public void setCity_id(String city_id){
         this.city_id = city_id;
     }
     public String getCity_id(){
         return this.city_id;
     }
     public void setCounty(String county){
         this.county = county;
     }
     public String getCounty(){
         return this.county;
     }
     public void setCounty_id(String county_id){
         this.county_id = county_id;
     }
     public String getCounty_id(){
         return this.county_id;
     }
     public void setIsp(String isp){
         this.isp = isp;
     }
     public String getIsp(){
         return this.isp;
     }
     public void setIsp_id(String isp_id){
         this.isp_id = isp_id;
     }
     public String getIsp_id(){
         return this.isp_id;
     }
     public void setIp(String ip){
         this.ip = ip;
     }
     public String getIp(){
         return this.ip;
     }
 }

接下来写实现IPUtils.java

 public class IPUtils {
     static final String URL = "http://ip.taobao.com/service/";
     public interface IPService{
         @GET("getIpInfo.php")
         Call<IPModel> getIpMsg(@Query("ip")String ip);
     }
 　　
     static Retrofit retrofit = new Retrofit.Builder().baseUrl(URL).addConverterFactory(GsonConverterFactory.create()).build();

     public static IPService ipService = retrofit.create(IPService.class);

 }

好了，现在可以用了，在activity中使用

 　　　　　Call<IPModel> call = IPUtils.gitHubService.getIpMsg("这里填写我的ip");
         call.enqueue(new Callback<IPModel>() {
             @Override
             public void onResponse(Call<IPModel> call, Response<IPModel> response) {
                 //这里的response就可以提取数据了
                 Log.i(TAG, response.body().getData().getCountry());
             }

             @Override
             public void onFailure(Call<IPModel> call, Throwable t) {
 //                Log.e("MainActivity", t.toString());
             }
         });