android开发中Retrofit的使用

项目中需要用到retrofit，就写了一个简单的demo，通过get请求去showapi提供的猜一猜接口获取谜语和谜底，返回的数据是json格式的，如下

{
	"showapi_res_code": 0,
	"showapi_res_error": "",
	"showapi_res_body": {
		"Answer": "肚里有文章",
		"Title": "吃棉花拉线团",
		"id": "19663"
	}
}

具体效果如下：

获取猜一猜的链接如下，在这里就主要说下后面拼接的参数有id,showapi_appid,showapi_timestamp,showapi_sign,id为null时随机返回，showapi_appid是你在申请ShowAPI使用时的app id，showapi_sign是你在申请ShowAPI对应app的secret，showapi_timestamp为当前的时间，待会在retrofit的java interface会用到。

https://route.showapi.com/151-2?id=19663&showapi_appid=6135&showapi_timestamp=20150911150757&showapi_sign=67bce2329b8346fbb8f76bcd9c97b626

1.根据我们要访问的url确定创建API接口，代码如下

package acitvity.jason.com.retrofitdemo.rest.service;

import acitvity.jason.com.retrofitdemo.rest.model.ApiResponse;
import retrofit.Callback;
import retrofit.http.GET;
import retrofit.http.Query;

/**
 * Created by jason.Yin on 9/10/15.
 * E-mail:[email protected]
 */
public interface RiddlessService {
    //https://route.showapi.com/151-2?id=&showapi_appid=6135&showapi_timestamp=20150910150022&showapi_sign=55f25393057839b57110f6730eb4ca6a
    //url中只有showapi_timestamp需要变化的
    @GET("/151-2?id=&showapi_appid=6137&showapi_sign=5a648105eb0841c88454ffc32377e760")
     void getRiddles(@Query("showapi_timestamp") String timeStamp, Callback<ApiResponse> callback);
}

2.根据我们需要的json字段创建bean对象

package acitvity.jason.com.retrofitdemo.model;

import com.google.gson.annotations.SerializedName;

import org.parceler.Parcel;

/**
 * Created by jason.Yin on 9/10/15.
 * E-mail:[email protected]
 * <p/>
 * "showapi_res_body": {
 * "Answer": "露了馅",
 * "Title": "饺子脱皮",
 * "id": "22242"
 * }
 */
@Parcel
public class ResponseBody {

    @SerializedName("Title")
    private String riddlesContent;

    @SerializedName("Answer")
    private String riddlesAnswer;

    public String getRiddlesContent() {
        return riddlesContent;
    }

    public String getRiddlesAnswer() {
        return riddlesAnswer;
    }

    @Override
    public String toString() {
        return "ResponseBody{" +
                "riddlesContent='" + riddlesContent + '\'' +
                ", riddlesAnswer='" + riddlesAnswer + '\'' +
                '}';
    }
}

package acitvity.jason.com.retrofitdemo.rest.model;

import com.google.gson.annotations.SerializedName;

import org.parceler.Parcel;

import acitvity.jason.com.retrofitdemo.model.ResponseBody;

/**
 * Created by jason.Yin on 9/10/15.
 * E-mail:[email protected]
 */
@Parcel
public class ApiResponse {
    @SerializedName("showapi_res_body")
    private ResponseBody responseBody;

    public ResponseBody getResponseBody() {
        return responseBody;
    }
}

3.创建retrofit利用gson解析json数据的TypeAdapterFactory

package acitvity.jason.com.retrofitdemo.rest;

import com.google.gson.Gson;
import com.google.gson.JsonElement;
import com.google.gson.JsonObject;
import com.google.gson.TypeAdapter;
import com.google.gson.TypeAdapterFactory;
import com.google.gson.reflect.TypeToken;
import com.google.gson.stream.JsonReader;
import com.google.gson.stream.JsonWriter;

import java.io.IOException;

/**
 * Created by jason.Yin on 9/10/15.
 * E-mail:[email protected]
 */
public class ItemTypeAdapterFactory implements TypeAdapterFactory{
    @Override
    public <T> TypeAdapter<T> create(Gson gson, TypeToken<T> type) {
        final  TypeAdapter<T> delegate = gson.getDelegateAdapter(this,type);
        final  TypeAdapter<JsonElement> elementTypeAdapter = gson.getAdapter(JsonElement.class);
        return new TypeAdapter<T>() {
            @Override
            public void write(JsonWriter out, T value) throws IOException {
                delegate.write(out,value);
            }

            @Override
            public T read(JsonReader in) throws IOException {
                JsonElement jsonElement = elementTypeAdapter.read(in);
                if (jsonElement.isJsonObject()){
                    JsonObject jsonObject = jsonElement.getAsJsonObject();
                    //showapi_res_code只需要把这个换成你自己需要的字段就行
                    if (jsonObject.has("showapi_res_code") && jsonObject.get("showapi_res_code").getAsInt() == -1){
                        throw new IllegalArgumentException(jsonObject.get("message").getAsString());
                    }
                }
                return delegate.fromJsonTree(jsonElement);
            }
        }.nullSafe();
    }
}

4.创建RestAdapter访问网络数据

package acitvity.jason.com.retrofitdemo.rest;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;

import acitvity.jason.com.retrofitdemo.rest.service.RiddlessService;
import retrofit.RestAdapter;
import retrofit.converter.GsonConverter;

/**
 * Created by jason.Yin on 9/10/15.
 * E-mail:[email protected]
 */
public class RestClient {
    private static final String BASE_URL = "https://route.showapi.com";

    private RiddlessService riddlessService;

    public RestClient() {
        Gson gson = new GsonBuilder()
                .registerTypeAdapterFactory(new ItemTypeAdapterFactory())
                .create();

        RestAdapter restAdapter = new RestAdapter.Builder().setLogLevel(RestAdapter.LogLevel.FULL).setEndpoint(BASE_URL).setConverter(new GsonConverter(gson)).build();


        riddlessService = restAdapter.create(RiddlessService.class);


    }

    public RiddlessService getRiddlessService() {
        return riddlessService;
    }
}

5.在Activity中使用RestAdapter访问网络数据

package acitvity.jason.com.retrofitdemo;

import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

import java.text.SimpleDateFormat;
import java.util.Date;

import acitvity.jason.com.retrofitdemo.model.ResponseBody;
import acitvity.jason.com.retrofitdemo.rest.RestClient;
import acitvity.jason.com.retrofitdemo.rest.model.ApiResponse;
import butterknife.Bind;
import butterknife.ButterKnife;
import retrofit.Callback;
import retrofit.RetrofitError;
import retrofit.client.Response;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    @Bind(R.id.tv_no_network)
    TextView displayNetworkStatus;

    @Bind(R.id.tv_riddles_title)
    TextView riddlesTitle;

    @Bind(R.id.tv_riddles_answer)
    TextView riddlewAnswer;

    @Bind(R.id.bt_show_answer)
    Button showAnswer;

    private ResponseBody responseContent;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ButterKnife.bind(this);

        getRiddles();

        showAnswer.setOnClickListener(this);

    }

    @Override
    protected void onResume() {
        super.onResume();
        if (isNetworkConnected()) {
            displayNetworkStatus.setVisibility(View.GONE);
        } else {
            displayNetworkStatus.setVisibility(View.VISIBLE);
            riddlesTitle.setVisibility(View.GONE);
            riddlewAnswer.setVisibility(View.GONE);
        }
    }

    private boolean isNetworkConnected() {
        ConnectivityManager mgr = (ConnectivityManager) this.getSystemService(CONNECTIVITY_SERVICE);
        if (mgr != null) {
            NetworkInfo networkInfo = mgr.getActiveNetworkInfo();
            if (networkInfo != null) {
                return networkInfo.isConnected();
            }
        }
        return false;
    }

    public void getRiddles() {
        SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyyMMddHHmmss");
        String date = simpleDateFormat.format(new Date());
        Log.d("jason", "date=" + date);
        new RestClient().getRiddlessService().getRiddles(date, new Callback<ApiResponse>() {
            @Override
            public void success(ApiResponse apiResponse, Response response) {
                responseContent = apiResponse.getResponseBody();
                riddlesTitle.setText(responseContent.getRiddlesContent());
                showAnswer.setVisibility(View.VISIBLE);
            }

            @Override
            public void failure(RetrofitError error) {
                Log.d("aa", "error" + error.toString());
                riddlesTitle.setVisibility(View.GONE);
                riddlewAnswer.setVisibility(View.GONE);
                displayNetworkStatus.setVisibility(View.VISIBLE);
                displayNetworkStatus.setText(error.toString());

            }
        });
    }

    @Override
    public void onClick(View view) {
        if (R.id.bt_show_answer == view.getId()) {
            if ("显示谜底".equals(showAnswer.getText())) {
                riddlewAnswer.setVisibility(View.VISIBLE);
                riddlewAnswer.setText(responseContent.getRiddlesAnswer());
                showAnswer.setText("换个谜语");
            } else {
                getRiddles();
                showAnswer.setText("显示谜底");
                riddlewAnswer.setVisibility(View.GONE);
            }
        }
    }
}

在build.gradle需要配置下面的一些库

apply plugin: 'com.android.application'

android {
    compileSdkVersion 23
    buildToolsVersion "23.0.1"

    defaultConfig {
        applicationId "acitvity.jason.com.retrofitdemo"
        minSdkVersion 11
        targetSdkVersion 23
        versionCode 1
        versionName "1.0"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }

    packagingOptions {
        exclude 'META-INF/services/javax.annotation.processing.Processor'
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    compile 'com.android.support:appcompat-v7:23.0.1'
    compile 'com.squareup.retrofit:retrofit:1.6.1'
    compile 'com.jakewharton:butterknife:7.0.1'
    compile 'org.parceler:parceler:1.0.3'
    compile 'com.google.code.gson:gson:2.3.1'
}

基本上就这些了，主要是用retrofit去访问网络，还用到了butterknife,parceler,gson这些库文件简化代码的书写， 源码下载地址