网络通信框架之retrofit

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主页: [https://github.com/square/retrofit](https://github.com/square/retrofit)

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注意: 使用Retrofit的前提是**服务器端代码遵循REST规范 !!!!!**

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功能:
* 效率非常高
* 可以直接将结果转换称Java类
* 主要是配合RxJava一起使用

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配置：

    implementation 'com.squareup.retrofit2:retrofit:2.0.2'
    implementation 'com.squareup.retrofit2:converter-gson:2.0.2'
    implementation 'com.google.code.gson:gson:2.8.5'
    implementation 'com.squareup.retrofit2:adapter-rxjava:2.0.2'
    // OkHttp3
    api "com.squareup.okhttp3:okhttp:3.10.0"
    api "com.squareup.okhttp3:logging-interceptor:3.10.0"
    //网络日志
    implementation('com.github.ihsanbal:LoggingInterceptor:3.0.0') {
        exclude group: 'org.json', module: 'json'
    }

HttpManager.java

package com.loaderman.demo.http;

import android.os.Build;

import com.ihsanbal.logging.Level;
import com.ihsanbal.logging.LoggingInterceptor;
import com.loaderman.demo.BuildConfig;
import com.loaderman.demo.MyApplication;

import java.io.File;
import java.io.IOException;

import okhttp3.Cache;
import okhttp3.Interceptor;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;
import okhttp3.internal.platform.Platform;
import retrofit2.Retrofit;
import retrofit2.adapter.rxjava.RxJavaCallAdapterFactory;
import retrofit2.converter.gson.GsonConverterFactory;

public class HttpManager {

    private static HttpManager apiManager;
    private static final String TAG = "HttpManager";
    private static final Interceptor REWRITE_CACHE_CONTROL_INTERCEPTOR = new Interceptor() {
        @Override
        public Response intercept(Chain chain) throws IOException {
            int maxAge = 60 * 5; // 在线缓存在5分钟内可读取
            Request request = chain
                    .request()
                    .newBuilder()
                    .addHeader("User-Agent", Build.BRAND + "/" + Build.MODEL + "/" + Build.VERSION.RELEASE)//添加请求头
                    .header("Cache-Control", "public, max-age=" + maxAge)
                    .build();

            return chain.proceed(request);
        }
    };
    private static final LoggingInterceptor httpLoggingInterceptor = new LoggingInterceptor.Builder()
            .loggable(BuildConfig.DEBUG)
            .setLevel(Level.BASIC)
            .log(Platform.INFO)
            .request("Request")
            .response("Response")
            .build();

    private static File httpCacheDirectory = new File(MyApplication.applicationContext.getCacheDir(), "mCache");
    private static int cacheSize = 10 * 1024 * 1024; // 10 MiB
    private static Cache cache = new Cache(httpCacheDirectory, cacheSize);
    private static OkHttpClient client = new OkHttpClient.Builder()
            .addNetworkInterceptor(REWRITE_CACHE_CONTROL_INTERCEPTOR)
            .addInterceptor(REWRITE_CACHE_CONTROL_INTERCEPTOR)
            .addInterceptor(httpLoggingInterceptor)
            .cache(cache)
            .build();

    public static HttpManager getInstence() {

        if (apiManager == null) {
            synchronized (HttpManager.class) {
                if (apiManager == null) {
                    apiManager = new HttpManager();
                }
            }
        }
        return apiManager;
    }

    private static Apiservice apiservice;

    public Apiservice getHttpService() {
        if (apiservice == null) {
            synchronized (new Object()) {
                if (apiservice == null) {
                    Retrofit retrofit = new Retrofit.Builder()
                            .baseUrl("http://192.168.0.104:8080")
                            .addConverterFactory(GsonConverterFactory.create()) //设置数据解析器
                            .addCallAdapterFactory(RxJavaCallAdapterFactory.create())
                            .client(client)
                            .build();
                    apiservice = retrofit.create(Apiservice.class);
                }
            }
        }
        return apiservice;
    }
}

package com.loaderman.demo.http;

import com.loaderman.demo.bean.User;

import java.util.List;
import java.util.Map;

import okhttp3.RequestBody;
import retrofit2.Call;
import retrofit2.http.Body;
import retrofit2.http.Field;
import retrofit2.http.FormUrlEncoded;
import retrofit2.http.GET;

import retrofit2.http.Headers;
import retrofit2.http.Multipart;
import retrofit2.http.POST;
import retrofit2.http.PUT;
import retrofit2.http.Part;
import retrofit2.http.Path;
import retrofit2.http.Query;
import retrofit2.http.QueryMap;

public interface Apiservice {
//    Path是网址中的参数,例如:trades/{userId}
//    Query是问号后面的参数,例如:trades/{userId}?token={token}
//    QueryMap 相当于多个@Query
//    Field用于Post请求,提交单个数据,然后要加@FormUrlEncoded
//    Body相当于多个@Field,以对象的方式提交
//    @Streaming:用于下载大文件
//    @Header,@Headers、加请求头

   // 具体查看： https://square.github.io/retrofit/
    @GET("/user/user1.json")
    Call<User> getUser();
    @POST("users/{user}/repos")
    Call<List<User>> listRepos(@Path("user") String user);//@Path("user") 将参数替换到UR中 例如传 zhangsan ,那么URl为：users/zhangsan/repos

    @GET("users/list?sort=desc") //可以对数据进行排序
    Call<User> getList();

    @POST("users/new")
    Call<User> createUser(@Body User user);//可传实体类

    @Headers("Cache-Control: max-age=640000")
    @GET("user/list")
    Call<List<User>> userList();

    @Multipart
    @PUT("user/photo")
    Call<User> updateUser(@Part("photo") RequestBody photo, @Part("description") RequestBody description);

    @FormUrlEncoded
    @POST("user/edit")
    Call<User> updateUser(@Field("first_name") String first, @Field("last_name") String last);

    @GET("group/{id}/users")
    Call<List<User>> groupList(@Path("id") int groupId, @QueryMap Map<String, String> options);

    @GET("group/{id}/users")
    Call<List<User>> groupList(@Path("id") int groupId, @Query("sort") String sort);
}

使用：

package com.loaderman.demo;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.View;
import android.widget.TextView;
import android.widget.Toast;

import com.loaderman.demo.bean.User;

import com.loaderman.demo.http.HttpManager;

import retrofit2.Call;
import retrofit2.Callback;
import retrofit2.Response;
public class MainActivity extends AppCompatActivity {

    private TextView tvMsg;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        tvMsg = findViewById(R.id.tv_msg);

    }
    public void onClick(View view) {
        switch (view.getId()) {
            case R.id.btn_get:
                HttpManager.getInstence().getHttpService().getUser().enqueue(new Callback<User>() {
                    @Override
                    public void onResponse(Call<User> call, Response<User> response) {
                        boolean successful = response.isSuccessful();
                        System.out.println("isSuccessful"+ successful);
                        if (successful){
                            User user = response.body();
                            tvMsg.setText(user.toString());
                            System.out.println("onResponse"+ user);
                            Toast.makeText(MainActivity.this,user.toString(),Toast.LENGTH_LONG).show();
                        }else {
                            Toast.makeText(MainActivity.this,response.code()+response.message(),Toast.LENGTH_LONG).show();
                        }
                    }
                    @Override
                    public void onFailure(Call<User> call, Throwable t) {
                        System.out.println("onFailure"+t.toString());
                    }
                });

                break;
        }
    }

}

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