Android 网络请求库Retrofit使用详解
Posted 路宇
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前言：
首先了解Retrofit注解，以下注解本人都会讲到.
1、首先在android项目中引入需要的依赖
implementation 'com.github.bumptech.glide:glide:4.8.0'
implementation 'com.squareup.retrofit2:converter-gson:2.9.0'
2、创建一个单例类，返回Retrofit对象
public class RetrofitManager
private RetrofitManager()
/**
* 1.首先使用Retrofit.Builder来构建一个Retrofit对象，
* 2.baseUrl()方法用于指定所有Retrofit请求的根路径
* 3.addConverterFactory()方法用于指定Retrofit在解析数据时所使用的转换库，这里指定成GsonConverterFactory
* 用的是Gson库
*/
public static Retrofit retrofit = new Retrofit.Builder()
.baseUrl("http://192.168.5.171:9102")
.addConverterFactory(GsonConverterFactory.create())
.build();
public static Retrofit getRetrofit()
return retrofit;
3、创建对应的接口Api，写对应的请求方法和参数
public interface Api
@GET("/get/text")
Call<JsonResult> getJson();
@GET("/get/param")
Call<ParamModel> getParam(@Query("keyword") String keyword,
@Query("page") int page,
@Query("order") int order);
@GET("/get/param")
Call<ParamModel> getParamQueryMap(@QueryMap Map<String, Object> queryMap);
@POST("/post/string")
Call<PostParamModel> getPostQuery(@Query("string") String string);
@POST
Call<PostParamModel> postParamUrl(@Url String url);
@POST("/post/comment")
Call<PostParamModel> postWithBody(@Body CommentBody body);
/**
* @Part 和 @Multipart结合使用 一般用于上传文件
*/
@Multipart
@POST("/file/upload")
Call<PostParamModel> postUploadFile(@Part MultipartBody.Part part, @Header("token") String token);
/**
* @Part 和 @Multipart结合使用 一般用于上传文件
*/
@Headers("token:398429865hdsfhaj", "client:Android", "version:1.1.0")
@Multipart
@POST("/files/upload")
Call<PostParamModel> postUploadFiles(@Part ArrayList<MultipartBody.Part> parts);
/**
* @PartMap 一般用于上传文件和参数时使用。
*/
@Multipart
@POST("/file/params/upload")
Call<PostParamModel> postUploadFileWithParams(@Part MultipartBody.Part part,
@PartMap Map<String, Object> map,
@HeaderMap Map<String, String> headerMap);
@FormUrlEncoded
@POST("/login")
Call<PostParamModel> postLogin(@Field("userName") String userName,
@Field("password") String password);
@FormUrlEncoded
@POST("/login")
Call<PostParamModel> postLoginFileMap(@FieldMap Map<String, String> fieldMap);
@Streaming
@GET
Call<ResponseBody> downloadFile(@Url String url);
4、创建对应的activity_request.xml
<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto">
<data>
<variable
name="presenter"
type="com.example.customview.retrofit.RequestActivity.Presenter" />
</data>
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<Button
android:id="@+id/btn_request"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="@()->presenter.getWithParams()"
android:text="getWithParams-@Query"
android:textAllCaps="false"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<Button
android:id="@+id/btn_request_query_map"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="@()->presenter.getWithParamsQueryMap()"
android:text="getWithParams-@QueryMap"
android:textAllCaps="false"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@id/btn_request" />
<Button
android:id="@+id/btn_post_query"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="@()->presenter.postParamQuery()"
android:text="postWithParam-@Query"
android:textAllCaps="false"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@id/btn_request_query_map" />
<Button
android:id="@+id/btn_post_url"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="@()->presenter.postParamUrl()"
android:text="postWithParam-@Url"
android:textAllCaps="false"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@id/btn_post_query" />
<Button
android:id="@+id/btn_post_body"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="@()->presenter.postWithBody()"
android:text="postWithBody-@Body"
android:textAllCaps="false"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@id/btn_post_url" />
<Button
android:id="@+id/btn_post_file"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="@()->presenter.postUploadFile()"
android:text="postUploadFile"
android:textAllCaps="false"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@id/btn_post_body" />
<Button
android:id="@+id/btn_post_files"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="@()->presenter.postUploadFiles()"
android:text="postUploadFiles"
android:textAllCaps="false"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@id/btn_post_file" />
<Button
android:id="@+id/btn_post_file_param"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="@()->presenter.postUploadFileParams()"
android:text="postUploadFileParams"
android:textAllCaps="false"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@id/btn_post_files" />
<Button
android:id="@+id/btn_post_login"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="@()->presenter.postLogin()"
android:text="postLogin-@Field"
android:textAllCaps="false"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@id/btn_post_file_param" />
<Button
android:id="@+id/btn_post_login_filed_map"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="@()->presenter.postLoginFiledMap()"
android:text="postUploadFileParams-@FieldMap"
android:textAllCaps="false"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@id/btn_post_login" />
<Button
android:id="@+id/btn_post_down_load"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="@()->presenter.downFile()"
android:text="downFile"
android:textAllCaps="false"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@id/btn_post_login_filed_map" />
</androidx.constraintlayout.widget.ConstraintLayout>
</layout>
5、在对应的Activity进行编码，注释已经给出
/**
* @Author: ly
* @Date: 2023/2/24
* @Description: Retrofit的使用
*/
public class RequestActivity extends AppCompatActivity
private static final String TAG = "RequestActivity";
private ActivityRequestBinding binding;
@Override
protected void onCreate(@Nullable Bundle savedInstanceState)
super.onCreate(savedInstanceState);
binding = DataBindingUtil.setContentView(this, R.layout.activity_request);
binding.setPresenter(new Presenter());
private Api getApi()
Retrofit retrofit = RetrofitManager.getRetrofit();
return retrofit.create(Api.class);
public class Presenter
/**
* get请求,请求参数为@Query
*/
public void getWithParams()
//1.创建retrofit对象
Api api = getApi();
//3.当调用了Api.getParam()方法，就回返回Call<ParamModel>对象
Call<ParamModel> call = api.getParam("测试", 10, 1);
/**
* 之后们再调用一下它的enqueue()方法Retrofit就会根据注解
* 中配置的服务器接口地址去进行网络请求了，服务器响应的数据会回调到enqueue()方法中传
* 入的Callback实现里面。需要注意的是，当发起请求的时候，Retrofit会自动在内部开启子线
* 程，当数据回调到Callback中之后，Retrofit又会自动切换回主线程，整个操作过程中我们都
* 不用考虑线程切换问题。在Callback的onResponse()方法中，调用response.body()方
* 法将会得到Retrofit解析后的对象，也就是ParamModel类型的数据。
*/
call.enqueue(new Callback<ParamModel>()
@Override
public void onResponse(Call<ParamModel> call, Response<ParamModel> response)
if (response.code() == HttpURLConnection.HTTP_OK)
Log.i(TAG, "getWithParams: " + response.body());
@Override
public void onFailure(Call<ParamModel> call, Throwable t)
);
/**
* get请求,请求参数为@QueryMap
*/
public void getWithParamsQueryMap()
Api api = getApi();
Map<String, Object> map = new HashMap<>();
map.put("keyword", "关键字");
map.put("page", 10);
map.put("order", 0);
Call<ParamModel> call = api.getParamQueryMap(map);
call.enqueue(new Callback<ParamModel>()
@Override
public void onResponse(Call<ParamModel> call, Response<ParamModel> response)
Log.i(TAG, "getWithParamsQueryMap: " + response.body());
@Override
public void onFailure(Call<ParamModel> call, Throwable t)
);
/**
* post请求，请求参数为@Query
*/
public void postParamQuery()
Api api = getApi();
Call<PostParamModel> call = api.getPostQuery("测试的新数据");
call.enqueue(new Callback<PostParamModel>()
@Override
public void onResponse(Call<PostParamModel> call, Response<PostParamModel> response)
if (response.code() == HttpsURLConnection.HTTP_OK)
Log.i(TAG, "postParamQuery: " + response.body());
@Override
public void onFailure(Call<PostParamModel> call, Throwable t)
);
/**
* post请求，请求参数为@Url
*/
public void postParamUrl()
String url = "post/string?string=Android开发";
Api api = getApi();
Call<PostParamModel> call = api.postParamUrl(url);
call.enqueue(new Callback<PostParamModel>()
@Override
public void onResponse(Call<PostParamModel> call, Response<PostParamModel> response)
if (response.code() == HttpsURLConnection.HTTP_OK)
Log.i(TAG, "postParamUrl: " + response.body());
@Override
public void onFailure(Call<PostParamModel> call, Throwable t)
Log.i(TAG, "postParamUrl: " + t.toString());
);
/**
* post请求，请求参数注解@Body
*/
public void postWithBody()
Api api = getApi();
CommentBody body = new CommentBody("45651", "这条评论非常不错！");
Call<PostParamModel> call = api.postWithBody(body);
call.enqueue(new Callback<PostParamModel>()
@Override
public void onResponse(Call<PostParamModel> call, Response<PostParamModel> response)
if (response.code() == HttpURLConnection.HTTP_OK)
Log.i(TAG, "postWithBody: " + response.body());
@Override
public void onFailure(Call<PostParamModel> call, Throwable t)
);
/**
* post请求，进行单文件上传
*/
public void postUploadFile()
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O)
if (ContextCompat.checkSelfPermission(RequestActivity.this, Manifest.permission.READ_EXTERNAL_STORAGE) != PackageInfo.REQUESTED_PERMISSION_GRANTED
|| ContextCompat.checkSelfPermission(RequestActivity.this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageInfo.REQUESTED_PERMISSION_GRANTED
)
requestPermissions(new String[]Manifest.permission.READ_EXTERNAL_STORAGE, Manifest.permission.WRITE_EXTERNAL_STORAGE, 200);
else
InputPicture();
else
InputPicture();
/**
* post请求，进行多文件上传
*/
public void postUploadFiles()
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O)
if (ContextCompat.checkSelfPermission(RequestActivity.this, Manifest.permission.READ_EXTERNAL_STORAGE) != PackageInfo.REQUESTED_PERMISSION_GRANTED
|| ContextCompat.checkSelfPermission(RequestActivity.this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageInfo.REQUESTED_PERMISSION_GRANTED
)
requestPermissions(new String[]Manifest.permission.READ_EXTERNAL_STORAGE, Manifest.permission.WRITE_EXTERNAL_STORAGE, 300);
else
postUploadImages();
else
postUploadImages();
/**
* 文件上传并携带参数
*/
public void postUploadFileParams()
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O)
if (ContextCompat.checkSelfPermission(RequestActivity.this, Manifest.permission.READ_EXTERNAL_STORAGE) != PackageInfo.REQUESTED_PERMISSION_GRANTED
|| ContextCompat.checkSelfPermission(RequestActivity.this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageInfo.REQUESTED_PERMISSION_GRANTED
)
requestPermissions(new String[]Manifest.permission.READ_EXTERNAL_STORAGE, Manifest.permission.WRITE_EXTERNAL_STORAGE, 400);
else
postUploadImageParams();
else
postUploadImageParams();
/**
* 登录
*/
public void postLogin()
Call<PostParamModel> call = getApi().postLogin("Android开发", "a123456");
call.enqueue(new Callback<PostParamModel>()
@Override
public void onResponse(Call<PostParamModel> call, Response<PostParamModel> response)
if (HttpURLConnection.HTTP_OK == response.code())
Log.i(TAG, "postLogin: " + response.body());
@Override
public void onFailure(Call<PostParamModel> call, Throwable t)
Log.i(TAG, "onFailure: " + t.toString());
);
/**
* post请求进行登录，请求参数注解为@FieldMap
*/
public void postLoginFiledMap()
Map<String, String> map = new HashMap<>();
map.put("userName", "Android开发者");
map.put("password", "a123456789");
Call<PostParamModel> call = getApi().postLoginFileMap(map);
call.enqueue(new Callback<PostParamModel>()
@Override
public void onResponse(Call<PostParamModel> call, Response<PostParamModel> response)
if (HttpURLConnection.HTTP_OK == response.code())
Log.i(TAG, "onResponse: " + response.body());
@Override
public void onFailure(Call<PostParamModel> call, Throwable t)
Log.i(TAG, "onResponse: " + t.toString());
);
/**
* 文件下载
*/
public void downFile()
Call<ResponseBody> call = getApi().downloadFile("/download/11");
call.enqueue(new Callback<ResponseBody>()
@Override
public void onResponse(Call<ResponseBody> call, Response<ResponseBody> response)
if (HttpURLConnection.HTTP_OK == response.code())
ResponseBody body = response.body();
//要知道文件名称
Headers headers = response.headers();
String fileNameHeader = headers.get("Content-disposition");
String fileName = "未命名.png";
if (fileName != null)
fileName = fileNameHeader.replace("attachment; filename=", "");
Log.i(TAG, "fileName: " + fileName);
writeToDisk(response, fileName);
// for (int i = 0; i < headers.size(); i++)
// String key = headers.name(i);
// String value = headers.value(i);
// Log.i(TAG, "key: " + key + " name:" + value);
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