Retrofit2.0 使用教程

版权声明，转载请著名出处：http://blog.csdn.net/wo_ha/article/details/77866493

引言

俗话说：代码是程序员的最好的教程，这篇文章记录的是我在学习使用Retrofit的代码笔记，其中里面的很多注解或原理我也没有弄明白，但是这不影响我的正常使用啊，当然这篇文章针对的是初学者，如果是老司机的话就请绕道了，如果大家有更好的看法或建议可以在文末进行评论，我会及时更新到文章中，近期我也会更新RxJava的简单使用和RxJava结合Retrofit使用的教程，希望大家喜欢，欢迎大家持续关注！

开始使用

导入依赖

//  retrofit的依赖
compile 'com.squareup.retrofit2:retrofit:2.1.0'
//将JSON字符串转换为对象需要使用的依赖
compile 'com.squareup.retrofit2:converter-gson:2.1.0'

IpMode类由Json字符串GsonFromat生成

{
"code": 0,
"data": {
"country": "中国",
"country_id": "CN",
"area": "西南",
"area_id": "500000",
"region": "四川省",
"region_id": "510000",
"city": "成都市",
"city_id": "510100",
"county": "",
"county_id": "-1",
"isp": "电信",
"isp_id": "100017",
"ip": "118.114.168.175"
}
}

1. Get简单请求

注：Retrofit2 的baseUlr 必须以 /（斜线） 结束，不然会抛出一个IllegalArgumentException,所以如果你看到别的教程没有以 / 结束，那么多半是直接从Retrofit 1.X 照搬过来的。

//请求的接口
public interface IpService {
@Headers({
"Accept-Encoding: application/json",
"User-Agent: MoonRetrofit"  //必须要有这个Hearder，否则报错 java.lang.IllegalArgumentException: @Headers annotation is empty.
})
@GET("getIpInfo.php?ip=59.108.54.37")
Call<IpMode> getIpMsgGet();
/**
* 采用指定的全路径访问
* @param url   网址的全路径
* @return
*/
@Headers({
"User-Agent: MoonRetrofit"
})
@GET
Call<IpMode> getIpMsgGet1(@Url String url);
｝

public void getSimple(View view) {
// Get简单请求
final String url = "http://ip.taobao.com/service/";
Retrofit retrofit = new Retrofit
.Builder()
.baseUrl(url)
.addConverterFactory(GsonConverterFactory.create())
.build();
IpService ipService = retrofit.create(IpService.class);
Call<IpMode> ipMsg = ipService.getIpMsgGet();
ipMsg.enqueue(new Callback<IpMode>() {
@Override
public void onResponse(Call<IpMode> call, Response<IpMode> response) {
IpMode ipMode = response.body();
Log.e(TAG, "onResponse: " + ipMode);
Toast.makeText(MainActivity.this, ipMode + "", Toast.LENGTH_LONG).show();
}
@Override
public void onFailure(Call<IpMode> call, Throwable t) {
Log.e(TAG, "onFailure: ");
t.printStackTrace();
Toast.makeText(MainActivity.this, t + "", Toast.LENGTH_LONG).show();
}
});
getSimple();// Get简单请求 ，采用全路径来访问
}
private void getSimple() {
// Get简单请求 ，采用全路径来访问
final String url = "http://ip.taobao.com/service/";
Retrofit retrofit = new Retrofit
.Builder()
.baseUrl(url)
.addConverterFactory(GsonConverterFactory.create())
.build();
IpService ipService = retrofit.create(IpService.class);
Call<IpMode> ipMsg = ipService.getIpMsgGet1("http://ip.taobao.com/service/getIpInfo.php?ip=118.114.168.175");
ipMsg.enqueue(new Callback<IpMode>() {
@Override
public void onResponse(Call<IpMode> call, Response<IpMode> response) {
IpMode ipMode = response.body();
Log.e(TAG, "onResponse: " + ipMode);
Toast.makeText(MainActivity.this, ipMode + "", Toast.LENGTH_LONG).show();
}
@Override
public void onFailure(Call<IpMode> call, Throwable t) {
Log.e(TAG, "onFailure: ");
t.printStackTrace();
Toast.makeText(MainActivity.this, t + "", Toast.LENGTH_LONG).show();
}
});
}

2. Get带参数请求(路径)可以通过参数动态修改网址的路径

/**
* 指定路径的访问
*
* @param pathStr 路径
* @return
*/
@Headers({
"Accept-Encoding: application/json",
"User-Agent: MoonRetrofit"
})
@GET("{path}/getIpInfo.php?ip=59.108.54.37")//{path}与@Path("path")参数对应，接受参数后{path}被替换
Call<IpMode> getIpMsgGet(@Path("path") String pathStr);

public void getParamesPath(View view) {
//        Get带参数请求(路径)
final String baseUrl = "http://ip.taobao.com/";
Retrofit retrofit = new Retrofit
.Builder()
.baseUrl(baseUrl)
.addConverterFactory(GsonConverterFactory.create())
.build();
IpService ipService = retrofit.create(IpService.class);
Call<IpMode> ipMsg = ipService.getIpMsgGet("service");   //,"getIpInfo.php?ip=59.108.54.37"
ipMsg.enqueue(new Callback<IpMode>() {
@Override
public void onResponse(Call<IpMode> call, Response<IpMode> response) {
IpMode ipMode = response.body();
Log.e(TAG, "onResponse: " + ipMode);
Toast.makeText(MainActivity.this, ipMode + "", Toast.LENGTH_LONG).show();
}
@Override
public void onFailure(Call<IpMode> call, Throwable t) {
Log.e(TAG, "onFailure: ");
t.printStackTrace();
Toast.makeText(MainActivity.this, t + "", Toast.LENGTH_LONG).show();
}
});
}

3. Get带参数请求(IP)可以动态修改网址？后面的参数

/**
* 指定IP访问
* 会组成全路径：http://ip.taobao.com/service/getIpInfo.php?ip=118.114.168.175
* 在路径后自动添加  ?ip=ipStr
*
* @param ipStr
* @return
*/
@Headers({
"Accept-Encoding: application/json",
"User-Agent: MoonRetrofit"
})
@GET("service/getIpInfo.php")
Call<IpMode> getIpMsgFromIpGet(@Query("ip") String ipStr);

public void getParamesIp(View view) {
//        Get带参数请求(IP)
final String baseUrl = "http://ip.taobao.com/";
Retrofit retrofit = new Retrofit
.Builder()
.baseUrl(baseUrl)
.addConverterFactory(GsonConverterFactory.create())
.build();
IpService ipService = retrofit.create(IpService.class);
Call<IpMode> ipMsg = ipService.getIpMsgFromIpGet("59.108.54.37");   //,"getIpInfo.php?ip=59.108.54.37"
ipMsg.enqueue(new Callback<IpMode>() {
@Override
public void onResponse(Call<IpMode> call, Response<IpMode> response) {
IpMode ipMode = response.body();
Log.e(TAG, "onResponse: " + ipMode);
Toast.makeText(MainActivity.this, ipMode + "", Toast.LENGTH_LONG).show();
}
@Override
public void onFailure(Call<IpMode> call, Throwable t) {
Log.e(TAG, "onFailure: ");
t.printStackTrace();
Toast.makeText(MainActivity.this, t + "", Toast.LENGTH_LONG).show();
}
});
}

4. Get带参数请求(路径和IP)可以通过参数动态修改网址的路径和网址？后面的请求参数

@Headers({
"Accept-Encoding: application/json",
"User-Agent: MoonRetrofit"
})
@GET("{path}")
Call<IpMode> getIpMsgGet(@Path("path") String pathStr, @Query("ip") String ipStr);

public void getParamesPathIp(View view) {
//        Get带参数请求(路径和IP)
final String baseUrl = "http://ip.taobao.com/";
Retrofit retrofit = new Retrofit
.Builder()
.baseUrl(baseUrl)
.addConverterFactory(GsonConverterFactory.create())
.build();
IpService ipService = retrofit.create(IpService.class);
Call<IpMode> ipMsg = ipService.getIpMsgGet("service/getIpInfo.php", "59.108.54.37");   //,"getIpInfo.php?ip=59.108.54.37"
ipMsg.enqueue(new Callback<IpMode>() {
@Override
public void onResponse(Call<IpMode> call, Response<IpMode> response) {
IpMode ipMode = response.body();
Log.e(TAG, "onResponse: " + ipMode);
Toast.makeText(MainActivity.this, ipMode + "", Toast.LENGTH_LONG).show();
}
@Override
public void onFailure(Call<IpMode> call, Throwable t) {
Log.e(TAG, "onFailure: ");
t.printStackTrace();
Toast.makeText(MainActivity.this, t + "", Toast.LENGTH_LONG).show();
}
});
}

5.Get带参数请求(动态指定查询条件组)

/**
* 动态指定查询条件组
*
* @param quaryMap
* @return
*/
@Headers({
"Accept-Encoding: application/json",
"User-Agent: MoonRetrofit"
})
@GET("service/getIpInfo.php")
Call<IpMode> getIpMsgGet(@QueryMap Map<String, String> quaryMap);

public void getParamesQuaryMap(View view) {
//        Get带参数请求(动态指定查询条件组)
final String baseUrl = "http://ip.taobao.com/";
Retrofit retrofit = new Retrofit
.Builder()
.baseUrl(baseUrl)
.addConverterFactory(GsonConverterFactory.create())
.build();
IpService ipService = retrofit.create(IpService.class);
HashMap<String, String> hashMap = new HashMap<>();
hashMap.put("ip", "59.108.54.37"); //Key 和 Value要对应，其中Key名要与网站对应
Call<IpMode> ipMsg = ipService.getIpMsgGet(hashMap);
ipMsg.enqueue(new Callback<IpMode>() {
@Override
public void onResponse(Call<IpMode> call, Response<IpMode> response) {
IpMode ipMode = response.body();
Log.e(TAG, "onResponse: " + ipMode);
Toast.makeText(MainActivity.this, ipMode + "", Toast.LENGTH_LONG).show();
}
@Override
public void onFailure(Call<IpMode> call, Throwable t) {
Log.e(TAG, "onFailure: ");
t.printStackTrace();
Toast.makeText(MainActivity.this, t + "", Toast.LENGTH_LONG).show();
}
});
}

6.Post带参数请求

/**
* 带参数的POST请求
* 用@Field("ip")标注请求的参数键值
*
* @param ip
* @return
*/
@Headers({
"Accept-Encoding: application/json", //
"User-Agent: MoonRetrofit"
})
@FormUrlEncoded  //注明是一个表单请求
@POST("service/getIpInfo.php")
Call<IpMode> getIpMsgPost(@Field("ip") String ip);
@Headers({
"Accept-Encoding: application/json", //
"User-Agent: MoonRetrofit"
})
@FormUrlEncoded  //注明是一个表单请求
@POST("service/getIpInfo.php")
Call<IpMode> getIpMsgPost(@FieldMap Map<String, String> quaryMap);

public void postParames(View view) {
//        Post带参数请求
String url = "http://ip.taobao.com/";
Retrofit retrofit = new Retrofit.Builder()
.baseUrl(url)
.addConverterFactory(GsonConverterFactory.create())
.build();
IpService ipService = retrofit.create(IpService.class);
//        Call<IpMode> ipMsg = ipService.getIpMsgPost("59.108.54.37");
HashMap<String, String> hashMap = new HashMap<>();
hashMap.put("ip", "59.108.54.37");
Call<IpMode> ipMsg = ipService.getIpMsgPost(hashMap);
ipMsg.enqueue(new Callback<IpMode>() {
@Override
public void onResponse(Call<IpMode> call, Response<IpMode> response) {
IpMode ipMode = response.body();
Log.e(TAG, "onResponse: " + ipMode);
Toast.makeText(MainActivity.this, ipMode + "", Toast.LENGTH_LONG).show();
}
@Override
public void onFailure(Call<IpMode> call, Throwable t) {
Log.e(TAG, "onFailure: ");
t.printStackTrace();
Toast.makeText(MainActivity.this, t + "", Toast.LENGTH_LONG).show();
}
});
}

7. 下载图片或文件

/**
* 下载图片，返回的是OkHttp库的Call<ResponseBody>， ResponseBody里面是字节数据
* 百度的首页图
*
* @return
*/
@Headers({
"Accept-Encoding: application/json",
"User-Agent: MoonRetrofit"
})
@Streaming
@GET("5aV1bjqh_Q23odCf/static/superman/img/logo/logo_white_fe6da1ec.png")
Call<ResponseBody> getImgMsgGet();
/**
* 使用全路径的网址下载图片
*
* @param fileUrl
* @return
*/
@GET
Call<ResponseBody> getImgMsgGet(@Url String fileUrl);

public void getDownloadImg(View view) {
//        Get下载图片
String url = "https://ss0.bdstatic.com/";
Retrofit retrofit = new Retrofit.Builder()
.baseUrl(url)
.build();
IpService ipService = retrofit.create(IpService.class);
Call<ResponseBody> imgMsgGet = ipService.getImgMsgGet();
imgMsgGet.enqueue(new Callback<ResponseBody>() {
@Override
public void onResponse(Call<ResponseBody> call, Response<ResponseBody> response) {
try {
byte[] bytes = response.body().bytes();
Bitmap bitmap = BitmapFactory.decodeByteArray(bytes, 0, bytes.length);
imageview.setImageBitmap(bitmap);
} catch (IOException e) {
e.printStackTrace();
}
Log.e(TAG, "onResponse: 图片请求成功");
Toast.makeText(MainActivity.this, "图片请求成功", Toast.LENGTH_LONG).show();
}
@Override
public void onFailure(Call<ResponseBody> call, Throwable t) {
Log.e(TAG, "onFailure: ");
t.printStackTrace();
Toast.makeText(MainActivity.this, t + "", Toast.LENGTH_LONG).show();
}
});
//使用全路径
Call<ResponseBody> imgMsgGet2 = ipService.getImgMsgGet("http://img1.3lian.com/2015/a1/105/d/40.jpg");
imgMsgGet2.enqueue(new Callback<ResponseBody>() {
@Override
public void onResponse(Call<ResponseBody> call, Response<ResponseBody> response) {
File file = new File(MainActivity.this.getCacheDir(), "laowang.jpg");
try {
byte[] bytes = response.body().bytes();
Bitmap bitmap = BitmapFactory.decodeByteArray(bytes, 0, bytes.length);
imageview.setImageBitmap(bitmap);
//保存为文件
FileOutputStream fileOutputStream = new FileOutputStream(file, false);
fileOutputStream.write(bytes);
fileOutputStream.flush();
fileOutputStream.close();
} catch (Exception e) {
e.printStackTrace();
}
Log.e(TAG, "onResponse: 图片请求成功２,ex=" + file.exists() + ",path=" + file.getAbsolutePath());
Toast.makeText(MainActivity.this, "图片请求成功２", Toast.LENGTH_LONG).show();
}
@Override
public void onFailure(Call<ResponseBody> call, Throwable t) {
Log.e(TAG, "onFailure: ２");
t.printStackTrace();
Toast.makeText(MainActivity.this, t + "２", Toast.LENGTH_LONG).show();
}
});
}

8. POST上传文件

/**
*  POST上传文件
*  注解@Multipart 表示允许多个@Part
*  如需要多个文件上传可以使用@PartMap
* @param file
* @return
*/
@Multipart
@POST("fileService")
Call<IpMode> uploadFile(@Part MultipartBody.Part file);

public void postUpImg(View view) {// POST上传图片
File file = new File(MainActivity.this.getCacheDir(), "laowang.jpg");
RequestBody body = RequestBody.create(MediaType.parse("application/otcet-stream"), file);//构建文件的RequestBody
MultipartBody.Part part = MultipartBody.Part.createFormData("file", file.getName(), body);//构建文件的Part
String url = "https://ss0.bdstatic.com/";
Retrofit retrofit = new Retrofit.Builder()
.baseUrl(url)
.addConverterFactory(GsonConverterFactory.create())
.build();
IpService ipService = retrofit.create(IpService.class);
Call<IpMode> call = ipService.uploadFile(part);
call.enqueue(new Callback<IpMode>() {
@Override
public void onResponse(Call<IpMode> call, Response<IpMode> response) {
Log.e(TAG, "onResponse: 图片上传成功," + response.headers());
Toast.makeText(MainActivity.this, "图片上传成功", Toast.LENGTH_LONG).show();
}
@Override
public void onFailure(Call<IpMode> call, Throwable t) {
Log.e(TAG, "onFailure: ");
t.printStackTrace();
Toast.makeText(MainActivity.this, t + "", Toast.LENGTH_LONG).show();
}
});
}