OkHttp3用法全解析

来源：互联网发布：存储过程拼接sql语句编辑：程序博客网时间：2024/06/09 21:16

1.使用前准备

Android Studio 配置gradle：

compile 'com.squareup.okhttp3:okhttp:3.2.0'
compile 'com.squareup.okio:okio:1.7.0'

添加网络权限：

2.异步GET请求

private void getAsynHttp() {
mOkHttpClient=new OkHttpClient();
Request.Builder requestBuilder = new Request.Builder().url("http://www.baidu.com");
//可以省略，默认是GET请求
requestBuilder.method("GET",null);
Request request = requestBuilder.build();
Call mcall= mOkHttpClient.newCall(request);
mcall.enqueue(new Callback() {
@Override
public void onFailure(Call call, IOException e) {
}

@Override
public void onResponse(Call call, Response response) throws IOException {
if (null != response.cacheResponse()) {
String str = response.cacheResponse().toString();
Log.i("wangshu", "cache---" + str);
} else {
response.body().string();
String str = response.networkResponse().toString();
Log.i("wangshu", "network---" + str);
}

runOnUiThread(new Runnable() {
@Override
public void run() {
Toast.makeText(getApplicationContext(), "请求成功", Toast.LENGTH_SHORT).show();
}

});
}

2.异步POST请求

OkHttp3异步POST请求和OkHttp2.x有一些差别就是没有FormEncodingBuilder这个类，替代它的是功能更加强大的FormBody：

private void postAsynHttp() {
mOkHttpClient=new OkHttpClient();
RequestBody formBody = new FormBody.Builder()
.add("size", "10")
.build();
Request request = new Request.Builder()
.url("http://api.1-blog.com/biz/bizserver/article/list.do")
.post(formBody)
.build();
Call call = mOkHttpClient.newCall(request);
call.enqueue(new Callback() {
@Override
public void onFailure(Call call, IOException e) {
}

@Override
public void onResponse(Call call, Response response) throws IOException {
String str = response.body().string();
Log.i("wangshu", str);
runOnUiThread(new Runnable() {
@Override
public void run() {
Toast.makeText(getApplicationContext(), "请求成功", Toast.LENGTH_SHORT).show();
}

});
}

3.异步上传文件

上传文件本身也是一个POST请求，上一篇没有讲，这里我们补上。首先定义上传文件类型：

public static final MediaType MEDIA_TYPE_MARKDOWN
= MediaType.parse("text/x-markdown; charset=utf-8");

将sdcard根目录的wangshu.txt文件上传到服务器上：

private void postAsynFile() {
mOkHttpClient=new OkHttpClient();
File file = new File("/sdcard/wangshu.txt");
Request request = new Request.Builder()
.url("https://api.github.com/markdown/raw")
.post(RequestBody.create(MEDIA_TYPE_MARKDOWN, file))
.build();
mOkHttpClient.newCall(request).enqueue(new Callback() {
@Override
public void onFailure(Call call, IOException e) {
}

@Override
public void onResponse(Call call, Response response) throws IOException {
Log.i("wangshu",response.body().string());
}

});
}

当然如果想要改为同步的上传文件只要调用 mOkHttpClient.newCall(request).execute()就可以了。

在wangshu.txt文件中有一行字“Android网络编程（六）OkHttp3用法全解析”我们运行程序点击发送文件按钮，最终请求网络返回的结果就是我们txt文件中的内容：

这里写图片描述

当然不要忘了添加如下权限：

4.异步下载文件

下载文件同样在上一篇没有讲到，实现起来比较简单，在这里下载一张图片，我们得到Response后将流写进我们指定的图片文件中就可以了。

private void downAsynFile() {
mOkHttpClient = new OkHttpClient();
String url = "http://img.my.csdn.net/uploads/201603/26/1458988468_5804.jpg";
Request request = new Request.Builder().url(url).build();

mOkHttpClient.newCall(request).enqueue(new Callback() {
@Override
public void onFailure(Call call, IOException e) {
}

@Override
public void onResponse(Call call, Response response) {
InputStream inputStream = response.body().byteStream();
FileOutputStream fileOutputStream = null;
try {
fileOutputStream = new FileOutputStream(new File("/sdcard/wangshu.jpg"));
byte[] buffer = new byte[2048];
int len = 0;
while ((len = inputStream.read(buffer)) != -1) {
fileOutputStream.write(buffer, 0, len);
}

fileOutputStream.flush();
} catch (IOException e) {
Log.i("wangshu", "IOException");
e.printStackTrace();
}

Log.d("wangshu", "文件下载成功");
}

});
}

5.异步上传Multipart文件

这种场景很常用，我们有时会上传文件同时还需要传其他类型的字段，OkHttp3实现起来很简单，需要注意的是没有服务器接收我这个Multipart文件，所以这里只是举个例子，具体的应用还要结合实际工作中对应的服务器。

首先定义上传文件类型：

private static final MediaType MEDIA_TYPE_PNG = MediaType.parse("image/png");
private void sendMultipart(){
mOkHttpClient = new OkHttpClient();
RequestBody requestBody = new MultipartBody.Builder()
.setType(MultipartBody.FORM)
.addFormDataPart("title", "wangshu")
.addFormDataPart("image", "wangshu.jpg",
RequestBody.create(MEDIA_TYPE_PNG, new File("/sdcard/wangshu.jpg")))
.build();

Request request = new Request.Builder()

.header("Authorization", "Client-ID " + "...")
.url("https://api.imgur.com/3/image")
.post(requestBody)
.build();
mOkHttpClient.newCall(request).enqueue(new Callback() {
@Override
public void onFailure(Call call, IOException e) {
}

@Override
public void onResponse(Call call, Response response) throws IOException {
Log.i("wangshu", response.body().string());
}

});
}

6.设置超时时间和缓存

和OkHttp2.x有区别的是不能通过OkHttpClient直接设置超时时间和缓存了，而是通过OkHttpClient.Builder来设置，通过builder配置好OkHttpClient后用builder.build()来返回OkHttpClient，所以我们通常不会调用new OkHttpClient()来得到OkHttpClient，而是通过builder.build()：

File sdcache = getExternalCacheDir();
int cacheSize = 10 * 1024 * 1024;
OkHttpClient.Builder builder = new OkHttpClient.Builder()
.connectTimeout(15, TimeUnit.SECONDS)
.writeTimeout(20, TimeUnit.SECONDS)
.readTimeout(20, TimeUnit.SECONDS)
.cache(new Cache(sdcache.getAbsoluteFile(), cacheSize));
OkHttpClient mOkHttpClient=builder.build();

7.关于取消请求和封装

OkHttpFinal，它目前是基于OkHttp3来进行封装的。链接描述

8.关于源码Demo

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