Question

okhttp框架使用手机网络为什么不能访问服务器

Answer 1

POST TO A SERVER
Posting a String:
public static final MediaType jsonReq
= MediaType.parse(application/json; charset=utf-8);

OkHttpClient client = new OkHttpClient();

String post(String url, String json) throws IOException {
RequestBody body = RequestBody.create(jsonReq, json);
Request request = new Request.Builder()
.url(url)
.post(body)
.build();
Response response = client.newCall(request).execute();
return response.body().string();
}

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

private final OkHttpClient client = new OkHttpClient();

public void run() throws Exception {
RequestBody requestBody = new RequestBody() {
@Override public MediaType contentType() {
return MEDIA_TYPE_MARKDOWN;
}

@Override public void writeTo(BufferedSink sink) throws IOException {
sink.writeUtf8(Numbers
);
sink.writeUtf8(-------
);
for (int i = 2; i <= 997; i++) {
sink.writeUtf8(String.format( * %s = %s
, i, factor(i)));
}
}

private String factor(int n) {
for (int i = 2; i < n; i++) {
int x = n / i;
if (x * i == n) return factor(x) + × + i;
}
return Integer.toString(n);
}
};

Request request = new Request.Builder()
.url(https://api.github.com/markdown/raw)
.post(requestBody)
.build();

Response response = client.newCall(request).execute();
if (!response.isSuccessful()) throw new IOException(Unexpected code + response);

System.out.println(response.body().string());
}

Posting a File:
public static final MediaType MEDIA_TYPE_MARKDOWN
= MediaType.parse(text/x-markdown; charset=utf-8);

private final OkHttpClient client = new OkHttpClient();

public void run() throws Exception {
File file = new File(README.md);

Request request = new Request.Builder()
.url(https://api.github.com/markdown/raw)
.post(RequestBody.create(MEDIA_TYPE_MARKDOWN, file))
.build();

Response response = client.newCall(request).execute();
if (!response.isSuccessful()) throw new IOException(Unexpected code + response);

System.out.println(response.body().string());
}

Posting from parameters:
private final OkHttpClient client = new OkHttpClient();

public void run() throws Exception {
RequestBody formBody = new FormEncodingBuilder()
.add(search, Jurassic Park)
.build();
Request request = new Request.Builder()
.url(https://en.wikipedia.org/w/index.php)
.post(formBody)
.build();

Response response = client.newCall(request).execute();
if (!response.isSuccessful()) throw new IOException(Unexpected code + response);

System.out.println(response.body().string());
}

Posting a multipart request:
private static final String IMGUR_CLIENT_ID = ...;
private static final MediaType MEDIA_TYPE_PNG = MediaType.parse(image/png);

private final OkHttpClient client = new OkHttpClient();

public void run() throws Exception {
// Use the imgur image upload API as documented at https://api.imgur.com/endpoints/image
RequestBody requestBody = new MultipartBuilder()
.type(MultipartBuilder.FORM)
.addPart(
Headers.of(Content-Disposition, form-data; name= itle),
RequestBody.create(null, Square Logo))
.addPart(
Headers.of(Content-Disposition, form-data; name=image),
RequestBody.create(MEDIA_TYPE_PNG, new File(website/static/logo-square.png)))
.build();

Request request = new Request.Builder()
.header(Authorization, Client-ID + IMGUR_CLIENT_ID)
.url(https://api.imgur.com/3/image)
.post(requestBody)
.build();

Response response = client.newCall(request).execute();
if (!response.isSuccessful()) throw new IOException(Unexpected code + response);

System.out.println(response.body().string());
}

Posing Json with Gson
private final OkHttpClient client = new OkHttpClient();
private final Gson gson = new Gson();

public void run() throws Exception {
Request request = new Request.Builder()
.url(https://api.github.com/gists/c2a7c39532239ff261be)
.build();
Response response = client.newCall(request).execute();
if (!response.isSuccessful()) throw new IOException(Unexpected code + response);

Gist gist = gson.fromJson(response.body().charStream(), Gist.class);
for (Map.Entry entry : gist.files.entrySet()) {
System.out.println(entry.getKey());
System.out.println(entry.getValue().content);
}
}

static class Gist {
Map files;
}

static class GistFile {
String content;
}

Response Caching：
为了缓存响应，你需要一个你可以读写的缓存目录，和缓存大小的限制。这个缓存目录应该是私有的，不信任的程序应不能读取缓存内容。
一个缓存目录同时拥有多个缓存访问是错误的。大多数程序只需要调用一次 new OkHttp() ，在第一次调用时配置好缓存，然后其他地方只需要调用这个实例就可以了。否则两个缓存示例互相干扰，破坏响应缓存，而且有可能会导致程序崩溃。
响应缓存使用HTTP头作为配置。你可以在请求头中添加 Cache-Control: max-stale=3600 ,OkHttp缓存会支持。你的服务通过响应头确定响应缓存多长时间，例如使用 Cache-Control: max-age=9600 。