OkHttp 3.4入门

OkHttp 3.4入门

配置方法

（一）导入Jar包
http://repo1.maven.org/maven2/com/squareup/okhttp3/okhttp/3.4.0-RC1/okhttp-3.4.0-RC1.jar

（二）Gradle

compile 'com.squareup.okhttp3:okhttp:3.4.0-RC1'

使用方法
HTTP GET
private void get_String(){
Request request = new Request.Builder()
.url("http://publicobject.com/helloworld.txt")
.build();
new OkHttpClient().newCall(request).enqueue(new Callback() {
@Override
public void onFailure(Call call, IOException e) {
}
@Override
public void onResponse(Call call, Response response) throws IOException {
if (!response.isSuccessful())
throw new IOException("Unexpected code " + response);
Headers responseHeaders = response.headers();
for (int i = 0, size = responseHeaders.size(); i < size; i++) {
System.out.println(responseHeaders.name(i) + ": "
+ responseHeaders.value(i)); }
System.out.println(response.body().string());
}
});
}

HTTP POST

POST json数据
public static final MediaType JSON = MediaType.parse("application/json; charset=utf-8");OkHttpClient client = new OkHttpClient();

String post(String url, String json) throws IOException { RequestBody body = RequestBody.create(JSON, json); Request request = new Request.Builder() .url(url) .post(body) .build(); Response response = client.newCall(request).execute(); f (response.isSuccessful()) { return response.body().string(); } else { throw new IOException("Unexpected code " + response); }}

POST提交键值对
OkHttpClient client = new OkHttpClient();

String post(String url, String json) throws IOException { RequestBody formBody = new FormEncodingBuilder()
//.add("platform", "android") //.add("name", "bug") //.add("subject", "XXXXXXXXXXXXXXX")
.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()) { return response.body().string(); } else { throw new IOException("Unexpected code " + response); }}

Headers（提取响应头）

Request request = new Request.Builder()
.url("https://api.github.com/repos/square/okhttp/issues")
.header("User-Agent", "OkHttp Headers.java")
.addHeader("Accept", "application/json; q=0.5")
.addHeader("Accept", "application/vnd.github.v3+json")

.addHeader("Cookie", "cookie")
.build();
try {
Response response = mClient.newCall(request).execute();
if (!response.isSuccessful()) throw new IOException("Unexpected code " + response);
/* System.out.println("Server: " + response.header("Server"));
System.out.println("Date: " + response.header("Date"));
System.out.println("Vary: " + response.headers("Vary"));*/
Log.i("WY", "数据：" + response.toString());
} catch (IOException e) {
e.printStackTrace();
}

Get请求Gson数据

static class Gist {
Map<String, GistFile> files;
}
static class GistFile {
String content;
}
public void run_JSON() throws Exception {
Request request = new Request.Builder()
.url("https://api.github.com/gists/c2a7c39532239ff261be")
.build();
new OkHttpClient().newCall(request).enqueue(new Callback() {
@Override
public void onFailure(Call call, IOException e) {
}
@Override
public void onResponse(Call call, Response response) throws IOException {
if (!response.isSuccessful()) throw new IOException("Unexpected code " + response);
Gist gist = gson.fromJson(response.body().charStream(), Gist.class);
for (Map.Entry<String, GistFile> entry : gist.files.entrySet()) {
System.out.println("111 "+entry.getKey());
System.out.println(entry.getValue().content);
}
}
});
}

独立请求设置
由于在一个程序中只能声明一个OkHttpClient实例，如果要更改连接超时时间，或者其他参数可使用newBuilder进行设置。
public class PreRequestClass {
private final OkHttpClient client = new OkHttpClient();
public void run() throws Exception {
Request request = new Request.Builder()
.url("http://httpbin.org/delay/1") // This URL is served with a 1 second delay.
.build();
// Copy to customize OkHttp for this request.
OkHttpClient copy = client.newBuilder()
.readTimeout(5000, TimeUnit.MILLISECONDS)
.build();
copy.newCall(request).enqueue(new Callback() {
@Override
public void onFailure(Call call, IOException e) {
}
@Override
public void onResponse(Call call, Response response) throws IOException {
System.out.println("Response 1 succeeded: " + response);
}
});
OkHttpClient copy2 = client.newBuilder()
.readTimeout(3000, TimeUnit.MILLISECONDS)
.build();
copy2.newCall(request).enqueue(new Callback() {
@Override
public void onFailure(Call call, IOException e) {
}
@Override
public void onResponse(Call call, Response response) throws IOException {
System.out.println("Response 2 succeeded: " + response);
}
});
}
}

（Post方式提交String）

使用HTTP POST提交请求到服务。这个例子提交了一个markdown文档到web服务，以HTML方式渲染markdown。因为整个请求体都在内存中，因此避免使用此api提交大文档（大于1MB）。

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 {

String postBody = "" + "Releases\n" + "--------\n" + "\n"

+ " * _1.2_ August 11, 2013\n";

Request request = new Request.Builder()

.url("https://api.github.com/markdown/raw")

.post(RequestBody.create(MEDIA_TYPE_MARKDOWN, postBody))

.build();

Response response = client.newCall(request).execute();

if (!response.isSuccessful()) throw new IOException("Unexpected code " + response);

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

}

Post Streaming（Post方式提交流）

以流的方式POST提交请求体。请求体的内容由流写入产生。这个例子是流直接写入Okio的BufferedSink。你的程序可能会使用OutputStream，你可以使用BufferedSink.outputStream()来获取。.

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\n");

sink.writeUtf8("-------\n");

for (int i = 2; i <= 997; i++) {

sink.writeUtf8(String.format(" * %s = %s\n", 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（Post方式提交文件）

以文件作为请求体是十分简单的。

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 a multipart request（Post方式提交分块请求）

MultipartBuilder可以构建复杂的请求体，与HTML文件上传形式兼容。多块请求体中每块请求都是一个请求体，可以定义自己的请求 头。这些请求头可以用来描述这块请求，例如他的Content-Disposition。如果Content-Length和Content-Type可 用的话，他们会被自动添加到请求头中。

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 MultipartBody.Builder()

.setType(MultipartBody.FORM)

.addFormDataPart("title", "Square Logo")

.addFormDataPart("image", "logo-square.png", 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());

}

Response Caching（响应缓存）

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。

private final OkHttpClient client;

public CacheResponse(File cacheDirectory) throws Exception {

int cacheSize = 10 * 1024 * 1024; // 10 MiB

Cache cache = new Cache(cacheDirectory, cacheSize);

client = new OkHttpClient.Builder()

.cache(cache)

.build();

}

public void run() throws Exception {

Request request = new Request.Builder()

.url("http://publicobject.com/helloworld.txt")

.build();

Response response1 = client.newCall(request).execute();

if (!response1.isSuccessful()) throw new IOException("Unexpected code " + response1);

String response1Body = response1.body().string();

System.out.println("Response 1 response: " + response1);

System.out.println("Response 1 cache response: " + response1.cacheResponse());

System.out.println("Response 1 network response: " + response1.networkResponse());

Response response2 = client.newCall(request).execute();

if (!response2.isSuccessful()) throw new IOException("Unexpected code " + response2);

String response2Body = response2.body().string();

System.out.println("Response 2 response: " + response2);

System.out.println("Response 2 cache response: " + response2.cacheResponse());

System.out.println("Response 2 network response: " + response2.networkResponse());

System.out.println("Response 2 equals Response 1? " + response1Body.equals(response2Body));

}

为了防止使用缓存的响应，可以用CacheControl.FORCE_NETWORK。为了防止它使用网络，使用 CacheControl.FORCE_CACHE。需要注意的是：如果您使用FORCE_CACHE和网络的响应需求，OkHttp则会返回一个504 提示，告诉你不可满足请求响应。

Handling authentication（处理验证）

OkHttp会自动重试未验证的请求。当响应是401 Not Authorized时，Authenticator会被要求提供证书。Authenticator的实现中需要建立一个新的包含证书的请求。如果没有证书可用，返回null来跳过尝试。

private final OkHttpClient client;

public Authenticate() {

client = new OkHttpClient.Builder()

.authenticator(new Authenticator() {

@Override

public Request authenticate(Route route, Response response) throws IOException {

System.out.println("Authenticating for response: " + response);

System.out.println("Challenges: " + response.challenges());

String credential = Credentials.basic("jesse", "password1");

return response.request().newBuilder()

.header("Authorization", credential)

.build();

}

}).build();

}

public void run() throws Exception {

Request request = new Request.Builder()

.url("http://publicobject.com/secrets/hellosecret.txt")

.build();

Response response = client.newCall(request).execute();

if (!response.isSuccessful()) throw new IOException("Unexpected code " + response);

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

}

不用header添加参数，formbody添加方法：

可以遍历formBody，循环添加 formBody

最好的办法是重写 FormBody，追加添加参数的方法。

private void intercep() {

OkHttpClient.Builder httpClient = new OkHttpClient.Builder();
httpClient.addInterceptor(new Interceptor() {
@Override
public okhttp3.Response intercept(Chain chain) throws IOException {
Request original = chain.request();
//请求定制：添加请求
Request.Builder requestBuilder = original.newBuilder()
.header("APIKEY", "API_KEY");
//请求体定制：统一添加token参数
if (original.body() instanceof FormBody) {
FormBody.Builder newFormBody = new FormBody.Builder();
FormBody oidFormBody = (FormBody) original.body();
for (int i = 0; i < oidFormBody.size(); i++) {
newFormBody.addEncoded(oidFormBody.encodedName(i), oidFormBody.encodedValue(i));
}
newFormBody.add("token", "API_TOKEN");
requestBuilder.method(original.method(), newFormBody.build());
}
Request request = requestBuilder.build();
return chain.proceed(request);
}
});
}

OkHttp官方文档：https://github.com/square/okhttp/wiki

源码下载

来自为知笔记(Wiz)