java-工具-輕量級http開發庫Unirest

輕量級http開發庫Unirest

一. 特點

可以被PHP、Ruby、Python、Java、Objective-C等語言調用
支持GET、POST、PUT、UPDATE、DELETE操作，調用方法和返回類型對所有語言都是相同的
可以利用下面代碼發送httprequest

Unirest.post("http://httpbin.org/post")
	  .queryString("name", "Mark")
	  .field("last", "Polo")
	  .asJson()

特點：

• 請求：GET, POST, PUT, PATCH, DELETE, HEAD, OPTIONS
• 異步+同步模式
• 支持表單參數、文件上傳
• gzip、基本的本地認證、proxy、timeout
• 默認headers、HttpClient、HttpAsyncClient、轉json

maven

<dependency>
    <groupId>com.mashape.unirest</groupId>
    <artifactId>unirest-java</artifactId>
    <version>1.4.9</version>
</dependency>

二. 使用

創建request
基本的post請求

HttpResponse<JsonNode> jsonResponse = Unirest.post("http://httpbin.org/post")
            .header("accept", "application/json")
            .queryString("apiKey", "123")
            .field("parameter", "value")
            .field("foo", "bar")
            .asJson();

當執行了asType方法之后，Requests就被生成了，可以轉換的內容為Json, Binary, String, Object
.body(String|JsonNode|Object)，當使用.body(Object) 時需要額外的配置參數
.fields(Map<String, Object> fields)會把每個k-v填入form表單
.headers(Map<String, String> headers)填入headers參數

Serialization
當執行asObject(Class)或者.body(Object)之前，需要一個ObjectMapper的定制實現，在最初就要運行，因為ObjectMapper是全局共享的
比如使用Jackson序列化json，如下

// Only one time
Unirest.setObjectMapper(new ObjectMapper() {
    private com.fasterxml.jackson.databind.ObjectMapper jacksonObjectMapper
                = new com.fasterxml.jackson.databind.ObjectMapper();

    public <T> T readValue(String value, Class<T> valueType) {
        try {
            return jacksonObjectMapper.readValue(value, valueType);
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    public String writeValue(Object value) {
        try {
            return jacksonObjectMapper.writeValueAsString(value);
        } catch (JsonProcessingException e) {
            throw new RuntimeException(e);
        }
    }
});

// Response to Object
HttpResponse<Book> bookResponse = Unirest.get("http://httpbin.org/books/1").asObject(Book.class);
Book bookObject = bookResponse.getBody();

HttpResponse<Author> authorResponse = Unirest.get("http://httpbin.org/books/{id}/author")
    .routeParam("id", bookObject.getId())
    .asObject(Author.class);

Author authorObject = authorResponse.getBody();

// Object to Json
HttpResponse<JsonNode> postResponse = Unirest.post("http://httpbin.org/authors/post")
        .header("accept", "application/json")
        .header("Content-Type", "application/json")
        .body(authorObject)
        .asJson();

Route Parameters
在RUL中添加動態參數，可以通過URL中添加占位符，然后再利用routeParam函數

Unirest.get("http://httpbin.org/{method}")
  .routeParam("method", "get")
  .queryString("name", "Mark")
  .asJson();

這里的占位符會被get代替

異步請求
很多時候，需要使用asynchronous模式，使用異步回調

Future<HttpResponse<JsonNode>> future = Unirest.post("http://httpbin.org/post")
					  .header("accept", "application/json")
					  .field("param1", "value1")
					  .field("param2", "value2")
					  .asJsonAsync(new Callback<JsonNode>() {
    public void failed(UnirestException e) {
        System.out.println("The request has failed");
    }

    public void completed(HttpResponse<JsonNode> response) {
         int code = response.getStatus();
         Map<String, String> headers = response.getHeaders();
         JsonNode body = response.getBody();
         InputStream rawBody = response.getRawBody();
    }

    public void cancelled() {
        System.out.println("The request has been cancelled");
    }
});

文件上傳
使用java創建multipart請求很瑣碎，下面代碼簡化這一個過程

HttpResponse<JsonNode> jsonResponse = Unirest.post("http://httpbin.org/post")
  .header("accept", "application/json")
  .field("parameter", "value")
  .field("file", new File("/tmp/file"))
  .asJson();

定制實體body

HttpResponse<JsonNode> jsonResponse = Unirest.post("http://httpbin.org/post")
  .header("accept", "application/json")
  .body("{\"parameter\":\"value\", \"foo\":\"bar\"}")
  .asJson();

比特流body

final InputStream stream = new FileInputStream(new File(getClass().getResource("/image.jpg").toURI()));
final byte[] bytes = new byte[stream.available()];
stream.read(bytes);
stream.close();
final HttpResponse<JsonNode> jsonResponse = Unirest.post("http://httpbin.org/post")
  .field("name", "Mark")
  .field("file", bytes, "image.jpg")
  .asJson();

InputStream body

HttpResponse<JsonNode> jsonResponse = Unirest.post("http://httpbin.org/post")
  .field("name", "Mark")
  .field("file", new FileInputStream(new File(getClass().getResource("/image.jpg").toURI())), ContentType.APPLICATION_OCTET_STREAM, "image.jpg")
  .asJson();

Basic Authentication
調用basicAuth(username, password)

HttpResponse<JsonNode> response = 
	Unirest.get("http://httpbin.org/headers").basicAuth("username", "password").asJson();

三. Request & Response

Java版本的是構造這模式,通過下面這些方式獲取HttpRequest

GetRequest request = Unirest.get(String url);
GetRequest request = Unirest.head(String url);
HttpRequestWithBody request = Unirest.post(String url);
HttpRequestWithBody request = Unirest.put(String url);
HttpRequestWithBody request = Unirest.patch(String url);
HttpRequestWithBody request = Unirest.options(String url);
HttpRequestWithBody request = Unirest.delete(String url);

收到反饋時，返回一個Object，object對於不同的語言應該有相同的keys

.getStatus() - HTTP Response Status Code (Example: 200)
.getStatusText() - HTTP Response Status Text (Example: "OK")
.getHeaders() - HTTP Response Headers
.getBody() - Parsed response body where applicable, for example JSON responses are parsed to Objects / Associative Arrays.
.getRawBody() - Un-parsed response body

四. 高級配置

可以設置一些高級的配置，調整Unirest
定制HTTP clients,可以修改HttpClient和HttpAsyncClient的實現，然后設置進Unirest中

Unirest.setHttpClient(httpClient);
Unirest.setAsyncHttpClient(asyncHttpClient);

Timeouts以ms為單位
默認連接超時10000，socket超時60000，設置為0為關閉

Unirest.setTimeouts(long connectionTimeout, long socketTimeout);

默認的Request Headers,每個request都會發出去

Unirest.setDefaultHeader("Header1", "Value1");
Unirest.setDefaultHeader("Header2", "Value2");

清除默認的頭

Unirest.clearDefaultHeaders();

並發,可以設置並發級別，通過設置同步或者異步的client
默認pool中全部的連接限制，maxTotal設置為200，並且maxPerRoute目標host設置為20

Unirest.setConcurrency(int maxTotal, int maxPerRoute);

代理

Unirest.setProxy(new HttpHost("127.0.0.1", 8000));

退出應用
Unirest開啟后台一個event loop,需要手動調用執行退出

Unirest.shutdown();

python使用的例子
http://www.open-open.com/lib/view/open1415237017090.html