Apache HttpClient4使用教程

基于HttpClient 4.5.2

  1. 執(zhí)行GET請求

    CloseableHttpClient httpClient = HttpClients.custom()
                .build();
CloseableHttpResponse response = httpClient.execute(new HttpGet("https://www.baidu.com"));
System.out.println(EntityUtils.toString(response.getEntity()));

  2. 執(zhí)行POST請求

    1. 提交form表單參數(shù) 
      CloseableHttpClient httpClient = HttpClients.custom()
        .build();
HttpPost httpPost = new HttpPost("https://www.explame.com");
List<NameValuePair> formParams = new ArrayList<NameValuePair>();
//表單參數(shù)
formParams.add(new BasicNameValuePair("name1", "value1"));
formParams.add(new BasicNameValuePair("name2", "value2"));
UrlEncodedFormEntity entity = new UrlEncodedFormEntity(formParams, "utf-8");
httpPost.setEntity(entity);
CloseableHttpResponse response = httpClient.execute(httpPost);
System.out.println(EntityUtils.toString(response.getEntity()));
    2. 提交payload參數(shù) 
      CloseableHttpClient httpClient = HttpClients.custom()
            .build();
HttpPost httpPost = new HttpPost("https://www.explame.com");
StringEntity entity = new StringEntity("{\"id\": \"1\"}");
httpPost.setEntity(entity);
CloseableHttpResponse response = httpClient.execute(httpPost);
System.out.println(EntityUtils.toString(response.getEntity()));
    3. post上傳文件 
      CloseableHttpClient httpClient = HttpClients.custom()
        .build();
HttpPost httpPost = new HttpPost("https://www.example.com");
MultipartEntityBuilder multipartEntityBuilder = MultipartEntityBuilder.create();
//要上傳的文件
multipartEntityBuilder.addBinaryBody("file", new File("temp.txt"));
httpPost.setEntity(multipartEntityBuilder.build());
CloseableHttpResponse response = httpClient.execute(httpPost);
System.out.println(EntityUtils.toString(response.getEntity()));
    4. post提交multipart/form-data類型參數(shù) 
      CloseableHttpClient httpClient = HttpClients.custom()
        .build();
HttpPost httpPost = new HttpPost("https://www.example.com");
MultipartEntityBuilder multipartEntityBuilder = MultipartEntityBuilder.create();
multipartEntityBuilder.addTextBody("username","wycm");
multipartEntityBuilder.addTextBody("passowrd","123");
//文件
multipartEntityBuilder.addBinaryBody("file", new File("temp.txt"));
httpPost.setEntity(multipartEntityBuilder.build());
CloseableHttpResponse response = httpClient.execute(httpPost);
System.out.println(EntityUtils.toString(response.getEntity()));

  3. 設置User-Agent

        CloseableHttpClient httpClient = HttpClients.custom()
            .setUserAgent("Mozilla/5.0")
            .build();
    CloseableHttpResponse response = httpClient.execute(new HttpGet("https://www.baidu.com"));
    System.out.println(EntityUtils.toString(response.getEntity()));

  4. 設置重試處理器
    當請求超時, 會自動重試，最多3次

    HttpRequestRetryHandler retryHandler = (exception, executionCount, context) -> {
    if (executionCount >= 3) {
        return false;
    }
    if (exception instanceof InterruptedIOException) {
        return true;
    }
    if (exception instanceof UnknownHostException) {
        return true;
    }
    if (exception instanceof ConnectTimeoutException) {
        return true;
    }
    if (exception instanceof SSLException) {
        return true;
    }
    HttpClientContext clientContext = HttpClientContext.adapt(context);
    HttpRequest request = clientContext.getRequest();
    boolean idempotent = !(request instanceof HttpEntityEnclosingRequest);
    if (idempotent) {
        return true;
    }
    return false;
};
CloseableHttpClient httpClient = HttpClients.custom()
        .setRetryHandler(retryHandler)
        .build();
httpClient.execute(new HttpGet("https://www.baidu.com"));

  5. 重定向策略

    1. HttpClient默認情況
      會對302、307的GET和HEAD請求以及所有的303狀態(tài)碼做重定向處理
    2. 關閉自動重定向 
      CloseableHttpClient httpClient = HttpClients.custom()
         //關閉httpclient重定向
        .disableRedirectHandling()
        .build();
    3. POST支持302狀態(tài)碼重定向 
      CloseableHttpClient httpClient = HttpClients.custom()
    //post 302支持重定向
    .setRedirectStrategy(new LaxRedirectStrategy())
    .build();
CloseableHttpResponse response = httpClient.execute(new HttpPost("https://www.explame.com"));
System.out.println(EntityUtils.toString(response.getEntity()));

  6. 定制cookie

    • 方式一：通過addHeader方式設置（不推薦這種方式） 
          CloseableHttpClient httpClient = HttpClients.custom()
            .build();
    HttpGet httpGet = new HttpGet("http://www.example.com");
    httpGet.addHeader("Cookie", "name=value");
    httpClient.execute(httpGet);
      由于HttpClient默認會維護cookie狀態(tài)。如果這個請求response中有Set-Cookie頭，那下次請求的時候httpclient默認會把這個Cookie帶上。并且會新建一行header。如果再遇到
      httpGet.addHeader("Cookie", "name=value");
      那么下次請求則會有兩行name為Cookie的header。
    • 方式二：通過CookieStore的方式，以瀏覽器中的cookie為例（推薦） 
      //此處直接粘貼瀏覽器cookie
final String RAW_COOKIES = "name1=value1; name2=value2";
final CookieStore cookieStore = new BasicCookieStore();
for (String rawCookie : RAW_COOKIES.split("; ")){
    String[] s = rawCookie.split("=");
    BasicClientCookie cookie = new BasicClientCookie(s[0], s[1]);
    cookie.setDomain("baidu.com");
    cookie.setPath("/");
    cookie.setSecure(false);
    cookie.setAttribute("domain", "baidu.com");
    Calendar calendar = Calendar.getInstance();
    calendar.add(Calendar.DAY_OF_MONTH, +5);
    cookie.setExpiryDate(calendar.getTime());
    cookieStore.addCookie(cookie);
}
CloseableHttpClient httpClient = HttpClients.custom()
        .setDefaultCookieStore(cookieStore)
        .build();
httpClient.execute(new HttpGet("https://www.baidu.com"));
      這種方式把定制的cookie交給httpclient維護。

  7. cookie管理

    • 方式一：初始化HttpClient時，傳入一個自己CookieStore對象 
      CookieStore cookieStore = new BasicCookieStore();
CloseableHttpClient httpClient = HttpClients.custom()
        .setDefaultCookieStore(cookieStore)
        .build();
httpClient.execute(new HttpGet("https://www.baidu.com"));
//請求一次后,清理cookie再發(fā)起一次新的請求
cookieStore.clear();
httpClient.execute(new HttpGet("https://www.baidu.com"));
    • 方式二：每次執(zhí)行請求的時候傳入自己的HttpContext對象 
      //注:HttpClientContext不是線程安全的，不要多個線程維護一個HttpClientContext
HttpClientContext httpContext = HttpClientContext.create();
CloseableHttpClient httpClient = HttpClients.custom()
        .build();
httpClient.execute(new HttpGet("https://www.baidu.com"), httpContext);
//請求一次后,清理cookie再發(fā)起一次新的請求
httpContext.getCookieStore().clear();
httpClient.execute(new HttpGet("https://www.baidu.com"));

  8. http代理的配置

    CloseableHttpClient httpClient = HttpClients.custom()
        //設置代理
        .setRoutePlanner(new DefaultProxyRoutePlanner(new HttpHost("localhost", 8888)))
        .build();
CloseableHttpResponse response = httpClient.execute(new HttpGet("http://www.example.com"));
System.out.println(EntityUtils.toString(response.getEntity()));

  9. SSL配置

    //默認信任
SSLContext sslContext = SSLContexts.custom()
        .loadTrustMaterial(KeyStore.getInstance(KeyStore.getDefaultType())
                , (chain, authType) -> true).build();
Registry<ConnectionSocketFactory> socketFactoryRegistry =
        RegistryBuilder.<ConnectionSocketFactory>create()
                .register("http", new SocketProxyPlainConnectionSocketFactory())
                .register("https", new SocketProxySSLConnectionSocketFactory(sslContext))
                .build();
CloseableHttpClient httpClient = HttpClients.custom()
        .setConnectionManager(new PoolingHttpClientConnectionManager(socketFactoryRegistry))
        .build();
HttpClientContext httpClientContext = HttpClientContext.create();
httpClientContext.setAttribute("socks.address", new InetSocketAddress("127.0.0.1", 1086));
CloseableHttpResponse response = httpClient.execute(new HttpGet("https://httpbin.org/ip"), httpClientContext);
System.out.println(EntityUtils.toString(response.getEntity()));

  10. socket代理配置

    static class SocketProxyPlainConnectionSocketFactory extends PlainConnectionSocketFactory{
    @Override
    public Socket createSocket(final HttpContext context) {
        InetSocketAddress socksAddr = (InetSocketAddress) context.getAttribute("socks.address");
        if (socksAddr != null){
            Proxy proxy = new Proxy(Proxy.Type.SOCKS, socksAddr);
            return new Socket(proxy);
        } else {
            return new Socket();
        }
    }
}
static class SocketProxySSLConnectionSocketFactory extends SSLConnectionSocketFactory {
    public SocketProxySSLConnectionSocketFactory(final SSLContext sslContext) {
        super(sslContext, NoopHostnameVerifier.INSTANCE);
    }

    @Override
    public Socket createSocket(final HttpContext context) {
        InetSocketAddress socksAddr = (InetSocketAddress) context.getAttribute("socks.address");
        if (socksAddr != null){
            Proxy proxy = new Proxy(Proxy.Type.SOCKS, socksAddr);
            return new Socket(proxy);
        } else {
            return new Socket();
        }
    }

}
/**
 * socket代理配置
 */
public static void socketProxy() throws Exception {
    //默認信任
    SSLContext sslContext = SSLContexts.custom()
            .loadTrustMaterial(KeyStore.getInstance(KeyStore.getDefaultType())
                    , (X509Certificate[] chain, String authType) -> true).build();
    Registry<ConnectionSocketFactory> socketFactoryRegistry =
            RegistryBuilder.<ConnectionSocketFactory>create()
                    .register("http", new SocketProxyPlainConnectionSocketFactory())
                    .register("https", new SocketProxySSLConnectionSocketFactory(sslContext))
                    .build();
    CloseableHttpClient httpClient = HttpClients.custom()
            .setConnectionManager(new PoolingHttpClientConnectionManager(socketFactoryRegistry))
            .build();
    HttpClientContext httpClientContext = HttpClientContext.create();
    httpClientContext.setAttribute("socks.address", new InetSocketAddress("127.0.0.1", 1086));
    CloseableHttpResponse response = httpClient.execute(new HttpGet("https://httpbin.org/ip"), httpClientContext);
    System.out.println(EntityUtils.toString(response.getEntity()));
}

  11. 下載文件

    CloseableHttpClient httpClient = HttpClients.custom().build();
CloseableHttpResponse response = httpClient.execute(new HttpGet("https://www.example.com"));
InputStream is = response.getEntity().getContent();
Files.copy(is, new File("temp.png").toPath(), StandardCopyOption.REPLACE_EXISTING);

最后

版權聲明
作者：wycm
出處：http://www.lxweimin.com/p/e6980bb463e9
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