基于HttpClient 4.5.2
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执行GET请求
CloseableHttpClient httpClient = HttpClients.custom() .build(); CloseableHttpResponse response = httpClient.execute(new HttpGet("https://www.baidu.com")); System.out.println(EntityUtils.toString(response.getEntity())); -
执行POST请求
- 提交form表单参数
CloseableHttpClient httpClient = HttpClients.custom() .build(); HttpPost httpPost = new HttpPost("https://www.explame.com"); ListformParams = new ArrayList (); //表单参数 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())); - 提交payload参数
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())); - post上传文件
CloseableHttpClient httpClient = HttpClients.custom() .build(); HttpPost httpPost = new HttpPost("https://www.example.com"); MultipartEntityBuilder multipartEntityBuilder = MultipartEntityBuilder.create(); //要上传的文件 multipartEntityBuilder.addBinaryBody("file", new File("temp.txt")); httpPost.setEntity(multipartEntityBuilder.build()); CloseableHttpResponse response = httpClient.execute(httpPost); System.out.println(EntityUtils.toString(response.getEntity())); - post提交multipart/form-data类型参数
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()));
- 提交form表单参数
-
设置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())); -
设置重试处理器
当请求超时, 会自动重试，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")); -
重定向策略
- HttpClient默认情况
会对302、307的GET和HEAD请求以及所有的303状态码做重定向处理 - 关闭自动重定向
CloseableHttpClient httpClient = HttpClients.custom() //关闭httpclient重定向 .disableRedirectHandling() .build(); - POST支持302状态码重定向
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()));
- HttpClient默认情况
-
定制cookie
- 方式一：通过addHeader方式设置（不推荐这种方式）
由于HttpClient默认会维护cookie状态。如果这个请求response中有Set-Cookie头，那下次请求的时候httpclient默认会把这个Cookie带上。并且会新建一行header。如果再遇到CloseableHttpClient httpClient = HttpClients.custom() .build(); HttpGet httpGet = new HttpGet("http://www.example.com"); httpGet.addHeader("Cookie", "name=value"); httpClient.execute(httpGet);
httpGet.addHeader("Cookie", "name=value");
那么下次请求则会有两行name为Cookie的header。 - 方式二：通过CookieStore的方式，以浏览器中的cookie为例（推荐）
这种方式把定制的cookie交给httpclient维护。//此处直接粘贴浏览器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"));
- 方式一：通过addHeader方式设置（不推荐这种方式）
-
cookie管理
- 方式一：初始化HttpClient时，传入一个自己CookieStore对象
CookieStore cookieStore = new BasicCookieStore(); CloseableHttpClient httpClient = HttpClients.custom() .setDefaultCookieStore(cookieStore) .build(); httpClient.execute(new HttpGet("https://www.baidu.com")); //请求一次后,清理cookie再发起一次新的请求 cookieStore.clear(); httpClient.execute(new HttpGet("https://www.baidu.com")); - 方式二：每次执行请求的时候传入自己的HttpContext对象
//注:HttpClientContext不是线程安全的，不要多个线程维护一个HttpClientContext HttpClientContext httpContext = HttpClientContext.create(); CloseableHttpClient httpClient = HttpClients.custom() .build(); httpClient.execute(new HttpGet("https://www.baidu.com"), httpContext); //请求一次后,清理cookie再发起一次新的请求 httpContext.getCookieStore().clear(); httpClient.execute(new HttpGet("https://www.baidu.com"));
- 方式一：初始化HttpClient时，传入一个自己CookieStore对象
-
http代理的配置
CloseableHttpClient httpClient = HttpClients.custom() //设置代理 .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())); -
SSL配置
//默认信任 SSLContext sslContext = SSLContexts.custom() .loadTrustMaterial(KeyStore.getInstance(KeyStore.getDefaultType()) , (chain, authType) -> true).build(); RegistrysocketFactoryRegistry = RegistryBuilder. 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())); -
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 { //默认信任 SSLContext sslContext = SSLContexts.custom() .loadTrustMaterial(KeyStore.getInstance(KeyStore.getDefaultType()) , (X509Certificate[] chain, String authType) -> true).build(); RegistrysocketFactoryRegistry = RegistryBuilder. 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())); } -
下载文件
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
- 完整Demo源码下载地址:https://github.com/wycm/HttpClientDemo
版权声明
作者：wycm
出处：https://www.jianshu.com/p/e6980bb463e9
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