使用httpClient模拟浏览器发送请求

1. 使用httpClient发送无参数get请求，代码如下

		//创建一个httpClient对象
		CloseableHttpClient httpClient=HttpClients.createDefault();
		//创建一个Get对象
		HttpGet get=new HttpGet("http://www.sogou.com");
		//执行请求
		CloseableHttpResponse response = httpClient.execute(get);
		//取响应的结果
		int statusCode = response.getStatusLine().getStatusCode();
		System.out.println(statusCode);
		HttpEntity entity = response.getEntity();
		String string = EntityUtils.toString(entity,"utf-8");
		System.out.println(string);
		//关闭httpClient
		response.close();
		httpClient.close();

2. 使用httpClient发送带参数的get请求，有两种方式
   第一种，在上述无参数的方法中，在创建get对象时，将参数附在url后面，例如：HttpGet get=new HttpGet(“http://www.sogou.com？query=“花千骨””);
   第二种方法，创建一个URL对象，将参数添加进URL对象中，再使用URL对象创建get对象，代码如下：

		//创建一个httpclient对象
		CloseableHttpClient httpClient=HttpClients.createDefault();
		//创建一个url对象并添加参数
		URIBuilder uriBuilder=new URIBuilder("https://www.sogou.com/sie");
		uriBuilder.addParameter("query", "花千骨");
		HttpGet get=new HttpGet(uriBuilder.build());
		//执行请求，获得响应
		CloseableHttpResponse response = httpClient.execute(get);
		//取响应的结果
		int statusCode = response.getStatusLine().getStatusCode();
		System.out.println(statusCode);
		HttpEntity entity = response.getEntity();
		String string = EntityUtils.toString(entity,"utf-8");
		System.out.println(string);
		//关闭httpclient
		response.close();
		httpClient.close();

3. 使用httpClient发送无参数的post请求，与无参数的get请求类似，区别只是不创建get对象，而是创建post对象，代码如下：

CloseableHttpClient httpClient=HttpClients.createDefault();
		//创建一个post对象
		HttpPost post=new HttpPost("http://localhost:8082/httpclient/post.html");
		CloseableHttpResponse response = httpClient.execute(post);
		String string = EntityUtils.toString(response.getEntity());
		System.out.println(string);
		response.close();
		httpClient.close();

4. 使用httpClient发送有参数的post请求，比较复杂，需创建Entity对象，先模拟表单，创建一个基类是实现NameValuePair接口的list，然后将参数使用BasicNameValuePair类添加进list当中，在将此list封装成Entity对象，然后设置给post，代码如下：

CloseableHttpClient httpClient=HttpClients.createDefault();
		//创建一个post对象
		HttpPost post=new HttpPost("http://localhost:8082/httpclient/post.html");
		//创建一个Entity，模拟一个表单
		List<NameValuePair> kvList=new ArrayList<>();
		kvList.add(new BasicNameValuePair("name", "zhangsan"));
		kvList.add(new BasicNameValuePair("password","123456"));
		//包装成一个Entity对象
		StringEntity entity=new UrlEncodedFormEntity(kvList);
		//设置请求的内容
		post.setEntity(entity);
		CloseableHttpResponse response = httpClient.execute(post);
		String string = EntityUtils.toString(response.getEntity());
		System.out.println(string);
		response.close();
		httpClient.close();