【一】HttpClient4.3.1简单入门实例

2019独角兽企业重金招聘Python工程师标准>>>

1、先看一下示例代码

public class HttpClientTest {
    public static void main(String args[]) {
        //创建HttpClientBuilder
        HttpClientBuilder httpClientBuilder = HttpClientBuilder.create();
        //HttpClient
        CloseableHttpClient closeableHttpClient = httpClientBuilder.build();

        HttpGet httpGet = new HttpGet("http://www.gxnu.edu.cn/default.html");
        System.out.println(httpGet.getRequestLine());
        try {
            //执行get请求
            HttpResponse httpResponse = closeableHttpClient.execute(httpGet);
            //获取响应消息实体
            HttpEntity entity = httpResponse.getEntity();
            //响应状态
            System.out.println("status:" + httpResponse.getStatusLine());
            //判断响应实体是否为空
            if (entity != null) {
                System.out.println("contentEncoding:" + entity.getContentEncoding());
                System.out.println("response content:" + EntityUtils.toString(entity));
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {

//关闭流并释放资源
                closeableHttpClient.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

以下内容来自 HttpClient4.3.1 API文档： http://hc.apache.org/httpcomponents-client-ga/httpclient/apidocs/overview-summary.html

2、HttpClientBuilder

HttpClientBuilder用于创建CloseableHttpClient实例。看了一下API文档，AbstractHttpClient、 AutoRetryHttpClient、 DefaultHttpClient等都被弃用了，使用HttpClientBuilder代替。

3、CloseableHttpClient

实现接口：Closeable, AutoCloseable, HttpClient；子类：AbstractHttpClient

4、HttpGet

非线程安全；HttpGet有三个构造方法：HttpGet()、HttpGet(String uri)、HttpGet(URI uri)

5、HttpResponse

服务器在接收和解释请求之后返回一个HTTP响应信息

Response      = Status-Line
                     *(( general-header
                      | response-header
                      | entity-header ) CRLF)
                     CRLF
                     [ message-body ]

转载于:https://my.oschina.net/tanweijie/blog/195287