HttpClient-GET和POST请求示例

1.get请求

@Test public void sendGet() {

// 获取连接客户端工具
CloseableHttpClient httpClient = HttpClients.createDefault();

String entityStr = null;
CloseableHttpResponse response = null;

try {
    /*
     * 由于GET请求的参数都是拼装在URL地址后方，所以我们要构建一个URL，带参数
     */
    URIBuilder uriBuilder = new URIBuilder("http://www.baidu.com");
    /** 第一种添加参数的形式 */
    /*uriBuilder.addParameter("name", "root");
    uriBuilder.addParameter("password", "123456");*/
    /** 第二种添加参数的形式 */
    List<NameValuePair> list = new LinkedList<>();
    BasicNameValuePair param1 = new BasicNameValuePair("name", "root");
    BasicNameValuePair param2 = new BasicNameValuePair("password", "123456");
    list.add(param1);
    list.add(param2);
    uriBuilder.setParameters(list);

    // 根据带参数的URI对象构建GET请求对象
    HttpGet httpGet = new HttpGet(uriBuilder.build());

    /* 
     * 添加请求头信息
     */
    // 浏览器表示
    httpGet.addHeader("User-Agent", "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.6)");
    // 传输的类型
    httpGet.addHeader("Content-Type", "application/x-www-form-urlencoded");

    // 执行请求
    response = httpClient.execute(httpGet);
    // 获得响应的实体对象
    HttpEntity entity = response.getEntity();
    // 使用Apache提供的工具类进行转换成字符串
    entityStr = EntityUtils.toString(entity, "UTF-8");
} catch (ClientProtocolException e) {
    System.err.println("Http协议出现问题");
    e.printStackTrace();
} catch (ParseException e) {
    System.err.println("解析错误");
    e.printStackTrace();
} catch (URISyntaxException e) {
    System.err.println("URI解析异常");
    e.printStackTrace();
} catch (IOException e) {
    System.err.println("IO异常");
    e.printStackTrace();
} finally {
    // 释放连接
    if (null != response) {
        try {
            response.close();
            httpClient.close();
        } catch (IOException e) {
            System.err.println("释放连接出错");
            e.printStackTrace();
        }
    }
}

// 打印响应内容
System.out.println(entityStr);

}

2.POST请求

@Test public void sendPost() { // 获取连接客户端工具 CloseableHttpClient httpClient = HttpClients.createDefault();

String entityStr = null;
CloseableHttpResponse response = null;

try {

    // 创建POST请求对象
    HttpPost httpPost = new HttpPost("http://www.baidu.com");

    /*
     * 添加请求参数
     */
    // 创建请求参数
    List<NameValuePair> list = new LinkedList<>();
    BasicNameValuePair param1 = new BasicNameValuePair("name", "root");
    BasicNameValuePair param2 = new BasicNameValuePair("password", "123456");
    list.add(param1);
    list.add(param2);
    // 使用URL实体转换工具
    UrlEncodedFormEntity entityParam = new UrlEncodedFormEntity(list, "UTF-8");
    httpPost.setEntity(entityParam);

    /* 
     * 添加请求头信息
     */
    // 浏览器表示
    httpPost.addHeader("User-Agent", "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.6)");
    // 传输的类型
    httpPost.addHeader("Content-Type", "application/x-www-form-urlencoded");

    // 执行请求
    response = httpClient.execute(httpPost);
    // 获得响应的实体对象
    HttpEntity entity = response.getEntity();
    // 使用Apache提供的工具类进行转换成字符串
    entityStr = EntityUtils.toString(entity, "UTF-8");

    // System.out.println(Arrays.toString(response.getAllHeaders()));

} catch (ClientProtocolException e) {
    System.err.println("Http协议出现问题");
    e.printStackTrace();
} catch (ParseException e) {
    System.err.println("解析错误");
    e.printStackTrace();
} catch (IOException e) {
    System.err.println("IO异常");
    e.printStackTrace();
} finally {
    // 释放连接
    if (null != response) {
        try {
            response.close();
            httpClient.close();
        } catch (IOException e) {
            System.err.println("释放连接出错");
            e.printStackTrace();
        }
    }
}

// 打印响应内容
System.out.println(entityStr);

}