HttpClient

HttpClient4.x 使用详解

最新推荐文章于 2025-01-26 17:56:43 发布

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最新推荐文章于 2025-01-26 17:56:43 发布

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原文链接：http://www.cnblogs.com/huangwenjie/p/9230254.html

本文介绍了Apache HttpClient4.1及之后版本的重要变化，包括从Apache Commons迁移到Apache HttpComponents，并对比了新旧版本的主要区别。提供了HttpClient4.x的常用操作示例，如GET和POST请求的实现方式，同时涉及了如何解决请求过程中的参数乱码问题。

HttpClient 4.1 以后不再在Apache Commons下，而是位于Apache HttpComponents

org.apache.commons.httpclient.HttpClient与org.apache.http.client.HttpClient的区别：
Commons的HttpClient项目现在是生命的尽头，不再被开发,已被Apache HttpComponents项目HttpClient和的HttpCore
模组取代，提供更好的性能和更大的灵活性。
目前版本为HttpClient 4.5.5 (GA)
HttpClient的官网示例页面
一般用法

    public final static void main(String[] args) throws Exception {
        CloseableHttpClient httpclient = HttpClients.createDefault();
        try {
            HttpGet httpget = new HttpGet("http://httpbin.org/get");

            System.out.println("Executing request " + httpget.getRequestLine());
            CloseableHttpResponse response = httpclient.execute(httpget);
            try {
                System.out.println("----------------------------------------");
                System.out.println(response.getStatusLine());

                // Get hold of the response entity
                HttpEntity entity = response.getEntity();

                // If the response does not enclose an entity, there is no need
                // to bother about connection release
                if (entity != null) {
                    InputStream instream = entity.getContent();
                    try {
                        instream.read();
                        // do something useful with the response

                        byte[] bytes = new byte[0];
                        bytes = new byte[instream.available()];
                        instream.read(bytes);
                        String str = new String(bytes);
                        System.out.println("str: " + str);

                        String string = EntityUtils.toString(entity, "UTF-8");
                        System.out.println("string: " + string);
                    } catch (IOException ex) {
                        // In case of an IOException the connection will be released
                        // back to the connection manager automatically
                        throw ex;
                    } finally {
                        // Closing the input stream will trigger connection release
                        instream.close();
                    }
                }
            } finally {
                response.close();
            }
        } finally {
            httpclient.close();
        }
    }

最简单post请求

    public static void main(String[] args) throws Exception {
        List<NameValuePair> formparams = new ArrayList<NameValuePair>();
        formparams.add(new BasicNameValuePair("account", ""));
        formparams.add(new BasicNameValuePair("password", ""));
        HttpEntity reqEntity = new UrlEncodedFormEntity(formparams, "UTF-8");

        RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(5000)// 一、连接超时：connectionTimeout-->指的是连接一个url的连接等待时间
                .setSocketTimeout(5000)// 二、读取数据超时：SocketTimeout-->指的是连接上一个url，获取response的返回等待时间
                .setConnectionRequestTimeout(5000).build();

        HttpClient client = HttpClients.createDefault();
        HttpPost post = new HttpPost("http://cnivi.com.cn/login");
        post.setEntity(reqEntity);
        post.setConfig(requestConfig);
        HttpResponse response = client.execute(post);

        if (response.getStatusLine().getStatusCode() == 200) {
            HttpEntity resEntity = response.getEntity();
            String message = EntityUtils.toString(resEntity, "UTF-8");
            System.out.println(message);
        } else {
            System.out.println("请求失败");
        }
    }

解决参数乱码问题

HttpEntity entity = new StringEntity(xml, ContentType.create("text/xml", Consts.UTF_8));

参考资料

转载于:https://www.cnblogs.com/huangwenjie/p/9230254.html