使用HttpClient调用外部系统接口2-HttpClient 模拟登陆，保持会话并进行后续操作

绝地灬酷狼 2022-05-14 10:17 139阅读 0赞

下面主要说明 Form-Based 的验证方式的演示代码，如果登陆时需要一个验证码的话，那只有自己想办法怎么得到这个码了：

package com.example.demo;
    
    import org.apache.commons.httpclient.Cookie;
    import org.apache.commons.httpclient.HttpClient;
    import org.apache.commons.httpclient.NameValuePair;
    import org.apache.commons.httpclient.cookie.CookiePolicy;
    import org.apache.commons.httpclient.methods.GetMethod;
    import org.apache.commons.httpclient.methods.PostMethod;
    
    public class HttpClientLogin {
        public
        static void main(String[] args) {
            //登陆 Url
            String loginUrl = "http://192.168.1.100:8080/xx/login.do";
    
            //需登陆后访问的 Url
            String dataUrl = "http://192.168.1.100:8999/xx/user_info.html?userid=123456";
    
            HttpClient httpClient = new HttpClient();
    
            //模拟登陆，按实际服务器端要求选用 Post 或 Get 请求方式
            PostMethod postMethod = new PostMethod(loginUrl);
    
            //设置登陆时要求的信息，一般就用户名和密码，验证码自己处理了
            NameValuePair[] data = {
                    new NameValuePair("username", "aaa"),
                    new NameValuePair("password", "123456"),
                    new NameValuePair("code", "anyany")
            };
    
            postMethod.setRequestBody(data);
    
            try {
                //设置 HttpClient 接收 Cookie,用与浏览器一样的策略
                httpClient.getParams().setCookiePolicy(CookiePolicy.BROWSER_COMPATIBILITY);
    
                httpClient.executeMethod(postMethod);
    
                //获得登陆后的 Cookie
                Cookie[] cookies = httpClient.getState().getCookies();
    
                String tmpcookies = "";
                for (Cookie c : cookies) {
                    tmpcookies += c.toString() + ";";
                }
    
                //进行登陆后的操作
                GetMethod getMethod = new GetMethod(dataUrl);
    
                //每次访问需授权的网址时需带上前面的 cookie 作为通行证
                getMethod.setRequestHeader("cookie", tmpcookies);
    
                //你还可以通过 PostMethod/GetMethod 设置更多的请求后数据
                //例如，referer 从哪里来的，UA 像搜索引擎都会表名自己是谁，无良搜索引擎除外,这个也可以不要
    //            postMethod.setRequestHeader("Referer", "http://localhost:8080");
    //            postMethod.setRequestHeader("User-Agent", "aaa Spot");
    
                httpClient.executeMethod(getMethod);
    
                //打印出返回数据，检验一下是否成功
                String text = getMethod.getResponseBodyAsString();
                System.out.println(text);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

要引入jar包

<dependency>
    	<groupId>commons-httpclient</groupId>
    	<artifactId>commons-httpclient</artifactId>
    	<version>3.0.1</version>
    </dependency>

参考文章：[https://blog.csdn.net/sdbzwangdongdong/article/details/39557501][https_blog.csdn.net_sdbzwangdongdong_article_details_39557501]

[https_blog.csdn.net_sdbzwangdongdong_article_details_39557501]: https://blog.csdn.net/sdbzwangdongdong/article/details/39557501