java 模拟web登陆httpClient并保存cookie

场景：调用接口完成某项操作，但是接口是强登录的，需要cookie, 且cookie会过期；服务器会限制登录的次数，如果一个账号频繁登录，则在短时间内无法正常登录，因此无法做到每调用接口一次就登录一次，且这样的效率也会比较低；

方法： 采用httpClient获取cookie, 并在接口上加入cookie校验；

核心代码：

0. 需要加入的jar包

import org.apache.commons.lang.StringUtils;
import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.methods.GetMethod;
import org.apache.http.Header;
import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;
import org.apache.http.StatusLine;
import org.apache.http.client.CookieStore;

import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.commons.httpclient.methods.GetMethod;

import org.apache.http.client.methods.HttpPost;

import org.apache.http.cookie.Cookie;
import org.apache.http.impl.client.BasicCookieStore;

import org.apache.http.impl.client.HttpClients;
import org.apache.http.protocol.BasicHttpContext;
import org.apache.http.protocol.HttpContext;

  需要导入pom.xml文件的依赖

       <dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>httpclient</artifactId>
            <version>4.5.5</version>
        </dependency>
        <dependency>
            <groupId>commons-httpclient</groupId>
            <artifactId>commons-httpclient</artifactId>
            <version>3.1</version>
        </dependency>

1. 获取cookie， 其中

getUrl(loginUrl, username, password); 是将url进行拼接，loginUrl 加上登陆需要的参数拼接为一个请求， 其中loginUrl就是登录url

public String getCookies(String username, String password){
        CookieStore cookieStore = new BasicCookieStore();
        HttpContext localContext = new BasicHttpContext();
        localContext.setAttribute(COOKIE_STORE, cookieStore);
        HttpClient client = HttpClients.createDefault();
        String authUrl = getUrl(loginUrl, username, password);
        System.out.println("authUrl = " + authUrl);
        HttpPost post = new HttpPost(authUrl);
        try {
            response = client.execute(post, localContext);
            StatusLine statusLine = response.getStatusLine();
            int statusCode = statusLine.getStatusCode();
            System.out.println("first execute code :" + statusCode);
            if(statusCode == HttpStatus.SC_MOVED_PERMANENTLY || statusCode == HttpStatus.SC_MOVED_TEMPORARILY){
                Header firsRedirectHeader = response.getFirstHeader("location");
                String firstRedirectUrl = firsRedirectHeader.getValue();
                HttpGet get = new HttpGet(firstRedirectUrl);
                HttpResponse getResponse = client.execute(get, localContext);
                StatusLine statusLine2 = getResponse.getStatusLine();
                int statusCode2 = statusLine2.getStatusCode();
                System.out.println("second execute code :" + statusCode2);
                System.out.println("cookie :" + cookieStore.getCookies());
                List<Cookie> cookieList = cookieStore.getCookies();
                StringBuffer tmpCookie = new StringBuffer();
                for(int i = 0 ; i < cookieList.size(); i++) {
                    tmpCookie.append(cookieList.get(i).getName()).append("=");
                    tmpCookie.append(cookieList.get(i).getValue()).append(";");
                    tmpCookie.append("domain=").append(cookieList.get(i).getDomain()).append(";");
                    tmpCookie.append("path=").append(cookieList.get(i).getPath()).append(";");
                }
                get.releaseConnection();
                return tmpCookie.toString();

            }
        } catch (IOException e) {
            e.printStackTrace();
        }finally {
            if(post != null){
                post.releaseConnection();
            }
        }
        return "-1";

    }

// formData 里面需要填充的内容根据浏览器f12调试模式中，获取到请求的信息

private String getUrl(String url, String username, String password){
        if(StringUtils.isEmpty(url)){
            System.out.println("url is empty");
            return "-1";
        }
        formData = new HashMap<String, String>();
        formData.put("username", username);
        formData.put("password", password);
        formData.put("app", "web");
        formData.put("product", "xxx");//产品根据实际情况定
        formData.put("tp", "urstoken");
        formData.put("cf", "7");
        formData.put("fr", "1");
        formData.put("ru", "https://xxxxxxxn");  //链接可以根据自己在浏览器的信息中拿到，不同的登录该部分地址是不一样的
        formData.put("er", "https://xxxxx");
        String arguments = MaptoUrl(formData);
        return url + arguments;
    }

　

public String MaptoUrl(Map<String, String> map){
    String arguments="?";
    Iterator iterator = map.entrySet().iterator();
    Boolean first_args = true;
    while(iterator.hasNext()){
        Map.Entry entry = (Map.Entry) iterator.next();
        Object key = entry.getKey();
        Object val = entry.getValue();
        String key_str = (String) key;
        String val_str = (String) val;
        if(first_args == false){
            arguments = arguments + "&";
        }
        first_args = false;
        arguments = arguments + key_str;
        arguments = arguments + "=";
        arguments = arguments + val_str;

    }
    return arguments;
}

　　

　

2.  获取到有效的cookie, 因为第一步获取到cookie后，cookie在一段时间内可能会失效，因此为了后面接口中带入有效的cookie, 这里还需要该函数来获取真正有效的cookie;

  public String getValidCookie(String cookie){
            if(cookie.contains("DICT_SESS")){
                return cookie;
            }else{
                Login login = new Login();
                String validCookie = login.getCookies(username, password);
                return validCookie;
            }
    }

3. 真正执行接口的代码， for循环2次，第一次是去请求接口，如果接口返回的结果是403权限被拒绝，则需要调用login.getValidCookie()方法登录一次，获取真正的cookie.，然后进行第二次接口请求；

  如果接口返回的结果是0， 则表示cookie依然有效，则直接返回true;   其中参数url是需要真正请求的接口；

 public Boolean executeMethod(String url) {
        String result = "-1";
        for(int i = 0; i < 2; i++) {
            GetMethod getMethod = new GetMethod(url);
            getMethod.setRequestHeader("cookie", cookie);
            try {
                httpClient.executeMethod(getMethod);
                System.out.println("method result  = " + getMethod.getResponseBodyAsString());
                result = getMethod.getResponseBodyAsString();
            } catch (IOException e) {
                e.printStackTrace();
            }
            JSONObject obj = JSONObject.parseObject(result);
            if ("0".equals(obj.get("err").toString())) {
                return true;
            }else if ("403".equals(obj.get("err").toString())) {
                cookie = login.getValidCookie(cookie);
                continue;
            }else{
                return false;
            }
        }
        return false;

    }

4. 在类加载的时候先登录一次，保存cookie,且是全局变量；则在第3步更新cookie的时候，就可以更新该变量；

   Login login = new Login();

private String cookie = login.getCookies(username, password);

HttpClient httpClient = new HttpClient(); 

public static void main(String[] args) {
        Login httpclientDemo = new Login();
        org.apache.commons.httpclient.HttpClient httpClient = new org.apache.commons.httpclient.HttpClient();
        String cookie = httpclientDemo.getCookies("username", "password");
        System.out.println("final cookie = " + cookie);
        String url = yyyyy";//需要请求的url
        GetMethod getMethod = new GetMethod(url);
        getMethod.setRequestHeader("cookie", cookie);
        try {
            httpClient.executeMethod(getMethod);
            System.out.println("method result  = " + getMethod.getResponseBodyAsString());
        } catch (IOException e) {
            e.printStackTrace();
        }


    }

　　

总结： 第三步判断cookie失效重新请求的实现方法有点不太好，希望大家多多交流；