java okhhtp下载学信网学籍信息

学信网的登录有验证码，是那种计算数字或者汉字识别的，很难识别。最近连学籍信息和学历信息也换成图片了，常规的正则 css xpath都不能使。

下载图片，需要先登录，获取登陆后的cookie和学籍信息的图片url。这一步由webview获得，用户自行登录，不需要理会验证码。

使用okhttp。需要导入这两个包。

package com.touna.httprequest;

import java.io.File;
import java.io.FileOutputStream;
import java.util.concurrent.TimeUnit;

import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;

public class HttpReq {

    //private  OkHttpClient client = new OkHttpClient();
    private final Request.Builder builder = new Request.Builder();
    private final OkHttpClient  client = new OkHttpClient.Builder()
            .readTimeout(30, TimeUnit.SECONDS)
            .connectTimeout(30, TimeUnit.SECONDS)
            .writeTimeout(30, TimeUnit.SECONDS)
            .build(); //设置各种超时时间

    /**
     @param  isAddXuexinHeader 是否加入学信网header到请求头
     */
    public HttpReq(boolean isAddXuexinHeader){
        if (isAddXuexinHeader == true){
            builder.addHeader("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8");
            builder.addHeader("Accept-Encoding","gzip, deflate, sdch, br");
            builder.addHeader("Accept-Language","zh-CN,zh;q=0.8");
            builder.addHeader("Cache-Control","max-age=0");
            builder.addHeader("Connection","keep-alive");
            builder.addHeader("Host","my.chsi.com.cn");
            builder.addHeader("If-Modified-Since","Tue, 13 Mar 2018 10:14:31 GMT");
            builder.addHeader("Upgrade-Insecure-Requests","1");
            builder.addHeader( "User-Agent","Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/55.0.2883.87 Safari/537.36");
        }
    }

    /**
    @param cookie 加入cookie到请求头
    */
    public void addCookieToHeader(String cookie){
        builder.addHeader("cookie",cookie);
    }

    /**
     @param url get请求的url
     */
    public String get(String url)  {
        builder.url(url);
        final Request request = builder.build();
        try (Response response = client.newCall(request).execute()) {
            return response.body().string();
        }catch (Exception e){
            e.printStackTrace();
            return "";
        }
    }

    /**
    @param  url 图片的地址
    * */
    public void savePicture(String url)  {
        builder.url(url);
        final Request request = builder.build();
        try (Response response = client.newCall(request).execute()) {
            byte[] bt = response.body().bytes();
            byte2image(bt, "./xueji.png");
        }catch (Exception e){
            e.printStackTrace();
        }
    }

    private void byte2image(byte[] data,String path){
        try {
            File file = new File(path);
            FileOutputStream fos = new FileOutputStream(file);
            fos.write(data, 0, data.length);
            fos.flush();
            fos.close();
            System.out.println("保存图片成功。。");
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public static void testBaidu(){
        HttpReq baiduHttp = new HttpReq(false);
        String respStr = baiduHttp.get("http://www.baidu.com");
        System.out.println(respStr);
    }

    public static void main(String[] args)  {
           // testBaidu();
        HttpReq xuexinHttp = new HttpReq(true);
        xuexinHttp.addCookieToHeader("JSESSIONID=06E39F1AE8D1EA9BFD8F34D");  //由webview执行js返回。
        xuexinHttp.savePicture("https://my.chsi.com.cn/archive/gdjy/photo/show.action?pid=2367c5f88b78b088e484a51eb3"); //由webview执行js返回。

} 
}