java 实现 github第三方登陆代码模板

HttpRequestUtils类

用于方便进行http请求

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.URL;
import java.net.URLConnection;
import java.util.HashMap;
import java.util.Map;

/**
 * @author cimo
 */
public class HttpRequestUtils {

    /**
     * 向指定 URL 发送POST方法的请求
     *
     * @param url 发送请求的 URL
     * @param param 请求参数，请求参数应该是 name1=value1&name2=value2 的形式。
     * @return 所代表远程资源的响应结果
     */
    public static String sendPost(String url, String param) {
        PrintWriter out = null;
        BufferedReader in = null;
        String result = "";
        try {
            URL realUrl = new URL(url);
            // 打开和URL之间的连接
            URLConnection conn = realUrl.openConnection();
            // 设置通用的请求属性
            conn.setRequestProperty("accept", "*/*");
            conn.setRequestProperty("Content-type", "application/json");
            conn.setRequestProperty("connection", "Keep-Alive");
            conn.setRequestProperty("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
            conn.setReadTimeout(15000);
            // 发送POST请求必须设置如下两行
            conn.setDoOutput(true);
            conn.setDoInput(true);
            // 获取URLConnection对象对应的输出流
            out = new PrintWriter(conn.getOutputStream());
            // 发送请求参数
            out.print(param);
            // flush输出流的缓冲
            out.flush();
            // 定义BufferedReader输入流来读取URL的响应
            in = new BufferedReader( new InputStreamReader(conn.getInputStream(),"utf-8") );
            String line;
            while ((line = in.readLine()) != null) {
                result += line;
            }
        } catch (Exception e) {
            System.out.println("发送 POST 请求出现异常！"+e);
            e.printStackTrace();
        }
        //使用finally块来关闭输出流、输入流
        finally{
            try{
                if(out!=null){
                    out.close();
                }
                if(in!=null){
                    in.close();
                }
            }
            catch(IOException ex){
                ex.printStackTrace();
            }
        }
        return result;
    }

    /**
     * 向指定URL发送GET方法的请求
     *
     * @param url 发送请求的URL
     * @return URL 所代表远程资源的响应结果
     */
    public static String sendGet(String url) {
        String result = "";
        BufferedReader in = null;
        try {
            String urlNameString = url;
            URL realUrl = new URL(urlNameString);
            // 打开和URL之间的连接
            URLConnection connection = realUrl.openConnection();
            // 设置通用的请求属性
            connection.setRequestProperty("accept", "*/*");
            connection.setRequestProperty("connection", "Keep-Alive");
            connection.setRequestProperty("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
            // 建立实际的连接
            connection.connect();
            // 定义 BufferedReader输入流来读取URL的响应
            in = new BufferedReader(new InputStreamReader(
                    connection.getInputStream()));
            String line;
            while ((line = in.readLine()) != null) {
                result += line;
            }
        } catch (Exception e) {
            System.out.println("发送GET请求出现异常！" + e);
            e.printStackTrace();
        }
        // 使用finally块来关闭输入流
        finally {
            try {
                if (in != null) {
                    in.close();
                }
            } catch (Exception e2) {
                e2.printStackTrace();
            }
        }
        return result;
    }
    /**
     * 将字符串转换成map
     * @param responseEntity map字符串
     * @return  map对象
     */
    public static Map<String,String> getMap(String responseEntity) {

        Map<String, String> map = new HashMap<>();
        // 以&来解析字符串
        String[] result = responseEntity.split("\\&");

        for (String str : result) {
            // 以=来解析字符串
            String[] split = str.split("=");
            // 将字符串存入map中
            if (split.length == 1) {
                map.put(split[0], null);
            } else {
                map.put(split[0], split[1]);
            }

        }
        return map;
    }

}

GithubConfig类

用于保存Github授权信息配置文件

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.URL;
import java.net.URLConnection;
/**
 * @author cimo
 */
public class GithubConfig {

    /**
     * github授权的 Client ID
     */
    private static final String CLIENT_ID = "你的 Client ID";

    /**
     * github授权的 Client Secret
     */
    private static final String CLIENT_SECRET = "你的 Client Secret";

    /**
     * 结果回调地址
     */
    private static final String CALLBACK_URL = "你在Github上填写的回调地址";

    /**
     * 获取code的url
     */
    public static final String CODE_URL = "https://github.com/login/oauth/authorize?client_id="+CLIENT_ID;

    /**
     * @param code 获取到的code
     * @return 获取token的url
     */
    public static String getTokenUrl(String code) {
        return "https://github.com/login/oauth/access_token?client_id="+CLIENT_ID+"&client_secret="+CLIENT_SECRET+"&code="+code+"&redirect_uri="+CALLBACK_URL;
    }

    /**
     * @param token 获取到的token
     * @return 通过token获取github用户信息
     */
    public static String getUerInfoUrl(String token) throws IOException {
        String result = "";
        BufferedReader in = null;
        try {
            String baseUrl = "https://api.github.com/user";
            URL realUrl = new URL(baseUrl);
            // 打开和URL之间的连接
            URLConnection connection = realUrl.openConnection();
            //将token加入请求头
            connection.setRequestProperty("Authorization","token "+token);
            // 建立实际的连接
            connection.connect();
            // 定义 BufferedReader输入流来读取URL的响应
            in = new BufferedReader(new InputStreamReader( connection.getInputStream()));
            String line;
            while ((line = in.readLine()) != null) {
                result += line;
            }
        } catch (Exception e) {
            System.out.println("发送token请求出现异常！" + e);
            e.printStackTrace();
        }
        // 使用finally块来关闭输入流
        finally {
            try {
                if (in != null) {
                    in.close();
                }
            } catch (Exception e2) {
                e2.printStackTrace();
            }
        }
        return result;

    }
}

发出请求后回调的地址

这里为了方便一点用servlet实现

import javax.servlet.annotation.WebServlet;
import java.io.IOException;

/**
 * @author cimo
 */
@WebServlet(name = "GithubLogingCallBack")
public class GithubLogingCallBack extends javax.servlet.http.HttpServlet {
    @Override
    protected void doPost(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) throws javax.servlet.ServletException, IOException {

    }

    @Override
    protected void doGet(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) throws javax.servlet.ServletException, IOException {

        //获取code地址：https://github.com/login/oauth/authorize?client_id=你的client_id
        String code = request.getParameter("code");
        System.out.println("code："+code);

        //申请令牌
        String result = HttpRequestUtils.sendGet( GithubConfig.getTokenUrl(code) );
        System.out.println("result："+result);

        //从result中截取令牌
        String access_token = HttpRequestUtils.getMap(result).get("access_token");
        System.out.println("access_token："+access_token);

        //通过令牌获取用户信息
        String userInfo = GithubConfig.getUerInfoUrl(access_token);
        System.out.println("用户信息："+userInfo);
        
        //将token加入响应头,并返回用户信息
        response.setHeader("Authorization","token "+accessToken);
        response.getWriter().println(userInfo);

    }
}