[구글] GOOGLE Oauth 로그인 API (2)

GOOGLE  Oauth 클라이언트ID를 생성 하였다면 해당 로그인 로직을 구현하겠습니다.

 

1.AccessToken 처리

	/**
	 * GOOGLE AccessToken 처리
	 */
	@Override
	public String getGoogleAccessToken(String authorize_code) {
		String access_Token = "";
		String reqURL = "https://www.googleapis.com/oauth2/v4/token";
		
	    try {
	        URL url = new URL(reqURL);
	        HttpURLConnection conn = (HttpURLConnection) url.openConnection();
	        
	        //POST 요청을 위해 기본값이 false인 setDoOutput을 true로
	        conn.setRequestMethod("POST");
	        conn.setDoOutput(true);
	        //POST 요청에 필요로 요구하는 파라미터 스트림을 통해 전송
	        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(conn.getOutputStream()));
	        StringBuilder sb = new StringBuilder();
	        sb.append("grant_type=authorization_code");
	        sb.append("&client_id=ClientId");
	        sb.append("&client_secret=ClientSecret");
	        sb.append("&redirect_uri=RedirectUri");
	        sb.append("&code="+authorize_code);
	        sb.append("&state=url_parameter");
	        bw.write(sb.toString());
	        bw.flush();
	        
	        //결과 코드가 200이라면 성공
	        int responseCode = conn.getResponseCode();
	        if(responseCode==200){
	            //요청을 통해 얻은 JSON타입의 Response 메세지 읽어오기
	            BufferedReader br = new BufferedReader(new InputStreamReader(conn.getInputStream()));
	            String line = "";
	            String result = "";
	            
	            while ((line = br.readLine()) != null) {
	                result += line;
	            }
	            
	            //Gson 라이브러리에 포함된 클래스로 JSON파싱 객체 생성
	            JsonParser parser = new JsonParser();
	            JsonElement element = parser.parse(result);
	            System.out.println("result : "+result);
	            access_Token = element.getAsJsonObject().get("access_token").getAsString();
	          //refresh_Token = element.getAsJsonObject().get("refresh_token").getAsString();
	            br.close();
	            bw.close();
	        }
	    } catch (IOException e) {
	        e.printStackTrace();
	    } 
	    
	    return access_Token;
	}

---

2. 회득한 AccessToken으로 유저정보 가져오기

	/**
	 * GOOGLE USER INFO
	 * @param access_Token
	 */
	@Override
	public void getGoogleUserInfo(String access_Token) {
		 //요청하는 클라이언트마다 가진 정보가 다를 수 있기에 HashMap타입으로 선언
	    HashMap<String, Object> googleUserInfo = new HashMap<>();
	    //String reqURL = "https://www.googleapis.com/oauth2/v1/userinfo?alt=json&access_token="+access_Token;
	    String reqURL = "https://www.googleapis.com/userinfo/v2/me?access_token="+access_Token;
	    try {
	        URL url = new URL(reqURL);
	        HttpURLConnection conn = (HttpURLConnection) url.openConnection();

	        //요청에 필요한 Header에 포함될 내용
	        conn.setRequestProperty("Authorization", "Bearer " + access_Token);

	        int responseCode = conn.getResponseCode();
	        System.out.println("responseCode : "+responseCode);
	        if(responseCode == 200){
		        BufferedReader br = new BufferedReader(new InputStreamReader(conn.getInputStream()));
		        
		        String line = "";
		        String result = "";
		        
		        while ((line = br.readLine()) != null) {
		            result += line;
		        }
		        JsonParser parser = new JsonParser();
		        System.out.println("result : "+result);
		        JsonElement element = parser.parse(result);
		        
		        String name = element.getAsJsonObject().get("name").getAsString();
		        String email = element.getAsJsonObject().get("email").getAsString();
		        String id = "GOOGLE_"+element.getAsJsonObject().get("id").getAsString();
		        
		        googleUserInfo.put("name", name);
		        googleUserInfo.put("email", email);
		        googleUserInfo.put("id", id);
		        
		        System.out.println("login Controller : " + googleUserInfo);
	        }
	    } catch (IOException e) {
	        e.printStackTrace();
	    }
	}

---

3. Controller처리

feat.구글 같은경우 scope로 구글에 어떤 항목에 정보를 요청할지 목록을 정함으로 googlescopes 문서 참조 

https://developers.google.com/identity/protocols/googlescopes

OAuth 2.0 Scopes for Google APIs  |  Google ID 플랫폼  |  Google Developers

	/**
	 * sns Login
	 */
	@RequestMapping( "/index" )
	public String view(
			ModelMap model ) {
		
		String googleUrl = "https://accounts.google.com/o/oauth2/auth?client_id=client_id&redirect_uri=redirect_uri&access_type=offline&response_type=code&scope=email%20profile&state=url_parameter";
		model.addAttribute( "googleUrl", googleUrl );
		return "/index";
	}


	/**
	 * GOOGLE Login 
	 * @param code
	 * @throws IOException 
	 */
	@RequestMapping( "/googleLogin" )
	public void  googleLogin(
			@RequestParam("code") String code,
			HttpServletResponse response
			) throws IOException {
		String access_Token = snsLoginService.getAccessToken(code);
		
        //리다이렉트 url
		String referer = (String)request.getHeader("REFERER")!=null? (String)request.getHeader("REFERER") : "http://localhost:8080";
		
		snsLoginService.getUserInfo(access_Token);
		
		response.setContentType("text/html; charset=UTF-8");
        PrintWriter out = response.getWriter();
        //Login Popup창 닫고 page referer url로 새로고침
        out.println("<script>window.close(); opener.parent.location="+"'"+referer+"'"+";</script>");
        out.flush();
	}

---

4.index.jsp

<a id="custom-login-btn" href="javascript:void(0);" onclick="window.open('${googleUrl}','googleLogin','width=430,height=500,location=no,status=no,scrollbars=yes');"">
	<img src="/images/btn_google_signin_dark_normal_web.png" width="300"/>
</a>