Facebook學分java jsp回調示例

Question

我找不到使用facebook credits api創建回調的示例，使用Java & JSP。我發佈了我的Java/JSP版本的callback.php示例。請用您的應用程序ID和密鑰更換的appid和祕密密鑰變量：

callback.jsp

<%@ page import="java.net.*" %> 
<%@ page import="java.util.*" %> 
<%@ page import="java.security.*" %> 
<%@ page import= "javax.crypto.*" %> 
<%@ page import= "javax.crypto.spec.*" %> 
<%@ page import="org.apache.commons.codec.binary.Base64" %> 
<%@ page import="org.json.simple.parser.JSONParser" %> 
<%@ page import="org.json.simple.JSONObject"%> 
<%@ page import="org.json.simple.JSONArray"%> 

<%! 
    //decode input string to base 64 
    public byte[] base64UrlDecode(String input){ 
     return new Base64(true).decode(input.replace("-","+").replace("_","/").trim()); 
    } 

    public String base64UrlEncode(byte[] input){   
     Base64 encoder = new Base64(); 
     String encodedInput = "";  
     try{ 
      encodedInput = encoder.encodeBase64URLSafeString(input);    
     }catch (Exception e) { 
       e.printStackTrace(); 
     } 
     return encodedInput; 
    } 
    /* 
    * http://javaboutique.internet.com/tutorials/InitForms/special.html 
    */ 
    public String replace(String s, String one, String another) { 
     // In a string replace one substring with another 
     if (s.equals("")) return ""; 
     String res = ""; 
     int i = s.indexOf(one,0); 
     int lastpos = 0; 
     while (i != -1) { 
       res += s.substring(lastpos,i) + another; 
       lastpos = i + one.length(); 
       i = s.indexOf(one,lastpos); 
     } 
     res += s.substring(lastpos); // the rest 
     return res; 
    } 

    public Map parseSignedRequest(String signedRequest, String secretKey){ 

     Map data = null; 

     if(signedRequest != null){ 

      String[] split = signedRequest.split("\\.", 2); 

      //Get signature and payload data portions of signed request string 
      String encoded_sig = split[0]; 
      String payload = split[1]; 
      JSONParser parser = new JSONParser(); 
      //parse json object 

      try { 
       data = (Map) parser.parse(new String(base64UrlDecode(payload))); 
      } catch (Exception e) { 
       e.printStackTrace(); 
      } 
      String algorithm = (String) data.get("algorithm"); 
      String userID = ((String) data.get("user_id")); 
      String authToken= ((String) data.get("oauth_token"));   
      // 
      String signature = ""; 
      String expectedSignature = "";   
      if(!algorithm.equalsIgnoreCase("HMAC-SHA256")){ 
       System.out.println("ERROR: unknown algorithm"); 
       return null; 
      } 

      byte[] sig = base64UrlDecode(encoded_sig);  

      try{    
       //Decode 
       Mac mac = Mac.getInstance("HmacSHA256"); 
       SecretKeySpec key = new SecretKeySpec(secretKey .getBytes("UTF-8"), "HmacSHA256"); 
       mac.init(key); 
       byte[] expectedSig = mac.doFinal(payload.getBytes("UTF-8")); 
       signature = base64UrlEncode(sig); 
       expectedSignature = base64UrlEncode(expectedSig);      
      } catch (Exception e) { 
        e.printStackTrace(); 
      } 

      if(!signature.equalsIgnoreCase("")){ 
       if(!signature.equalsIgnoreCase(expectedSignature)){ 
        System.out.println("ERROR: Bad signed JSON signature"); 
        return null; 
       } 
      } 
     }//end if 
     return data; 
    }// 
%> 

<% 
    //facebook code 
    String appId = "xxxxxxx"; 
    String secretKey = "xxxxxxxxxx";  

    String errorReason = request.getParameter("error_reason"); 
    String signedRequest = request.getParameter("signed_request"); 
    String responseType = request.getParameter("response_type"); 

    /* 
    * Parse the signed_request to verify it's from Facebook 
    */ 
    Map requestMap = parseSignedRequest(signedRequest, secretKey); 

    // Grab values passed to this callback 
    String method = request.getParameter("method"); 
    String order_id = request.getParameter("order_id"); 
    JSONObject item = new JSONObject(); 
    JSONObject returnData = new JSONObject(); 
    JSONArray itemArray = new JSONArray(); 
    String returnvalue = ""; 

    if (requestMap == null) { 
     // Handle an unauthenticated request here 
     System.out.println("ERROR: Handle an unauthenticated request here"); 
    } 

    if(method.equalsIgnoreCase("payments_status_update")){ 
     //grab the order status 
     String nextState = ""; 
     String status = request.getParameter("status"); 
     String orderId = request.getParameter("order_id");  

     JSONParser parser = new JSONParser(); 
     Map userjson = null; 

     try { 
      userjson = (Map) parser.parse(request.getParameter("order_details")); 
     }catch(Exception pe) {} 

     // Write your apps logic here for validating and recording a 
     // purchase here. 
     // 
     // Generally you will want to move states from `placed` -> `settled` 
     // here, then grant the purchasing user's in-game item to them. 
     if (status.equalsIgnoreCase("placed")) { 
      nextState = "settled"; 
      item.put("status",nextState); 
      item.put("order_id",orderId); 
      //display date or add code to insert into a database 
      JSONArray itemsArray=(JSONArray)userjson.get("items"); 
      for(int i=0; i < itemsArray.size(); i++){ 
       JSONObject itemObj = (JSONObject)itemsArray.get(i); 
       System.out.println("item[" + i + "]= Buyer(" + userjson.get("buyer") + ") purchased Qty(" + userjson.get("amount") + ") " + itemObj.get("title") + " @ $" + itemObj.get("price")); 
      }    
     } 
     // Compose returning data 
     returnData.put("content", item); 
     returnData.put("method", "payments_status_update"); 
     returnvalue = returnData.toJSONString();   
    } else if (method.equalsIgnoreCase("payments_get_items")) {     

     String item_info = request.getParameter("order_info"); 
     //remove escape characters 
     item_info = item_info.replaceAll("\"", ""); 

     if (item_info.equalsIgnoreCase("abc123")) { 
      // Per the credits api documentation, you should pass in an item 
      // reference and then query your internal DB for the proper 
      // information. Then set the item information here to be 
      // returned to facebook then shown to the user for confirmation. 
      item.put("title","BFF Locket"); 
      item.put("price",1); 
      item.put("description","This is a BFF Locket..."); 
      item.put("image_url","http://www.facebook.com/images/gifts/21.png"); 
      item.put("product_url","http://www.facebook.com/images/gifts/21.png");   
     } else { 

      // For the sake of the sample, we will default to this item if 
      // the `order_info` reference passed from your JS call is not matched 
      // above. 
      item.put("title","A Facebook Hat"); 
      item.put("price",1); 
      item.put("description","The coolest hat you\'ve ever seen."); 
      item.put("image_url","http://www.facebook.com/images/gifts/740.png"); 
      item.put("product_url","http://www.facebook.com/images/gifts/740.png"); 
     } 
     itemArray.add(item); 
     returnData.put("content", itemArray); 
     returnData.put("method", "payments_get_items"); 
     returnvalue = returnData.toJSONString();    
    } 
    //return output data 
    out.print(returnvalue); 
    out.flush(); 
%> 

Answer 1

你可以參考this tutorial。這將幫助您在創建appID和secreat後使用Facebook api。