1. import com.francisli.processing.http.*;
2. 
   
3. String clientID = " "; //put your clientID here Get it from instagram site: http://instagram.com/developer/
4. 
   
5. int totalCheck = 9;
6. int currentItem = 0;
7. 
   
8. PImage[] userphoto = new PImage[totalCheck];
9. PImage[] profilepicture = new PImage[totalCheck];
10. String[] username = new String[totalCheck];
11. String[] userID = new String[totalCheck];
12. float likedCount[];
13. 
    
14. HttpClient client;
15. HttpClient Personal;
16. 
    
17. void setup() {
18.   
19.   size(800, 800, P2D);
20.   smooth();
21.   // create new client
22.   client = new HttpClient(this, "api.instagram.com");
23.  
24.   // use https
25.   client.useSSL = true;
26.   
27.   // search for the popular photos
28.   String mediaLookup = "popular";
29.  
30.   // instantiate a new HashMap
31.   HashMap params = new HashMap();
32.  
33.   // pass parameters as key-value pairs
34.   params.put("client_id", clientID);
35.  
36.   for (int i=0;i<totalCheck-1;i++){
37.     // make the request
38.     client.GET("v1/media/popular?client_id="+clientID);
39.   }
40. 
    
41. }
42. 
    
43. void draw() {
44.       // mostly used to draw the images onscreen
45.   if (currentItem==totalCheck-1){
46. 
    
47.   imageMode(CENTER);
48.     for (int i=0;i<totalCheck;i++){
49.           
50.       imageMode(CENTER);   
51.       if (profilepicture[i] != null) {
52.         image(profilepicture[i], 82, 90, 90, 90);
53.       }  
54.       if (userphoto[i] != null) {
55.         image(userphoto[i], 100*i-50, height/2-30, 100, 100);
56.       }
57.     }
58.   }
59. }
60. 
    
61. void responseReceived(HttpRequest request, HttpResponse response) {
62. 
    
63.   //// we get the server response as a JSON object
64.   JSONObject content = response.getContentAsJSONObject();
65. 
    
66.   //  println(content);
67. 
    
68.   //// get the "data" value, which is an array
69.   if (content.get("data") != null) {
70.     
71.     currentItem ++; 
72.     
73.     JSONObject data = content.get("data");
74. 
    
75.     //// get the first element in the array
76.     JSONObject first = data.get(0);
77. 
    
78. // the first bit just prints the information in the console...
79.     //// the "user" value is another dictionary, from which we can get the "full_name" string value
80.     if (first.get("user").get("id").stringValue() != null) {
81.       println(first.get("user").get("id").stringValue());
82.     }
83.     
84.     if (first.get("user").get("full_name").stringValue() != null) {
85.       println(first.get("user").get("full_name").stringValue());
86.     }
87.     //// get profile picture
88.     if (first.get("user").get("profile_picture").stringValue() != null) {
89.       println(first.get("user").get("profile_picture").stringValue());
90.     }
91.     //// the "images" value is another dictionary, from which we can get different image URL data
92.     if (first.get("images").get("standard_resolution").get("url").stringValue() != null) {
93.       println(first.get("images").get("standard_resolution").get("url").stringValue());
94.     }
95.     if (first.get("likes").get("count").intValue() != 0) {
96.       println("Likes: "+first.get("likes").get("count").intValue());
97.       likes[currentItem] = first.get("likes").get("count").intValue();
98.     }
99. 
    
100. // the second bit puts the information in an array.    
101.     if (first.get("user").get("id").stringValue() != null) {
102.       userID[currentItem] = first.get("user").get("id").stringValue();
103.     }  
104.     if (first.get("user").get("full_name").stringValue() != null) {
105.       username[currentItem] = first.get("user").get("full_name").stringValue();
106.     }
107.     if (first.get("user").get("profile_picture").stringValue() != null) {
108.       String profilepicture_url = first.get("user").get("profile_picture").stringValue();
109.       profilepicture[currentItem] = loadImage(profilepicture_url, "png");
110.     }
111.     if (first.get("user").get("profile_picture").stringValue() != null) {
112.       String userphoto_url = first.get("images").get("standard_resolution").get("url").stringValue();
113.       userphoto[currentItem] = loadImage(userphoto_url, "png");
114.     }
115.     println(currentItem);
116.   }
117. }

1. HttpClient client;
   HttpRequest firstRequest;
   HttpRequest secondRequest;
   
   
   void setup() {
     client = new HttpClient(this, "server.com")
     firstRequest = client.GET("/path/to/resource");
   }
   
   
   void responseReceived(HttpRequest request, HttpResponse response) {
     if (request == firstRequest) {
       //// parse the data, etc
       secondRequest = client.GET("/path/to/second/resource/");
     } else if (request == secondRequest) {
       //// do what you want with the response from the second request
     }
   }
   
   
   void draw() {
     //// draw draw draw
   }

2. void responseReceived(HttpRequest request, HttpResponse response) {
3. //  println(response.getContentAsString());
4.        if (request == firstRequest) {
5.         //// we get the server response as a JSON object
6.         JSONObject results = response.getContentAsJSONObject();
7.   
8.          JSONObject data = results.get("data");
9.          JSONObject first = data.get(0);
10.          
11.           //    println(data.size());
12.           for (int i=0; i<data.size();i++){
13.               JSONObject userList = data.get(i);
14.                         // all this does is find the id of the user
15.               JSONObject listLikes = userList.get("likes").get("data");
16.               println("likes");
17. 
    
18.             for (int j=0;j<listLikes.size();j++){
19.                    JSONObject likerIDs = listLikes.get(j).get("id");
20.                    println(likerIDs); 
21.             }
22.       
23.             JSONObject listComments = userList.get("comments").get("data");
24.                   println("comments");
25.             
26.             for (int j=0;j<listComments.size();j++){
27.                    JSONObject commenterIDs = listComments.get(j).get("from").get("id");
28.                    println(commenterIDs); 
29.             }
30.         }
31.      }
32. }
33. 
    

But for things like network / Internet requests, delay() can be useful: you can issue a request, loop on a small delay() (to avoid using too much the CPU with tight loops) and check if you got an answer to this request. Loop until you have this answer (using eg. a boolean variable set in responseReceived()), then you can issue the second request.
It is blocking until all requests are fulfilled, but it is safer.

2. void responseReceived(HttpRequest request, HttpResponse response) {
3.  if (request == firstRequest) {
4.   JSONObject results = response.getContentAsJSONObject();
5.   
6.     JSONObject data = results.get("data");
7.     JSONObject first = data.get(0);
8.          
9.     for (int i=0; i<data.size();i++){
10.       JSONObject userList = data.get(i);
11.       
12.       JSONObject listLikes = userList.get("likes").get("data");
13.       for (int j=0;j<listLikes.size();j++){
14.               JSONObject likerIDs = listLikes.get(j);
15.               int tempHolder = likerIDs.get("id").intValue();
16.               users[usersTotal] = tempHolder;
17.               usersTotal ++;
18.               likerTotal ++;
19.               secondRequest = client.GET("v1/users/"+tempHolder+"/followed-by/?client_id="+clientID);
20.       }
21.       
22.       JSONObject listComments = userList.get("comments").get("data");
23.       for (int j=0;j<listComments.size();j++){
24.          JSONObject commenterIDs = listComments.get(j).get("from").get("id");
25.          int tempHolder = commenterIDs.intValue();
26.          users[usersTotal] = tempHolder;
27.          usersTotal ++;
28.          commenterTotal ++; 
29.          secondRequest = client.GET("v1/users/"+tempHolder+"/followed-by/?client_id="+clientID);
30.       }
31.       
32.     }
33.     println(" there are "+likerTotal+" people who like this image");
34.     println(" there are "+commenterTotal+" people who commented on this image");
35.     
36.     } else if (request == secondRequest){
37.        JSONObject specific = response.getContentAsJSONObject();
38.        JSONObject data = specific.get("data");
39.        println(specific.get("media")); 
40.        println(specific.get("follows")); 
41.        println(specific.get("followed")); 
42.    }
43. }