← Exit Codelab
⏱ 12 mins remaining

Java

Learn how the Java SDK works

Steps in this module

  1. Introduction
  2. Installation
  3. Creating an instance of AtClient
  4. Getting Secondary.Address
  5. Key Types
  6. PublicKey interactions
  7. SelfKey interactions
  8. SharedKey interactions
  9. CLIs

PublicKey interactions

PublicKeys are meant for public data. Authorized or unauthorized users are able to know of the existence of these keys (via scan) and the data is not encrypted.

Putting a PublicKey Example

Sample code on how to put a public key associated with a public non-encrypted value into your secondary server. Any unauthenticated/authenticated atSign will be able to see the data without decrypting anything.

// 1. establish constants
String ROOT_URL = "root.atsign.org:64"; // root url of the atsign server for fetching secondary address
String ATSIGN_STR = "@bob"; // atSign that we will pkam auth (must have keys in keys directory) 
boolean VERBOSE = true; // true for more print logs 
String KEY_NAME = "test"; // name of the key we will create and put
String VALUE = "I like pizza"; // value we will associate with the key

// 2. create AtSign object
AtSign atSign = new AtSign(ATSIGN_STR);

// 3. atClient factory method
AtClient atClient = null;
try {
    atClient = AtClient.withRemoteSecondary(ROOT_URL, atSign, VERBOSE);
} catch (AtException e) {
    System.err.println("Failed to connect to remote server " + e);
    e.printStackTrace();
}

// 4. create a new public key
PublicKey pk = new KeyBuilders.PublicKeyBuilder(atSign).key(KEY_NAME).build();

// 5. put the key
String response = null;
try {
    response = atClient.put(pk, VALUE).get();
} catch (InterruptedException | ExecutionException e) {
    System.err.println("Failed to put key " + e);
    e.printStackTrace();
}
System.out.println(response); // data:<CommitId>

Getting a PublicKey example

Learn how to fetch public data on either your secondary server or another atSign’s secondary server. No decryption is done by AtClient in this process. Be sure that the sharedBy atSign is the atSign that owns this AtKey (aka the atSign that owns the public data) because this is the atSign’s secondary server that AtClient will be looking into.

// 1. establish arguments
String ROOT_URL = "root.atsign.org:64"; // root url of the atsign server for fetching secondary address
String ATSIGN_STR = "@bob"; // atSign that we will pkam auth (must have keys in keys directory)
boolean VERBOSE = true; // true for more print logs
String KEY_NAME = "test"; // name of the key we will get

// 2. create AtSign object
AtSign atSign = new AtSign(ATSIGN_STR);

// 3. atClient factory method
AtClient atClient = null;
try {
    atClient = AtClient.withRemoteSecondary(ROOT_URL, atSign, VERBOSE);
} catch (AtException e) {
    System.err.println("Failed to connect to remote server " + e);
    e.printStackTrace();
}

// 4. create the key
PublicKey pk = new KeyBuilders.PublicKeyBuilder(atSign).key(KEY_NAME).build();

// 5. get the value associated with the key
String response = null;
try {
    response = atClient.get(pk).get();
} catch (InterruptedException | ExecutionException e) {
    System.err.println("Failed to get key " + e);
    e.printStackTrace();
}
System.out.println(response);

Deleting a PublicKey example

Learn how to delete a public key from your secondary server. You can only delete keys in your own secondary server and must be authenticated (aka the sharedBy atSign must be you, in possession of the .atKeys file).

// 1. establish constants
String ROOT_URL = "root.atsign.org:64";
String ATSIGN_STR = "@bob";
boolean VERBOSE = true;
String KEY_NAME = "test";

// 2. create AtSign instance
AtSign atSign = new AtSign(ATSIGN_STR);
        
// 3. create AtClient instance using factory methods
AtClient atClient = null;
try {
    atClient = AtClient.withRemoteSecondary(ROOT_URL, atSign, VERBOSE);
} catch (AtException e) {
    System.err.println(e);
    e.printStackTrace();
}
// 4. create public key
PublicKey pk = new KeyBuilders.PublicKeyBuilder(atSign).key(KEY_NAME).build();

// 5. delete the key
String response = null;
try {
    response = atClient.delete(pk).get();
} catch (InterruptedException | ExecutionException | CancellationException e) {
    System.err.println(e);
    e.printStackTrace();
}
System.out.println(response);
Back
Next