Java erc20 token standard chaincode implementation Signed-off-by: renjithpta <renjithkn@gmail.com>

Signed-off-by: renjithpta <renjithkn@gmail.com>

asset-transfer-basic/rest-api-typescript/README.md

@@ -58,7 +58,7 @@ The `202 ACCEPTED` response includes a `jobId` which can be used with the `/api/
 Jobs are not used to get assets, because evaluating transactions is typically much faster.
 
 Related files:
-- [src/asset.router.ts](src/asset.router.ts)  
+- [src/assets.router.ts](src/assets.router.ts)  
   Defines the main `/api/assets` endpoint.
 - [src/fabric.ts](src/fabric.ts)  
   All the sample code which interacts with the Fabric network via the Fabric SDK.
@@ -66,7 +66,7 @@ Related files:
   Defines the `/api/jobs` endpoint for getting job status.
 - [src/jobs.ts](src/jobs.ts)
   Job queue implementation details.
-- [src/transactions.router.ts]()  
+- [src/transactions.router.ts](src/transactions.router.ts)  
   Defines the `/api/transactions` endpoint for getting transaction status.
 
 **Note:** If you are not specifically interested in REST APIs, you should only need to look at the files in the [Fabric network connections](#fabric-network-connections) and [Error handling](#error-handling) sections above.

asset-transfer-basic/rest-api-typescript/package-lock.json

@@ -5570,9 +5570,9 @@
       "dev": true
     },
     "node_modules/moment": {
-      "version": "2.29.1",
+      "version": "2.29.2",
-      "resolved": "https://registry.npmjs.org/moment/-/moment-2.29.1.tgz",
+      "resolved": "https://registry.npmjs.org/moment/-/moment-2.29.2.tgz",
-      "integrity": "sha512-kHmoybcPV8Sqy59DwNDY3Jefr64lK/by/da0ViFcuA4DH0vQg5Q6Ze5VimxkfQNSC+Mls/Kx53s7TjP1RhFEDQ==",
+      "integrity": "sha512-UgzG4rvxYpN15jgCmVJwac49h9ly9NurikMWGPdVxm8GZD6XjkKPxDTjQQ43gtGgnV3X0cAyWDdP2Wexoquifg==",
       "engines": {
         "node": "*"
       }
@@ -11993,9 +11993,9 @@
       "dev": true
     },
     "moment": {
-      "version": "2.29.1",
+      "version": "2.29.2",
-      "resolved": "https://registry.npmjs.org/moment/-/moment-2.29.1.tgz",
+      "resolved": "https://registry.npmjs.org/moment/-/moment-2.29.2.tgz",
-      "integrity": "sha512-kHmoybcPV8Sqy59DwNDY3Jefr64lK/by/da0ViFcuA4DH0vQg5Q6Ze5VimxkfQNSC+Mls/Kx53s7TjP1RhFEDQ=="
+      "integrity": "sha512-UgzG4rvxYpN15jgCmVJwac49h9ly9NurikMWGPdVxm8GZD6XjkKPxDTjQQ43gtGgnV3X0cAyWDdP2Wexoquifg=="
     },
     "moment-timezone": {
       "version": "0.5.33",

test-network-k8s/docs/CA.md

@@ -72,7 +72,7 @@ simplified, but realistic CA deployment illustrating key touch points with Kuber
 
 ### Future Enhancements: 
 
-- **_Bring your own Certificates_** :  It would be nice to boostrap the network using a single, top-level signing authority, 
+- **_Bring your own Certificates_** :  It would be nice to bootstrap the network using a single, top-level signing authority, 
   rather than generating self-signed certificates when the system is bootstrapped.  Ideally this will be realized by 
   introducing an [Intermediate CA](https://hyperledger-fabric-ca.readthedocs.io/en/latest/deployguide/ca-deploy-topology.html#when-would-i-want-an-intermediate-ca)
   and/or alternate signing chains backed by formal (e.g. letsencrypt, Thawte, Verisign, etc.) certificate authorities. 

test-network-k8s/docs/CHANNELS.md

@@ -33,7 +33,7 @@ In order to construct a Fabric channel, the following steps must be performed:
    
 4. Network orderers are joined to the channel using the channel participation API.
 
-5. Network peers are joioned to the channel.
+5. Network peers are joined to the channel.
 
 
 ## Aggregating the Channel MSP 

test-network-k8s/docs/HIGH_AVAILABILITY.md

@@ -4,7 +4,7 @@ The peers have been configured so they implemented a essential failover/high-ava
 
 Two important notes:
 
-1. The word 'gateway' in the k8s definitions is being used in a generic way. It is not tied to the concept of the 'Fabric Gateway' component. However using the 'Fabric-Gateway' with the udpated SDKs, make connecting to Fabric even easier. There is a single connection, that can easily be handled with core k8s abilities. Attempting the approach described below with the older SDKs is not recommended.
+1. The word 'gateway' in the k8s definitions is being used in a generic way. It is not tied to the concept of the 'Fabric Gateway' component. However using the 'Fabric-Gateway' with the updated SDKs, make connecting to Fabric even easier. There is a single connection, that can easily be handled with core k8s abilities. Attempting the approach described below with the older SDKs is not recommended.
 2. Long Lived gRPC connections. Remember that the connections between components in Fabric are long-lived gRPC connections. From a client application's perspective that means the connection will be load-balanced when initially connected, but unless the connection breaks, it will not be 're-load-balanced'. It's important to keep this in mind.
 
 ## Peer Gateway Services
@@ -39,7 +39,7 @@ The selector is `org: org2` that is defined in the specification of the Peer's D
 ```
 
 ## Kube Proxy Configuration
-The proxy configuration is set to be `ipvs`. This gives a lot more scope for different load balancing algorthms.
+The proxy configuration is set to be `ipvs`. This gives a lot more scope for different load balancing algorithms.
 "Round Robin" is the default configuration (as used in this test network). For more information check this [deep dive](https://kubernetes.io/blog/2018/07/09/ipvs-based-in-cluster-load-balancing-deep-dive) on the Kubernetes blog.
 
 For this KIND cluster, this is configured by updating the cluster configuration, add the following yaml.

test-network-k8s/network

@@ -174,6 +174,11 @@ elif [ "${MODE}" == "chaincode" ]; then
 elif [ "${MODE}" == "anchor" ]; then
   update_anchor_peers $@
 
+elif [ "${MODE}" == "load-images-for-rest-easy" ]; then
+  log "Loading images for fabric-rest-sample to KIND:"
+  load_docker_images_for_rest_sample
+  log "🏁 - Images loaded."
+
 elif [ "${MODE}" == "rest-easy" ]; then
   log "Launching fabric-rest-sample application:"
   launch_rest_sample

test-network-k8s/scripts/kind.sh

@@ -13,6 +13,7 @@ function pull_docker_images() {
   docker pull ${FABRIC_CONTAINER_REGISTRY}/fabric-peer:$FABRIC_VERSION
   docker pull ${FABRIC_CONTAINER_REGISTRY}/fabric-tools:$FABRIC_VERSION
   docker pull ghcr.io/hyperledgendary/fabric-ccaas-asset-transfer-basic:latest
+  docker pull couchdb:3.2.1
 
   pop_fn
 }
@@ -30,6 +31,25 @@ function load_docker_images() {
   pop_fn
 }
 
+function pull_docker_images_for_rest_sample() {
+  push_fn "Pulling docker images for fabric-rest-sample"
+
+  docker pull ghcr.io/hyperledger/fabric-rest-sample:latest
+  docker pull redis:6.2.5
+
+  pop_fn
+}
+
+function load_docker_images_for_rest_sample() {
+  push_fn "Loading docker images for fabric-rest-sample to KIND control plane"
+
+  kind load docker-image ghcr.io/hyperledgendary/fabric-ccaas-asset-transfer-basic:latest
+  kind load docker-image redis:6.2.5
+
+  pop_fn
+}
+
+
 function apply_nginx_ingress() {
   push_fn "Launching ingress controller"
 
@@ -183,6 +203,8 @@ function kind_init() {
   if [ "${STAGE_DOCKER_IMAGES}" == true ]; then
     pull_docker_images
     load_docker_images
+    pull_docker_images_for_rest_sample
+    load_docker_images_for_rest_sample
   fi
 
   wait_for_cert_manager

test-network/addOrg3/ccp-generate.sh

@@ -23,7 +23,7 @@ function yaml_ccp {
         -e "s/\${CAPORT}/$3/" \
         -e "s#\${PEERPEM}#$PP#" \
         -e "s#\${CAPEM}#$CP#" \
-        ccp-template.yaml | sed -e $'s/\\\\n/\\\n        /g'
+        ccp-template.yaml | sed -e $'s/\\\\n/\\\n          /g'
 }
 
 ORG=3

test-network/addOrg3/ccp-template.yaml

@@ -19,7 +19,7 @@ peers:
     url: grpcs://localhost:${P0PORT}
     tlsCACerts:
       pem: |
-        ${PEERPEM}
+          ${PEERPEM}
     grpcOptions:
       ssl-target-name-override: peer0.org${ORG}.example.com
       hostnameOverride: peer0.org${ORG}.example.com
@@ -28,7 +28,8 @@ certificateAuthorities:
     url: https://localhost:${CAPORT}
     caName: ca-org${ORG}
     tlsCACerts:
-      pem: |
+      pem: 
-        ${CAPEM}
+        - |
+          ${CAPEM}
     httpOptions:
       verify: false

token-erc-20/chaincode-java/Dockerfile

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: Apache-2.0
 # the first stage 
 FROM gradle:jdk11 AS GRADLE_BUILD
 

token-erc-20/chaincode-java/src/main/java/org/hyperledger/fabric/samples/erc20/ContractErrors.java

@@ -10,7 +10,7 @@ package org.hyperledger.fabric.samples.erc20;
 
 public enum ContractErrors {
     BALANCE_NOT_FOUND,
-    UNAUTHERIZED_SENDER,
+    UNAUTHORIZED_SENDER,
     INVALID_AMOUNT,
     NOT_FOUND,
     INVALID_TRANSFER,

token-erc-20/chaincode-java/src/main/java/org/hyperledger/fabric/samples/erc20/ERC20TokenContract.java

@@ -18,9 +18,11 @@ import static org.hyperledger.fabric.samples.erc20.ContractErrors.INVALID_AMOUNT
 import static org.hyperledger.fabric.samples.erc20.ContractErrors.INVALID_TRANSFER;
 import static org.hyperledger.fabric.samples.erc20.ContractErrors.NOT_FOUND;
 import static org.hyperledger.fabric.samples.erc20.ContractErrors.NO_ALLOWANCE_FOUND;
-import static org.hyperledger.fabric.samples.erc20.ContractErrors.UNAUTHERIZED_SENDER;
+import static org.hyperledger.fabric.samples.erc20.ContractErrors.UNAUTHORIZED_SENDER;
 import static org.hyperledger.fabric.samples.erc20.utils.ContractUtility.stringIsNullOrEmpty;
 
+import com.owlike.genson.Genson;
+import org.hyperledger.fabric.Logger;
 import org.hyperledger.fabric.contract.Context;
 import org.hyperledger.fabric.contract.ContractInterface;
 import org.hyperledger.fabric.contract.annotation.Contact;
@@ -54,6 +56,8 @@ import org.hyperledger.fabric.shim.ledger.CompositeKey;
 @Default
 public final class ERC20TokenContract implements ContractInterface {
 
+  final Logger logger = Logger.getLogger(ERC20TokenContract.class);
+
   /**
    * Mint creates new tokens and adds them to minter's account balance. This function triggers a
    * Transfer event.
@@ -69,18 +73,15 @@ public final class ERC20TokenContract implements ContractInterface {
     String clientMSPID = ctx.getClientIdentity().getMSPID();
     ChaincodeStub stub = ctx.getStub();
     if (!clientMSPID.equalsIgnoreCase(ContractConstants.MINTER_ORG_MSPID.getValue())) {
-
       throw new ChaincodeException(
-          "Client is not authorized to mint new tokens", UNAUTHERIZED_SENDER.toString());
+          "Client is not authorized to mint new tokens", UNAUTHORIZED_SENDER.toString());
     }
-
     // Get ID of submitting client identity
     String minter = ctx.getClientIdentity().getId();
     if (amount <= 0) {
       throw new ChaincodeException(
           "Mint amount must be a positive integer", INVALID_AMOUNT.toString());
     }
-
     CompositeKey balanceKey = stub.createCompositeKey(BALANCE_PREFIX.getValue(), minter);
     String currentBalanceStr = stub.getStringState(balanceKey.toString());
     // If minter current balance doesn't yet exist, we'll create it with a current balance of 0
@@ -90,7 +91,6 @@ public final class ERC20TokenContract implements ContractInterface {
     }
     // Used safe math .
     long updatedBalance = Math.addExact(currentBalance, amount);
-
     stub.putStringState(balanceKey.toString(), String.valueOf(updatedBalance));
     // Increase totalSupply
     String totalSupplyStr = stub.getStringState(TOTAL_SUPPLY_KEY.getValue());
@@ -102,7 +102,11 @@ public final class ERC20TokenContract implements ContractInterface {
     totalSupply = Math.addExact(totalSupply, amount);
     stub.putStringState(TOTAL_SUPPLY_KEY.getValue(), String.valueOf(totalSupply));
     Transfer transferEvent = new Transfer("0x0", minter, amount);
-    stub.setEvent(TRANSFER_EVENT.getValue(), transferEvent.toJSONString().getBytes(UTF_8));
+    stub.setEvent(TRANSFER_EVENT.getValue(), this.marshal(transferEvent));
+    logger.info(
+        String.format(
+            "minter account %s balance updated from %d to %d",
+            minter, currentBalance, updatedBalance));
   }
 
   /**
@@ -121,26 +125,27 @@ public final class ERC20TokenContract implements ContractInterface {
     ChaincodeStub stub = ctx.getStub();
     if (!clientMSPID.equalsIgnoreCase(ContractConstants.MINTER_ORG_MSPID.getValue())) {
       throw new ChaincodeException(
-          "Client is not authorized to burn tokens", UNAUTHERIZED_SENDER.toString());
+          "Client is not authorized to burn tokens", UNAUTHORIZED_SENDER.toString());
     }
-
     String minter = ctx.getClientIdentity().getId();
-
     if (amount <= 0) {
       throw new ChaincodeException(
           "Burn amount must be a positive integer", INVALID_AMOUNT.toString());
     }
-
     CompositeKey balanceKey = stub.createCompositeKey(BALANCE_PREFIX.getValue(), minter);
     String currentBalanceStr = stub.getStringState(balanceKey.toString());
     if (stringIsNullOrEmpty(currentBalanceStr)) {
       throw new ChaincodeException("The balance does not exist", BALANCE_NOT_FOUND.toString());
     }
     long currentBalance = Long.parseLong(currentBalanceStr);
+    // Check if the sender has enough tokens to burn.
+
+    if (currentBalance < amount) {
+      String errorMessage = String.format("Client account %s has insufficient funds", minter);
+      throw new ChaincodeException(errorMessage, INSUFFICIENT_FUND.toString());
+    }
     long updatedBalance = Math.subtractExact(currentBalance, amount);
-
     stub.putStringState(balanceKey.toString(), String.valueOf(updatedBalance));
-
     // Decrease totalSupply
     String totalSupplyBytes = stub.getStringState(TOTAL_SUPPLY_KEY.getValue());
     if (stringIsNullOrEmpty(totalSupplyBytes)) {
@@ -148,10 +153,13 @@ public final class ERC20TokenContract implements ContractInterface {
     }
     long totalSupply = Math.subtractExact(Long.parseLong(totalSupplyBytes), amount);
     stub.putStringState(TOTAL_SUPPLY_KEY.getValue(), String.valueOf(totalSupply));
-
     // Emit the Transfer event
     final Transfer transferEvent = new Transfer(minter, "0x0", amount);
-    stub.setEvent(TRANSFER_EVENT.getValue(), transferEvent.toJSONString().getBytes(UTF_8));
+    stub.setEvent(TRANSFER_EVENT.getValue(), this.marshal(transferEvent));
+    logger.info(
+        String.format(
+            "minter account %s balance updated from %d to %d",
+            minter, currentBalance, updatedBalance));
   }
 
   /**
@@ -168,7 +176,7 @@ public final class ERC20TokenContract implements ContractInterface {
     String from = ctx.getClientIdentity().getId();
     this.transferHelper(ctx, from, to, value);
     final Transfer transferEvent = new Transfer(from, to, value);
-    ctx.getStub().setEvent(TRANSFER_EVENT.getValue(), transferEvent.toJSONString().getBytes(UTF_8));
+    ctx.getStub().setEvent(TRANSFER_EVENT.getValue(), this.marshal(transferEvent));
   }
 
   /**
@@ -187,6 +195,7 @@ public final class ERC20TokenContract implements ContractInterface {
       String errorMessage = String.format("Balance of the owner  %s not exists", owner);
       throw new ChaincodeException(errorMessage, NOT_FOUND.toString());
     }
+    logger.info(String.format("%s has balance of %s tokens", owner, balance));
     return Long.parseLong(balance);
   }
 
@@ -207,7 +216,9 @@ public final class ERC20TokenContract implements ContractInterface {
       String errorMessage = String.format("The account  %s does not exist", clientAccountID);
       throw new ChaincodeException(errorMessage, NOT_FOUND.toString());
     }
-    return Long.parseLong(balanceBytes);
+    long balance = Long.parseLong(balanceBytes);
+    logger.info(String.format("%s has balance of %d tokens", clientAccountID, balance));
+    return balance;
   }
 
   /**
@@ -235,6 +246,7 @@ public final class ERC20TokenContract implements ContractInterface {
     if (stringIsNullOrEmpty(totalSupply)) {
       throw new ChaincodeException("Total Supply  not found", NOT_FOUND.toString());
     }
+    logger.info(String.format("TotalSupply: %s tokens", totalSupply));
     return Long.parseLong(totalSupply);
   }
 
@@ -253,7 +265,11 @@ public final class ERC20TokenContract implements ContractInterface {
         stub.createCompositeKey(ALLOWANCE_PREFIX.getValue(), owner, spender);
     stub.putStringState(allowanceKey.toString(), String.valueOf(value));
     Approval approval = new Approval(owner, spender, value);
-    stub.setEvent(APPROVAL.getValue(), approval.toJSONString().getBytes(UTF_8));
+    stub.setEvent(APPROVAL.getValue(), this.marshal(approval));
+    logger.info(
+        String.format(
+            "client %s approved a withdrawal allowance of %d for spender %s",
+            owner, value, spender));
   }
 
   /**
@@ -270,12 +286,15 @@ public final class ERC20TokenContract implements ContractInterface {
     CompositeKey allowanceKey =
         stub.createCompositeKey(ALLOWANCE_PREFIX.getValue(), owner, spender);
     String allowanceBytes = stub.getStringState(allowanceKey.toString());
-    if (stringIsNullOrEmpty(allowanceBytes)) {
+    long allowance = 0;
-      String errorMessage =
+    if (!stringIsNullOrEmpty(allowanceBytes)) {
-          String.format("Spender account %s has no allowance from %s", spender, owner);
+      allowance = Long.parseLong(allowanceBytes);
-      throw new ChaincodeException(errorMessage);
     }
-    return Long.parseLong(allowanceBytes);
+    logger.info(
+        String.format(
+            "The allowance left for spender %s to withdraw from owner %s: %d",
+            spender, owner, allowance));
+    return allowance;
   }
 
   /**
@@ -292,14 +311,12 @@ public final class ERC20TokenContract implements ContractInterface {
     String spender = ctx.getClientIdentity().getId();
     ChaincodeStub stub = ctx.getStub();
     // Retrieve the allowance of the spender
-
     CompositeKey allowanceKey = stub.createCompositeKey(ALLOWANCE_PREFIX.getValue(), from, spender);
     String currentAllowanceStr = stub.getStringState(allowanceKey.toString());
     if (stringIsNullOrEmpty(currentAllowanceStr)) {
       String errorMessage = String.format("Spender %s has no allowance from %s", spender, from);
       throw new ChaincodeException(errorMessage, NO_ALLOWANCE_FOUND.toString());
     }
-
     long currentAllowance = Long.parseLong(currentAllowanceStr);
     // Check if the transferred value is less than the allowance
     if (currentAllowance < value) {
@@ -307,13 +324,16 @@ public final class ERC20TokenContract implements ContractInterface {
           String.format("Spender %s does not have enough allowance to spend", spender);
       throw new ChaincodeException(errorMessage, INSUFFICIENT_FUND.toString());
     }
-
     this.transferHelper(ctx, from, to, value);
     // Decrease the allowance
     long updatedAllowance = currentAllowance - value;
     stub.putStringState(allowanceKey.toString(), String.valueOf(updatedAllowance));
     final Transfer transferEvent = new Transfer(from, to, value);
-    stub.setEvent(TRANSFER_EVENT.getValue(), transferEvent.toJSONString().getBytes(UTF_8));
+    stub.setEvent(TRANSFER_EVENT.getValue(), marshal(transferEvent));
+    logger.info(
+        String.format(
+            "spender %s allowance updated from %d to %d",
+            spender, currentAllowance, updatedAllowance));
   }
 
   /**
@@ -344,33 +364,33 @@ public final class ERC20TokenContract implements ContractInterface {
       String errorMessage = String.format("Client account %s has no balance", from);
       throw new ChaincodeException(errorMessage, INSUFFICIENT_FUND.toString());
     }
-
     long fromCurrentBalance = Long.parseLong(fromCurrentBalanceStr);
-
     // Check if the sender has enough tokens to spend.
     if (fromCurrentBalance < value) {
       String errorMessage = String.format("Client account %s has insufficient funds", from);
       throw new ChaincodeException(errorMessage, INSUFFICIENT_FUND.toString());
     }
-
     // Retrieve the current balance of the recipient
     CompositeKey toBalanceKey = stub.createCompositeKey(BALANCE_PREFIX.getValue(), to);
     String toCurrentBalanceStr = stub.getStringState(toBalanceKey.toString());
-
     long toCurrentBalance = 0;
     // If recipient current balance doesn't yet exist, we'll create it with a
     // current balance of 0
     if (!stringIsNullOrEmpty(toCurrentBalanceStr)) {
       toCurrentBalance = Long.parseLong(toCurrentBalanceStr.trim());
     }
-
     // Update the balance
     long fromUpdatedBalance = Math.subtractExact(fromCurrentBalance, value);
     long toUpdatedBalance = Math.addExact(toCurrentBalance, value);
-
     stub.putStringState(fromBalanceKey.toString(), String.valueOf(fromUpdatedBalance));
-
     stub.putStringState(toBalanceKey.toString(), String.valueOf(toUpdatedBalance));
+    logger.info(
+        String.format(
+            "client %s balance updated from %d to %d",
+            from, fromCurrentBalance, fromUpdatedBalance));
+    logger.info(
+        String.format(
+            "recipient %s balance updated from %d to %d", to, toCurrentBalance, toUpdatedBalance));
   }
 
   /**
@@ -400,13 +420,10 @@ public final class ERC20TokenContract implements ContractInterface {
    */
   @Transaction(intent = Transaction.TYPE.EVALUATE)
   public String TokenName(final Context ctx) {
-
     String tokenName = ctx.getStub().getStringState(ContractConstants.NAME_KEY.getValue());
-
     if (stringIsNullOrEmpty(tokenName)) {
       throw new ChaincodeException("Token name not found", NOT_FOUND.toString());
     }
-
     return tokenName;
   }
 
@@ -422,7 +439,6 @@ public final class ERC20TokenContract implements ContractInterface {
     if (stringIsNullOrEmpty(tokenSymbol)) {
       throw new ChaincodeException("Token symbol not found", NOT_FOUND.toString());
     }
-
     return tokenSymbol;
   }
 
@@ -441,4 +457,13 @@ public final class ERC20TokenContract implements ContractInterface {
     }
     return Integer.parseInt(decimals);
   }
+  /**
+   * marshal the event data
+   *
+   * @param obj the object to marshal.
+   * @return marshalled object.
+   */
+  private byte[] marshal(final Object obj) {
+    return new Genson().serialize(obj).getBytes(UTF_8);
+  }
 }

token-erc-20/chaincode-java/src/main/java/org/hyperledger/fabric/samples/erc20/model/Approval.java

@@ -1,6 +1,8 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ */
 package org.hyperledger.fabric.samples.erc20.model;
 
-import com.owlike.genson.Genson;
 import com.owlike.genson.annotation.JsonProperty;
 import org.hyperledger.fabric.contract.annotation.DataType;
 import org.hyperledger.fabric.contract.annotation.Property;
@@ -46,27 +48,11 @@ public final class Approval {
     return owner;
   }
 
-  public void setOwner(final String owner1) {
-    this.owner = owner1;
-  }
-
   public String getSpender() {
     return spender;
   }
 
-  public void setSpender(final String spender1) {
-    this.spender = spender1;
-  }
-
   public long getValue() {
     return value;
   }
-
-  public void setValue(final long value1) {
-    this.value = value1;
-  }
-
-  public String toJSONString() {
-    return new Genson().serialize(this);
-  }
 }

token-erc-20/chaincode-java/src/main/java/org/hyperledger/fabric/samples/erc20/model/Transfer.java

@@ -1,6 +1,8 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ */
 package org.hyperledger.fabric.samples.erc20.model;
 
-import com.owlike.genson.Genson;
 import com.owlike.genson.annotation.JsonProperty;
 import org.hyperledger.fabric.contract.annotation.DataType;
 import org.hyperledger.fabric.contract.annotation.Property;
@@ -46,28 +48,11 @@ public final class Transfer {
     return from;
   }
 
-  public void setFrom(final String from1) {
-    this.from = from1;
-  }
-
   public String getTo() {
     return to;
   }
 
-  public void setTo(final String to1) {
-    this.to = to1;
-  }
-
   public long getValue() {
     return value;
   }
-
-  public void setValue(final long value1) {
-    this.value = value1;
-  }
-
-  /** @return String JSON */
-  public String toJSONString() {
-    return new Genson().serialize(this);
-  }
 }

token-erc-20/chaincode-java/src/main/java/org/hyperledger/fabric/samples/erc20/utils/ContractUtility.java

@@ -12,6 +12,7 @@ public final class ContractUtility {
   private ContractUtility() {
   }
 
+
   public static boolean stringIsNullOrEmpty(final String string) {
         return string == null || string.isEmpty();
   }

token-erc-20/chaincode-java/src/test/java/org/hyperledger/fabric/samples/erc20/TokenERC20ContractTest.java

@@ -1,3 +1,6 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ */
 package org.hyperledger.fabric.samples.erc20;
 
 import org.hyperledger.fabric.contract.ClientIdentity;
@@ -333,6 +336,37 @@ public class TokenERC20ContractTest {
           .hasMessage("Transfer amount cannot be negative");
     }
 
+    @Test
+    public void whenTokenTransferSameId() {
+
+      ERC20TokenContract contract = new ERC20TokenContract();
+      Context ctx = mock(Context.class);
+      ChaincodeStub stub = mock(ChaincodeStub.class);
+      ClientIdentity ci = mock(ClientIdentity.class);
+      when(ctx.getClientIdentity()).thenReturn(ci);
+      when(ci.getMSPID()).thenReturn(MINTER_ORG_MSPID.getValue());
+      when(ci.getId()).thenReturn(org1UserId);
+      when(ctx.getStub()).thenReturn(stub);
+      String to =
+          "x509::CN=User2@org2.example.com, L=San Francisco, ST=California,"
+              + " C=US::CN=ca.org2.example.com, O=org2.example.com, L=San Francisco, ST=California, C=US";
+
+      CompositeKey ckFrom = mock(CompositeKey.class);
+      when(stub.createCompositeKey(BALANCE_PREFIX.getValue(), org1UserId)).thenReturn(ckFrom);
+      when(ckFrom.toString()).thenReturn(BALANCE_PREFIX.getValue() + org1UserId);
+      when(stub.getStringState(ckFrom.toString())).thenReturn("1000");
+      CompositeKey ckTo = mock(CompositeKey.class);
+      when(stub.createCompositeKey(BALANCE_PREFIX.getValue(), to)).thenReturn(ckTo);
+      when(ckTo.toString()).thenReturn(BALANCE_PREFIX.getValue() + to);
+      when(stub.getStringState(ckTo.toString())).thenReturn(null);
+
+      Throwable thrown = catchThrowable(() -> contract.Transfer(ctx, org1UserId, 10));
+      assertThat(thrown)
+          .isInstanceOf(ChaincodeException.class)
+          .hasNoCause()
+          .hasMessage("Cannot transfer to and from same client account");
+    }
+
     @Test
     public void invokeTokenBurnTest() {
 
@@ -362,10 +396,10 @@ public class TokenERC20ContractTest {
       ClientIdentity ci = mock(ClientIdentity.class);
       when(ctx.getClientIdentity()).thenReturn(ci);
       when(ci.getMSPID()).thenReturn("Org2MSP");
-      when(ci.getId()).thenReturn(org1UserId);
+      when(ci.getId()).thenReturn(spender);
       CompositeKey ck = mock(CompositeKey.class);
-      when(stub.createCompositeKey(BALANCE_PREFIX.getValue(), org1UserId)).thenReturn(ck);
+      when(stub.createCompositeKey(BALANCE_PREFIX.getValue(), spender)).thenReturn(ck);
-      when(ck.toString()).thenReturn(BALANCE_PREFIX.getValue() + org1UserId);
+      when(ck.toString()).thenReturn(BALANCE_PREFIX.getValue() + spender);
       when(stub.getStringState(ck.toString())).thenReturn(null);
       when(ctx.getStub()).thenReturn(stub);
       when(stub.getStringState(TOTAL_SUPPLY_KEY.getValue())).thenReturn("1000");
@@ -377,6 +411,30 @@ public class TokenERC20ContractTest {
           .hasNoCause()
           .hasMessage("Client is not authorized to burn tokens");
     }
+
+    @Test
+    public void whenTokenBurnNegativeAmountTest() {
+      ERC20TokenContract contract = new ERC20TokenContract();
+      Context ctx = mock(Context.class);
+      ChaincodeStub stub = mock(ChaincodeStub.class);
+      ClientIdentity ci = mock(ClientIdentity.class);
+      when(ctx.getClientIdentity()).thenReturn(ci);
+      when(ci.getMSPID()).thenReturn("Org1MSP");
+      when(ci.getId()).thenReturn(org1UserId);
+      CompositeKey ck = mock(CompositeKey.class);
+      when(stub.createCompositeKey(BALANCE_PREFIX.getValue(), org1UserId)).thenReturn(ck);
+      when(ck.toString()).thenReturn(BALANCE_PREFIX.getValue() + org1UserId);
+      when(stub.getStringState(ck.toString())).thenReturn(null);
+      when(ctx.getStub()).thenReturn(stub);
+      when(stub.getStringState(TOTAL_SUPPLY_KEY.getValue())).thenReturn("1000");
+      when(stub.getStringState(ck.toString())).thenReturn("1000");
+
+      Throwable thrown = catchThrowable(() -> contract.Burn(ctx, -100));
+      assertThat(thrown)
+          .isInstanceOf(ChaincodeException.class)
+          .hasNoCause()
+          .hasMessage("Burn amount must be a positive integer");
+    }
   }
 
   @Nested