CORE-15353: Trade class clean up and ReadMe update

Removed unused Trade constructor and renamed Trade.ProposalId to Trade.TradeId because that is what it is. Updated the Accept flow request body in the ReadMe file.

java-samples/corda5-negotiation-cordapp/README.md

@@ -87,13 +87,15 @@ check the result. Enter Bob's hash id and the modify flow ID which is "ModifyFlo
 #### Step 4: Accept the new proposal from bob  `AcceptFlow`
 In this step, Alice will accept the new proposal from Bob.
 Goto `POST /flow/{holdingidentityshorthash}`, enter Alice's identity short hash and request body, we also need to 
-provide the proposalId, which is same as the proposal ID used in ModifyFlow body. 
+provide the proposalId, which is same as the proposal ID used in ModifyFlow body and also Alice's own details 
+(this is because the Accept smart contract requires this information)
 ```
 {
   "clientRequestId": "AcceptFlow",
   "flowClassName": "com.r3.developers.samples.negotiation.workflows.accept.AcceptFlowRequest",
   "requestBody": {
-      "proposalID": "<use the proposal id here>"
+      "proposalID": "<use the proposal id here>",
+      "acceptor": "CN=Alice, OU=Test Dept, O=R3, L=London, C=GB"
   }
 }
 ```

java-samples/corda5-negotiation-cordapp/contracts/src/main/java/com/r3/developers/samples/negotiation/Trade.java

@@ -18,31 +18,19 @@ public class Trade implements ContractState {
     private final int amount;
     private final Member buyer;
     private final Member seller;
-    private final UUID proposalID;
+    private final UUID tradeID;
     private final MemberX500Name acceptor;
     public List<PublicKey> participants;
 
-
-    @ConstructorForDeserialization
-    public Trade(int amount, Member buyer, Member seller, UUID proposalID, MemberX500Name acceptor, List<PublicKey> participants) {
-        this.amount = amount;
-        this.buyer = buyer;
-        this.seller = seller;
-        this.proposalID = proposalID;
-        this.acceptor = acceptor;
-        this.participants = participants;
-    }
-
     public Trade(int amount, Member buyer, Member seller, MemberX500Name acceptor, List<PublicKey> participants) {
         this.amount = amount;
         this.buyer = buyer;
         this.seller = seller;
         this.acceptor = acceptor;
-        this.proposalID = UUID.randomUUID();
+        this.tradeID = UUID.randomUUID();
         this.participants = participants;
     }
 
-
     public int getAmount() {
         return amount;
     }
@@ -55,8 +43,8 @@ public Member getBuyer() {
         return buyer;
     }
 
-    public UUID getProposalID() {
-        return proposalID;
+    public UUID getTradeID() {
+        return tradeID;
     }
     public MemberX500Name getAcceptor() {
         return acceptor;

java-samples/corda5-negotiation-cordapp/workflows/src/main/java/com/r3/developers/samples/negotiation/workflows/accept/AcceptFlowRequest.java

@@ -88,7 +88,7 @@ public String call(@NotNull ClientRequestBody requestBody) {
             UtxoSignedTransaction signedTransaction = transactionBuilder.toSignedTransaction();
             FlowSession counterPartySession = flowMessaging.initiateFlow(counterParty.getName());
             flowEngine.subFlow(new FinalizeFlow.FinalizeRequest(signedTransaction, List.of(counterPartySession)));
-            return output.getProposalID().toString();
+            return output.getTradeID().toString();
         } catch (Exception e) {
             throw new CordaRuntimeException(e.getMessage());
         }