[FAB-3221] Java cc getFunctionAndParameters()

ChaincodeStub:
 - add getFunction()
 - add getParameters()
 - rename getArgsAsStrings() to getStringArgs()

Change-Id: Iea537353f3c40b205b8f5fb0213a85733b5dbdab
Signed-off-by: Luis Sanchez <[email protected]>

Author: Luis Sanchez

core/chaincode/shim/java/src/main/java/org/hyperledger/fabric/shim/ChaincodeStub.java

@@ -16,11 +16,10 @@
 package org.hyperledger.fabric.shim;
 
 import static java.nio.charset.StandardCharsets.UTF_8;
+import static java.util.stream.Collectors.toList;
 
-import java.nio.charset.StandardCharsets;
 import java.util.Arrays;
 import java.util.List;
-import java.util.stream.Collectors;
 
 import org.hyperledger.fabric.protos.peer.ChaincodeEventPackage.ChaincodeEvent;
 import org.hyperledger.fabric.protos.peer.ProposalResponsePackage.Response;
@@ -41,9 +40,31 @@ public interface ChaincodeStub {
 	 * {@link Chaincode#init(ChaincodeStub)} or
 	 * {@link Chaincode#invoke(ChaincodeStub)}.
 	 * 
-	 * @return a list of arguments cast to a UTF-8 string
+	 * @return a list of arguments cast to UTF-8 strings
 	 */
-	List<String> getArgsAsStrings();
+	List<String> getStringArgs();
+	
+	/**
+	 * A convenience method that returns the first argument of the chaincode
+	 * invocation for use as a function name.
+	 * 
+	 * The bytes of the first argument are decoded as a UTF-8 string.  
+	 * 
+	 * @return the function name
+	 */
+	String getFunction();
+	
+	/**
+	 * A convenience method that returns all except the first argument of the
+	 * chaincode invocation for use as the parameters to the function returned
+	 * by #{@link ChaincodeStub#getFunction()}.
+	 * 
+	 * The bytes of the arguments are decoded as a UTF-8 strings and returned as
+	 * a list of string parameters..
+	 * 
+	 * @return a list of parameters
+	 */
+	List<String> getParameters();
 
 	/**
 	 * Returns the transaction id
@@ -134,7 +155,7 @@ default Response invokeChaincode(String chaincodeName, List<byte[]> args) {
 	 * @return
 	 */
 	default Response invokeChaincodeWithStringArgs(String chaincodeName, List<String> args, String channel) {
-		return invokeChaincode(chaincodeName, args.stream().map(x->x.getBytes(StandardCharsets.UTF_8)).collect(Collectors.toList()), channel);
+		return invokeChaincode(chaincodeName, args.stream().map(x->x.getBytes(UTF_8)).collect(toList()), channel);
 	}
 
 	/**

core/chaincode/shim/java/src/main/java/org/hyperledger/fabric/shim/ChaincodeStubImpl.java

@@ -16,6 +16,8 @@
 
 package org.hyperledger.fabric.shim;
 
+import static java.util.stream.Collectors.toList;
+
 import java.util.Collections;
 import java.util.List;
 import java.util.stream.Collectors;
@@ -54,10 +56,26 @@ public List<byte[]> getArgs() {
 	 * @see org.hyperledger.fabric.shim.ChaincodeStub#getArgsAsStrings()
 	 */
 	@Override
-	public List<String> getArgsAsStrings() {
+	public List<String> getStringArgs() {
 		return args.stream().map(x -> x.toStringUtf8()).collect(Collectors.toList());
 	}
 
+	/* (non-Javadoc)
+	 * @see org.hyperledger.fabric.shim.ChaincodeStub#getFunction()
+	 */
+	@Override
+	public String getFunction() {
+		return getStringArgs().size() > 0 ? getStringArgs().get(0) : null;
+	}
+	
+	/* (non-Javadoc)
+	 * @see org.hyperledger.fabric.shim.ChaincodeStub#getParameters()
+	 */
+	@Override
+	public List<String> getParameters() {
+		return getStringArgs().stream().skip(1).collect(toList());
+	}
+	
 	/* (non-Javadoc)
 	 * @see org.hyperledger.fabric.shim.ChaincodeStub#setEvent(java.lang.String, byte[])
 	 */

examples/chaincode/java/LinkExample/src/main/java/example/LinkExample.java

@@ -43,9 +43,8 @@ public Response init(ChaincodeStub stub) {
 	@Override
 	public Response invoke(ChaincodeStub stub) {
         try {
-            final List<String> argList = stub.getArgsAsStrings();
-            final String function = argList.get(0);
-            final List<String> args = argList.subList(0, argList.size());
+            final String function = stub.getFunction();
+            final List<String> args = stub.getParameters();
 
             switch (function) {
             case "init":

examples/chaincode/java/SimpleSample/src/main/java/example/SimpleSample.java

@@ -22,8 +22,6 @@
 import static org.hyperledger.fabric.shim.ChaincodeHelper.newInternalServerErrorResponse;
 import static org.hyperledger.fabric.shim.ChaincodeHelper.newSuccessResponse;
 
-import java.util.List;
-
 import javax.json.Json;
 
 import org.apache.commons.logging.Log;
@@ -44,19 +42,18 @@ public class SimpleSample extends ChaincodeBase {
 
 	@Override
 	public Response init(ChaincodeStub stub) {
-		final List<String> args = stub.getArgsAsStrings();
-		if(!args.get(0).equals("init")) {
-			return newBadRequestResponse(format("Unknown function: %s", args.get(0)));
+		final String function = stub.getFunction();
+		if(!function.equals("init")) {
+			return newBadRequestResponse(format("Unknown function: %s", function));
 		}
-		return init(stub, args.stream().skip(1).toArray(String[]::new));
+		return init(stub, stub.getParameters().stream().toArray(String[]::new));
 	}
 
 	@Override
 	public Response invoke(ChaincodeStub stub) {
 		try {
-			final List<String> argList = stub.getArgsAsStrings();
-			final String function = argList.get(0);
-			final String[] args = argList.stream().skip(1).toArray(String[]::new);
+			final String function = stub.getFunction();
+			final String[] args = stub.getParameters().stream().toArray(String[]::new);
 
 			switch (function) {
 			case "transfer":

examples/chaincode/java/chaincode_example02/src/main/java/example/Example02.java

@@ -39,12 +39,12 @@ public class Example02 extends ChaincodeBase {
 	@Override
 	public Response init(ChaincodeStub stub) {
 		try {
-			final List<String> args = stub.getArgsAsStrings();
-			switch (args.get(0)) {
+			final String function = stub.getFunction();
+			switch (function) {
 			case "init":
-				return init(stub, args.stream().skip(1).toArray(String[]::new));
+				return init(stub, stub.getParameters().stream().toArray(String[]::new));
 			default:
-				return newBadRequestResponse(format("Unknown function: %s", args.get(0)));
+				return newBadRequestResponse(format("Unknown function: %s", function));
 			}
 		} catch (NumberFormatException e) {
 			return newBadRequestResponse(e.toString());
@@ -59,9 +59,8 @@ public Response init(ChaincodeStub stub) {
 	public Response invoke(ChaincodeStub stub) {
 
 		try {
-			final List<String> argList = stub.getArgsAsStrings();
-			final String function = argList.get(0);
-			final String[] args = argList.stream().skip(1).toArray(String[]::new);
+			final String function = stub.getFunction();
+			final String[] args = stub.getParameters().stream().toArray(String[]::new);
 
 			switch (function) {
 			case "invoke":

examples/chaincode/java/chaincode_example04/src/main/java/example/Example04.java

@@ -37,7 +37,7 @@ public Response init(ChaincodeStub stub) {
 		// expects to be called with: { "init", key, value }
 		try {
 
-			final List<String> args = stub.getArgsAsStrings();
+			final List<String> args = stub.getStringArgs();
 			if(args.size() != 3) {
 				return newBadRequestResponse("Incorrect number of arguments. Expecting \"init\" plus 2 more.");
 			}
@@ -59,9 +59,8 @@ public Response init(ChaincodeStub stub) {
 	public Response invoke(ChaincodeStub stub) {
 		// expects to be called with: { "invoke"|"query", chaincodeName, key }
 		try {
-			final List<String> argList = stub.getArgsAsStrings();
-			final String function = argList.get(0);
-			final String[] args = argList.stream().skip(1).toArray(String[]::new);
+			final String function = stub.getFunction();
+			final String[] args = stub.getParameters().stream().toArray(String[]::new);
 
 			switch (function) {
 			case "invoke":

examples/chaincode/java/chaincode_example05/src/main/java/example/Example05.java

@@ -35,7 +35,7 @@ public Response init(ChaincodeStub stub) {
 		// expects to be called with: { "init", key, value }
 		try {
 
-			final List<String> args = stub.getArgsAsStrings();
+			final List<String> args = stub.getStringArgs();
 			if(args.size() != 3) {
 				return newBadRequestResponse("Incorrect number of arguments. Expecting \"init\" plus 2 more.");
 			}
@@ -57,9 +57,8 @@ public Response init(ChaincodeStub stub) {
 	public Response invoke(ChaincodeStub stub) {
 		// expects to be called with: { "invoke"|"query", chaincodeName, key }
 		try {
-			final List<String> argList = stub.getArgsAsStrings();
-			final String function = argList.get(0);
-			final String[] args = argList.stream().skip(1).toArray(String[]::new);
+			final String function = stub.getFunction();
+			final String[] args = stub.getParameters().stream().toArray(String[]::new);
 
 			switch (function) {
 			case "invoke":

examples/chaincode/java/chaincode_example06/src/main/java/example/Example06.java

@@ -32,10 +32,10 @@ public Response init(ChaincodeStub stub) {
 
 	@Override
 	public Response invoke(ChaincodeStub stub) {
-		if(stub.getArgsAsStrings().isEmpty())
+		if(stub.getArgs().isEmpty())
 			return newBadRequestResponse(format("No arguments specified."));
 
-		switch (stub.getArgsAsStrings().get(0)) {
+		switch (stub.getStringArgs().get(0)) {
 		case "runtimeException":
 			throw new RuntimeException("Exception thrown as requested.");
 		default:

examples/chaincode/java/eventsender/src/main/java/example/EventSender.java

@@ -44,12 +44,11 @@ public Response init(ChaincodeStub stub) {
 	public Response invoke(ChaincodeStub stub) {
 
 		try {
-			final List<String> argList = stub.getArgsAsStrings();
-			final String function = argList.get(0);
+			final String function = stub.getFunction();
 
 			switch (function) {
 			case "invoke":
-				return doInvoke(stub, argList.stream().skip(1).collect(toList()));
+				return doInvoke(stub, stub.getParameters());
 			case "query":
 				return doQuery(stub);
 			default: