Support codegen directly from Truffle json contract files

README.rst

@@ -44,6 +44,8 @@ Features
 - Ethereum wallet support
 - Auto-generation of Java smart contract wrappers to create, deploy, transact with and call smart
   contracts from native Java code
+    - from solc output; or
+    - from Truffle `.json` contract files.
 - Reactive-functional API for working with filters
 - Support for Parity's
   `Personal <https://github.com/paritytech/parity/wiki/JSONRPC-personal-module>`__, and Geth's
@@ -251,7 +253,24 @@ Now you can create and deploy your smart contract:
            GAS_PRICE, GAS_LIMIT,
            <param1>, ..., <paramN>).send();  // constructor params
 
-Or use an existing contract:
+Alternatively, if you use `Truffle <http://truffleframework.com/>`_, you can make use of its `.json` output files:
+
+.. code-block:: bash
+
+   # Inside your Truffle project
+   $ truffle compile
+   $ truffle deploy
+
+Then generate the wrapper code using web3j's `Command line tools`_:
+
+.. code-block:: bash
+
+   $ cd /path/to/your/web3j/java/project
+   $ web3j truffle generate /path/to/<truffle-smart-contract-output>.json -o /path/to/src/main/java -p com.your.organisation.name
+
+Whether using `Truffle` or `solc` directly, either way you get a ready-to-use Java wrapper for your contract.
+
+So, to use an existing contract:
 
 .. code-block:: java
 

codegen/src/main/java/org/web3j/codegen/FunctionWrapperGenerator.java

@@ -0,0 +1,69 @@
+package org.web3j.codegen;
+
+import java.io.File;
+
+import static org.web3j.codegen.Console.exitError;
+
+/**
+ * Abstract base class for the concrete function wrapper generators.
+ */
+abstract class FunctionWrapperGenerator {
+
+    static final String JAVA_TYPES_ARG = "--javaTypes";
+    static final String SOLIDITY_TYPES_ARG = "--solidityTypes";
+
+    final File destinationDirLocation;
+    final String basePackageName;
+    final boolean useJavaNativeTypes;
+
+    FunctionWrapperGenerator(
+            String destinationDirLocation,
+            String basePackageName,
+            boolean useJavaNativeTypes) {
+
+        this.destinationDirLocation = new File(destinationDirLocation);
+        this.basePackageName = basePackageName;
+        this.useJavaNativeTypes = useJavaNativeTypes;
+    }
+
+    static boolean useJavaNativeTypes(String argVal, String usageString) {
+        boolean useJavaNativeTypes = true;
+        if (SOLIDITY_TYPES_ARG.equals(argVal)) {
+            useJavaNativeTypes = false;
+        } else if (JAVA_TYPES_ARG.equals(argVal)) {
+            useJavaNativeTypes = true;
+        } else {
+            exitError(usageString);
+        }
+        return useJavaNativeTypes;
+    }
+
+    static String parsePositionalArg(String[] args, int idx) {
+        if (args != null && args.length > idx) {
+            return args[idx];
+        } else {
+            return "";
+        }
+    }
+
+    static String parseParameterArgument(String[] args, String... parameters) {
+        for (String parameter : parameters) {
+            for (int i = 0; i < args.length; i++) {
+                if (args[i].equals(parameter)
+                        && i + 1 < args.length) {
+                    String parameterValue = args[i + 1];
+                    if (!parameterValue.startsWith("-")) {
+                        return parameterValue;
+                    }
+                }
+            }
+        }
+        return "";
+    }
+
+    static String getFileNameNoExtension(String fileName) {
+        String[] splitName = fileName.split("\\.(?=[^.]*$)");
+        return splitName[0];
+    }
+
+}

codegen/src/main/java/org/web3j/codegen/SolidityFunctionWrapper.java

@@ -5,7 +5,9 @@
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 import java.util.concurrent.Callable;
 import javax.lang.model.element.Modifier;
 
@@ -81,24 +83,74 @@ public SolidityFunctionWrapper(boolean useNativeJavaTypes) {
         this.useNativeJavaTypes = useNativeJavaTypes;
     }
 
+    @SuppressWarnings("unchecked")
     public void generateJavaFiles(
             String contractName, String bin, String abi, String destinationDir,
             String basePackageName)
             throws IOException, ClassNotFoundException {
+        generateJavaFiles(contractName, bin,
+                loadContractDefinition(abi),
+                destinationDir, basePackageName,
+                null);
+    }
+
+    void generateJavaFiles(
+            String contractName, String bin, List<AbiDefinition> abi, String destinationDir,
+            String basePackageName, Map<String, String> addresses)
+            throws IOException, ClassNotFoundException {
         String className = Strings.capitaliseFirstLetter(contractName);
 
         TypeSpec.Builder classBuilder = createClassBuilder(className, bin);
 
         classBuilder.addMethod(buildConstructor(Credentials.class, CREDENTIALS));
         classBuilder.addMethod(buildConstructor(TransactionManager.class, TRANSACTION_MANAGER));
         classBuilder.addMethods(
-                buildFunctionDefinitions(className, classBuilder, loadContractDefinition(abi)));
+                buildFunctionDefinitions(className, classBuilder, abi));
         classBuilder.addMethod(buildLoad(className, Credentials.class, CREDENTIALS));
         classBuilder.addMethod(buildLoad(className, TransactionManager.class, TRANSACTION_MANAGER));
 
+        addAddressesSupport(classBuilder, addresses);
+
         write(basePackageName, classBuilder.build(), destinationDir);
     }
 
+    private void addAddressesSupport(TypeSpec.Builder classBuilder, Map<String, String> addresses) {
+        if (addresses != null) {
+
+            ClassName stringType = ClassName.get(String.class);
+            ClassName mapType = ClassName.get(HashMap.class);
+            TypeName mapStringString = ParameterizedTypeName.get(mapType, stringType, stringType);
+            FieldSpec addressesStaticField = FieldSpec
+                    .builder(mapStringString, "_addresses",
+                            Modifier.PROTECTED, Modifier.STATIC, Modifier.FINAL)
+                    .build();
+            classBuilder.addField(addressesStaticField);
+
+            final CodeBlock.Builder staticInit = CodeBlock.builder();
+            staticInit.addStatement("_addresses = new HashMap<>()");
+            addresses.forEach((k, v) ->
+                    staticInit.addStatement(String.format("_addresses.put(\"%1s\", \"%2s\")", k, v))
+            );
+            classBuilder.addStaticBlock(staticInit.build());
+
+            // See org.web3j.tx.Contract#getStaticDeployedAddress(String)
+            MethodSpec getAddress = MethodSpec
+                    .methodBuilder("getStaticDeployedAddress")
+                    .addModifiers(Modifier.PROTECTED)
+                    .returns(stringType)
+                    .addParameter(stringType, "networkId")
+                    .addCode(
+                            CodeBlock
+                                    .builder()
+                                    .addStatement("return _addresses.get(networkId)")
+                                    .build())
+                    .build();
+            classBuilder.addMethod(getAddress);
+
+        }
+    }
+
+
     private TypeSpec.Builder createClassBuilder(String className, String binary) {
 
         String javadoc = CODEGEN_WARNING + getWeb3jVersion();

codegen/src/main/java/org/web3j/codegen/SolidityFunctionWrapperGenerator.java

@@ -18,22 +18,16 @@
 /**
  * Java wrapper source code generator for Solidity ABI format.
  */
-public class SolidityFunctionWrapperGenerator {
+public class SolidityFunctionWrapperGenerator extends FunctionWrapperGenerator {
 
     private static final String USAGE = "solidity generate "
             + "[--javaTypes|--solidityTypes] "
             + "<input binary file>.bin <input abi file>.abi "
             + "-p|--package <base package name> "
             + "-o|--output <destination base directory>";
 
-    static final String JAVA_TYPES_ARG = "--javaTypes";
-    static final String SOLIDITY_TYPES_ARG = "--solidityTypes";
-
-    private String binaryFileLocation;
-    private String absFileLocation;
-    private File destinationDirLocation;
-    private String basePackageName;
-    private boolean useJavaNativeTypes;
+    private final String binaryFileLocation;
+    private final String absFileLocation;
 
     private SolidityFunctionWrapperGenerator(
             String binaryFileLocation,
@@ -42,11 +36,9 @@ private SolidityFunctionWrapperGenerator(
             String basePackageName,
             boolean useJavaNativeTypes) {
 
+        super(destinationDirLocation, basePackageName, useJavaNativeTypes);
         this.binaryFileLocation = binaryFileLocation;
         this.absFileLocation = absFileLocation;
-        this.destinationDirLocation = new File(destinationDirLocation);
-        this.basePackageName = basePackageName;
-        this.useJavaNativeTypes = useJavaNativeTypes;
     }
 
     public static void run(String[] args) throws Exception {
@@ -72,14 +64,7 @@ public static void main(String[] args) throws Exception {
             exitError(USAGE);
         }
 
-        boolean useJavaNativeTypes = true;
-        if (fullArgs[0].equals(SOLIDITY_TYPES_ARG)) {
-            useJavaNativeTypes = false;
-        } else if (fullArgs[0].equals(JAVA_TYPES_ARG)) {
-            useJavaNativeTypes = true;
-        } else {
-            exitError(USAGE);
-        }
+        boolean useJavaNativeTypes = useJavaNativeTypes(fullArgs[0], USAGE);
 
         String binaryFileLocation = parsePositionalArg(fullArgs, 1);
         String absFileLocation = parsePositionalArg(fullArgs, 2);
@@ -102,27 +87,11 @@ public static void main(String[] args) throws Exception {
                 .generate();
     }
 
-    private static String parsePositionalArg(String[] args, int idx) {
-        if (args != null && args.length > idx) {
-            return args[idx];
-        } else {
-            return "";
-        }
-    }
-
-    private static String parseParameterArgument(String[] args, String... parameters) {
-        for (String parameter : parameters) {
-            for (int i = 0; i < args.length; i++) {
-                if (args[i].equals(parameter)
-                        && i + 1 < args.length) {
-                    String parameterValue = args[i + 1];
-                    if (!parameterValue.startsWith("-")) {
-                        return parameterValue;
-                    }
-                }
-            }
-        }
-        return "";
+    static List<AbiDefinition> loadContractDefinition(File absFile)
+            throws IOException {
+        ObjectMapper objectMapper = ObjectMapperFactory.getObjectMapper();
+        AbiDefinition[] abiDefinition = objectMapper.readValue(absFile, AbiDefinition[].class);
+        return Arrays.asList(abiDefinition);
     }
 
     private void generate() throws IOException, ClassNotFoundException {
@@ -157,15 +126,5 @@ private void generate() throws IOException, ClassNotFoundException {
         }
     }
 
-    private static List<AbiDefinition> loadContractDefinition(File absFile)
-            throws IOException {
-        ObjectMapper objectMapper = ObjectMapperFactory.getObjectMapper();
-        AbiDefinition[] abiDefinition = objectMapper.readValue(absFile, AbiDefinition[].class);
-        return Arrays.asList(abiDefinition);
-    }
 
-    static String getFileNameNoExtension(String fileName) {
-        String[] splitName = fileName.split("\\.(?=[^.]*$)");
-        return splitName[0];
-    }
 }