diff --git a/src/main/java/Main.java b/src/main/java/Main.java
index bc82379..8188324 100644
--- a/src/main/java/Main.java
+++ b/src/main/java/Main.java
@@ -9,6 +9,9 @@ import parser.ASTBuilder;
 import parser.generated.SimpleJavaLexer;
 import parser.generated.SimpleJavaParser;
 import semantic.SemanticAnalyzer;
+import ast.ClassNode;
+import ast.ProgramNode;
+import bytecode.ByteCodeGenerator;
 
 import java.io.IOException;
 import java.nio.file.Paths;
diff --git a/src/main/java/ast/ExpressionNode.java b/src/main/java/ast/ExpressionNode.java
new file mode 100644
index 0000000..891d87c
--- /dev/null
+++ b/src/main/java/ast/ExpressionNode.java
@@ -0,0 +1,4 @@
+package ast;
+
+public class ExpressionNode {
+}
diff --git a/src/main/java/ast/FieldNode.java b/src/main/java/ast/FieldNode.java
index 3bf6d2b..0f17f69 100644
--- a/src/main/java/ast/FieldNode.java
+++ b/src/main/java/ast/FieldNode.java
@@ -1,10 +1,10 @@
 package ast;
 
-public class FieldNode {
-    String type;
+public class FieldNode extends MemberNode {
+    TypeNode type;
     String name;
 
-    public FieldNode(String type, String name){
+    public FieldNode(TypeNode type, String name){
         this.type = type;
         this.name = name;
     }
diff --git a/src/main/java/ast/MethodNode.java b/src/main/java/ast/MethodNode.java
index b9a8ab4..1db789c 100644
--- a/src/main/java/ast/MethodNode.java
+++ b/src/main/java/ast/MethodNode.java
@@ -1,11 +1,17 @@
 package ast;
 
+import java.util.ArrayList;
+import java.util.List;
+
 public class MethodNode extends MemberNode{
-    public String visibility;
+    public TypeNode visibility;
     public String name;
 
-    public MethodNode(String visibility, String name){
+    public ParameterListNode parameters;
+
+    public MethodNode(TypeNode visibility, String name, ParameterListNode parameters){
         this.visibility = visibility;
         this.name = name;
+        this.parameters = parameters;
     }
 }
diff --git a/src/main/java/ast/ParameterListNode.java b/src/main/java/ast/ParameterListNode.java
new file mode 100644
index 0000000..6096b69
--- /dev/null
+++ b/src/main/java/ast/ParameterListNode.java
@@ -0,0 +1,12 @@
+package ast;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class ParameterListNode {
+    List<ParameterNode> parameters = new ArrayList<>();
+
+    public ParameterListNode(){
+        parameters
+    }
+}
diff --git a/src/main/java/ast/ParameterNode.java b/src/main/java/ast/ParameterNode.java
new file mode 100644
index 0000000..fc2d84a
--- /dev/null
+++ b/src/main/java/ast/ParameterNode.java
@@ -0,0 +1,11 @@
+package ast;
+
+public class ParameterNode extends ASTNode {
+    public TypeNode type;
+    public String identifier;
+
+    public ParameterNode(TypeNode type, String identifier) {
+        this.type = type;
+        this.identifier = identifier;
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/ast/ProgramNode.java b/src/main/java/ast/ProgramNode.java
index d22af33..1fed1c0 100644
--- a/src/main/java/ast/ProgramNode.java
+++ b/src/main/java/ast/ProgramNode.java
@@ -1,12 +1,9 @@
-package ast;
+public class ParameterNode extends ASTNode {
+    public TypeNode type;
+    public String identifier;
 
-import java.util.ArrayList;
-import java.util.List;
-
-public class ProgramNode extends ASTNode {
-    public List<ClassNode> classes = new ArrayList<>();
-
-    public void addClass(ClassNode classNode) {
-        classes.add(classNode);
+    public ParameterNode(TypeNode type, String identifier) {
+        this.type = type;
+        this.identifier = identifier;
     }
-}
+}
\ No newline at end of file
diff --git a/src/main/java/ast/StatementNode.java b/src/main/java/ast/StatementNode.java
new file mode 100644
index 0000000..059a96a
--- /dev/null
+++ b/src/main/java/ast/StatementNode.java
@@ -0,0 +1,7 @@
+package ast;
+
+import ast.ASTNode;
+
+public abstract class StatementNode extends ASTNode {
+}
+
diff --git a/src/main/java/ast/TypeNode.java b/src/main/java/ast/TypeNode.java
index 1f657df..51a3dc7 100644
--- a/src/main/java/ast/TypeNode.java
+++ b/src/main/java/ast/TypeNode.java
@@ -1,5 +1,9 @@
 package ast;
 
-public class TypeNode {
-    String type;
+public class TypeNode extends ASTNode {
+    public String typeName;
+
+    public TypeNode(String typeName) {
+        this.typeName = typeName;
+    }
 }
diff --git a/src/main/java/ast/VariableDeclarationStatementNode.java b/src/main/java/ast/VariableDeclarationStatementNode.java
new file mode 100644
index 0000000..6222942
--- /dev/null
+++ b/src/main/java/ast/VariableDeclarationStatementNode.java
@@ -0,0 +1,13 @@
+package ast;
+
+public class VariableDeclarationStatementNode extends StatementNode {
+    public TypeNode type;
+    public String identifier;
+    public ExpressionNode expression; // Nullable for cases without initialization
+
+    public VariableDeclarationStatementNode(TypeNode type, String identifier, ExpressionNode expression) {
+        this.type = type;
+        this.identifier = identifier;
+        this.expression = expression;
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/bytecode/ClassCodeGen.java b/src/main/java/bytecode/ClassCodeGen.java
new file mode 100644
index 0000000..619068a
--- /dev/null
+++ b/src/main/java/bytecode/ClassCodeGen.java
@@ -0,0 +1,39 @@
+package bytecode;
+
+import ast.ClassNode;
+import org.objectweb.asm.ClassWriter;
+import org.objectweb.asm.Opcodes;
+
+import java.io.FileOutputStream;
+import java.io.IOException;
+
+public class ClassCodeGen {
+    public void generateClassCode(ClassNode classNode) {
+        ClassWriter classWriter = new ClassWriter(ClassWriter.COMPUTE_FRAMES | ClassWriter.COMPUTE_MAXS);
+        classWriter.visit(Opcodes.V1_8, Opcodes.ACC_PUBLIC, classNode.name, null,
+                "java/lang/Object", null);
+
+        FieldCodeGen fieldCodeGen = new FieldCodeGen();
+        fieldCodeGen.generateFieldCode(classWriter);
+
+        MethodCodeGen methodCodeGen = new MethodCodeGen();
+        methodCodeGen.generateMethodCode(classWriter);
+
+        classWriter.visitEnd();
+        printIntoClassFile(classWriter.toByteArray(), classNode.name);
+
+        classWriter.visitEnd();
+    }
+
+    private void printIntoClassFile(byte[] byteCode, String name) {
+        String filePath = "./classFileOutput/" + name + ".class";
+
+        try {
+            FileOutputStream fileOutputStream = new FileOutputStream(filePath);
+            fileOutputStream.write(byteCode);
+            fileOutputStream.close();
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+}
diff --git a/src/main/java/parser/ASTBuilder.java b/src/main/java/parser/ASTBuilder.java
index df2d1b3..f659299 100644
--- a/src/main/java/parser/ASTBuilder.java
+++ b/src/main/java/parser/ASTBuilder.java
@@ -4,6 +4,9 @@ import ast.*;
 import parser.generated.SimpleJavaBaseVisitor;
 import parser.generated.SimpleJavaParser;
 
+import java.util.ArrayList;
+import java.util.List;
+
 public class ASTBuilder extends SimpleJavaBaseVisitor<ASTNode> {
     @Override
     public ASTNode visitProgram(SimpleJavaParser.ProgramContext ctx) {
@@ -25,4 +28,65 @@ public class ASTBuilder extends SimpleJavaBaseVisitor<ASTNode> {
         return classNode;
     }
 
+    @Override
+    public ASTNode visitFieldDeclaration(SimpleJavaParser.FieldDeclarationContext ctx) {
+        TypeNode type = (TypeNode) visit(ctx.type());
+        String identifier = ctx.IDENTIFIER().getText();
+        return new FieldNode(type, identifier);
+    }
+
+    @Override
+    public ASTNode visitMethodDeclaration(SimpleJavaParser.MethodDeclarationContext ctx) {
+        TypeNode returnType = (TypeNode) visit(ctx.type());
+        String methodName = ctx.IDENTIFIER().getText();
+        ParameterListNode = (ParameterListNode) visit(ctx.parameterList());
+        List<ParameterNode> parameters = new ArrayList<>();
+        for (SimpleJavaParser.ParameterContext parameter : ctx.parameterList()) {
+            parameters.add(parameter);
+        }
+        MethodNode method = new MethodNode(returnType, methodName);
+
+        for (SimpleJavaParser.ParameterContext paramCtx : ctx.parameterList().parameter()) {
+            method.parameters.add((ParameterNode) visit(paramCtx));
+        }
+
+        for (SimpleJavaParser.StatementContext stmtCtx : ctx.statement()) {
+            method.statements.add((StatementNode) visit(stmtCtx));
+        }
+
+        return method;
+    }
+    @Override
+    public ASTNode visitType(SimpleJavaParser.TypeContext ctx) {
+        return new TypeNode(ctx.getText());
+    }
+
+    @Override
+    public ASTNode visitStatement(SimpleJavaParser.StatementContext ctx) {
+        if (ctx.variableDeclarationStatement() != null) {
+            return visitVariableDeclarationStatement(ctx.variableDeclarationStatement());
+        } else if (ctx.assignmentStatement() != null) {
+            return visitAssignmentStatement(ctx.assignmentStatement());
+        }
+
+        return null;
+    }
+
+    @Override
+    public ASTNode visitParameterList(SimpleJavaParser.ParameterListContext ctx) {
+        List<ParameterNode> parameters = new ArrayList<>();
+        for (SimpleJavaParser.ParameterContext paramCtx : ctx.parameter()) {
+            parameters.add((ParameterNode) visitParameter(paramCtx));
+        }
+        return new ParameterListNode(parameters);  // Assuming you want to keep a dedicated node for the list
+    }
+
+    @Override
+    public ASTNode visitParameter(SimpleJavaParser.ParameterContext ctx) {
+        TypeNode type = (TypeNode) visit(ctx.type());  // Assuming visitType returns a TypeNode
+        String identifier = ctx.IDENTIFIER().getText();
+        return new ParameterNode(type, identifier);
+    }
+
+
 }
diff --git a/src/main/test/java/MainTest.java b/src/main/test/java/MainTest.java
index c956827..46ad4ee 100644
--- a/src/main/test/java/MainTest.java
+++ b/src/main/test/java/MainTest.java
@@ -1,4 +1,19 @@
+import org.antlr.v4.runtime.CharStream;
+import org.antlr.v4.runtime.CharStreams;
 import org.junit.jupiter.api.Test;
+import org.antlr.v4.runtime.CharStream;
+import org.antlr.v4.runtime.CharStreams;
+import org.antlr.v4.runtime.CommonTokenStream;
+import org.antlr.v4.runtime.tree.ParseTree;
+import parser.ASTBuilder;
+import parser.generated.SimpleJavaLexer;
+import parser.generated.SimpleJavaParser;
+import ast.ClassNode;
+import ast.ProgramNode;
+import bytecode.ByteCodeGenerator;
+
+import java.io.IOException;
+import java.nio.file.Paths;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
@@ -7,10 +22,14 @@ import static org.junit.jupiter.api.Assertions.assertEquals;
  */
 public class MainTest {
     @Test
-    void testAdd() {
-        //Calculator calculator = new Calculator();
-        //int result = calculator.add(2, 3);
-        //assertEquals(5, result, "2 + 3 should equal 5");
+    void testEmptyClass() {
+        CharStream codeCharStream = null;
+        try {
+            codeCharStream = CharStreams.fromPath(Paths.get("src/main/java/Example.java"));
+            Main.parsefile(codeCharStream);
+        } catch (IOException e) {
+            System.err.println("Error reading the file: " + e.getMessage());
+        }
     }
 }