Created PbObjectMapper to map through objects

Author: rumpfc

pom.xml

@@ -29,6 +29,17 @@
             <artifactId>protobuf-java</artifactId>
             <version>3.14.0</version>
         </dependency>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-api</artifactId>
+            <version>5.7.0</version>
+        </dependency>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-engine</artifactId>
+            <version>5.7.0</version>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 
 

src/main/java/com/rumpf/proto/PbFieldType.java

@@ -1,6 +1,7 @@
 package com.rumpf.proto;
 
 import com.google.protobuf.CodedInputStream;
+import com.rumpf.proto.mapper.PbObjectMapper;
 
 import java.util.function.Predicate;
 
@@ -18,7 +19,7 @@ public enum PbFieldType {
     DOUBLE(1, c -> double.class.isAssignableFrom(c) || Double.class.isAssignableFrom(c), CodedInputStream::readDouble, (v, c) -> c.writeDoubleNoTag((Double)v)),
     STRING(2, String.class::isAssignableFrom, CodedInputStream::readString, (v, c) -> c.writeStringNoTag((String)v)),
     BYTES(2, byte[].class::isAssignableFrom, CodedInputStream::readByteArray, (v, c) -> c.writeByteArrayNoTag((byte[])v)),
-    MESSAGE(2, ProtobufObject.class::isAssignableFrom, CodedInputStream::readByteArray, (v, c) -> c.writeByteArrayNoTag(((ProtobufObject)v).write())),
+    MESSAGE(2, Object.class::isAssignableFrom, CodedInputStream::readByteArray, (v, c) -> c.writeByteArrayNoTag(new PbObjectMapper().write(v))),
     FIXED32(5, c -> int.class.isAssignableFrom(c) || Integer.class.isAssignableFrom(c), CodedInputStream::readFixed32, (v, c) -> c.writeFixed32NoTag((Integer)v)),
     SFIXED32(5, c -> int.class.isAssignableFrom(c) || Integer.class.isAssignableFrom(c), CodedInputStream::readSFixed32, (v, c) -> c.writeSFixed32NoTag((Integer)v)),
     FLOAT(5, c -> float.class.isAssignableFrom(c) || Float.class.isAssignableFrom(c), CodedInputStream::readFloat, (v, c) -> c.writeFloatNoTag((Float)v))

src/main/java/com/rumpf/proto/ProtobufObject.java

@@ -4,7 +4,6 @@
 import com.google.protobuf.CodedOutputStream;
 import com.rumpf.proto.PbFieldType;
 import com.rumpf.proto.PbModifier;
-import com.rumpf.proto.ProtobufObject;
 
 import java.io.IOException;
 import java.lang.reflect.Field;
@@ -15,11 +14,11 @@ public abstract class AbstractMessageField implements MessageField {
     protected final int fieldNumber;
     protected final PbModifier modifier;
     protected final PbFieldType type;
-    protected final ProtobufObject pbObject;
+    protected final Object object;
 
-    protected AbstractMessageField(ProtobufObject pbObject, Field field, int fieldNumber, PbFieldType type, PbModifier modifier) {
+    protected AbstractMessageField(Object object, Field field, int fieldNumber, PbFieldType type, PbModifier modifier) {
         this.field = field;
-        this.pbObject = pbObject;
+        this.object = object;
         this.fieldNumber = fieldNumber;
         this.type = type;
         this.modifier = modifier;

src/main/java/com/rumpf/proto/field/AbstractMessageField.java

@@ -9,7 +9,7 @@
 
 public class MessageFieldFactory {
 
-    public static MessageField newMessageField(ProtobufObject pbObject, Field field) {
+    public static MessageField newMessageField(Object pbObject, Field field) {
         PbField f = field.getAnnotation(PbField.class);
 
         PbFieldType type = f.type();

src/main/java/com/rumpf/proto/field/MessageFieldFactory.java

@@ -2,7 +2,6 @@
 
 import com.rumpf.proto.PbFieldType;
 import com.rumpf.proto.ProtobufEnum;
-import com.rumpf.proto.ProtobufObject;
 
 import java.lang.reflect.Field;
 
@@ -51,7 +50,7 @@ public String getMessage() {
                 msg += byte[].class.getName();
                 break;
             case MESSAGE:
-                msg += "class which extends " + ProtobufObject.class.getName();
+                msg += "class";
                 break;
             case ENUM:
                 msg += "enum which implements " + ProtobufEnum.class.getName();

src/main/java/com/rumpf/proto/field/NotCompatibleFieldTypeException.java

@@ -1,11 +1,10 @@
 package com.rumpf.proto.field;
 
-import com.google.protobuf.CodedInputStream;
 import com.google.protobuf.CodedOutputStream;
 import com.rumpf.proto.PbFieldType;
 import com.rumpf.proto.PbModifier;
 import com.rumpf.proto.ProtobufEnum;
-import com.rumpf.proto.ProtobufObject;
+import com.rumpf.proto.mapper.PbObjectMapper;
 
 import java.io.IOException;
 import java.lang.reflect.Constructor;
@@ -18,7 +17,7 @@ public class RepeatedMessageField extends SingleMessageField {
 
     private Collection coll;
 
-    public RepeatedMessageField(ProtobufObject pbObject, Field field, int fieldNumber, PbFieldType type, PbModifier modifier) {
+    public RepeatedMessageField(Object pbObject, Field field, int fieldNumber, PbFieldType type, PbModifier modifier) {
         super(pbObject, field, fieldNumber, type, modifier);
     }
 
@@ -59,7 +58,7 @@ private void initCollection() {
 
         try {
             field.setAccessible(true);
-            field.set(pbObject, coll);
+            field.set(object, coll);
         } catch (IllegalAccessException e) {
             e.printStackTrace();
         } finally {
@@ -101,17 +100,12 @@ public void write(CodedOutputStream cos) throws IOException {
 
     }
 
-    private ProtobufObject toPbObject(Object value) {
+    private Object toPbObject(Object value) {
         if(value instanceof byte[]) {
             try {
                 byte[] data = (byte[]) value;
-                Constructor<?> constructor = getCollectionGenericClass().getConstructor();
-                Object o = constructor.newInstance();
-                if(o instanceof ProtobufObject) {
-                    ((ProtobufObject)o).read(data);
-                    return (ProtobufObject)o;
-                }
-            } catch (IllegalAccessException | IllegalArgumentException | NoSuchMethodException | InvocationTargetException | InstantiationException | IOException e) {
+                return new PbObjectMapper().read(data);
+            } catch (IllegalArgumentException | IOException e) {
                 e.printStackTrace();
             }
         }

src/main/java/com/rumpf/proto/field/RepeatedMessageField.java

@@ -3,6 +3,7 @@
 import com.google.protobuf.CodedInputStream;
 import com.google.protobuf.CodedOutputStream;
 import com.rumpf.proto.*;
+import com.rumpf.proto.mapper.PbObjectMapper;
 
 import java.io.IOException;
 import java.lang.reflect.Constructor;
@@ -12,8 +13,8 @@
 
 public class SingleMessageField extends AbstractMessageField {
 
-    public SingleMessageField(ProtobufObject pbObject, Field field, int fieldNumber, PbFieldType type, PbModifier modifier) {
-        super(pbObject, field, fieldNumber, type, modifier);
+    public SingleMessageField(Object object, Field field, int fieldNumber, PbFieldType type, PbModifier modifier) {
+        super(object, field, fieldNumber, type, modifier);
     }
 
     public int getFieldNumber() {
@@ -37,7 +38,7 @@ protected Object get() {
         Object value = null;
         try {
             field.setAccessible(true);
-            value = field.get(pbObject);
+            value = field.get(object);
         } catch (IllegalAccessException e) {
             e.printStackTrace();
         } finally {
@@ -63,7 +64,7 @@ public void write(CodedOutputStream cos) throws IOException {
     private void setPrimitive(Object value) {
         try {
             field.setAccessible(true);
-            field.set(pbObject, value);
+            field.set(object, value);
             field.setAccessible(false);
         } catch (IllegalAccessException | IllegalArgumentException e) {
             e.printStackTrace();
@@ -74,7 +75,7 @@ private void setEnum(Object value) {
         if(value instanceof Integer) {
             try {
                 field.setAccessible(true);
-                field.set(pbObject, ProtobufEnum.findById(field.getType(), (Integer)value));
+                field.set(object, ProtobufEnum.findById(field.getType(), (Integer)value));
                 field.setAccessible(false);
             } catch (IllegalAccessException | IllegalArgumentException e) {
                 e.printStackTrace();
@@ -86,15 +87,14 @@ private void setMessage(Object value) {
         if(value instanceof byte[]) {
             try {
                 byte[] data = (byte[]) value;
-                Constructor<?> constructor = field.getType().getConstructor();
-                Object o = constructor.newInstance();
-                if(o instanceof ProtobufObject) {
-                    ((ProtobufObject)o).read(data);
-                    field.setAccessible(true);
-                    field.set(pbObject, o);
-                    field.setAccessible(false);
-                }
-            } catch (IllegalAccessException | IllegalArgumentException | NoSuchMethodException | InvocationTargetException | InstantiationException | IOException e) {
+                PbObjectMapper mapper = new PbObjectMapper();
+                Object o = mapper.read(data);
+
+                field.setAccessible(true);
+                field.set(this.object, o);
+                field.setAccessible(false);
+
+            } catch (IllegalAccessException | IllegalArgumentException | IOException e) {
                 e.printStackTrace();
             }
         }

src/main/java/com/rumpf/proto/field/SingleMessageField.java

@@ -0,0 +1,88 @@
+package com.rumpf.proto.mapper;
+
+import com.google.protobuf.CodedInputStream;
+import com.google.protobuf.CodedOutputStream;
+import com.rumpf.proto.PbField;
+import com.rumpf.proto.field.MessageField;
+import com.rumpf.proto.field.MessageFieldFactory;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.lang.reflect.Constructor;
+import java.lang.reflect.InvocationTargetException;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.Map;
+
+public class PbObjectMapper {
+
+    private final Map<Integer, MessageField> messageFields;
+
+    public PbObjectMapper() {
+        messageFields = new HashMap<>();
+    }
+
+    private <T> T createInstance(Class<T> clazz) {
+        try {
+            Constructor<T> constructor = clazz.getConstructor();
+            constructor.setAccessible(true);
+
+            return constructor.newInstance();
+        } catch (NoSuchMethodException | IllegalAccessException | InstantiationException | InvocationTargetException e) {
+            e.printStackTrace();
+        }
+
+        return null;
+    }
+
+    private void initMessageFields(Object object) {
+        messageFields.clear();
+
+        Arrays.stream(object.getClass().getDeclaredFields())
+                .filter(f -> f.isAnnotationPresent(PbField.class))
+                .map(f -> MessageFieldFactory.newMessageField(object, f))
+                .forEach(mf -> messageFields.put(mf.getFieldNumber(), mf));
+    }
+
+    public byte[] write(Object object) throws IOException {
+        initMessageFields(object);
+
+        ByteArrayOutputStream os = new ByteArrayOutputStream();
+        CodedOutputStream cos = CodedOutputStream.newInstance(os);
+
+        for(MessageField field : messageFields.values()) {
+            field.write(cos);
+        }
+
+        cos.flush();
+        return os.toByteArray();
+    }
+
+    public Object read(byte[] data) throws IOException {
+        return read(data, Object.class);
+    }
+
+    public <T> T read(byte[] data, Class<T> clazz) throws IOException {
+        T object = createInstance(clazz);
+
+        if(object == null) {
+            return null;
+        }
+
+        initMessageFields(object);
+
+        CodedInputStream cis = CodedInputStream.newInstance(data);
+
+        while (!cis.isAtEnd()) {
+            int tag = cis.readTag();
+
+            if(messageFields.containsKey(tag >> 3)) {
+                messageFields.get(tag >> 3).read(cis);
+            } else {
+                cis.skipField(tag);
+            }
+        }
+
+        return object;
+    }
+}