wip

10 files changed, 337 insertions, 95 deletions

diff --git a/container-compiler-plugin/src/main/java/io/trygvis/container/compiler/EntityHandler.java b/container-compiler-plugin/src/main/java/io/trygvis/container/compiler/EntityHandler.java
index df7a673..f9247e0 100644
--- a/container-compiler-plugin/src/main/java/io/trygvis/container/compiler/EntityHandler.java
+++ b/container-compiler-plugin/src/main/java/io/trygvis/container/compiler/EntityHandler.java
@@ -1,43 +1,90 @@
 package io.trygvis.container.compiler;
 
-import io.trygvis.container.compiler.entity.EntityMirror;
 import io.trygvis.container.compiler.model.ClassG;
 import io.trygvis.container.compiler.model.Parameters;
+import io.trygvis.persistence.EntityMirror;
+import io.trygvis.persistence.FieldMirror;
+import io.trygvis.persistence.GeneratorSupport;
+import io.trygvis.persistence.SqlEntity;
+import io.trygvis.persistence.TypeHandler;
 
 import javax.annotation.processing.ProcessingEnvironment;
+import javax.lang.model.element.AnnotationMirror;
+import javax.lang.model.element.AnnotationValue;
+import javax.lang.model.element.Element;
+import javax.lang.model.element.ExecutableElement;
 import javax.lang.model.element.TypeElement;
 import javax.lang.model.element.VariableElement;
+import javax.lang.model.type.TypeMirror;
 import javax.tools.JavaFileObject;
 import java.io.PrintWriter;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Map;
+import java.util.Set;
 
-import static io.trygvis.container.compiler.entity.EntityMirror.FieldMirror;
+import static io.trygvis.persistence.FieldMirror.PrimitiveFieldMirror;
 import static java.lang.Character.isUpperCase;
 import static javax.lang.model.util.ElementFilter.fieldsIn;
-import static org.springframework.util.StringUtils.collectionToDelimitedString;
 
 public class EntityHandler extends AbstractHandler {
+    GeneratorSupport generatorSupport = new GeneratorSupport();
+
     public EntityHandler(ProcessingEnvironment processingEnv) {
         super(processingEnv);
     }
 
+    public void phase1(Set<? extends Element> sqlEntities) throws Exception {
+        System.out.println("io.trygvis.container.compiler.EntityHandler.phase1");
+        for (Element entity : sqlEntities) {
+//            SqlEntity sqlEntity = entity.getAnnotation(SqlEntity.class);
+//            Class<? extends TypeHandler> typeHandlerClass = sqlEntity.value();
+
+            AnnotationMirror sqlEntity = findAnnotation(SqlEntity.class, entity.getAnnotationMirrors());
+            for (Map.Entry<? extends ExecutableElement, ? extends AnnotationValue> v : sqlEntity.getElementValues().entrySet()) {
+                switch (v.getKey().getSimpleName().toString()) {
+                    case "value":
+                        Class<?> typeHandlerClass = getClass().getClassLoader().loadClass(v.getValue().getValue().toString());
+
+                        TypeHandler typeHandler = (TypeHandler) typeHandlerClass.newInstance();
+                        String type = entity.asType().toString();
+                        generatorSupport.addTypeHandler(type, typeHandler);
+                        System.out.println("Loaded TypeHandler for " + type + " through " + typeHandlerClass.getCanonicalName());
+                        break;
+                }
+            }
+            System.out.println("sqlEntity.getElementValues() = " + sqlEntity.getElementValues());
+        }
+    }
+
+    private AnnotationMirror findAnnotation(Class<?> c, List<? extends AnnotationMirror> annotations) {
+        TypeElement t = elements.getTypeElement(c.getCanonicalName());
+        for (AnnotationMirror a : annotations) {
+            if (types.isSameType(a.getAnnotationType(), t.asType())) {
+                return a;
+            }
+        }
+
+        throw new RuntimeException("Could not find annotation " + c.getSimpleName());
+    }
+
     public void processEntity(TypeElement element) throws Exception {
-        EntityMirror entityMirror = new EntityMirror(sqlName(element.getSimpleName().toString()));
+        EntityMirror entityMirror = new EntityMirror(generatorSupport, element.asType(), sqlName(element.getSimpleName().toString()));
 
         for (VariableElement f : fieldsIn(elements.getAllMembers(element))) {
-            entityMirror.add(fromElement(f));
+            entityMirror.add(fromElement(generatorSupport, f));
         }
 
         String p = elements.getPackageOf(element).getQualifiedName().toString();
         String className = element.getSimpleName() + "_Sql";
 
         ClassG g = new ClassG(p, className, null);
-        g.addPublicFinalField(String.class, "insertInto");
-        String insertInto = insertInto(entityMirror);
+        g.addPublicFinalField(String.class, "insertIntoSql");
+        String insertInto = entityMirror.insertIntoSql();
         List<String> body = new ArrayList<>();
-        body.add("this.insertInto = \"" + insertInto + "\";");
+        body.add("this.insertIntoSql = \"" + insertInto + "\";");
         g.addConstructor(new Parameters(), body);
+        entityMirror.insertInto(g);
 
         String fileName = (p.length() == 0 ? "" : p + ".") + className;
         JavaFileObject sourceFile = processingEnv.getFiler().createSourceFile(fileName, element);
@@ -46,25 +93,21 @@ public class EntityHandler extends AbstractHandler {
         }
     }
 
-    public static String insertInto(EntityMirror entityMirror) {
-        List<String> names = new ArrayList<>();
-        List<String> placeholders = new ArrayList<>();
-        for (FieldMirror field : entityMirror.fields) {
-            names.add(field.sqlName);
-            placeholders.add("?");
-        }
-        return "INSERT INTO " + entityMirror.tableName + "(" + collectionToDelimitedString(names, ", ") + ") " +
-                "VALUES(" + collectionToDelimitedString(placeholders, ", ") + ");";
-    }
-
-    public FieldMirror fromElement(VariableElement var) {
-        System.out.println("io.trygvis.container.compiler.entity.EntityMirror.FieldMirror.fromElement");
+    public FieldMirror fromElement(GeneratorSupport generatorSupport, VariableElement var) {
         System.out.print("element = ");
+        TypeMirror type = var.asType();
         elements.printElements(new PrintWriter(System.out), var);
         String javaName = var.getSimpleName().toString();
         String sqlName = sqlName(javaName);
         boolean notNull = false;
-        FieldMirror field = new FieldMirror(javaName, sqlName, notNull);
+        FieldMirror field;
+        if (generatorSupport.isPrimitive(type)) {
+            field = new PrimitiveFieldMirror(var, javaName, sqlName, notNull);
+        } else if (generatorSupport.hasTypeHandler(type)) {
+            field = new FieldMirror.ReferenceFieldMirror(var, javaName, sqlName, notNull);
+        } else {
+            throw new RuntimeException("Missing type handler for type: " + type);
+        }
         System.out.println("field = " + field);
         return field;
     }
@@ -73,7 +116,7 @@ public class EntityHandler extends AbstractHandler {
         StringBuilder builder = new StringBuilder();
         for (char c : javaName.toCharArray()) {
             char lower = Character.toLowerCase(c);
-            if(isUpperCase(c) && builder.length() > 0) {
+            if (isUpperCase(c) && builder.length() > 0) {
                 builder.append("_");
             }
             builder.append(lower);
diff --git a/container-compiler-plugin/src/main/java/io/trygvis/container/compiler/MyProcessor.java b/container-compiler-plugin/src/main/java/io/trygvis/container/compiler/MyProcessor.java
index 6843659..735d688 100644
--- a/container-compiler-plugin/src/main/java/io/trygvis/container/compiler/MyProcessor.java
+++ b/container-compiler-plugin/src/main/java/io/trygvis/container/compiler/MyProcessor.java
@@ -1,6 +1,7 @@
 package io.trygvis.container.compiler;
 
 import io.trygvis.container.log.Log;
+import io.trygvis.persistence.SqlEntity;
 import org.springframework.transaction.annotation.Transactional;
 
 import javax.annotation.processing.Completion;
@@ -31,19 +32,16 @@ public class MyProcessor implements Processor {
 
     @Override
     public Set<String> getSupportedOptions() {
-        System.out.println("io.trygvis.container.compiler.MyProcessor.getSupportedOptions");
         return emptySet();
     }
 
     @Override
     public SourceVersion getSupportedSourceVersion() {
-        System.out.println("io.trygvis.container.compiler.MyProcessor.getSupportedSourceVersion");
         return SourceVersion.RELEASE_7;
     }
 
     @Override
     public void init(ProcessingEnvironment processingEnv) {
-        System.out.println("io.trygvis.container.compiler.MyProcessor.init");
         this.processingEnv = processingEnv;
         elements = processingEnv.getElementUtils();
         types = processingEnv.getTypeUtils();
@@ -51,13 +49,11 @@ public class MyProcessor implements Processor {
 
     @Override
     public Iterable<? extends Completion> getCompletions(Element element, AnnotationMirror annotation, ExecutableElement member, String userText) {
-        System.out.println("io.trygvis.container.compiler.MyProcessor.getCompletions");
         return emptyList();
     }
 
     @Override
     public Set<String> getSupportedAnnotationTypes() {
-        System.out.println("io.trygvis.container.compiler.MyProcessor.getSupportedAnnotationTypes");
         return new HashSet<>(asList(
                 Transactional.class.getName(),
                 Log.class.getName(),
@@ -66,34 +62,39 @@ public class MyProcessor implements Processor {
 
     @Override
     public boolean process(Set<? extends TypeElement> annotations, RoundEnvironment roundEnv) {
-        System.out.println("io.trygvis.container.compiler.MyProcessor.process");
-        System.out.println("annotations = " + annotations);
-//        Set<? extends Element> transactional = roundEnv.getElementsAnnotatedWith(Transactional.class);
+        try {
+            return work(annotations, roundEnv);
+        } catch (RuntimeException e) {
+            throw e;
+        } catch (Exception e) {
+            throw new RuntimeException(e);
+        }
+    }
 
+    public boolean work(Set<? extends TypeElement> annotations, RoundEnvironment roundEnv) throws Exception {
         TypeElement tx = elements.getTypeElement(Transactional.class.getCanonicalName());
         TypeElement log = elements.getTypeElement(Log.class.getCanonicalName());
         TypeElement entity = elements.getTypeElement(Entity.class.getCanonicalName());
 
+        EntityHandler entityHandler = new EntityHandler(processingEnv);
+
+        Set<? extends Element> sqlEntities = roundEnv.getElementsAnnotatedWith(SqlEntity.class);
+        entityHandler.phase1(sqlEntities);
+
         for (Element element : roundEnv.getRootElements()) {
-            try {
-                System.out.println("Processing: " + element);
-                for (AnnotationMirror annotationMirror : element.getAnnotationMirrors()) {
-                    DeclaredType annotationType = annotationMirror.getAnnotationType();
-
-                    if (types.isSameType(tx.asType(), annotationType)) {
-                        new TransactionalHandler(processingEnv).processTransactional((TypeElement) element);
-                    }
-                    if (types.isSameType(log.asType(), annotationType)) {
-                        new LogHandler(processingEnv).processLog((TypeElement) element);
-                    }
-                    if (types.isSameType(entity.asType(), annotationType)) {
-                        new EntityHandler(processingEnv).processEntity((TypeElement) element);
-                    }
+            System.out.println("Processing: " + element);
+            for (AnnotationMirror annotationMirror : element.getAnnotationMirrors()) {
+                DeclaredType annotationType = annotationMirror.getAnnotationType();
+
+                if (types.isSameType(tx.asType(), annotationType)) {
+                    new TransactionalHandler(processingEnv).processTransactional((TypeElement) element);
+                }
+                if (types.isSameType(log.asType(), annotationType)) {
+                    new LogHandler(processingEnv).processLog((TypeElement) element);
+                }
+                if (types.isSameType(entity.asType(), annotationType)) {
+                    entityHandler.processEntity((TypeElement) element);
                 }
-            } catch (RuntimeException e) {
-                throw e;
-            } catch (Exception e) {
-                throw new RuntimeException(e);
             }
         }
         return true;
diff --git a/container-compiler-plugin/src/main/java/io/trygvis/container/compiler/entity/EntityMirror.java b/container-compiler-plugin/src/main/java/io/trygvis/container/compiler/entity/EntityMirror.java
deleted file mode 100644
index ae7077c..0000000
--- a/container-compiler-plugin/src/main/java/io/trygvis/container/compiler/entity/EntityMirror.java
+++ /dev/null
@@ -1,38 +0,0 @@
-package io.trygvis.container.compiler.entity;
-
-import java.util.ArrayList;
-import java.util.List;
-
-public class EntityMirror {
-    public final List<FieldMirror> fields = new ArrayList<>();
-    public final String tableName;
-
-    public EntityMirror(String tableName) {
-        this.tableName = tableName;
-    }
-
-    public void add(FieldMirror field) {
-        fields.add(field);
-    }
-
-    public static class FieldMirror {
-        private final String javaName;
-        public final String sqlName;
-        private final boolean notNull;
-
-        public FieldMirror(String javaName, String sqlName, boolean notNull) {
-            this.javaName = javaName;
-            this.sqlName = sqlName;
-            this.notNull = notNull;
-        }
-
-        @Override
-        public String toString() {
-            return "FieldMirror{" +
-                    "javaName='" + javaName + '\'' +
-                    ", sqlName='" + sqlName + '\'' +
-                    ", notNull=" + notNull +
-                    '}';
-        }
-    }
-}
diff --git a/container-compiler-plugin/src/main/java/io/trygvis/container/compiler/model/ClassG.java b/container-compiler-plugin/src/main/java/io/trygvis/container/compiler/model/ClassG.java
index cf68cba..8ff91a0 100644
--- a/container-compiler-plugin/src/main/java/io/trygvis/container/compiler/model/ClassG.java
+++ b/container-compiler-plugin/src/main/java/io/trygvis/container/compiler/model/ClassG.java
@@ -31,7 +31,6 @@ public class ClassG {
         }
 
         String canonicalName = type.toString();
-        System.out.println("canonicalName = " + canonicalName);
 
         for (TypeRef i : imports) {
             if (i.canonicalName().equals(canonicalName)) {
@@ -45,10 +44,6 @@ public class ClassG {
     }
 
     public TypeRef addImport(Class<?> klass) {
-//        if (klass.isPrimitive()) {
-//            return TypeRef.PRIMITIVE;
-//        }
-
         String canonicalName = klass.getCanonicalName();
         String simpleName = klass.getSimpleName();
         String name = simpleName;
@@ -104,6 +99,9 @@ public class ClassG {
             if (i.isPrimitive()) {
                 continue;
             }
+            if(i.canonicalName().indexOf('.') == -1) {
+                continue;
+            }
             writer.println("import " + i.canonicalName() + ";");
         }
         writer.println();
@@ -144,7 +142,24 @@ public class ClassG {
             parameters.add("final " + p.klass.name + " " + p.name);
         }
 
-        writer.println("    public " + returnString + " " + method.name + "(" + collectionToDelimitedString(parameters, ", ") + ") {");
+        writer.print("    public " + returnString + " " + method.name + "(" + collectionToDelimitedString(parameters, ", ") + ")");
+        if(method.exceptions.isEmpty()) {
+            writer.println(" {");
+        }
+        else {
+            writer.println(" throws");
+            ArrayList<TypeRef> typeRefs = new ArrayList<>(method.exceptions);
+            for (int i = 0; i < typeRefs.size(); i++) {
+                TypeRef e = typeRefs.get(i);
+                writer.print("        " + e.name);
+                if(i < typeRefs.size() - 1) {
+                    writer.println(",");
+                }
+                else {
+                    writer.println(" {");
+                }
+            }
+        }
         for (String s : method.body) {
             writer.print("        ");
             writer.println(s);
diff --git a/container-compiler-plugin/src/main/java/io/trygvis/container/compiler/model/MethodRef.java b/container-compiler-plugin/src/main/java/io/trygvis/container/compiler/model/MethodRef.java
index 36f61e8..a59e9a6 100644
--- a/container-compiler-plugin/src/main/java/io/trygvis/container/compiler/model/MethodRef.java
+++ b/container-compiler-plugin/src/main/java/io/trygvis/container/compiler/model/MethodRef.java
@@ -1,18 +1,27 @@
 package io.trygvis.container.compiler.model;
 
 import java.util.List;
+import java.util.Set;
+import java.util.TreeSet;
+
+import static java.util.Collections.addAll;
 
 public class MethodRef {
     public final TypeRef returnType;
     public final String name;
     public final ParameterRef[] parameters;
+    public final Set<TypeRef> exceptions = new TreeSet<>();
     public final List<String> body;
 
-    public
-    MethodRef(TypeRef returnType, String name, ParameterRef[] parameters, List<String> body) {
+    public MethodRef(TypeRef returnType, String name, ParameterRef[] parameters, List<String> body) {
         this.returnType = returnType;
         this.name = name;
         this.parameters = parameters;
         this.body = body;
     }
+
+    public MethodRef exception(TypeRef... exceptions) {
+        addAll(this.exceptions, exceptions);
+        return this;
+    }
 }
diff --git a/container-compiler-plugin/src/main/java/io/trygvis/persistence/EntityMirror.java b/container-compiler-plugin/src/main/java/io/trygvis/persistence/EntityMirror.java
new file mode 100644
index 0000000..fe50e17
--- /dev/null
+++ b/container-compiler-plugin/src/main/java/io/trygvis/persistence/EntityMirror.java
@@ -0,0 +1,65 @@
+package io.trygvis.persistence;
+
+import io.trygvis.container.compiler.model.ClassG;
+import io.trygvis.container.compiler.model.ParameterRef;
+import io.trygvis.container.compiler.model.TypeRef;
+
+import javax.lang.model.type.TypeMirror;
+import java.sql.Connection;
+import java.sql.PreparedStatement;
+import java.sql.SQLException;
+import java.util.ArrayList;
+import java.util.List;
+
+import static org.apache.commons.lang.StringUtils.join;
+
+public class EntityMirror {
+    public final GeneratorSupport generatorSupport;
+    public final List<FieldMirror> fields = new ArrayList<>();
+    public final TypeMirror javaName;
+    public final String tableName;
+
+    public EntityMirror(GeneratorSupport generatorSupport, TypeMirror javaName, String tableName) {
+        this.generatorSupport = generatorSupport;
+        this.javaName = javaName;
+        this.tableName = tableName;
+    }
+
+    public void add(FieldMirror field) {
+        fields.add(field);
+    }
+
+    public String insertIntoSql() {
+        List<String> names = new ArrayList<>();
+        List<String> placeholders = new ArrayList<>();
+        for (FieldMirror field : fields) {
+            names.add(field.sqlName);
+            placeholders.add("?");
+        }
+
+        return "INSERT INTO " + tableName + "(" + join(names, ", ") + ") " +
+                "VALUES(" + join(placeholders, ", ") + ");";
+    }
+
+    public void insertInto(ClassG g) {
+        TypeRef conType = g.addImport(Connection.class);
+        TypeRef psType = g.addImport(PreparedStatement.class);
+        TypeRef objectType = g.addImport(javaName);
+        ParameterRef con = new ParameterRef(conType, "con");
+        ParameterRef object = new ParameterRef(objectType, "o");
+
+        List<String> body = new ArrayList<>();
+
+        body.add("try(" + psType.name + " stmt = " + con.name + ".prepareStatement(insertIntoSql)) {");
+        for (int i = 0; i < fields.size(); i++) {
+            FieldMirror field = fields.get(i);
+            TypeHandler typeHandler = generatorSupport.typeHandler(field.element);
+            body.add("    stmt." + typeHandler.resultSetSetter(i + 1, "o", field) + ";");
+        }
+        body.add("    stmt.executeUpdate();");
+        body.add("}");
+
+        g.addMethod(body, TypeRef.VOID, "insertInto", con, object).
+                exception(g.addImport(SQLException.class));
+    }
+}
diff --git a/container-compiler-plugin/src/main/java/io/trygvis/persistence/FieldMirror.java b/container-compiler-plugin/src/main/java/io/trygvis/persistence/FieldMirror.java
new file mode 100644
index 0000000..e14fb9f
--- /dev/null
+++ b/container-compiler-plugin/src/main/java/io/trygvis/persistence/FieldMirror.java
@@ -0,0 +1,63 @@
+package io.trygvis.persistence;
+
+import javax.lang.model.element.VariableElement;
+
+import static io.trygvis.persistence.FieldMirror.FieldType.PRIMITIVE;
+import static io.trygvis.persistence.FieldMirror.FieldType.REFERENCE;
+
+/**
+ * TODO: a single field might have to be mapped to multiple sql columns.
+ */
+public abstract class FieldMirror {
+    public final FieldType fieldType;
+    public final VariableElement element;
+    public final String javaName;
+    public final String sqlName;
+    public final boolean notNull;
+
+    public enum FieldType {
+        PRIMITIVE,
+        REFERENCE,
+    }
+
+    protected FieldMirror(FieldType fieldType, VariableElement element, String javaName, String sqlName, boolean notNull) {
+        this.fieldType = fieldType;
+        this.element = element;
+        this.javaName = javaName;
+        this.sqlName = sqlName;
+        this.notNull = notNull;
+    }
+
+    public static class PrimitiveFieldMirror extends FieldMirror {
+        public PrimitiveFieldMirror(VariableElement element, String javaName, String sqlName, boolean notNull) {
+            super(PRIMITIVE, element, javaName, sqlName, notNull);
+        }
+
+        @Override
+        public String toString() {
+            return "PrimitiveFieldMirror{" +
+                    "javaName='" + javaName + '\'' +
+                    ", sqlName='" + sqlName + '\'' +
+                    ", notNull=" + notNull +
+                    '}';
+        }
+    }
+
+    public static class  ReferenceFieldMirror extends FieldMirror {
+        public ReferenceFieldMirror(VariableElement element, String javaName, String sqlName, boolean notNull) {
+            super(REFERENCE, element, javaName, sqlName, notNull);
+        }
+
+        @Override
+        public String toString() {
+            return "ReferenceFieldMirror{" +
+                    "javaName='" + javaName + '\'' +
+                    ", sqlName='" + sqlName + '\'' +
+                    ", notNull=" + notNull +
+                    '}';
+        }
+    }
+
+    @Override
+    public abstract String toString();
+}
diff --git a/container-compiler-plugin/src/main/java/io/trygvis/persistence/GeneratorSupport.java b/container-compiler-plugin/src/main/java/io/trygvis/persistence/GeneratorSupport.java
new file mode 100644
index 0000000..7ac30d9
--- /dev/null
+++ b/container-compiler-plugin/src/main/java/io/trygvis/persistence/GeneratorSupport.java
@@ -0,0 +1,41 @@
+package io.trygvis.persistence;
+
+import javax.lang.model.element.Element;
+import javax.lang.model.element.VariableElement;
+import javax.lang.model.type.TypeMirror;
+import java.util.HashMap;
+import java.util.Map;
+
+public class GeneratorSupport {
+
+    private final Map<String, TypeHandler> primitiveTypeHandlers = new HashMap<>();
+    private final Map<String, TypeHandler> typeHandlers = new HashMap<>();
+
+    {
+        typeHandlers.put("java.lang.Integer", new TypeHandler.IntTypeHandler());
+        typeHandlers.put("java.lang.Long", new TypeHandler.LongTypeHandler());
+        typeHandlers.put("java.util.Date", new TypeHandler.DateTypeHandler());
+
+        primitiveTypeHandlers.putAll(typeHandlers);
+    }
+
+    public void addTypeHandler(String type, TypeHandler typeHandler) {
+        typeHandlers.put(type, typeHandler);
+    }
+
+    public TypeHandler typeHandler(Element element) {
+        String type = element.asType().toString();
+        TypeHandler typeHandler = typeHandlers.get(type);
+        if (typeHandler == null)
+            throw new RuntimeException("Unsupported field type: " + type);
+        return typeHandler;
+    }
+
+    public boolean isPrimitive(TypeMirror type) {
+        return primitiveTypeHandlers.containsKey(type.toString());
+    }
+
+    public boolean hasTypeHandler(TypeMirror type) {
+        return typeHandlers.containsKey(type.toString());
+    }
+}
diff --git a/container-compiler-plugin/src/main/java/io/trygvis/persistence/SqlEntity.java b/container-compiler-plugin/src/main/java/io/trygvis/persistence/SqlEntity.java
new file mode 100644
index 0000000..e298eee
--- /dev/null
+++ b/container-compiler-plugin/src/main/java/io/trygvis/persistence/SqlEntity.java
@@ -0,0 +1,17 @@
+package io.trygvis.persistence;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Retention(RetentionPolicy.CLASS)
+@Target(ElementType.TYPE)
+public @interface SqlEntity {
+    /**
+     * The name of a class that implements {@link io.trygvis.persistence.TypeHandler}.
+     *
+     * The class needs to be available at compile time, but not runtime.
+     */
+    String value();
+}
diff --git a/container-compiler-plugin/src/main/java/io/trygvis/persistence/TypeHandler.java b/container-compiler-plugin/src/main/java/io/trygvis/persistence/TypeHandler.java
new file mode 100644
index 0000000..252f4b4
--- /dev/null
+++ b/container-compiler-plugin/src/main/java/io/trygvis/persistence/TypeHandler.java
@@ -0,0 +1,26 @@
+package io.trygvis.persistence;
+
+public interface TypeHandler {
+    String resultSetSetter(int i, String o, FieldMirror field);
+
+    public static class IntTypeHandler implements TypeHandler {
+        @Override
+        public String resultSetSetter(int i, String o, FieldMirror field) {
+            return "setInt(" + i + ", " + o + "." + field.javaName + ")";
+        }
+    }
+
+    public static class LongTypeHandler implements TypeHandler {
+        @Override
+        public String resultSetSetter(int i, String o, FieldMirror field) {
+            return "setLong(" + i + ", " + o + "." + field.javaName + ")";
+        }
+    }
+
+    public static class DateTypeHandler implements TypeHandler {
+        @Override
+        public String resultSetSetter(int i, String o, FieldMirror field) {
+            return "setTimestamp(" + i + ", new java.sql.Timestamp(" + o + "." + field.javaName + ".getTime()))";
+        }
+    }
+}