Address issue #10:

* Give more meaningful exceptions from Entity#load()
* Remove default type mapping (it doesn't work with the new load API)
* Add mapping for java.util.Date.

Thanks to rothschild86 for this bug report.

src/com/roscopeco/ormdroid/DateTypeMapping.java

@@ -0,0 +1,53 @@
+/*
+ * Copyright 2012 Ross Bamford
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License. 
+ */
+package com.roscopeco.ormdroid;
+
+import java.util.Date;
+
+import android.database.Cursor;
+import android.database.sqlite.SQLiteDatabase;
+
+/*
+ * Map java.util.Date to the database.
+ * 
+ * This implementation just stashes the number of seconds
+ * since the epoch in a BIGINT.
+ */
+public class DateTypeMapping implements TypeMapping {
+  private Class<?> mJavaType; 
+  private String mSqlType;
+
+  public DateTypeMapping() {
+    mJavaType = Date.class;
+    mSqlType = "BIGINT";      
+  }
+
+  public Class<?> javaType() {
+    return mJavaType;
+  }
+
+  public String sqlType(Class<?> concreteType) {
+    return mSqlType;
+  }
+
+  public String encodeValue(SQLiteDatabase db, Object value) {
+    return "\"" + ((Date)value).getTime() + "\"";
+  }
+
+  public Object decodeValue(SQLiteDatabase db, Class<?> expectedType, Cursor c, int columnIndex) {
+    return new Date(c.getInt(columnIndex));
+  }
+}

src/com/roscopeco/ormdroid/Entity.java

@@ -174,7 +174,6 @@ static final class EntityMapping {
     static EntityMapping build(Class<? extends Entity> clz) {
       EntityMapping mapping = new EntityMapping();
       mapping.mMappedClass = clz;
-
       Table table = clz.getAnnotation(Table.class);
       if (table != null) {
         mapping.mTableName = table.name();
@@ -207,6 +206,15 @@ static EntityMapping build(Class<? extends Entity> clz) {
             (!Modifier.isPrivate(modifiers) || force) &&
             !seenFields.contains(f.getName()) && 
             !inverse) {
+
+          // Check we can map this type - if not, let's fail fast.
+          // This will save us wierd exceptions somewhere down the line...
+          if (TypeMapper.getMapping(f.getType()) == null) {
+            throw new TypeMappingException("Model " + 
+                                           clz.getName() + 
+                                           " has unmappable field: " + f);
+          }
+
           Column col = f.getAnnotation(Column.class);
           String name;
 
@@ -466,12 +474,15 @@ <T extends Entity> T load(SQLiteDatabase db, Cursor c) {
         }
 
         return model;
-      } catch (Exception e) {
+      } catch (InstantiationException e) {
         throw new ORMDroidException(
             "Failed to instantiate model class - does it have a public null constructor?",
             e);
+      } catch (IllegalAccessException e) {
+        throw new ORMDroidException(
+            "Access denied. Is your model's constructor non-public?",
+            e);
       }
-
     }
 
     /*

src/com/roscopeco/ormdroid/TypeMapper.java

@@ -22,8 +22,9 @@
  * 
  * <p>By default, ORMDroid provides a mapping for all primitive types
  * and Entity classes. All other types are mapped by the <em>default 
- * mapping</em>, which simply stores their <code>toString</code> results
- * in a <code>VARCHAR</code> column.</p>
+ * mapping</em> (if configured with {@link #setDefaultMapping(TypeMapping)}). 
+ * By default, there is no default mapping - attempting to use a model class
+ * with a field of an unmapped type will throw an exception.</p>
  * 
  * <p>Custom types may be mapped by registering an instance of 
  * {@link TypeMapping} via the {@link #mapType(TypeMapping) mapType} method.
@@ -41,7 +42,7 @@
  */
 public final class TypeMapper {
   private static final MappingList TYPEMAPS = new MappingList();
-  private static TypeMapping mDefaultMapping = new StringTypeMapping(Object.class, "VARCHAR");
+  private static TypeMapping mDefaultMapping = null;
 
   public static String sqlType(Class<?> type) {
     return getMapping(type).sqlType(type);
@@ -51,19 +52,14 @@ public static String sqlType(Class<?> type) {
    * Obtain the configured mapping the the specified Java type.
    * 
    * @param type the Java type. 
-   * @return the configured mapping.
+   * @return the configured mapping, or <code>null</code> if none.
    */
   public static TypeMapping getMapping(Class<?> type) {
     TypeMapping r = TYPEMAPS.findMapping(type);
     if (r != null) {
       return r;
     } else {
-      TypeMapping def = mDefaultMapping;
-      if (def != null) {
-        return def;
-      } else {
-        throw new TypeMappingException("No mapping found for type `" + type + "'");
-      }
+      return mDefaultMapping;
     }
   }
 
@@ -115,6 +111,7 @@ public static void setDefaultMapping(TypeMapping mapping) {
     mapType(new NumericTypeMapping(boolean.class, "TINYINT"));
     mapType(new NumericTypeMapping(Long.class, "BIGINT"));
     mapType(new NumericTypeMapping(long.class, "BIGINT"));
+    mapType(new DateTypeMapping());
     mapType(new EntityTypeMapping());
     mapType(new NumericTypeMapping(Integer.class, "INTEGER"));
     mapType(new NumericTypeMapping(int.class, "INTEGER"));