Fix exception thrown when constructor cannot be found if the constructor is not needed, add some more tests

beehive-jdbc-mapper/src/main/java/com/moparisthebest/jdbc/RowToObjectMapper.java

@@ -67,7 +67,7 @@ public class RowToObjectMapper<T> extends RowMapper {
 	protected final Object[] _args = new Object[1];
 
 	public RowToObjectMapper(ResultSet resultSet, Class<T> returnTypeClass) {
-		this(resultSet, returnTypeClass, null, null);	
+		this(resultSet, returnTypeClass, null, null);
 	}
 
 	public RowToObjectMapper(ResultSet resultSet, Class<T> returnTypeClass, Class<?> mapValType) {
@@ -99,6 +99,12 @@ public class RowToObjectMapper<T> extends RowMapper {
 
 		_fields = null;
 
+		try {
+			_columnCount = resultSet.getMetaData().getColumnCount();
+		} catch (SQLException e) {
+			throw new MapperException("RowToObjectMapper: SQLException: " + e.getMessage(), e);
+		}
+
 		// detect if returnTypeClass has a constructor that takes a ResultSet, if so, our job couldn't be easier...
 		boolean resultSetConstructor = false;
 		Constructor<T> constructor = null;
@@ -114,17 +120,12 @@ public class RowToObjectMapper<T> extends RowMapper {
 				if (!constructor.isAccessible())
 					constructor.setAccessible(true);
 			} catch (Throwable e1) {
-				throw new MapperException("Exception when trying to get constructor for : "+returnTypeClass.getName() + " Must have default no-arg constructor or one that takes a single ResultSet.", e1);
+				if(_columnCount != 1) // if column count is only 1, it might map directly to a type like a Long or something
+					throw new MapperException("Exception when trying to get constructor for : "+returnTypeClass.getName() + " Must have default no-arg constructor or one that takes a single ResultSet.", e1);
 			}
 		}
 		this.resultSetConstructor = resultSetConstructor;
 		this.constructor = constructor;
-
-		try {
-			_columnCount = resultSet.getMetaData().getColumnCount();
-		} catch (SQLException e) {
-			throw new MapperException("RowToObjectMapper: SQLException: " + e.getMessage(), e);
-		}
 	}
 
 	/**
@@ -218,6 +219,8 @@ public class RowToObjectMapper<T> extends RowMapper {
 		try {
 			resultObject = constructor.newInstance();
 		} catch (Throwable e) {
+			if(constructor == null) // then this is a different error
+				throw new MapperException("Exception when trying to get constructor for : "+_returnTypeClass.getName() + " Must have default no-arg constructor or one that takes a single ResultSet.", e);
 			throw new MapperException(e.getClass().getName() + " when trying to create instance of : "
 					+ _returnTypeClass.getName(), e);
 		}

beehive-jdbc-mapper/src/test/java/com/moparisthebest/jdbc/QueryMapperTest.java

@@ -6,9 +6,10 @@ import org.junit.Assert;
 import org.junit.BeforeClass;
 import org.junit.Test;
 
+import java.lang.reflect.Constructor;
 import java.sql.Connection;
 import java.sql.DriverManager;
-import java.util.Date;
+import java.util.*;
 
 import static com.moparisthebest.jdbc.TryClose.tryClose;
 
@@ -187,6 +188,34 @@ public class QueryMapperTest {
 		testPerson(reverseSetBoss2, bossUnderscore);
 	}
 
+	@Test
+	public void testSelectLong() throws Throwable {
+		Assert.assertEquals(new Long(1L), qm.toObject("SELECT person_no FROM person WHERE person_no = ?", Long.class, 1L));
+	}
+
+	@Test
+	public void testSelectListMap() throws Throwable {
+		final List<Map<String, String>> arrayMap = getListMap();
+		Assert.assertEquals(arrayMap, qm.toListMap("SELECT first_name, last_name FROM person WHERE person_no < 4", arrayMap.get(0).getClass(), String.class));
+	}
+
+	@Test
+	public void testSelectArrayMap() throws Throwable {
+		final List<Map<String, String>> arrayMap = getListMap();
+		Assert.assertEquals(arrayMap.toArray(new Map[arrayMap.size()]), qm.toArrayMap("SELECT first_name, last_name FROM person WHERE person_no < 4", arrayMap.get(0).getClass(), String.class));
+	}
+
+	private List<Map<String, String>> getListMap() {
+		final List<Map<String, String>> arrayMap = new ArrayList<Map<String, String>>();
+		for (final Person person : new Person[]{fieldPerson1, fieldBoss1, fieldBoss2}) {
+			final Map<String, String> map = new HashMap<String, String>();
+			map.put("last_name", person.getLastName());
+			map.put("first_name", person.getFirstName());
+			arrayMap.add(map);
+		}
+		return arrayMap;
+	}
+
 	private static void testPerson(final Person expected, final String query) throws Throwable {
 		final Person actual = qm.toObject(query, expected.getClass(), expected.getPersonNo());
 		//System.out.println("expected: " + expected);