From 8542d5beb22e6aff8ac8b2d49088a11b972b8a43 Mon Sep 17 00:00:00 2001
From: Gray Watson <gray.github@mailnull.com>
Date: Thu, 14 Jul 2016 21:46:24 -0400
Subject: [PATCH] Added test

---
 .../ormlite/field/CustomFieldNullTest.java    | 128 ++++++++++++++++++
 1 file changed, 128 insertions(+)
 create mode 100644 src/test/java/com/j256/ormlite/field/CustomFieldNullTest.java

diff --git a/src/test/java/com/j256/ormlite/field/CustomFieldNullTest.java b/src/test/java/com/j256/ormlite/field/CustomFieldNullTest.java
new file mode 100644
index 000000000..15fedf091
--- /dev/null
+++ b/src/test/java/com/j256/ormlite/field/CustomFieldNullTest.java
@@ -0,0 +1,128 @@
+package com.j256.ormlite.field;
+
+import java.sql.SQLException;
+import java.util.List;
+
+import org.junit.Test;
+
+import com.j256.ormlite.BaseCoreTest;
+import com.j256.ormlite.dao.Dao;
+import com.j256.ormlite.dao.DaoManager;
+import com.j256.ormlite.field.types.StringType;
+import com.j256.ormlite.support.DatabaseResults;
+import com.j256.ormlite.table.DatabaseTable;
+import com.j256.ormlite.table.TableUtils;
+
+/**
+ * Interesting test that checks for handling of null results in a customer persister. Thanks to Harshit Mittal.
+ * 
+ * See http://stackoverflow.com/questions/38371741/handle-null-case-inside-sqlargtojava-of-custom-persister-class
+ */
+public class CustomFieldNullTest extends BaseCoreTest {
+
+	@Test
+	public void testCustomNullHandler() throws SQLException {
+
+		TableUtils.createTableIfNotExists(connectionSource, Foo.class);
+		Dao<Foo, Long> dao = DaoManager.createDao(connectionSource, Foo.class);
+		Foo foo = new Foo();
+		dao.create(foo);
+
+		List<Foo> results = dao.queryForAll();
+		for (Foo result : results) {
+			System.out.println("Result value = '" + result.getValue() + "', length = " + result.getValue().length());
+		}
+
+		dao.executeRaw("INSERT INTO a (id, value) VALUES (NULL, NULL)");
+
+		results = dao.queryForAll();
+		for (Foo result : results) {
+			System.out.println("Result value = '" + result.getValue() + "', length = " + result.getValue().length());
+		}
+
+	}
+
+	@DatabaseTable(tableName = "a")
+	private static class Foo {
+
+		@DatabaseField(generatedId = true, columnName = "id")
+		private long id;
+
+		@DatabaseField(columnName = "value", persisterClass = StringPropertyPersister.class)
+		private final StringProperty value;
+
+		protected Foo() {
+			value = new SimpleStringProperty();
+		}
+
+		public String getValue() {
+			return value.getValue();
+		}
+	}
+
+	private static class StringPropertyPersister extends StringType {
+
+		private static final StringPropertyPersister INSTANCE = new StringPropertyPersister();
+
+		private StringPropertyPersister() {
+			super(SqlType.STRING, new Class<?>[] { StringProperty.class });
+		}
+
+		public static StringPropertyPersister getSingleton() {
+			return INSTANCE;
+		}
+
+		@Override
+		public Object javaToSqlArg(FieldType fieldType, Object javaObject) {
+			if (javaObject == null) {
+				return "";
+			} else {
+				StringProperty property = (StringProperty) javaObject;
+				return property.getValue();
+			}
+		}
+
+		@Override
+		public Object resultToJava(FieldType fieldType, DatabaseResults results, int columnPos) throws SQLException {
+			// we override this here because the base class does the null comparison
+			Object value = resultToSqlArg(fieldType, results, columnPos);
+			return sqlArgToJava(fieldType, value, columnPos);
+		}
+
+		@Override
+		public boolean isStreamType() {
+			// this forces the null check to be ignored
+			return true;
+		}
+
+		@Override
+		public Object sqlArgToJava(FieldType fieldType, Object sqlArg, int columnPos) {
+			if (sqlArg == null) {
+				return new SimpleStringProperty("");
+			} else {
+				return new SimpleStringProperty((String) sqlArg);
+			}
+		}
+	}
+
+	private static interface StringProperty {
+		public String getValue();
+	}
+
+	private static class SimpleStringProperty implements StringProperty {
+		String value;
+
+		public SimpleStringProperty() {
+			this.value = null;
+		}
+
+		public SimpleStringProperty(String value) {
+			this.value = value;
+		}
+
+		@Override
+		public String getValue() {
+			return value;
+		}
+	}
+}