CursorSimpleTest.java

/**
 *    Copyright 2009-2016 the original author or authors.
 *
 *    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 org.apache.ibatis.submitted.cursor_simple;

import org.apache.ibatis.cursor.Cursor;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.jdbc.ScriptRunner;
import org.apache.ibatis.session.RowBounds;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.Assert;
import org.junit.BeforeClass;
import org.junit.Test;

import java.io.IOException;
import java.io.Reader;
import java.sql.Connection;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.NoSuchElementException;

public class CursorSimpleTest {

    private static SqlSessionFactory sqlSessionFactory;

    @BeforeClass
    public static void setUp() throws Exception {
        // create a SqlSessionFactory
        Reader reader = Resources.getResourceAsReader("org/apache/ibatis/submitted/cursor_simple/mybatis-config.xml");
        sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
        reader.close();

        // populate in-memory database
        SqlSession session = sqlSessionFactory.openSession();
        Connection conn = session.getConnection();
        reader = Resources.getResourceAsReader("org/apache/ibatis/submitted/cursor_simple/CreateDB.sql");
        ScriptRunner runner = new ScriptRunner(conn);
        runner.setLogWriter(null);
        runner.runScript(reader);
        reader.close();
        session.close();
    }

    @Test
    public void shouldGetAllUser() {
        SqlSession sqlSession = sqlSessionFactory.openSession();
        Mapper mapper = sqlSession.getMapper(Mapper.class);
        Cursor<User> usersCursor = mapper.getAllUsers();
        try {
            Assert.assertFalse(usersCursor.isOpen());

            // Cursor is just created, current index is -1
            Assert.assertEquals(-1, usersCursor.getCurrentIndex());

            Iterator<User> iterator = usersCursor.iterator();

            // Check if hasNext, fetching is started
            Assert.assertTrue(iterator.hasNext());
            Assert.assertTrue(usersCursor.isOpen());
            Assert.assertFalse(usersCursor.isConsumed());

            // next() has not been called, index is still -1
            Assert.assertEquals(-1, usersCursor.getCurrentIndex());

            User user = iterator.next();
            Assert.assertEquals("User1", user.getName());
            Assert.assertEquals(0, usersCursor.getCurrentIndex());

            user = iterator.next();
            Assert.assertEquals("User2", user.getName());
            Assert.assertEquals(1, usersCursor.getCurrentIndex());

            user = iterator.next();
            Assert.assertEquals("User3", user.getName());
            Assert.assertEquals(2, usersCursor.getCurrentIndex());

            user = iterator.next();
            Assert.assertEquals("User4", user.getName());
            Assert.assertEquals(3, usersCursor.getCurrentIndex());

            user = iterator.next();
            Assert.assertEquals("User5", user.getName());
            Assert.assertEquals(4, usersCursor.getCurrentIndex());

            // Check no more elements
            Assert.assertFalse(iterator.hasNext());
            Assert.assertFalse(usersCursor.isOpen());
            Assert.assertTrue(usersCursor.isConsumed());
        } finally {
            sqlSession.close();
        }
    }

    @Test
    public void testCursorClosedOnSessionClose() {
        SqlSession sqlSession = sqlSessionFactory.openSession();
        Mapper mapper = sqlSession.getMapper(Mapper.class);
        Cursor<User> usersCursor = mapper.getAllUsers();
        try {
            Assert.assertFalse(usersCursor.isOpen());

            Iterator<User> iterator = usersCursor.iterator();

            // Check if hasNext, fetching is started
            Assert.assertTrue(iterator.hasNext());
            Assert.assertTrue(usersCursor.isOpen());
            Assert.assertFalse(usersCursor.isConsumed());

            // Consume only the first result
            User user = iterator.next();
            Assert.assertEquals("User1", user.getName());

            // Check there is still remaining elements
            Assert.assertTrue(iterator.hasNext());
            Assert.assertTrue(usersCursor.isOpen());
            Assert.assertFalse(usersCursor.isConsumed());
        } finally {
            sqlSession.close();
        }

        // The cursor was not fully consumed, but it should be close since we closed the session
        Assert.assertFalse(usersCursor.isOpen());
        Assert.assertFalse(usersCursor.isConsumed());
    }

    @Test
    public void testCursorWithRowBound() {
        SqlSession sqlSession = sqlSessionFactory.openSession();

        try {
            // RowBound starting at offset 1 and limiting to 2 items
            Cursor<User> usersCursor = sqlSession.selectCursor("getAllUsers", null, new RowBounds(1, 3));

            Iterator<User> iterator = usersCursor.iterator();

            User user = iterator.next();
            Assert.assertEquals("User2", user.getName());
            Assert.assertEquals(1, usersCursor.getCurrentIndex());

            // Calling hasNext() before next()
            Assert.assertTrue(iterator.hasNext());
            user = iterator.next();
            Assert.assertEquals("User3", user.getName());
            Assert.assertEquals(2, usersCursor.getCurrentIndex());

            // Calling next() without a previous hasNext() call
            user = iterator.next();
            Assert.assertEquals("User4", user.getName());
            Assert.assertEquals(3, usersCursor.getCurrentIndex());

            Assert.assertFalse(iterator.hasNext());
            Assert.assertFalse(usersCursor.isOpen());
            Assert.assertTrue(usersCursor.isConsumed());
        } finally {
            sqlSession.close();
        }
    }

    @Test
    public void testCursorIteratorNoSuchElementExceptionWithHasNext() {
        SqlSession sqlSession = sqlSessionFactory.openSession();

        Cursor<User> usersCursor = sqlSession.selectCursor("getAllUsers", null, new RowBounds(1, 1));
        try {
            Iterator<User> iterator = usersCursor.iterator();

            User user = iterator.next();
            Assert.assertEquals("User2", user.getName());
            Assert.assertEquals(1, usersCursor.getCurrentIndex());

            Assert.assertFalse(iterator.hasNext());
            iterator.next();
            Assert.fail("We should have failed since we call next() when hasNext() returned false");
        } catch (NoSuchElementException e) {
            Assert.assertFalse(usersCursor.isOpen());
            Assert.assertTrue(usersCursor.isConsumed());
        } finally {
            sqlSession.close();
        }
    }

    @Test
    public void testCursorIteratorNoSuchElementExceptionNoHasNext() {
        SqlSession sqlSession = sqlSessionFactory.openSession();

        Cursor<User> usersCursor = sqlSession.selectCursor("getAllUsers", null, new RowBounds(1, 1));
        try {
            Iterator<User> iterator = usersCursor.iterator();

            User user = iterator.next();
            Assert.assertEquals("User2", user.getName());
            Assert.assertEquals(1, usersCursor.getCurrentIndex());

            // Trying next() without hasNext()
            iterator.next();
            Assert.fail("We should have failed since we call next() when is no more items");
        } catch (NoSuchElementException e) {
            Assert.assertFalse(usersCursor.isOpen());
            Assert.assertTrue(usersCursor.isConsumed());
        } finally {
            sqlSession.close();
        }
    }


    @Test
    public void testCursorWithBadRowBound() {
        SqlSession sqlSession = sqlSessionFactory.openSession();

        try {
            // Trying to start at offset 10 (which does not exist, since there is only 4 items)
            Cursor<User> usersCursor = sqlSession.selectCursor("getAllUsers", null, new RowBounds(10, 2));
            Iterator<User> iterator = usersCursor.iterator();

            Assert.assertFalse(iterator.hasNext());
            Assert.assertFalse(usersCursor.isOpen());
            Assert.assertTrue(usersCursor.isConsumed());
        } finally {
            sqlSession.close();
        }
    }

    @Test
    public void testCursorMultipleHasNextCall() {
        SqlSession sqlSession = sqlSessionFactory.openSession();
        Mapper mapper = sqlSession.getMapper(Mapper.class);
        Cursor<User> usersCursor = mapper.getAllUsers();

        try {
            Iterator<User> iterator = usersCursor.iterator();

            Assert.assertEquals(-1, usersCursor.getCurrentIndex());

            User user = iterator.next();
            Assert.assertEquals("User1", user.getName());
            Assert.assertEquals(0, usersCursor.getCurrentIndex());

            Assert.assertTrue(iterator.hasNext());
            Assert.assertTrue(iterator.hasNext());
            Assert.assertTrue(iterator.hasNext());
            // assert that index has not changed after hasNext() call
            Assert.assertEquals(0, usersCursor.getCurrentIndex());
        } finally {
            sqlSession.close();
        }
    }

    @Test
    public void testCursorMultipleIteratorCall() {
        SqlSession sqlSession = sqlSessionFactory.openSession();
        Mapper mapper = sqlSession.getMapper(Mapper.class);
        Cursor<User> usersCursor = mapper.getAllUsers();

        Iterator<User> iterator2 = null;
        try {
            Iterator<User> iterator = usersCursor.iterator();
            User user = iterator.next();
            Assert.assertEquals("User1", user.getName());
            Assert.assertEquals(0, usersCursor.getCurrentIndex());

            iterator2 = usersCursor.iterator();
            iterator2.hasNext();
            Assert.fail("We should have failed since calling iterator several times is not allowed");
        } catch (IllegalStateException e) {
            Assert.assertNull("iterator2 should be null", iterator2);
            return;
        } finally {
            sqlSession.close();
        }
        Assert.fail("Should have returned earlier");
    }

    @Test
    public void testCursorMultipleCloseCall() throws IOException {
        SqlSession sqlSession = sqlSessionFactory.openSession();
        Mapper mapper = sqlSession.getMapper(Mapper.class);
        Cursor<User> usersCursor = mapper.getAllUsers();
        try {
            Assert.assertFalse(usersCursor.isOpen());

            Iterator<User> iterator = usersCursor.iterator();

            // Check if hasNext, fetching is started
            Assert.assertTrue(iterator.hasNext());
            Assert.assertTrue(usersCursor.isOpen());
            Assert.assertFalse(usersCursor.isConsumed());

            // Consume only the first result
            User user = iterator.next();
            Assert.assertEquals("User1", user.getName());

            usersCursor.close();
            // Check multiple close are no-op
            usersCursor.close();

            // hasNext now return false, since the cursor is closed
            Assert.assertFalse(iterator.hasNext());
            Assert.assertFalse(usersCursor.isOpen());
            Assert.assertFalse(usersCursor.isConsumed());
        } finally {
            sqlSession.close();
        }
    }

    @Test
    public void testCursorUsageAfterClose() throws IOException {
        SqlSession sqlSession = sqlSessionFactory.openSession();
        Mapper mapper = sqlSession.getMapper(Mapper.class);
        Cursor<User> usersCursor = mapper.getAllUsers();

        try {
            Iterator<User> iterator = usersCursor.iterator();
            User user = iterator.next();
            Assert.assertEquals("User1", user.getName());
            Assert.assertEquals(0, usersCursor.getCurrentIndex());

            user = iterator.next();
            Assert.assertEquals("User2", user.getName());
            Assert.assertEquals(1, usersCursor.getCurrentIndex());

            usersCursor.close();

            // hasNext now return false, since the cursor is closed
            Assert.assertFalse(iterator.hasNext());
            Assert.assertFalse(usersCursor.isOpen());
            Assert.assertFalse(usersCursor.isConsumed());

            // trying next() will fail
            iterator.next();

            Assert.fail("We should have failed with NoSuchElementException since Cursor is closed");
        } catch (NoSuchElementException e) {
            // We had an exception and current index has not changed
            Assert.assertEquals(1, usersCursor.getCurrentIndex());
            return;
        } finally {
            sqlSession.close();
        }

        Assert.fail("Should have returned earlier");
    }

    @Test
    public void shouldGetAllUserUsingAnnotationBasedMapper() {
        SqlSession sqlSession = sqlSessionFactory.openSession();
        sqlSession.getConfiguration().getMapperRegistry().addMapper(AnnotationMapper.class);
        AnnotationMapper mapper = sqlSession.getMapper(AnnotationMapper.class);
        Cursor<User> usersCursor = mapper.getAllUsers();
        try {
            Assert.assertFalse(usersCursor.isOpen());
            Assert.assertFalse(usersCursor.isConsumed());
            Assert.assertEquals(-1, usersCursor.getCurrentIndex());

            List<User> userList = new ArrayList<User>();
            for (User user : usersCursor){
                userList.add(user);
                Assert.assertEquals(userList.size() -1, usersCursor.getCurrentIndex());
            }

            Assert.assertFalse(usersCursor.isOpen());
            Assert.assertTrue(usersCursor.isConsumed());
            Assert.assertEquals(4, usersCursor.getCurrentIndex());

            Assert.assertEquals(5, userList.size());
            User user = userList.get(0);
            Assert.assertEquals("User1", user.getName());
            user = userList.get(1);
            Assert.assertEquals("User2", user.getName());
            user = userList.get(2);
            Assert.assertEquals("User3", user.getName());
            user = userList.get(3);
            Assert.assertEquals("User4", user.getName());
            user = userList.get(4);
            Assert.assertEquals("User5", user.getName());

        } finally {
            sqlSession.close();
        }
    }

}