MyBatisCursorItemReader

src/main/java/org/mybatis/spring/batch/MyBatisCursorItemReader.java

@@ -0,0 +1,126 @@
+/*
+ *    Copyright 2010-2013 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.mybatis.spring.batch;
+
+import static org.springframework.util.Assert.notNull;
+import static org.springframework.util.ClassUtils.getShortName;
+
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+
+import org.apache.ibatis.executor.resultset.CursorList;
+import org.apache.ibatis.session.ExecutorType;
+import org.apache.ibatis.session.SqlSession;
+import org.apache.ibatis.session.SqlSessionFactory;
+import org.springframework.batch.item.support.AbstractItemCountingItemStreamItemReader;
+import org.springframework.beans.factory.InitializingBean;
+
+/**
+ * @author Guillaume Darmont / guillaume@dropinocean.com
+ */
+public class MyBatisCursorItemReader<T> extends AbstractItemCountingItemStreamItemReader<T> implements InitializingBean {
+
+  private String queryId;
+
+  private SqlSessionFactory sqlSessionFactory;
+  private SqlSession sqlSession;
+
+  private Map<String, Object> parameterValues;
+
+  private CursorList<T> cursorList;
+  private Iterator<T> cursorIterator;
+
+  public MyBatisCursorItemReader() {
+    setName(getShortName(MyBatisCursorItemReader.class));
+  }
+
+  @Override
+  protected T doRead() throws Exception {
+    T next = null;
+    if (cursorIterator.hasNext()) {
+      next = cursorIterator.next();
+    }
+    return next;
+  }
+
+  @Override
+  protected void doOpen() throws Exception {
+    Map<String, Object> parameters = new HashMap<String, Object>();
+    if (parameterValues != null) {
+      parameters.putAll(parameterValues);
+    }
+
+    sqlSession = sqlSessionFactory.openSession(ExecutorType.SIMPLE);
+    List<T> list = sqlSession.selectList(queryId, parameters);
+    if (!(list instanceof CursorList)) {
+      throw new IllegalStateException(
+              "MyBatisCursorItemReader can only work with fetchType=\"CURSOR\". Please configure " + queryId
+                      + " correctly.");
+    }
+    cursorList = (CursorList<T>) list;
+    cursorIterator = cursorList.iterator();
+  }
+
+  @Override
+  protected void doClose() throws Exception {
+    // Ensure that cursorList is closed, even if resultset is partially consumed.
+    cursorList.closeResultSetAndStatement();
+    sqlSession.close();
+    cursorIterator = null;
+    cursorList = null;
+  }
+
+  /**
+   * Check mandatory properties.
+   *
+   * @see org.springframework.beans.factory.InitializingBean#afterPropertiesSet()
+   */
+  public void afterPropertiesSet() throws Exception {
+    notNull(sqlSessionFactory);
+    notNull(queryId);
+  }
+
+  /**
+   * Public setter for {@link SqlSessionFactory} for injection purposes.
+   *
+   * @param SqlSessionFactory sqlSessionFactory
+   */
+  public void setSqlSessionFactory(SqlSessionFactory sqlSessionFactory) {
+    this.sqlSessionFactory = sqlSessionFactory;
+  }
+
+  /**
+   * Public setter for the statement id identifying the statement in the SqlMap
+   * configuration file.
+   *
+   * @param queryId the id for the statement
+   */
+  public void setQueryId(String queryId) {
+    this.queryId = queryId;
+  }
+
+  /**
+   * The parameter values to be used for the query execution.
+   *
+   * @param parameterValues the values keyed by the parameter named used in
+   *                        the query string.
+   */
+  public void setParameterValues(Map<String, Object> parameterValues) {
+    this.parameterValues = parameterValues;
+  }
+}

src/test/java/org/mybatis/spring/batch/SpringBatchTest.java

@@ -1,12 +1,12 @@
 /*
- * Copyright 2010-2012 the original author or authors..
- *
+ * Copyright 2010-2012 The MyBatis Team.
+ * 
  * 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
- *
+ * 
+ * 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.
@@ -15,28 +15,41 @@
  */
 package org.mybatis.spring.batch;
 
-import static org.junit.Assert.*;
-
 import java.util.ArrayList;
 import java.util.List;
 
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
+
 import org.apache.ibatis.session.SqlSession;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.mybatis.spring.batch.domain.Employee;
-import org.springframework.batch.item.ParseException;
-import org.springframework.batch.item.UnexpectedInputException;
 import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Qualifier;
 import org.springframework.test.context.ContextConfiguration;
 import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
 import org.springframework.transaction.annotation.Transactional;
 
 @RunWith(SpringJUnit4ClassRunner.class)
-@ContextConfiguration(locations = { "classpath:org/mybatis/spring/batch/applicationContext.xml" })
+@ContextConfiguration(locations = {"classpath:org/mybatis/spring/batch/applicationContext.xml"})
 public class SpringBatchTest {
 
   @Autowired
-  private MyBatisPagingItemReader<Employee> reader;
+  @Qualifier("pagingNoNestedItemReader")
+  private MyBatisPagingItemReader<Employee> pagingNoNestedItemReader;
+
+  @Autowired
+  @Qualifier("pagingNestedItemReader")
+  private MyBatisPagingItemReader<Employee> pagingNestedItemReader;
+
+  @Autowired
+  @Qualifier("cursorNoNestedItemReader")
+  private MyBatisCursorItemReader<Employee> cursorNoNestedItemReader;
+
+  @Autowired
+  @Qualifier("cursorNestedItemReader")
+  private MyBatisCursorItemReader<Employee> cursorNestedItemReader;
 
   @Autowired
   private MyBatisBatchItemWriter<Employee> writer;
@@ -46,16 +59,76 @@ public class SpringBatchTest {
 
   @Test
   @Transactional
-  public void shouldDuplicateSalaryOfAllEmployees() throws UnexpectedInputException, ParseException, Exception {
+  public void shouldDuplicateSalaryOfAllEmployees() throws Exception {
     List<Employee> employees = new ArrayList<Employee>();
-    Employee employee = reader.read();
+    Employee employee = pagingNoNestedItemReader.read();
     while (employee != null) {
       employee.setSalary(employee.getSalary() * 2);
       employees.add(employee);
-      employee = reader.read();
+      employee = pagingNoNestedItemReader.read();
     }
     writer.write(employees);
 
-    assertEquals(20000, session.selectOne("check"));
+    assertEquals(20000, session.selectOne("checkSalarySum"));
+    assertEquals(employees.size(), session.selectOne("checkEmployeeCount"));
+  }
+
+  @Test
+  @Transactional
+  public void checkPagingReadingWithNestedInResultMap() throws Exception {
+    // This test is here to show that PagingReader can return wrong result in case of nested result maps
+    List<Employee> employees = new ArrayList<Employee>();
+    Employee employee = pagingNestedItemReader.read();
+    while (employee != null) {
+      employee.setSalary(employee.getSalary() * 2);
+      employees.add(employee);
+      employee = pagingNestedItemReader.read();
+    }
+    writer.write(employees);
+
+    // Assert that we have a WRONG employee count
+    assertNotEquals(employees.size(), session.selectOne("checkEmployeeCount"));
+  }
+
+  @Test
+  @Transactional
+  public void checkCursorReadingWithoutNestedInResultMap() throws Exception {
+    cursorNoNestedItemReader.doOpen();
+    try {
+      List<Employee> employees = new ArrayList<Employee>();
+      Employee employee = cursorNoNestedItemReader.read();
+      while (employee != null) {
+        employee.setSalary(employee.getSalary() * 2);
+        employees.add(employee);
+        employee = cursorNoNestedItemReader.read();
+      }
+      writer.write(employees);
+
+      assertEquals(20000, session.selectOne("checkSalarySum"));
+      assertEquals(employees.size(), session.selectOne("checkEmployeeCount"));
+    } finally {
+      cursorNoNestedItemReader.doClose();
+    }
+  }
+
+  @Test
+  @Transactional
+  public void checkCursorReadingWithNestedInResultMap() throws Exception {
+    cursorNestedItemReader.doOpen();
+    try {
+      List<Employee> employees = new ArrayList<Employee>();
+      Employee employee = cursorNestedItemReader.read();
+      while (employee != null) {
+        employee.setSalary(employee.getSalary() * 2);
+        employees.add(employee);
+        employee = cursorNestedItemReader.read();
+      }
+      writer.write(employees);
+
+      assertEquals(20000, session.selectOne("checkSalarySum"));
+      assertEquals(employees.size(), session.selectOne("checkEmployeeCount"));
+    } finally {
+      cursorNestedItemReader.doClose();
+    }
   }
 }

src/test/java/org/mybatis/spring/batch/applicationContext.xml

@@ -60,9 +60,26 @@
     </bean>
 
     <!-- item reader  -->
-    <bean id="reader" class="org.mybatis.spring.batch.MyBatisPagingItemReader">
+    <bean id="pagingNoNestedItemReader" class="org.mybatis.spring.batch.MyBatisPagingItemReader">
         <property name="sqlSessionFactory" ref="sqlSessionFactory" />
-        <property name="queryId" value="getEmployee" />
+        <property name="queryId" value="getEmployeeNoNestedPaging" />
+        <property name="pageSize" value="5"/>
+    </bean>
+
+    <bean id="pagingNestedItemReader" class="org.mybatis.spring.batch.MyBatisPagingItemReader">
+        <property name="sqlSessionFactory" ref="sqlSessionFactory" />
+        <property name="queryId" value="getEmployeeNestedPaging" />
+        <property name="pageSize" value="5"/>
+    </bean>
+
+    <bean id="cursorNoNestedItemReader" class="org.mybatis.spring.batch.MyBatisCursorItemReader">
+        <property name="sqlSessionFactory" ref="sqlSessionFactory" />
+        <property name="queryId" value="getEmployeeNoNestedCursor" />
+    </bean>
+
+    <bean id="cursorNestedItemReader" class="org.mybatis.spring.batch.MyBatisCursorItemReader">
+        <property name="sqlSessionFactory" ref="sqlSessionFactory" />
+        <property name="queryId" value="getEmployeeNestedCursor" />
     </bean>
 
     <bean id="writer" class="org.mybatis.spring.batch.MyBatisBatchItemWriter">

src/test/java/org/mybatis/spring/batch/dao/EmployeeMapper.xml

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8" ?>
 <!DOCTYPE mapper
-    PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
-    "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
+  PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
+  "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
 <!--
     Copyright 2010-2012 the original author or authors.
 
@@ -23,17 +23,44 @@
 -->
 <mapper namespace="org.mybatis.spring.batch.dao.UserDao">
 
-    <select id="getEmployee" resultType="org.mybatis.spring.batch.domain.Employee">
-        select * from employees
+    <select id="getEmployeeNoNestedPaging" resultType="org.mybatis.spring.batch.domain.Employee">
+        select distinct id,name,salary from employees limit #{_pagesize} offset #{_skiprows}
     </select>
 
-    <update id="updateEmployee" parameterType="org.mybatis.spring.batch.domain.Employee">
+    <select id="getEmployeeNestedPaging" resultMap="results">
+        select id,name,salary,skill from employees order by id limit #{_pagesize} offset #{_skiprows}
+    </select>
+
+  <select id="getEmployeeNoNestedCursor" resultType="org.mybatis.spring.batch.domain.Employee" fetchType="CURSOR"
+    resultOrdered="true">
+        select distinct id,name,salary from employees order by id
+    </select>
+
+  <select id="getEmployeeNestedCursor" resultMap="results" fetchType="CURSOR" resultOrdered="true">
+        select id,name,salary,skill from employees order by id
+    </select>
+
+  <resultMap id="results" type="org.mybatis.spring.batch.domain.Employee">
+    <id column="id" property="id" />
+    <result property="name" column="name" />
+    <result property="salary" column="salary" />
+    <collection property="skills" ofType="string">
+      <result column="skill" />
+    </collection>
+  </resultMap>
+
+  <update id="updateEmployee" parameterType="org.mybatis.spring.batch.domain.Employee">
         update employees set salary=#{salary} where id=#{id}
     </update>
 
-    <select id="check" resultType="int">
-        select sum(salary) from employees
+  <select id="checkSalarySum" resultType="int">
+        select sum(salary) from (select distinct id,salary from employees)
     </select>
 
+  <select id="checkEmployeeCount" resultType="int">
+        select count(distinct id)from employees
+    </select>
+
+
 
 </mapper>

src/test/java/org/mybatis/spring/batch/db/database-schema.sql

@@ -1,4 +1,4 @@
---    Copyright 2010-2012 the original author or authors.
+--    Copyright 2010-2012 The myBatis Team
 
 --    Licensed under the Apache License, Version 2.0 (the "License");
 --    you may not use this file except in compliance with the License.
@@ -18,5 +18,5 @@ create table employees (
     id integer not null,
     name varchar(80) not null,
     salary integer not null,
-    constraint pk_employee primary key (id)
+    skill varchar(80) not null
 );

src/test/java/org/mybatis/spring/batch/db/database-test-data.sql

@@ -1,4 +1,4 @@
---    Copyright 2010-2012 the original author or authors.
+--    Copyright 2010-2012 The myBatis Team
 
 --    Licensed under the Apache License, Version 2.0 (the "License");
 --    you may not use this file except in compliance with the License.
@@ -14,7 +14,11 @@
 
 --    version: $Id: db.sql 2398 2010-08-29 15:16:24Z simone.tripodi $
 
-insert into employees VALUES ( 1,  'Pocoyo' , 1000);
-insert into employees VALUES ( 2,  'Pato'   , 2000);
-insert into employees VALUES ( 3,  'Eli'    , 3000);
-insert into employees VALUES ( 4,  'Valentina'    , 4000);
+insert into employees VALUES ( 1,  'Pocoyo' , 1000, 's1');
+insert into employees VALUES ( 1,  'Pocoyo' , 1000, 's2');
+insert into employees VALUES ( 2,  'Pato'   , 2000, 's1');
+insert into employees VALUES ( 2,  'Pato'   , 2000, 's2');
+insert into employees VALUES ( 3,  'Eli'    , 3000, 's1');
+insert into employees VALUES ( 3,  'Eli'    , 3000, 's2');
+insert into employees VALUES ( 3,  'Eli'    , 3000, 's3');
+insert into employees VALUES ( 4,  'Valentina'    , 4000, 's1');