Mybatis简介

Mybatis的前身是iBatis，iBatis原本就是apache的一个开源项目，2010年该项目有apache迁移到了google code，并改名为MyBatis。

简介

MyBatis支持普通SQL查询，存储过程和高级映射的优秀持久层框架，消除了几乎所有的JDBC代码和参数的手动设置以及结果集的检索。MyBatis可以使用XML或者注解用于配置和映射，将接口和JavaBean映射成数据库的记录。

每一个MyBatis的应用程序都以一个SqlSessionFactory对象的实例为核心。SqlSessionFactory对象的实例可以通过SqlSessionFactoryBuilder对象来获得，SqlSessionFactoryBuilder对象可以从XML配置文件或从Configuration类获得。例如：

String resource ="com/alvinliang/mybatis/mybatis-config.xml";
InputStreamis= Resources.getResourceAsStream(resource);
SqlSessionFactory sqlSessionFactory =newSqlSessionFactoryBuilder().build(is);

XML配置文件包含了对MyBatis系统的核心设置，有获取数据库连接实例的数据源和决定事务范围和控制事务管理器。详细内容后面会讲，这里给出一个简单示例：

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
  PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
  "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
  <environments default="development">
    <environment id="development">
      <transactionManager type="JDBC"/>
      <dataSource type="POOLED">
        <property name="driver" value="${driver}"/>
        <property name="url" value="${url}"/>
        <property name="username" value="${username}"/>
        <property name="password" value="${password}"/>
      </dataSource>
    </environment>
  </environments>
  <mappers>
    <mapper resource="com/alvinliang/mybatis/BlogMapper.xml"/>
  </mappers>
</configuration>

还有很多可以配置，上面指出了最关键的部分。environment元素体里包含对事务管理和连接池的环境配置。mapppers元素包含了所有mapper映射器，这些mapper的xml文件包含了SQL代码和映射定义信息。
详细配置，见Mybatis官网

2.总体流程

（1）加载配置并初始化

触发条件：加载配置文件，将SQL配置文件加载成一个个MappedStatement对象。
关于MappedStatement是Mybatis的几个重要类，详细见

（2）接受调用请求

触发条件：调用MyBatis提供的API

传入参数：为SQL的ID和传入参数对象

处理过程：将请求传递给下层的请求的处理层进行处理。

（3）处理操作请求

触发条件：API接口层传递请求过来

传入参数：为SQL的ID和传入参数对象

处理过程：

(A)根据SQL的ID查找对应的MappedStatement对象。

(B)根据传入参数对象解析MappedStatement对象，得到最终要执行的SQL和执行传入参数。

(C)获取数据库连接，根据得到的最终SQL语句和执行传入参数到数据库执行，并得到执行结果。

(D)根据MappedStatement对象中的结果映射配置对得到的执行结果进行转换处理，并得到最终的处理结果。

(E)释放连接资源。

（4）返回处理结果将最终的处理结果返回。

3.功能框架

Mybatis可以分为三层：

（1） API接口层：提供给外部使用的接口API，开发人员可以通过本地API来操纵数据库。

（2）数据处理层：负责具体的SQL查找、SQL解析、SQL执行和执行结果映射处理等。

（3）基础支持层：负责最基本的功能支撑，包括连接管理、事务管理、配置加载和缓存处理等。

4.简单使用

先从SqlSessionFactory对象来获得SqlSession的实例，SqlSession对象包含了对数据库的所有执行SQL操作的方法。例如：

SqlSession session = sqlSessionFactory.openSession();
try {  
Blogblog = (Blog) session.selectOne("com.alvinliang.mybatis.BlogMapper.selectBlog", 1);
} finally {  
session.close();
}

下面给出映射的SQL语句：

<?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">
<mapper namespace="com.alvinliang.mybatis.BlogMapper">
  <select id="selectBlog" resultType="Blog">
    select * from Blog where id = #{id}
  </select>
</mapper>

这里只是给出了一个简洁的例子，其中在命名空间“com.alvinliang.mybatis.BlogMapper”中定义了一个名为“selectBlog”的映射语句，这样它允许你使用完全限定名“com.alvinliang.mybatis.BlogMapper.selectBlog”来调用映射语句。

注意：现在命名空间是必须的，而且命名空间使得接口绑定成为可能，使用命名空间并将它放在合适的Java包空间下，将会使你的代码变得简洁，会在很长的时间内提高MyBatis的作用。

范围和生命周期

SqlSessionFactoryBuilder

这个类可以被实例化，使用和丢弃。一旦你创建了SqlSessionFactory后，这个类就不需要了。因此SqlSessionFactoryBuilder实例的最佳范围就是方法范围（也就是本地方法变量）。你可以重用SqlSessionFactoryBuilder来创建多个SqlSessionFactory实例。

SqlSessionFactory

一旦被创建，SqlSessionFactory应该在你的应用执行期间都存在，没有理来处理或者重新创建它。使用SqlSessionFactory的最佳实践是在应用运行期间不要重复创建多次。因此SqlSessionFactory的生命周期是Application范围。很多方法可以做到，如单例模式或者静态单例模式。

SqlSession

每个线程都应该有它自己的SqlSession实例。SqlSession的实例不能被共享，也是线程不安全的。因此最佳范围应该是request或者method范围。绝对不能将SqlSession实例的引用放在一个类的静态字段甚至是实例字段中。也绝对不能将SqlSession实例引用放在任何类型的管理范围中，比如Servlet中的HttpSession。如果你正在使用Web框架，可以考虑将SqlSession放在一个和Http Request对象相似的范围内。下面的示例就是一个确保SqlSession关闭的基本模式：

SqlSession session = sqlSessionFactory.openSession();
try {
// do work
} finally {  
session.close();
}

在你的代码中一贯的使用这种模式，将会保证所有的数据库资源都正常的关闭。

完整的Example

**Step1: **Create a Maven project and configure MyBatis dependencies.

<project xmlns='http://maven.apache.org/POM/4.0.0' 
 xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance'
 xsi:schemaLocation='http://maven.apache.org/POM/4.0.0 
 http://maven.apache.org/xsd/maven-4.0.0.xsd'>
 <modelVersion>4.0.0</modelVersion>

 <groupId>com.sivalabs</groupId>
 <artifactId>mybatis-demo</artifactId>
 <version>0.0.1-SNAPSHOT</version>
 <packaging>jar</packaging>

 <name>mybatis-demo</name>
 <url>http://maven.apache.org</url>

 <properties>
  <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
 </properties>

 <build>
  <plugins>
   <plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-compiler-plugin</artifactId>
    <version>2.3.2</version>
    <configuration>
     <source>1.6</source>
     <target>1.6</target>
     <encoding>${project.build.sourceEncoding}</encoding>
    </configuration>
   </plugin>
  </plugins>
 </build>

 <dependencies>
  <dependency>
   <groupId>junit</groupId>
   <artifactId>junit</artifactId>
   <version>4.10</version>
   <scope>test</scope>
  </dependency>

  <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis</artifactId>
      <version>3.1.1</version>
  </dependency>
  <dependency>
             <groupId>mysql</groupId>
             <artifactId>mysql-connector-java</artifactId>
             <version>5.1.21</version>
             <scope>runtime</scope>
         </dependency>
 </dependencies>
</project>

Step#2: Create the table USER and a Java domain Object User as follows:

CREATE TABLE  user (
  user_id int(10) unsigned NOT NULL auto_increment,
  email_id varchar(45) NOT NULL,
  password varchar(45) NOT NULL,
  first_name varchar(45) NOT NULL,
  last_name varchar(45) default NULL,
  PRIMARY KEY  (user_id),
  UNIQUE KEY Index_2_email_uniq (email_id)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

package com.sivalabs.mybatisdemo.domain;
public class User 
{
 private Integer userId;
 private String emailId;
 private String password;
 private String firstName;
 private String lastName;

 @Override
 public String toString() {
  return 'User [userId=' + userId + ', emailId=' + emailId
    + ', password=' + password + ', firstName=' + firstName
    + ', lastName=' + lastName + ']';
 }
 //setters and getters 
}

Step#3: Create MyBatis configuration files.
a) Create jdbc.properties file in src/main/resources folder

jdbc.driverClassName=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/mybatis-demo
jdbc.username=root
jdbc.password=admin

b) Create mybatis-config.xml file in src/main/resources folder

<?xml version='1.0' encoding='UTF-8' ?>
<!DOCTYPE configuration
  PUBLIC '-//mybatis.org//DTD Config 3.0//EN'
  'http://mybatis.org/dtd/mybatis-3-config.dtd'>
<configuration>
 <properties resource='jdbc.properties'/>
 <typeAliases>
  <typeAlias type='com.sivalabs.mybatisdemo.domain.User' alias='User'></typeAlias>
 </typeAliases>
 <environments default='development'>
  <environment id='development'>
    <transactionManager type='JDBC'/>
    <dataSource type='POOLED'>    
   <property name='driver' value='${jdbc.driverClassName}'/>
   <property name='url' value='${jdbc.url}'/>
   <property name='username' value='${jdbc.username}'/>
   <property name='password' value='${jdbc.password}'/>
    </dataSource>
  </environment>
  </environments>
  <mappers>
 <mapper resource='com/sivalabs/mybatisdemo/mappers/UserMapper.xml'/>
  </mappers>
</configuration>

Step#4: Create an interface UserMapper.java in src/main/java folder in com.sivalabs.mybatisdemo.mappers package.

package com.sivalabs.mybatisdemo.mappers;

import java.util.List;
import com.sivalabs.mybatisdemo.domain.User;

public interface UserMapper 
{

 public void insertUser(User user);

 public User getUserById(Integer userId);

 public List<User> getAllUsers();

 public void updateUser(User user);

 public void deleteUser(Integer userId);

}

Step#5: Create UserMapper.xml file in src/main/resources folder in com.sivalabs.mybatisdemo.mappers package.

<?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'>

<mapper namespace='com.sivalabs.mybatisdemo.mappers.UserMapper'>

  <select id='getUserById' parameterType='int' resultType='com.sivalabs.mybatisdemo.domain.User'>
     SELECT 
      user_id as userId, 
      email_id as emailId , 
      password, 
      first_name as firstName, 
      last_name as lastName
     FROM USER 
     WHERE USER_ID = #{userId}
  </select>
  <!-- Instead of referencing Fully Qualified Class Names we can register Aliases in mybatis-config.xml and use Alias names. -->
   <resultMap type='User' id='UserResult'>
    <id property='userId' column='user_id'/>
    <result property='emailId' column='email_id'/>
    <result property='password' column='password'/>
    <result property='firstName' column='first_name'/>
    <result property='lastName' column='last_name'/>   
   </resultMap>

  <select id='getAllUsers' resultMap='UserResult'>
   SELECT * FROM USER
  </select>

  <insert id='insertUser' parameterType='User' useGeneratedKeys='true' keyProperty='userId'>
   INSERT INTO USER(email_id, password, first_name, last_name)
    VALUES(#{emailId}, #{password}, #{firstName}, #{lastName})
  </insert>

  <update id='updateUser' parameterType='User'>
    UPDATE USER 
    SET
     PASSWORD= #{password},
     FIRST_NAME = #{firstName},
     LAST_NAME = #{lastName}
    WHERE USER_ID = #{userId}
  </update>

  <delete id='deleteUser' parameterType='int'>
    DELETE FROM USER WHERE USER_ID = #{userId}
  </delete>

</mapper>

Step#6: Create MyBatisUtil.java to instantiate SqlSessionFactory.

package com.sivalabs.mybatisdemo.service;

import java.io.IOException;
import java.io.Reader;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

public class MyBatisUtil 
{
 private static SqlSessionFactory factory;

 private MyBatisUtil() {
 }

 static
 {
  Reader reader = null;
  try {
   reader = Resources.getResourceAsReader('mybatis-config.xml');
  } catch (IOException e) {
   throw new RuntimeException(e.getMessage());
  }
  factory = new SqlSessionFactoryBuilder().build(reader);
 }

 public static SqlSessionFactory getSqlSessionFactory() 
 {
  return factory;
 }
}

Step#7: Create UserService.java in src/main/java folder.

package com.sivalabs.mybatisdemo.service;

import java.util.List;
import org.apache.ibatis.session.SqlSession;
import com.sivalabs.mybatisdemo.domain.User;
import com.sivalabs.mybatisdemo.mappers.UserMapper;

public class UserService
{

 public void insertUser(User user) {
  SqlSession sqlSession = MyBatisUtil.getSqlSessionFactory().openSession();
  try{
  UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
  userMapper.insertUser(user);
  sqlSession.commit();
  }finally{
   sqlSession.close();
  }
 }

 public User getUserById(Integer userId) {
  SqlSession sqlSession = MyBatisUtil.getSqlSessionFactory().openSession();
  try{
  UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
  return userMapper.getUserById(userId);
  }finally{
   sqlSession.close();
  }
 }

 public List<User> getAllUsers() {
  SqlSession sqlSession = MyBatisUtil.getSqlSessionFactory().openSession();
  try{
  UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
  return userMapper.getAllUsers();
  }finally{
   sqlSession.close();
  }
 }

 public void updateUser(User user) {
  SqlSession sqlSession = MyBatisUtil.getSqlSessionFactory().openSession();
  try{
  UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
  userMapper.updateUser(user);
  sqlSession.commit();
  }finally{
   sqlSession.close();
  }

 }

 public void deleteUser(Integer userId) {
  SqlSession sqlSession = MyBatisUtil.getSqlSessionFactory().openSession();
  try{
  UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
  userMapper.deleteUser(userId);
  sqlSession.commit();
  }finally{
   sqlSession.close();
  }

 }

}

Step#8: Create a JUnit Test class to test UserService methods.

package com.sivalabs.mybatisdemo;

import java.util.List;

import org.junit.AfterClass;
import org.junit.Assert;
import org.junit.BeforeClass;
import org.junit.Test;

import com.sivalabs.mybatisdemo.domain.User;
import com.sivalabs.mybatisdemo.service.UserService;

public class UserServiceTest 
{
 private static UserService userService;

 @BeforeClass
    public static void setup() 
 {
  userService = new UserService();
 }

 @AfterClass
    public static void teardown() 
 {
  userService = null;
 }

    @Test
 public void testGetUserById() 
 {
  User user = userService.getUserById(1);
  Assert.assertNotNull(user);
  System.out.println(user);
 }

    @Test
    public void testGetAllUsers() 
    {
  List<User> users = userService.getAllUsers();
  Assert.assertNotNull(users);
  for (User user : users) 
  {
   System.out.println(user);
  }

 }

    @Test
    public void testInsertUser() 
    {
     User user = new User();
     user.setEmailId('test_email_'+System.currentTimeMillis()+'@gmail.com');
     user.setPassword('secret');
     user.setFirstName('TestFirstName');
     user.setLastName('TestLastName');

     userService.insertUser(user);
  Assert.assertTrue(user.getUserId() != 0);
  User createdUser = userService.getUserById(user.getUserId());
  Assert.assertNotNull(createdUser);
  Assert.assertEquals(user.getEmailId(), createdUser.getEmailId());
  Assert.assertEquals(user.getPassword(), createdUser.getPassword());
  Assert.assertEquals(user.getFirstName(), createdUser.getFirstName());
  Assert.assertEquals(user.getLastName(), createdUser.getLastName());

 }

    @Test
    public void testUpdateUser() 
    {
     long timestamp = System.currentTimeMillis();
  User user = userService.getUserById(2);
  user.setFirstName('TestFirstName'+timestamp);
     user.setLastName('TestLastName'+timestamp);
     userService.updateUser(user);
  User updatedUser = userService.getUserById(2);
  Assert.assertEquals(user.getFirstName(), updatedUser.getFirstName());
  Assert.assertEquals(user.getLastName(), updatedUser.getLastName());
 }

   @Test
   public void testDeleteUser() 
   {
     User user = userService.getUserById(4);
     userService.deleteUser(user.getUserId());
  User deletedUser = userService.getUserById(4);
  Assert.assertNull(deletedUser);   

 }
}

Now, I will explain how to perform CRUD operations using MyBatis Annotation support without need of Queries configuration in XML mapper files.

Step#1: Create a table BLOG and a java domain Object Blog.

CREATE TABLE  blog (
  blog_id int(10) unsigned NOT NULL auto_increment,
  blog_name varchar(45) NOT NULL,
  created_on datetime NOT NULL,
  PRIMARY KEY  (blog_id)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

package com.sivalabs.mybatisdemo.domain;

import java.util.Date;

public class Blog {

 private Integer blogId;
 private String blogName;
 private Date createdOn;

 @Override
 public String toString() {
  return 'Blog [blogId=' + blogId + ', blogName=' + blogName
    + ', createdOn=' + createdOn + ']';
 }
 //Seeters and getters
}

Step#2: Create UserMapper.java interface with SQL queries in Annotations.

package com.sivalabs.mybatisdemo.mappers;

import java.util.List;

import org.apache.ibatis.annotations.Delete;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Options;
import org.apache.ibatis.annotations.Result;
import org.apache.ibatis.annotations.Results;
import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.annotations.Update;

import com.sivalabs.mybatisdemo.domain.Blog;

public interface BlogMapper 
{
 @Insert('INSERT INTO BLOG(BLOG_NAME, CREATED_ON) VALUES(#{blogName}, #{createdOn})')
 @Options(useGeneratedKeys=true, keyProperty='blogId')
 public void insertBlog(Blog blog);

 @Select('SELECT BLOG_ID AS blogId, BLOG_NAME as blogName, CREATED_ON as createdOn FROM BLOG WHERE BLOG_ID=#{blogId}')
 public Blog getBlogById(Integer blogId);

 @Select('SELECT * FROM BLOG ')
 @Results({
  @Result(id=true, property='blogId', column='BLOG_ID'),
  @Result(property='blogName', column='BLOG_NAME'),
  @Result(property='createdOn', column='CREATED_ON')  
 })
 public List<Blog> getAllBlogs();

 @Update('UPDATE BLOG SET BLOG_NAME=#{blogName}, CREATED_ON=#{createdOn} WHERE BLOG_ID=#{blogId}')
 public void updateBlog(Blog blog);

 @Delete('DELETE FROM BLOG WHERE BLOG_ID=#{blogId}')
 public void deleteBlog(Integer blogId);

}

Step#3: Configure BlogMapper in mybatis-config.xml

<?xml version='1.0' encoding='UTF-8' ?>
<!DOCTYPE configuration
  PUBLIC '-//mybatis.org//DTD Config 3.0//EN'
  'http://mybatis.org/dtd/mybatis-3-config.dtd'>
<configuration>
 <properties resource='jdbc.properties'/>
 <environments default='development'>
  <environment id='development'>
    <transactionManager type='JDBC'/>
    <dataSource type='POOLED'>
   <!-- <property name='driver' value='com.mysql.jdbc.Driver'/>
   <property name='url' value='jdbc:mysql://localhost:3306/mybatis-demo'/>
   <property name='username' value='root'/>
   <property name='password' value='admin'/> -->
   <property name='driver' value='${jdbc.driverClassName}'/>
   <property name='url' value='${jdbc.url}'/>
   <property name='username' value='${jdbc.username}'/>
   <property name='password' value='${jdbc.password}'/>
    </dataSource>
  </environment>
  </environments>
  <mappers>
    <mapper class='com.sivalabs.mybatisdemo.mappers.BlogMapper'/>
  </mappers>
</configuration>

Step#4: Create BlogService.java

package com.sivalabs.mybatisdemo.service;

import java.util.List;

import org.apache.ibatis.session.SqlSession;

import com.sivalabs.mybatisdemo.domain.Blog;
import com.sivalabs.mybatisdemo.mappers.BlogMapper;

public class BlogService
{

 public void insertBlog(Blog blog) {
  SqlSession sqlSession = MyBatisUtil.getSqlSessionFactory().openSession();
  try{
  BlogMapper blogMapper = sqlSession.getMapper(BlogMapper.class);
  blogMapper.insertBlog(blog);
  sqlSession.commit();
  }finally{
   sqlSession.close();
  }
 }

 public Blog getBlogById(Integer blogId) {
  SqlSession sqlSession = MyBatisUtil.getSqlSessionFactory().openSession();
  try{
  BlogMapper blogMapper = sqlSession.getMapper(BlogMapper.class);
  return blogMapper.getBlogById(blogId);
  }finally{
   sqlSession.close();
  }
 }

 public List<Blog> getAllBlogs() {
  SqlSession sqlSession = MyBatisUtil.getSqlSessionFactory().openSession();
  try{
  BlogMapper blogMapper = sqlSession.getMapper(BlogMapper.class);
  return blogMapper.getAllBlogs();
  }finally{
   sqlSession.close();
  }
 }

 public void updateBlog(Blog blog) {
  SqlSession sqlSession = MyBatisUtil.getSqlSessionFactory().openSession();
  try{
  BlogMapper blogMapper = sqlSession.getMapper(BlogMapper.class);
  blogMapper.updateBlog(blog);
  sqlSession.commit();
  }finally{
   sqlSession.close();
  }  
 }

 public void deleteBlog(Integer blogId) {
  SqlSession sqlSession = MyBatisUtil.getSqlSessionFactory().openSession();
  try{
  BlogMapper blogMapper = sqlSession.getMapper(BlogMapper.class);
  blogMapper.deleteBlog(blogId);
  sqlSession.commit();
  }finally{
   sqlSession.close();
  }

 }

}

Step#5: Create JUnit Test for BlogService methods

package com.sivalabs.mybatisdemo;

import java.util.Date;
import java.util.List;

import org.junit.AfterClass;
import org.junit.Assert;
import org.junit.BeforeClass;
import org.junit.Test;

import com.sivalabs.mybatisdemo.domain.Blog;
import com.sivalabs.mybatisdemo.service.BlogService;

public class BlogServiceTest 
{
 private static BlogService blogService;

 @BeforeClass
    public static void setup() 
 {
  blogService = new BlogService();
 }

 @AfterClass
    public static void teardown() 
 {
  blogService = null;
 }

    @Test
 public void testGetBlogById() 
 {
  Blog blog = blogService.getBlogById(1);
  Assert.assertNotNull(blog);
  System.out.println(blog);
 }

    @Test
    public void testGetAllBlogs() 
    {
  List<Blog> blogs = blogService.getAllBlogs();
  Assert.assertNotNull(blogs);
  for (Blog blog : blogs) 
  {
   System.out.println(blog);
  }

 }

    @Test
    public void testInsertBlog() 
    {
     Blog blog = new Blog();
     blog.setBlogName('test_blog_'+System.currentTimeMillis());
     blog.setCreatedOn(new Date());

     blogService.insertBlog(blog);
  Assert.assertTrue(blog.getBlogId() != 0);
  Blog createdBlog = blogService.getBlogById(blog.getBlogId());
  Assert.assertNotNull(createdBlog);
  Assert.assertEquals(blog.getBlogName(), createdBlog.getBlogName());

 }

    @Test
    public void testUpdateBlog() 
    {
     long timestamp = System.currentTimeMillis();
  Blog blog = blogService.getBlogById(2);
  blog.setBlogName('TestBlogName'+timestamp);
     blogService.updateBlog(blog);
  Blog updatedBlog = blogService.getBlogById(2);
  Assert.assertEquals(blog.getBlogName(), updatedBlog.getBlogName());
 }

   @Test
   public void testDeleteBlog() 
   {
     Blog blog = blogService.getBlogById(4);
     blogService.deleteBlog(blog.getBlogId());
  Blog deletedBlog = blogService.getBlogById(4);
  Assert.assertNull(deletedBlog);
 }
}

最后编辑于：2017.12.08 06:45:09

人面猴
序言：七十年代末，一起剥皮案震惊了整个滨河市，随后出现的几起案子，更是在滨河造成了极大的恐慌，老刑警刘岩，带你破解...
沈念sama阅读 213,186评论 6赞 492
死咒
序言：滨河连续发生了三起死亡事件，死亡现场离奇诡异，居然都是意外死亡，警方通过查阅死者的电脑和手机，发现死者居然都...
沈念sama阅读 90,858评论 3赞 387
救了他两次的神仙让他今天三更去死
文/潘晓璐我一进店门，熙熙楼的掌柜王于贵愁眉苦脸地迎上来，“玉大人，你说我怎么就摊上这事。” “怎么了？”我有些...
开封第一讲书人阅读 158,620评论 0赞 348
道士缉凶录：失踪的卖姜人
文/不坏的土叔我叫张陵，是天一观的道长。经常有香客问我，道长，这世上最难降的妖魔是什么？我笑而不...
开封第一讲书人阅读 56,888评论 1赞 285
港岛之恋（遗憾婚礼）
正文为了忘掉前任，我火速办了婚礼，结果婚礼上，老公的妹妹穿的比我还像新娘。我一直安慰自己，他们只是感情好，可当我...
茶点故事阅读 66,009评论 6赞 385
恶毒庶女顶嫁案：这布局不是一般人想出来的
文/花漫我一把揭开白布。她就那样静静地躺着，像睡着了一般。火红的嫁衣衬着肌肤如雪。梳的纹丝不乱的头发上，一...
开封第一讲书人阅读 50,149评论 1赞 291
城市分裂传说
那天，我揣着相机与录音，去河边找鬼。笑死，一个胖子当着我的面吹牛，可吹牛的内容都是我干的。我是一名探鬼主播，决...
沈念sama阅读 39,204评论 3赞 412
双鸳鸯连环套：你想象不到人心有多黑
文/苍兰香墨我猛地睁开眼，长吁一口气：“原来是场噩梦啊……” “哼！你这毒妇竟也来了？” 一声冷哼从身侧响起，我...
开封第一讲书人阅读 37,956评论 0赞 268
万荣杀人案实录
序言：老挝万荣一对情侣失踪，失踪者是张志新（化名）和其女友刘颖，没想到半个月后，有当地人在树林里发现了一具尸体，经...
沈念sama阅读 44,385评论 1赞 303
护林员之死
正文独居荒郊野岭守林人离奇死亡，尸身上长有42处带血的脓包…… 初始之章·张勋以下内容为张勋视角年9月15日...
茶点故事阅读 36,698评论 2赞 327
白月光启示录
正文我和宋清朗相恋三年，在试婚纱的时候发现自己被绿了。大学时的朋友给我发了我未婚夫和他白月光在一起吃饭的照片。...
茶点故事阅读 38,863评论 1赞 341
活死人
序言：一个原本活蹦乱跳的男人离奇死亡，死状恐怖，灵堂内的尸体忽然破棺而出，到底是诈尸还是另有隐情，我是刑警宁泽，带...
沈念sama阅读 34,544评论 4赞 335
日本核电站爆炸内幕
正文年R本政府宣布，位于F岛的核电站，受9级特大地震影响，放射性物质发生泄漏。R本人自食恶果不足惜，却给世界环境...
茶点故事阅读 40,185评论 3赞 317
男人毒药：我在死后第九天来索命
文/蒙蒙一、第九天我趴在偏房一处隐蔽的房顶上张望。院中可真热闹，春花似锦、人声如沸。这庄子的主人今日做“春日...
开封第一讲书人阅读 30,899评论 0赞 21
一桩弑父案，背后竟有这般阴谋
文/苍兰香墨我抬头看了看天上的太阳。三九已至，却和暖如春，着一层夹袄步出监牢的瞬间，已是汗流浃背。一阵脚步声响...
开封第一讲书人阅读 32,141评论 1赞 267
情欲美人皮
我被黑心中介骗来泰国打工，没想到刚下飞机就差点儿被人妖公主榨干…… 1. 我叫王不留，地道东北人。一个月前我还...
沈念sama阅读 46,684评论 2赞 362
代替公主和亲
正文我出身青楼，却偏偏与公主长得像，于是被迫代替她去往敌国和亲。传闻我的和亲对象是个残疾皇子，可洞房花烛夜当晚...
茶点故事阅读 43,750评论 2赞 351

Mybatis简介

推荐阅读更多精彩内容