五、spring boot 1.5.4 集成 jpa+hibernate+jdbcTemplate

1.pom添加依赖

       <!-- spring data jpa,会注入tomcat jdbc pool/hibernate等 -->
　　　　 <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.42</version>
        </dependency>

2.添加数据源配置（DataSource啥的，一系列对象spring boot 都会给你注入的，配置配置即可！）

spring.datasource.url=jdbc:mysql://localhost/test?characterEncoding=utf8&useSSL=true
spring.datasource.username=root
spring.datasource.password=123456
spring.datasource.driver-class-name=com.mysql.jdbc.Driver

#database  pool config
# Number of ms to wait before throwing an exception if no connection is available.
spring.datasource.tomcat.max-wait=10000
# Maximum number of active connections that can be allocated from this pool at the same time.
spring.datasource.tomcat.max-active=300
# Validate the connection before borrowing it from the pool.
spring.datasource.tomcat.test-on-borrow=true
# initial pool size
spring.datasource.tomcat.initial-size=20

#=====================jpa config================================
#实体类维护数据库表结构的具体行为：update/create/create-drop/validate/none
spring.jpa.hibernate.ddl-auto=none
#打印sql语句
spring.jpa.show-sql=true
#格式化输出的json字符串
spring.jackson.serialization.indent_output=true

3.新建实体

@Entity
@Table(name="user")
public class User {

    @Id
    @Column(name="id")
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer id;

    @Column(name="number")
    private String number;

    @Column(name="name")
    private String name;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getNumber() {
        return number;
    }

    public void setNumber(String number) {
        this.number = number;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
}

4.dao层

public interface UserDao{

    User getById(int id);

    User getByNumber(String number);

    int addUser(User user);

    void deleteUserById(int id);

    User updateUser(User user);

}

@Repository
public class UserDaoImpl implements UserDao {

    @PersistenceContext
    private EntityManager entityManager;

    @Override
    public User getById(int id) {
        //find by primary key
        return this.entityManager.find(User.class,id);
    }

    @Override
    public User getByNumber(String number) {
        Query query = this.entityManager.createQuery("from User u where u.number=:number",User.class);
        query.setParameter("number",number);
        User user = (User)query.getSingleResult();
        return user;
    }

    @Override
    public int addUser(User user) {
        this.entityManager.persist(user);
        //print the id
        System.out.println(user.getId());
        return user.getId();
    }

    @Override
    public void deleteUserById(int id) {
        User user = this.entityManager.find(User.class,id); //关联到记录，方可删除
        this.entityManager.remove(user);
    }

    @Override
    public User updateUser(User user) {
        User userNew = this.entityManager.merge(user);
        return userNew;
    }
}

5.service层

public interface UserService {

    User getById(int id);

    User getByNumber(String number);

    int addUser(User user,boolean throwEx);

    void deleteUserById(int id);

    User updateUser(User user);
}

@Service
@Transactional
public class UserServiceImpl implements UserService {

    @Autowired
    private UserDao userDao;

    @Override
    @Transactional(readOnly = true)
    public User getById(int id) {
        return userDao.getById(id);
    }

    @Override
    @Transactional(readOnly = true)
    public User getByNumber(String number) {
        return userDao.getByNumber(number);
    }

    @Override
    public int addUser(User user,boolean throwEx) {
        int id= this.userDao.addUser(user);
        if(throwEx){
            throw new RuntimeException("throw a ex");
        }
        return id;
    }

    @Override
    public void deleteUserById(int id) {
        this.userDao.deleteUserById(id);
    }

    @Override
    public User updateUser(User user) {
        return this.userDao.updateUser(user);
    }

}

6.controller层

@Controller("user1")
@RequestMapping("/jpa/user")
public class UserController {
    /**
     * 日志（slf4j->logback）
     */
    private static final Logger logger = LoggerFactory.getLogger(UserController.class);

    @Autowired
    private UserService userService;

    /**
     * 返回text格式数据
     * @param id 主键id
     * @return 用户json字符串
     */
    @RequestMapping("/get/id/{id}")
    @ResponseBody
    public String getUserById(@PathVariable("id")String id){
        logger.info("request /user/get/id/{id}, parameter is "+id);
        User user = userService.getById(Integer.parseInt(id));
        return JSONObject.toJSONString(user);
    }

    /**
     * 返回json格式数据
     * @param number 编号
     * @return 用户
     */
    @RequestMapping("/get/number/{number}")
    @ResponseBody
    public User getUserByNumber(@PathVariable("number")String number){
        User user = userService.getByNumber(number);
        return user;
    }

    @RequestMapping("/add/{number}/{name}")
    @ResponseBody
    public String addUser(@PathVariable("number")String number,@PathVariable("name")String name,boolean throwEx){
        User user = new User();
        user.setNumber(number);
        user.setName(name);
        int id = -1;
        try{
            id = userService.addUser(user,throwEx);
        }catch (RuntimeException ex){
            System.out.println(ex.getMessage());
        }
        return String.valueOf(id);
    }

    @RequestMapping("/delete/{id}")
    @ResponseBody
    public void getUserById(@PathVariable("id")int id){
        this.userService.deleteUserById(id);
    }

    @RequestMapping("/update/{id}/{number}/{name}")
    @ResponseBody
    public User addUser(@PathVariable("id")int id, @PathVariable("number")String number, @PathVariable("name")String name){
        User user = new User();
        user.setId(id);
        user.setNumber(number);
        user.setName(name);
        return userService.updateUser(user);
    }
}

7. spring data jpa新使用方式，更高级

1.dao

@Repository
public interface UserRepository extends JpaRepository<User, Integer> {
    /**
     * spring data jpa 会自动注入实现（根据方法命名规范）
     * @return
     */
    User findByNumber(String number);

    @Modifying
    @Query("delete from User u where u.id = :id")
    void deleteUser(@Param("id")int id);
}

2.service

public interface UserService {

    User findById(int id);

    User findByNumber(String number);

    List<User> findAllUserByPage(int page,int size);

    User updateUser(User user,boolean throwEx);

    void deleteUser(int id);
}

@Service
@Transactional
public class UserServiceImpl implements UserService {

    @Autowired
    private UserRepository userRepository;

    @Override
    public User findById(int id) {
        return this.userRepository.findOne(id);
    }

    @Override
    public User findByNumber(String number) {
        return this.userRepository.findByNumber(number);
    }

    @Override
    public List<User> findAllUserByPage(int page,int size) {
        Pageable pageable = new PageRequest(page, size);
        Page<User> users =  this.userRepository.findAll(pageable);
        return users.getContent();
    }

    @Override
    public User updateUser(User user,boolean throwEx) {
        User userNew = this.userRepository.save(user);
        if(throwEx){
            throw new RuntimeException("throw a ex");
        }
        return userNew;
    }

    @Override
    public void deleteUser(int id) {
        this.userRepository.deleteUser(id);
    }
}

3.controller

@Controller("user2")
@RequestMapping("/datajpa/user")
public class UserController {
    /**
     * 日志（slf4j->logback）
     */
    private static final Logger logger = LoggerFactory.getLogger(UserController.class);

    @Autowired
    private UserService userService;

    /**
     * 返回text格式数据
     * @param id 主键id
     * @return 用户json字符串
     */
    @RequestMapping("/get/id/{id}")
    @ResponseBody
    public String getUserById(@PathVariable("id")String id){
        logger.info("request /user/get/id/{id}, parameter is "+id);
        User user = userService.findById(Integer.parseInt(id));
        return JSONObject.toJSONString(user);
    }

    /**
     * 返回json格式数据
     * @param number 编号
     * @return 用户
     */
    @RequestMapping("/get/number/{number}")
    @ResponseBody
    public User getUserByNumber(@PathVariable("number")String number){
        User user = userService.findByNumber(number);
        return user;
    }

    @RequestMapping("/get/all/{page}/{size}")
    @ResponseBody
    public List<User> getAllUserByPage(@PathVariable("page")int page,@PathVariable("size")int size){
        return this.userService.findAllUserByPage(page,size);
    }

    @RequestMapping("/update/{id}/{number}/{name}")
    @ResponseBody
    public User addUser(@PathVariable("id")int id, @PathVariable("number")String number, @PathVariable("name")String name,boolean throwEx){
        User user = new User();
        user.setId(id);
        user.setNumber(number);
        user.setName(name);
        User userNew = null;
        try{
            userService.updateUser(user,throwEx);
        }catch (RuntimeException ex){
            System.out.println(ex.getMessage());
        }
        return userNew;
    }

    @RequestMapping("/delete/{id}")
    @ResponseBody
    public void getUserById(@PathVariable("id")int id){
        this.userService.deleteUser(id);
    }

}

8.注入jdbcTemplate和transactionTemplate,使用传统方式操作数据库，更加灵活，方法如下

    @Autowired
    private JdbcTemplate jdbcTemplate;

    @Autowired
    private TransactionTemplate transactionTemplate;

    /**
     * 手动控制事物测试
     * @param throwEx
     */
    @Override
    public void testTransactionManually(boolean throwEx) {

        try {
            transactionTemplate.execute(new TransactionCallback<Boolean>() {

                /**
                 * 事物代码
                 *
                 * @param transactionStatus 事物状态
                 * @return 是否成功
                 */
                @Override
                public Boolean doInTransaction(TransactionStatus transactionStatus) {
                    User user = new User();
                    user.setId(1);
                    int a = new Random().nextInt(10); //0-9
                    user.setNumber("10000u" + a);
                    jdbcTemplate.update("UPDATE USER SET NUMBER=? WHERE ID=?", new Object[]{user.getNumber(), user.getId()}, new int[]{Types.VARCHAR, Types.INTEGER});
                    if (throwEx) {
                        throw new RuntimeException("try throw exception"); //看看会不会回滚
                    }
                    return true;
                }
            });
        }catch (RuntimeException ex){
            System.out.println(ex.getMessage());
        }

    }

    /**
     * 手动执行jdbc测试
     */
    @Override
    public void testJdbcTemplate() {
        User  user = new User();
        int a = new Random().nextInt(10); //0-9
        user.setNumber("10000i"+ a );
        user.setName("name"+a);
        this.jdbcTemplate.update("INSERT into USER(NUMBER,NAME )VALUES (?,?)",user.getNumber(),user.getName());
    }

至此，我已经讲了三种方式（jpa两种+jdbcTemplate）如何操作数据库了，你爱怎么用就怎么用，上述代码均是实践证明可行的！

项目源码：https://github.com/hdwang123/springboottest_onedb