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！