spring注解集成jpa

1，添加依赖jar包，注意spring和hibernate版本对应

<dependency>
            <groupId>org.springframework.data</groupId>
            <artifactId>spring-data-jpa</artifactId>
            <version>1.10.1.RELEASE</version>
        </dependency>

<!-- hibernate -->
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-core</artifactId>
            <version>${hibernate.version}</version>
        </dependency>
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-ehcache</artifactId>
            <version>${hibernate.version}</version>
        </dependency>
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-entitymanager</artifactId>
            <version>${hibernate.version}</version>
        </dependency>
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-c3p0</artifactId>
            <version>${hibernate.version}</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.9</version>
        </dependency>

2，新建persistenceConfig管理持久层bean

@Configuration
@EnableJpaRepositories({"com.zuixinkeji.smart_travel.dao"})
public class PersistentConfig {

	
	@Value("${driver}")
	private String driver;
	@Value("${url}")
	private String url;
	@Value("${username}")
	private String username;
	@Value("${password}")
	private String password;

	//配置数据源 
	public BasicDataSource dataSource(){
		BasicDataSource source=new BasicDataSource();
		source.setDriverClassName(driver);
		source.setUrl(url);
		source.setUsername(username);
		source.setPassword(password);
		return source;
	}
	
	//配置 JPA 的 EntityManagerFactory
	@Bean
	public LocalContainerEntityManagerFactoryBean entityManagerFactory() {
		LocalContainerEntityManagerFactoryBean em = new LocalContainerEntityManagerFactoryBean();
		em.setDataSource(dataSource());
		em.setJpaVendorAdapter(jpaVendorAdapter());
		em.setPackagesToScan("com.zuixinkeji.smart_travel.domain.entity");
		Map<String, Object> jpaProperties = new HashMap<String, Object>();
		jpaProperties.put("hibernate.ejb.naming_strategy", "org.hibernate.cfg.ImprovedNamingStrategy");
		jpaProperties.put("hibernate.show_sql", true);
		jpaProperties.put("hibernate.hbm2ddl.auto", "update");
		em.setJpaPropertyMap(jpaProperties);
		return em;
	}
	
	//指定实现JPA的适配器
	public HibernateJpaVendorAdapter jpaVendorAdapter() {
		HibernateJpaVendorAdapter bean = new HibernateJpaVendorAdapter();
		bean.setDatabasePlatform("org.hibernate.dialect.MySQLDialect");
		return bean;
	}
	
	//配置事务
	@Bean
	public JpaTransactionManager transactionManager() {
		JpaTransactionManager jpaTransactionManager = new JpaTransactionManager();
		jpaTransactionManager.setEntityManagerFactory(entityManagerFactory().getObject());
		return jpaTransactionManager;
	}
}

3，给实体类添加注解

@Entity
public class User implements Serializable{
	private static final long serialVersionUID = 1L;
	
	@Id
	private Integer id;
	private String username;
	private String password;
	
	public Integer getId() {
		return id;
	}
	public void setId(Integer id) {
		this.id = id;
	}
	public String getUsername() {
		return username;
	}
	public void setUsername(String username) {
		this.username = username;
	}
	public String getPassword() {
		return password;
	}
	public void setPassword(String password) {
		this.password = password;
	}
	
}

4，给dao层继承Repository

public interface UserDao extends Repository<User, Integer> {

	User findByUsername(String username);
	User findById (Integer id);
}

注意jpa的方法名查询不能使用select开头