springboot入门2—jpa访问mysql数据库

还是参照官方的例子

1，maven依赖

<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/maven-v4_0_0.xsd">  <modelVersion>4.0.0</modelVersion>  <groupId>springBootTestMysql</groupId>  <artifactId>springBootTestMysql</artifactId>  <packaging>war</packaging>  <version>0.0.1-SNAPSHOT</version>  <name>springBootTestMysql Maven Webapp</name>  <url>http://maven.apache.org</url>      <parent>  <groupId>org.springframework.boot</groupId>  <artifactId>spring-boot-starter-parent</artifactId>  <version>1.4.2.RELEASE</version>  </parent>  <properties>        <java.version>1.8</java.version>    </properties>  <distributionManagement><repository><id>releases</id><name>Releases</name><url>http://10.92.1.84:8081/nexus/content/repositories/releases</url></repository><snapshotRepository><id>snapshots</id><name>Snapshots</name><url>http://10.92.1.84:8081/nexus/content/repositories/snapshots</url></snapshotRepository></distributionManagement><repositories><repository><id>public</id><url>http://10.92.1.84:8081/nexus/content/groups/public</url><releases><enabled>true</enabled></releases><snapshots><enabled>true</enabled></snapshots></repository><repository><id>libs-central</id><name>libs-releases</name><url>http://10.92.35.161/nexus/content/repositories/releases</url><snapshots><enabled>false</enabled></snapshots></repository><repository><id>libs-snapshots</id><name>libs-snapshots</name><url>http://10.92.35.161/nexus/content/repositories/snapshots</url><snapshots /></repository><repository><id>15public</id><name>i5public</name><url>http://10.92.7.15:8081/nexus/content/repositories/public/</url></repository></repositories><pluginRepositories><pluginRepository><id>public</id><url>http://10.92.1.84:8081/nexus/content/groups/public</url><releases><enabled>true</enabled></releases><snapshots><enabled>true</enabled></snapshots></pluginRepository></pluginRepositories>  <dependencies>    <dependency>      <groupId>junit</groupId>      <artifactId>junit</artifactId>      <version>3.8.1</version>      <scope>test</scope>    </dependency>    <dependency>          <groupId>org.springframework.boot</groupId>          <artifactId>spring-boot-starter-web</artifactId>              </dependency>             <!-- JPA Data (We are going to use Repositories, Entities, Hibernate, etc...) -->            <dependency>              <groupId>org.springframework.boot</groupId>              <artifactId>spring-boot-starter-data-jpa</artifactId>                     </dependency>            <!-- Use MySQL Connector-J -->            <dependency>              <groupId>mysql</groupId>              <artifactId>mysql-connector-java</artifactId>                    </dependency>            <dependency>              <groupId>org.springframework.boot</groupId>              <artifactId>spring-boot-starter-test</artifactId>                         <scope>test</scope>          </dependency>    </dependencies>  <build>    <finalName>springBootTestMysql</finalName>  </build></project>

2，创建mysql数据库，由于我本机没安装mysql，这里使用docker，来创建一个mysql容器，随时可以删掉

a.直接使用mysql的官方镜像使用  docker pull mysql 命令，下载镜像

b.pull完成之后，直接run起来，run的时候可以使用-e参数制定mysql的root用户的密码 ， docker run -d -p3306:3306 -e MYSQL_ROOT_PASSWORD=123456 --name mysql mysql:1.0

c.进入mysql容器，建数据库，建表，  mysql -h ip -uusername -ppassword -P端口

3.In the sources folder, you create a resource file src/main/resources/application.properties

创建连接数据库所需要的properties文件，主要就是连接的地址啊，用户名，密码

spring.jpa.hibernate.ddl-auto=createspring.datasource.url=jdbc:mysql://localhost:3306/testspring.datasource.username=rootspring.datasource.password=123456

4. 创建实体类

/** * Copyright EXPRESS PAY 2017, Inc. All rights reserved. *//** *  */package hello.model;import javax.persistence.Entity;import javax.persistence.GeneratedValue;import javax.persistence.GenerationType;import javax.persistence.Id;/** * <p> * TODO。 * </p> * * @author lujia * @version 1.0  * @date 2017年7月11日 */@Entity   //This tells Hibernate to make a table out of this classpublic class User {    @Id    @GeneratedValue(strategy=GenerationType.AUTO)    private int id;    private String name;    private String sex;    /**      * 获取 id     * @return id     */    public int getId() {        return id;    }    /**      * 设置 id     * @param id id     */    public void setId(int id) {        this.id = id;    }    /**      * 获取 name     * @return name     */    public String getName() {        return name;    }    /**      * 设置 name     * @param name name     */    public void setName(String name) {        this.name = name;    }    /**      * 获取 sex     * @return sex     */    public String getSex() {        return sex;    }    /**      * 设置 sex     * @param sex sex     */    public void setSex(String sex) {        this.sex = sex;    }        }

5.创建 reository

/** * Copyright EXPRESS PAY 2017, Inc. All rights reserved. *//** *  */package hello.repository;import org.springframework.data.repository.CrudRepository;import hello.model.User;/** * <p> * TODO。 * </p> * * @author lujia * @version 1.0  * @date 2017年7月11日 *///This will be AUTO IMPLEMENTED by Spring into a Bean called userRepository//CRUD refers Create, Read, Update, Deletepublic interface UserRepository extends CrudRepository<User , Long>{    }

6.创建controller

/** * Copyright EXPRESS PAY 2017, Inc. All rights reserved. *//** *  */package lujia.springboot.hello;import javax.servlet.http.HttpServletRequest;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RequestParam;import org.springframework.web.bind.annotation.ResponseBody;/** * <p> * TODO。 * </p> * * @author lujia * @version 1.0  * @date 2017年7月12日 */@Controller@RequestMapping("/user")public class UserController {    @Autowired    private UserRepository userRepository;        @RequestMapping("/add")    @ResponseBody    public String addUser(@RequestParam String name,@RequestParam String sex){        User user=new User();        user.setName(name);        user.setSex(sex);        userRepository.save(user);        return "add user";    }          @RequestMapping("/getAllUsers")    public @ResponseBody Iterable<User> getAllUsers() {                return userRepository.findAll();    }}

7.启动类

/** * Copyright EXPRESS PAY 2017, Inc. All rights reserved. *//** *  */package lujia.springboot.hello;import org.springframework.boot.SpringApplication;import org.springframework.boot.autoconfigure.SpringBootApplication;/** * <p> * TODO。 * </p> * * @author lujia * @version 1.0  * @date 2017年7月12日 */@SpringBootApplicationpublic class Application {    public static void main(String[] args) {        SpringApplication.run(Application.class, args);    }}

直接运行启动类，springboot内置的tomcat默认开启8080端口访问， 这里有个坑，来看下@SpringBootApplication 注解，

/* * Copyright 2012-2016 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.springframework.boot.autoconfigure;import java.lang.annotation.Documented;import java.lang.annotation.ElementType;import java.lang.annotation.Inherited;import java.lang.annotation.Retention;import java.lang.annotation.RetentionPolicy;import java.lang.annotation.Target;import org.springframework.boot.SpringBootConfiguration;import org.springframework.boot.context.TypeExcludeFilter;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.ComponentScan;import org.springframework.context.annotation.ComponentScan.Filter;import org.springframework.context.annotation.Configuration;import org.springframework.context.annotation.FilterType;import org.springframework.core.annotation.AliasFor;/** * Indicates a {@link Configuration configuration} class that declares one or more * {@link Bean @Bean} methods and also triggers {@link EnableAutoConfiguration * auto-configuration} and {@link ComponentScan component scanning}. This is a convenience * annotation that is equivalent to declaring {@code @Configuration}, * {@code @EnableAutoConfiguration} and {@code @ComponentScan}. * * @author Phillip Webb * @author Stephane Nicoll * @since 1.2.0 */@Target(ElementType.TYPE)@Retention(RetentionPolicy.RUNTIME)@Documented@Inherited@SpringBootConfiguration@EnableAutoConfiguration@ComponentScan(excludeFilters = @Filter(type = FilterType.CUSTOM, classes = TypeExcludeFilter.class))

//@ComponentScan 默认扫描的是我们启动类同个包或者子包下的类，public @interface SpringBootApplication {/** * Exclude specific auto-configuration classes such that they will never be applied. * @return the classes to exclude */Class<?>[] exclude() default {};}

@ComponentScan 默认扫描的是我们启动类同个包或者子包下的类，刚开始不在一个包下，搞了半天，

8.测试

9 ,在项目基础上添加日志，使用logback

直接在 src/main/resources目录下，新建logback.xml

<configuration><!-- %m输出的信息,%p日志级别,%t线程名,%d日期,%c类的全名,,,, --><appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender"><encoder><pattern>%d %p (%file:%line\)- %m%n</pattern><charset>UTF-8</charset></encoder></appender><appender name="baselog"class="ch.qos.logback.core.rolling.RollingFileAppender"><File>E:\log\base.log</File><rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy"><fileNamePattern>base.log.%d.%i</fileNamePattern><timeBasedFileNamingAndTriggeringPolicyclass="ch.qos.logback.core.rolling.SizeAndTimeBasedFNATP"><!-- or whenever the file size reaches 64 MB --><maxFileSize>64 MB</maxFileSize></timeBasedFileNamingAndTriggeringPolicy></rollingPolicy><encoder><pattern>%d %p (%file:%line\)- %m%n</pattern><charset>UTF-8</charset> <!-- 此处设置字符集 --></encoder></appender><root level="info"><appender-ref ref="STDOUT" /></root><logger name="lujia.springboot.hello" level="DEBUG"><appender-ref ref="baselog" /></logger></configuration>  

10.修改userController添加日志打印

测试成功，

参考了一下别人写的jpa的发现springboot结合jpa操作数据库太方便了，分页，排序，查询都非常简单方便，可以快速启动一个工程，代码如下

/** * Copyright EXPRESS PAY 2017, Inc. All rights reserved. *//** *  */package lujia.springboot.hello.repository;import java.util.List;import org.springframework.data.jpa.repository.JpaRepository;import org.springframework.data.jpa.repository.Query;import org.springframework.data.repository.query.Param;import org.springframework.stereotype.Repository;import lujia.springboot.hello.model.Language;/** * <p> * </p> * * @author lujia * @version 1.0  * @date 2017年7月13日 */@Repositorypublic interface LanguageRepository extends JpaRepository<Language, Long>{        List<Language> findByName(String name);    List<Language> findByAge(String age);    List<Language> findByNameAndAge(String name,String age);    @Query("select l from Language l where l.name=:name and l.age=:age")    List<Language> withNameAndAge(@Param("name")String name,@Param("age")String age);    @Query("select l from Language l where l.id>:id")    List<Language> withID(@Param("id")Long id);}

/** * Copyright EXPRESS PAY 2017, Inc. All rights reserved. *//** *  */package lujia.springboot.hello.web;import java.util.List;import org.slf4j.Logger;import org.slf4j.LoggerFactory;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.data.domain.Page;import org.springframework.data.domain.PageRequest;import org.springframework.data.domain.Sort;import org.springframework.data.domain.Sort.Direction;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.ResponseBody;import org.springframework.web.bind.annotation.RestController;import lujia.springboot.hello.model.Language;import lujia.springboot.hello.repository.LanguageRepository;/** * <p> * </p> * * @author lujia * @version 1.0  * @date 2017年7月13日 */@RestController@RequestMapping("/language")public class LanguageController {    private static Logger logger=LoggerFactory.getLogger(LanguageController.class);    @Autowired    private LanguageRepository languageRepository;        @RequestMapping("/save")    @ResponseBody    public String save(String name,String age){        logger.debug("save 开始");        Language save = languageRepository.save(new Language(null,name,age));                logger.debug("save 结束");        return "save id="+save.getId();    }    @RequestMapping("/quesyByName")    @ResponseBody    public List<Language> quesyByName(String name){        logger.debug("quesyByName 开始");        List<Language> findByName = languageRepository.findByName(name);                logger.debug("quesyByName 结束");        return findByName;    }    @RequestMapping("/quesyByAge")    @ResponseBody    public List<Language> quesyByAge(String age){        logger.debug("quesyByAge 开始");        List<Language> quesyByAge = languageRepository.findByAge(age);                logger.debug("quesyByAge 结束");        return quesyByAge;    }        @RequestMapping("/quesyByNameAndAge")    @ResponseBody    public List<Language> quesyByNameAndAge(String name,String age){        logger.debug("quesyByNameAndAge 开始");        List<Language> lsit = languageRepository.findByNameAndAge(name, age);                logger.debug("quesyByNameAndAge 结束");        return lsit;    }    @RequestMapping("/withNameAndAge")    @ResponseBody    public List<Language> withNameAndAge(String name,String age){        logger.debug("quesyByNameAndAge 开始");        List<Language> lsit = languageRepository.withNameAndAge(name, age);                logger.debug("quesyByNameAndAge 结束");        return lsit;    }    @RequestMapping("/withID")    @ResponseBody    public List<Language> withID(Long id){        logger.debug("withID 开始");        List<Language> lsit = languageRepository.withID(id);                logger.debug("withID 结束");        return lsit;    }        @RequestMapping("/sort")    @ResponseBody    public List<Language> sort(){        logger.debug("sort 开始");        List<Language> lsit = languageRepository.findAll(new Sort(Direction.ASC, "age"));                logger.debug("sort 结束");        return lsit;    }    @RequestMapping("/page")    @ResponseBody    public Page<Language> page(int page,int size){        logger.debug("page 开始");       Page<Language> findAll = languageRepository.findAll(new PageRequest(page, size));              logger.debug("page 结束");        return findAll;    }        }