SpringBoot+MyBatis简单数据访问应用的实例代码

<?xml version="1.0" encoding="utf-8"?>
<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.example</groupid>
  <artifactid>example</artifactid>
  <version>1.0-snapshot</version>
  <packaging>jar</packaging> //这里设置为jar,因为我们会使用jar包部署运行
  <parent>
    <groupid>org.springframework.boot</groupid>
    <artifactid>spring-boot-starter-parent</artifactid>
    <version>1.4.2.release</version>
  </parent>
  <dependencies>
    <dependency>
      <groupid>org.springframework.boot</groupid>
      <artifactid>spring-boot-starter-web</artifactid>
    </dependency>
    <!-- https://mvnrepository.com/artifact/org.mybatis/mybatis -->
    <dependency>
      <groupid>org.mybatis.spring.boot</groupid>
      <artifactid>mybatis-spring-boot-starter</artifactid> //mybatis的jar包
      <version>1.1.1</version>
    </dependency>
    <dependency>
      <groupid>org.codehaus.jackson</groupid>
      <artifactid>jackson-mapper-asl</artifactid> //json数据格式和对象的转换jar包
      <version>1.9.8</version>
      <type>jar</type>
      <scope>compile</scope>
    </dependency>
    <dependency>
      <groupid>com.h2database</groupid> //内嵌数据库
      <artifactid>h2</artifactid> 
      <version>1.3.156</version>
    </dependency>
    <dependency>
      <groupid>org.projectlombok</groupid>
      <artifactid>lombok</artifactid> //lombok插件,方便model对象的处理
      <version>1.16.2</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
    <dependency>
      <groupid>mysql</groupid>
      <artifactid>mysql-connector-java</artifactid> //mysql驱动
      <version>5.1.18</version>
    </dependency>
  </dependencies>
  <build>
    <finalname>example</finalname> //打包后的jar包名称
    <plugins>
      <plugin>
        <groupid>org.springframework.boot</groupid>
        <artifactid>spring-boot-maven-plugin</artifactid> //必须要的springboot继承的maven插件，缺少了无法打包jar。
        <executions>
          <execution>
            <goals>
              <goal>repackage</goal>
            </goals>
          </execution>
        </executions>
      </plugin>
      <plugin>
        <artifactid>maven-resources-plugin</artifactid> //因为jar包中可能存在很多其他的配置资源,例如mapper文件所以打包为jar包需要将其加入，所以需要此资源打包插件
        <version>2.5</version>
        <executions>
          <execution>
            <id>copy-xmls</id>
            <phase>process-sources</phase>
            <goals>
              <goal>copy-resources</goal>
            </goals>
            <configuration>
              <outputdirectory>${basedir}/target/classes</outputdirectory>
              <resources>
                <resource>
                  <directory>${basedir}/src/main/java</directory>
                  <includes>
                    <include>**/*.xml</include>
                  </includes>
                </resource>
              </resources>
            </configuration>
          </execution>
        </executions>
      </plugin>
    </plugins>
    <resources> //打包包含相应的资源文件
      <resource>
        <directory>src/main/resources</directory> 
        <includes>
          <include>**/*.properties</include>
          <include>**/*.xml</include>
          <include>**/*.tld</include>
        </includes>
        <filtering>false</filtering>
      </resource>
      <resource>
        <directory>src/main/java</directory>
        <includes>
          <include>**/*.properties</include>
          <include>**/*.xml</include>
          <include>**/*.tld</include>
        </includes>
        <filtering>false</filtering>
      </resource>
    </resources>
  </build>
  <repositories>//设置仓库
    <repository>
      <id>spring-milestone</id>
      <url>http://repo.spring.io/libs-release</url>
    </repository>
  </repositories>
</project>

spring.datasource.url=jdbc:mysql://localhost:3306/数据库名称?useunicode=true&characterencoding=utf8
spring.datasource.username=用户名
spring.datasource.password=用户密码
spring.datasource.driver-class-name=com.mysql.jdbc.driver
mybatis.mapper-locations=classpath*:/mapper/*mapper.xml //mapper文件的路径
mybatis.type-aliases-package=map.model //mapper文件中的前缀
server.port=监听端口号,不设置默认8080

@data//@data lombok插件的注解自动添加get set方法
public class examplemodel {
  private long id;
  private string name;
}
//一个简单的model对象

@data
public class mybatishelper<t> {
  @autowired
  private sqlsession sqlsession; //这里自动注入mybatis的sqlsession
  private string namespace;
  public mybatishelper(string namespace) {
    this.namespace = namespace;
  }
  public string getsqlname(string sqlname) {
    return namespace +"."+ sqlname;
  }
  public integer create(string name, t obj) {
    return sqlsession.insert(getsqlname(name), obj);
  }
  public boolean update(string name, t obj) {
    return boolean.valueof(sqlsession.update(getsqlname(name), obj) > 0);
  }
  public t findbyid(string name, long id) {
    return sqlsession.selectone(getsqlname(name), id);
  }
  public boolean delete(string name, long id) {
    return boolean.valueof(sqlsession.delete(getsqlname(name), id) > 0);
  }
  public list<t> findall(string name){return sqlsession.selectlist(getsqlname(name));}
}

@component
public class examplemodeldao extends mybatishelper<examplemodel>{
  public examplemodeldao() {
    super("example.dao.");
  }
//todo 自定义操作
public integer finddatacounts(){
  return getsqlsession().selectone(getsqlname("finddatacounts"));//他会寻找example.dao.finddatacounts对应的方法执行
}
}

<?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="example.dao">//这里很重要就是前缀
  <resultmap id="examplemodelmap" type="examplemode">
    <id column="id" property="id"/>
    <result column="name" property="name"/>
  </resultmap> //自定义resultmap对象,利于对象的操作
  <sql id="tb"> //数据表标签
    example_data
  </sql>
  <sql id="value_exclude_id"> //除了主键以为的字段集合标签
    name
  </sql>
  <sql id="vls"> //插入属性的字段集合标签
    id,name
  </sql>
  <sql id="insert_value">//插入输入进来的字段值标签
    #{name}
  </sql>
  <insert id="create" parametertype="examplemodel">
    insert into <include refid="tb"/> (<include refid="value_exclude_id"/>) values (<include refid="insert_value"/>)
  </insert>//一看就明白了创建一个对象
  <select id="findbyid" parametertype="long" resultmap="examplemodelmap">//返回我们定义的resultmap
    select <include refid="vls"/> from <include refid="tb"/> where id = #{id}
  </select>
  <select id="findall" resultmap="examplemodelmap">
    select <include refid="vls"/> from <include refid="tb"/>
  </select>
  <select id="finddatacounts" resulttype="int">
    select count(1) from <include refid="tb"/>
  </select>//自定义的操作
</mapper>

@restcontroller
@crossorigin //这个是ajax跨域请求允许的注解，不用可以去掉
public class digmapdatacontroller {
  @autowired
  private exampleservice exampleservice;//service对象
  @requestmapping(value = "/create", method = requestmethod.post)
  public string create(@requestbody examplemodel examplemodel) {
    return string.valueof(exampleservice.create(examplemodel));
}
//@requestbody注解会接受前端的json数据并配合jackson自动转换为相应的对象
  @requestmapping(value = "/find/count",method = requestmethod.get)
  public integer findcounts() {
    return exampleservice.finddatacounts();
  }
}