ssm+dubbo/zk

1、原始

Connection conn = null;
String url = "jdbc:mysql://localhost:3306/emps?user=root&password=&useUnicode=true&characterEncoding=utf-8";
try {
    //加载驱动
    Class.forName("com.mysql.jdbc.Driver");
    conn = DriverManager.getConnection(url);
    //conn=DriverManager.getConnection()
    String sql = "select * from tm_project where proj_id=1";
    PreparedStatement ps = conn.prepareStatement(sql);
    ResultSet rs = ps.executeQuery("select * from tm_project where proj_id=2");
    if (rs.next()) {
        System.out.println(rs.getString("proj_name"));
    }
} catch (Exception e) {
    e.printStackTrace();
}

notice：1、没有rs.next不能使用rs.getXXX，报错（SQLException：Before start of result set）

2、mybatis only

①po、mapper.java、mapper.xml

②mybatis-mapper.xml

<settings>
    <!-- 全局映射器启用缓存 -->
    <setting name="cacheEnabled" value="true"/>
    <!-- 查询时，关闭关联对象即时加载以提高性能 -->
    <setting name="lazyLoadingEnabled" value="true"/>
    <!-- 设置关联对象加载的形态，此处为按需加载字段(加载字段由SQL指定)，不会加载关联表的所有字段，以提高性能 -->
    <setting name="aggressiveLazyLoading" value="false"/>
    <!-- 对于未知的SQL查询，允许返回不同的结果集以达到通用的效果 -->
    <setting name="multipleResultSetsEnabled" value="true"/>
    <!-- 允许使用列标签代替列名 -->
    <setting name="useColumnLabel" value="true"/>
    <!-- 允许使用自定义的主键值(比如由程序生成的UUID 32位编码作为键值)，数据表的PK生成策略将被覆盖 -->
    <setting name="useGeneratedKeys" value="true"/>
    <!-- 给予被嵌套的resultMap以字段-属性的映射支持 -->
    <setting name="autoMappingBehavior" value="FULL"/>
    <!-- 对于批量更新操作缓存SQL以提高性能  -->
    <!-- <setting name="defaultExecutorType" value="BATCH" /> -->
    <!-- 数据库超过25000秒仍未响应则超时 -->
    <setting name="defaultStatementTimeout" value=""/>
    <!--是否保留空字段-->
    <setting name="callSettersOnNulls" value="true"/>

    <setting name="jdbcTypeForNull" value="NULL" />
</settings>
<!-- 别名 -->
<typeAliases>
    <typeAlias type="com.ytud.provider.mybatis.po.Project" alias="project" />
</typeAliases>
<!-- 数据库 -->
<environments default="development">
    <environment id="development">
        <transactionManager type="JDBC"/>
        <!-- 配置数据库连接信息 -->
        <dataSource type="POOLED">
            <property name="driver" value="com.mysql.jdbc.Driver"/>
            <property name="url" value="jdbc:mysql://localhost:3306/db?useUnicode=true"/>
            <property name="username" value="root"/>
            <property name="password" value=""/>
        </dataSource>
    </environment>
</environments>
<!-- mapper映射 -->
<mappers>
    <mapper resource="mybatis\xml\*.xml"></mapper>
</mappers>

使用：
String resource = "mybatis/mybatis-mapper.xml";
InputStream is = demo02.class.getClassLoader().getResourceAsStream(resource);
SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(is);
SqlSession session = factory.openSession();
String statement = "com.ytud.provider.mybatis.mapper.ProjectMapper.selectByPrimaryKey";
int del = session.delete(statement);
System.out.println(del);
Project project = session.selectOne(statement, 2);
System.out.println(project.getProjName());

3、mybatis+spring

applicationContext.xml

<!--加载properties文件-->
<bean id="propertyConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
    <property name="locations">
        <list>
            <value>classpath:jdbc.properties</value>
        </list>
    </property>
</bean>

 <!-- 数据源 -->  <bean id="druidSource" class="com.alibaba.druid.pool.DruidDataSource"  destroy-method="close">  <!-- 数据库基本信息配置 -->  <property name="url" value="${mysql_url}"/>  <property name="username" value="${mysql_username}"/>  <property name="password" value="${mysql_password}"/>  <property name="driverClassName" value="${mysql_driver}"/>   <property name="filters" value="${druid.filters}"/>  <!-- 最大并发连接数 -->  <property name="maxActive" value="${druid.maxActive}"/>  <!-- 初始化连接数量 -->  <property name="initialSize" value="${druid.initialSize}"/>  <!-- 配置获取连接等待超时的时间 -->  <property name="maxWait" value="${druid.maxWait}"/>  <!-- 最小空闲连接数 -->  <property name="minIdle" value="${druid.minIdle}"/>  <!-- 配置间隔多久才进行一次检测，检测需要关闭的空闲连接，单位是毫秒 -->  <property name="timeBetweenEvictionRunsMillis"  value="${druid.timeBetweenEvictionRunsMillis}"/>  <!-- 配置一个连接在池中最小生存的时间，单位是毫秒 -->  <property name="minEvictableIdleTimeMillis" value="${druid.minEvictableIdleTimeMillis}"/>  <property name="validationQuery" value="${druid.validationQuery}"/>  <property name="testWhileIdle" value="${druid.testWhileIdle}"/>  <property name="testOnBorrow" value="${druid.testOnBorrow}"/>  <property name="testOnReturn" value="${druid.testOnReturn}"/>  <property name="maxOpenPreparedStatements" value="${druid.maxOpenPreparedStatements}"/>  <!-- 打开removeAbandoned功能 -->  <property name="removeAbandoned" value="${druid.removeAbandoned}"/>  <!-- 1800秒，也就是30分钟 -->  <property name="removeAbandonedTimeout" value="${druid.removeAbandonedTimeout}"/>  <!-- 关闭abanded连接时输出错误日志 -->  <property name="logAbandoned" value="${druid.logAbandoned}"/>   <property name="queryTimeout" value="${druid.queryTimeout}"/>  </bean>   <!-- spring-mybatis配置 -->  <bean class="org.mybatis.spring.SqlSessionFactoryBean" id="sqlSessionFactory">  <property name="dataSource" ref="druidSource"/>  <property name="mapperLocations" value="classpath:mybatis/xml/*.xml"/>  <property name="configLocation" value="classpath:mybatis/mybatis-config.xml"/>  </bean>   <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">  <property name="basePackage" value="com.ytud.provider.mybatis.mapper"/>  <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/>  </bean>

<!-- 自动扫描 -->
<context:component-scan base-package="com.ytud.service.impl" />

测试代码：
//JUnit
public class test1 {
    private ProjectApiImpl projectApiImpl;
    @Before
    public void before() {
        ApplicationContext ac = new ClassPathXmlApplicationContext("applicationContext.xml");
        projectApiImpl = (ProjectApiImpl) ac.getBean("projectApiImpl");
    }
    @Test
    public void test1() {
        ProjectModel project = projectApiImpl.getProject(1);
        System.out.println(project.getProjectName());
    }
}
//spring提供JUnit测试框架
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = {"classpath:applicationContext.xml"})
public class Demo02 {
    @Resource
    private ProjectApiImpl projectApiImpl;
    @Test
    public void test1() {
        ProjectModel project = projectApiImpl.getProject(1);
        System.out.println(project.getProjectName());
    }
}

4、mybatis+spring+spring mvc

web.xml
<!-- 加载Spring容器配置，applicationContext.xml -->
<listener>
    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<!-- 设置Spring容器加载所有的配置文件的路径 -->
<context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>classpath:applicationContext.xml</param-value>
</context-param>

<!-- SpringMVC核心控制器 -->
<servlet>
    <servlet-name>mvc-dispatcher</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <!-- 设置要加载的mvc配置文件，多个用","隔开，默认WEB-INF/[servlet-name]-servlet.xml -->
    <init-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:mvc-servlet-config.xml</param-value>
    </init-param>
    <!-- 启动容器时初始化servlet -->
    <load-on-startup></load-on-startup>
</servlet>
<servlet-mapping>
    <servlet-name>mvc-dispatcher</servlet-name>
    <!-- 表示哪些请求交给Spring Web MVC处理， "/"是用来定义默认servlet映射的。也可以如"*.html"表示拦截所有以html为扩展名的请求 -->
    <url-pattern>/</url-pattern>
</servlet-mapping>
<!-- 全局过滤器 -->
<filter>
    <filter-name>characterEncodingFilter</filter-name>
    <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
    <init-param>
        <param-name>encoding</param-name>
        <param-value>UTF-</param-value>
    </init-param>
    <init-param>
        <param-name>forceEncoding</param-name>
        <param-value>true</param-value>
    </init-param>
</filter>
<filter-mapping>
    <filter-name>characterEncodingFilter</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>

mvc-servlet-config.xml
<!-- spring扫描，@Controller -->
<context:component-scan base-package="com.ytud.web"/>

<!-- 没有jsonConverter，返回字符串出现乱码 -->
<bean name="jsonConverter"
      class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter"/>
<!-- springMVC 3.1 以后使用  启动Spring MVC的注解功能，完成请求和注解POJO的映射 -->
<bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping">
</bean>
<bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter">
    <property name="messageConverters">
        <list>
            <ref bean="jsonConverter"></ref>
        </list>
    </property>
</bean>

5、mybatis+spring+spring mvc+dubbox

<!-- 自动扫描 -->
<context:component-scan base-package="com.ytud.service.impl" />