Spring入门（三）

Spring 的JDBC模板

（一）Spring 其实提供了很多的持久化技术的模板类简化编程。
包括：
– JDBC
– Hibernate3.0
– IBatis（MyBatis）
– JPA

今天主要讲一下JDBC模板

（二）实战

1. 在mysql中创建student表

            包括id  name   age属性
   

   2.Maven依赖的引入

      所需maven依赖如下
   

<?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>groupId</groupId>
    <artifactId>hello</artifactId>
    <version>1.0-SNAPSHOT</version>

    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/org.springframework/spring-context -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>4.3.18.RELEASE</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.46</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-jdbc -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>4.3.18.RELEASE</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-tx -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-tx</artifactId>
            <version>4.3.18.RELEASE</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/commons-dbcp/commons-dbcp -->
        <dependency>
            <groupId>commons-dbcp</groupId>
            <artifactId>commons-dbcp</artifactId>
            <version>1.4</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/commons-pool/commons-pool -->
        <dependency>
            <groupId>commons-pool</groupId>
            <artifactId>commons-pool</artifactId>
            <version>1.6</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/com.mchange/c3p0 -->
        <dependency>
            <groupId>com.mchange</groupId>
            <artifactId>c3p0</artifactId>
            <version>0.9.5.2</version>
        </dependency>

    </dependencies>
</project>

3.

Student.java文件

public class Student {
    private Integer age;
    private String name;
    private Integer id;
    ......
  }

StudentMapper.java

public class StudentMapper  implements RowMapper<Student> {
    public Student mapRow(ResultSet resultSet, int i) throws SQLException {
        Student st=new Student();
        st.setId(resultSet.getInt("Id"));
        st.setName(resultSet.getString("name"));
        st.setAge(resultSet.getInt("age"));
        return st;
    }
}

StudentService.java

public interface StudentService {
    public void setDataSource(DataSource ds);

    public void create(String name, Integer age);

    public Student getStudent(Integer id);

    public List<Student> listStudents();

    public void delete(Integer id);

    public void update(Integer id, Integer age);
}

StudentJDBCTemplate.java

public class StudentJDBCTemplate implements StudentService {
    private DataSource dataSource;
    private JdbcTemplate jdbcTemplateObject;

    public void setDataSource(DataSource dataSource) {
        this.dataSource = dataSource;
        this.jdbcTemplateObject = new JdbcTemplate(dataSource);
    }

    public void create(String name, Integer age) {
        String SQL = "insert into Student (name, age) values (?, ?)";

        jdbcTemplateObject.update( SQL, name, age);
        System.out.println("Created Record Name = " + name + " Age = " + age);
        return;
    }

    public Student getStudent(Integer id) {
        String SQL = "select * from Student where id = ?";
        Student student = jdbcTemplateObject.queryForObject(SQL,
                new Object[]{id}, new StudentMapper());
        return student;
    }

    public List<Student> listStudents() {
        String SQL = "select * from Student";
        List <Student> students = jdbcTemplateObject.query(SQL,
                new StudentMapper());
        return students;
    }

    public void delete(Integer id) {
        String SQL = "delete from Student where id = ?";
        jdbcTemplateObject.update(SQL, id);
        System.out.println("Deleted Record with ID = " + id );
        return;
    }

    public void update(Integer id, Integer age) {
        String SQL = "update Student set age = ? where id = ?";
        jdbcTemplateObject.update(SQL, age, id);
        System.out.println("Updated Record with ID = " + id );
        return;
    }
}

MainApp.java测试文件

public class MainApp {
    public static void main(String[] args) {
        ApplicationContext context =
                new ClassPathXmlApplicationContext("beans.xml");

        StudentJDBCTemplate studentJDBCTemplate =
                (StudentJDBCTemplate)context.getBean("studentJDBCTemplate");

        System.out.println("------Records Creation--------" );
        studentJDBCTemplate.create("Zara", 11);
        studentJDBCTemplate.create("Nuha", 2);
        studentJDBCTemplate.create("Ayan", 15);

        System.out.println("------Listing Multiple Records--------" );
        List<Student> students = studentJDBCTemplate.listStudents();
        for (Student record : students) {
            System.out.print("ID : " + record.getId() );
            System.out.print(", Name : " + record.getName() );
            System.out.println(", Age : " + record.getAge());
        }

        System.out.println("----Updating Record with ID = 2 -----" );
        studentJDBCTemplate.update(2, 20);

        System.out.println("----Listing Record with ID = 2 -----" );
        Student student = studentJDBCTemplate.getStudent(2);
        System.out.print("ID : " + student.getId() );
        System.out.print(", Name : " + student.getName() );
        System.out.println(", Age : " + student.getAge());

    }
}

4.配置文件的编写

    提供几种方式，具体如下：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
                        http://www.springframework.org/schema/beans/spring-beans.xsd
                         http://www.springframework.org/schema/context
                         http://www.springframework.org/schema/context/spring-context-4.3.xsd
">


    <context:component-scan base-package="com.txp.dao"/>

    <!--配置Spring的内接连接池-->
    <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
        <property name="url" value="jdbc:mysql:///mybatis"/>
        <property name="username" value="root"/>
        <property name="password" value="root"/>
    </bean>

    <!--配置DBCP连接池-->
    <bean id="dataSource1" class="org.apache.commons.dbcp.BasicDataSource">
        <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
        <property name="url" value="jdbc:mysql:///mybatis"/>
        <property name="username" value="root"/>
        <property name="password" value="root"/>
    </bean>

    <!--配置DBCP连接池-->
    <bean id="dataSource2" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="com.mysql.jdbc.Driver"/>
        <property name="jdbcUrl" value="jdbc:mysql:///mybatis"/>
        <property name="user" value="root"/>
        <property name="password" value="root"/>
    </bean>
    <!--引入外部文件的方式：一-->
    <bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
        <property name="location" value="classpath:jdbc.properties"/>
    </bean>
    <!--引入外部文件的方式：二-->
    <context:property-placeholder location="classpath:jdbc.properties"/>
    <!--配置JDBC模板-->
    <bean id="studentJDBCTemplate" class="com.txp.dao.StudentJDBCTemplate">
        <property name="dataSource" ref="dataSource"/>
    </bean>
</beans> 

jdbc.properties文件内容

jdbc.driverClass=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql:///mybatis
jdbc.username=root
jdbc.password=root

最后的结果