Spring JDBC入门程序

要了解JdbcTemplate类与Spring JDBC框架相关的概念，下面通过编写一个简单的例子演示如何使用Spring JDBC框架，在这个示例中，将在以student表上实现插入数据和读取数据的操作。

CREATE TABLE student(
   id   INT NOT NULL AUTO_INCREMENT,
   name VARCHAR(20) NOT NULL,
   age  INT NOT NULL,
   PRIMARY KEY (id)
);

SQL

创建项目

首先打开Eclipse，创建一个Maven项目，选择：File -> New -> Other… ，然后选择：Maven Project如下所示 -

下一步(Next>)，如下所示 -

填入项目的一些必要信息，如项目名称，包的名称等。

注意：第一个选项“Create a simple project(skip archetype selection)”选中。

这样就创建好了一个名称为：firstapp 的java应用程序项目(在artifactId中指定)。更新pom.xml以包含Spring-JDBC依赖关系。添加以下几个类：Student.java，StudentMapper.java，MainApp.java，StudentDAO.java和StudentJDBCTemplate.java等文件，完整的项目结构如下所示 -

文件 : pom.xml 的内容 -

<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.yiibai</groupId>
    <artifactId>fistapp</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>
    <name>Student</name>
    <url>http://maven.apache.org</url>
    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>3.8.1</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.40</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>4.1.0.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>4.1.4.RELEASE</version>
        </dependency>
    </dependencies>
</project>

以下是数据访问对象接口文件：StudentDAO.java的代码内容：

package com.yiibai;

import java.util.List;
import javax.sql.DataSource;

public interface StudentDAO {
    /**
     * This is the method to be used to initialize database resources ie.
     * connection.
     */
    public void setDataSource(DataSource ds);

    /**
     * This is the method to be used to create a record in the Student table.
     */
    public void create(String name, Integer age);

    public Student getStudent(Integer id);

    /**
     * This is the method to be used to list down all the records from the
     * Student table.
     */
    public List<Student> listStudents();
}

Java

以下是文件：Student.java的代码内容：

package com.yiibai;

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

    public void setAge(Integer age) {
        this.age = age;
    }

    public Integer getAge() {
        return age;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getName() {
        return name;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public Integer getId() {
        return id;
    }
}

Java

以下是文件：StudentMapper.java的代码内容：

package com.yiibai;

import java.sql.ResultSet;
import java.sql.SQLException;
import org.springframework.jdbc.core.RowMapper;

public class StudentMapper implements RowMapper<Student> {
    public Student mapRow(ResultSet rs, int rowNum) throws SQLException {
        Student student = new Student();
        student.setId(rs.getInt("id"));
        student.setName(rs.getString("name"));
        student.setAge(rs.getInt("age"));
        return student;
    }
}

Java

以下是文件：StudentJDBCTemplate.java的代码内容：

package com.yiibai;

import java.util.List;
import javax.sql.DataSource;
import org.springframework.jdbc.core.JdbcTemplate;

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

    public Student getStudent(Integer id) {
        // TODO Auto-generated method stub
        return null;
    }
}

Java

以下是程序执行入口文件：MainApp.java的代码内容：

package com.yiibai;

import java.util.List;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import com.yiibai.StudentJDBCTemplate;

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

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

      System.out.println("------Records Creation--------" );
      studentJDBCTemplate.create("Maxsu", 19);
      studentJDBCTemplate.create("Minsu", 23);
      studentJDBCTemplate.create("Allen", 27);

      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());
      }
   }
}

Java

以下是Bean和数据库配置文件：application-beans.xml的代码内容：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
    http://www.springframework.org/schema/beans/spring-beans-3.0.xsd ">

    <!-- Initialization for data source -->
    <bean id="dataSource"
        class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="com.mysql.jdbc.Driver" />
        <property name="url" value="jdbc:mysql://localhost:3306/test" />
        <property name="username" value="root" />
        <property name="password" value="123456" />
    </bean>

    <!-- Definition for studentJDBCTemplate bean -->
    <bean id="studentJDBCTemplate" class="com.yiibai.StudentJDBCTemplate">
        <property name="dataSource" ref="dataSource" />
    </bean>

</beans>

XML

注意： application-beans.xml 文件的位置是：{workspace}/fistapp/src/main/java 目录，如果放置错了，程序可能会因为找不到此配置文件而出错。

完成创建源代码和bean和数据库连接信息的文件配置后，运行应用程序。这里先简单说明一下运行的步骤，在项目名称(firstapp)上点击右键，在弹出的菜单中选择：【Run As】-> 【Maven test】，如下 -

在运行测试成功后，应该会输出类似以下内容(含有 BUILD SUCCESS 的信息) -

[INFO] Scanning for projects...
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building Student 0.0.1-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ fistapp ---
[WARNING] Using platform encoding (UTF-8 actually) to copy filtered resources, i.e. build is platform dependent!
[INFO] Copying 0 resource
[INFO]
[INFO] --- maven-compiler-plugin:3.1:compile (default-compile) @ fistapp ---
[INFO] Nothing to compile - all classes are up to date
[INFO]
[INFO] --- maven-resources-plugin:2.6:testResources (default-testResources) @ fistapp ---
[WARNING] Using platform encoding (UTF-8 actually) to copy filtered resources, i.e. build is platform dependent!
[INFO] Copying 0 resource
[INFO]
[INFO] --- maven-compiler-plugin:3.1:testCompile (default-testCompile) @ fistapp ---
[INFO] Nothing to compile - all classes are up to date
[INFO]
[INFO] --- maven-surefire-plugin:2.12.4:test (default-test) @ fistapp ---
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 2.904 s
[INFO] Finished at: 2017-06-08T23:36:31+08:00
[INFO] Final Memory: 11M/114M
[INFO] ------------------------------------------------------------------------

Shell

接下来，点击类文件：MainApp.java 选择【Run As】->【Java Application】，如果应用程序一切正常，这将打印以下消息：