上一次我們說到了Spring的AOP

總體目錄在此

本節來說下：
Spring JDBC Template

代碼–》JDBC API–》JDBC驅動–》數據庫
代碼–》JDBC Template—》JDBC API–》JDBC驅動–》數據庫

JDBC Template提供統一的模板方法，在保留代碼靈活性的基礎上，儘量減少持久化代碼

JDBC Template基本使用
execute方法執行DDL（數據定義語言：定義表名，標題，列名，及其結構）語句
update與batchUpdate方法更新方法
update 對數據進行增刪改操作
batchUpdate批量增刪改
query和queryXXX方法查詢方法

查詢簡單數據項
獲取一個數據
獲取多個數據
獲取複雜對象（封裝爲Map）
查詢複雜對象RowMapper接口
call方法調用存儲過程

優點：
   簡單
   靈活
缺點：
    Java代碼和SQL代碼摻雜
    功能不豐富

對於如何在idea環境下配置數據源的詳細步驟，idea的內置功能很方便我們查看和配置我們的數據庫，此部分在文章末尾，請直接下滑
爲了逐個實現JDBCTemplate我們首先創建測試用數據庫

代碼如下

drop database if exists selection_course;

create database selection_course;
use selection_course;

create table course
(
   id                   int not null auto_increment,
   name                 char(20),
   score                int,
   primary key (id)
);

create table selection
(
   student              int not null,
   course               int not null,
   selection_time       datetime,
   score                int,
   primary key (student, course)
);

create table student
(
   id                   int not null auto_increment,
   name                 varchar(20),
   sex                  char(2),
   born                 date,
   primary key (id)
);

alter table selection add constraint FK_Reference_1 foreign key (course)
      references course (id) on delete restrict on update restrict;

alter table selection add constraint FK_Reference_2 foreign key (student)
      references student (id) on delete restrict on update restrict;

insert into course(id,name,score) values(1001,'英語',5);
insert into course(id,name,score) values(1002,'操作系統',5);
insert into course(id,name,score) values(1003,'數據結構',3);

commit;

接着我們建立新的maven工程
具體步驟詳見

鏈接

創建好之後我們的項目結構如下

創建好對應的包，然後我們修改下pom文件來引入我們項目所需要的依賴

<?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.jjyu</groupId>
    <artifactId>sc</artifactId>
    <version>1.0-SNAPSHOT</version>
    <properties><spring.version>4.0.2.RELEASE</spring.version>
            </properties>
    <dependencies>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.47</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-beans</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aop</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-tx</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
        </dependency>
    </dependencies>


</project>

一共這些，你引入對了嗎？
接下來爲了操作數據庫我們要在entity包中創建與數據庫對應的實體類
三個實體類如下所示

public class Course {
    private int id;
    private String name;
    private int score;
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public int getScore() {
        return score;
    }
    public void setScore(int score) {
        this.score = score;
    }
}

public class Selection {
    private int sid;
    private int cid;
    private Date selTime;
    private int score;
    public int getSid() {
        return sid;
    }
    public void setSid(int sid) {
        this.sid = sid;
    }
    public int getCid() {
        return cid;
    }
    public void setCid(int cid) {
        this.cid = cid;
    }
    public Date getSelTime() {
        return selTime;
    }
    public void setSelTime(Date selTime) {
        this.selTime = selTime;
    }
    public int getScore() {
        return score;
    }
    public void setScore(int score) {
        this.score = score;
    }
}

public class Student {
    private int id;
    private String name;
    private String sex;
    private Date born;
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getSex() {
        return sex;
    }
    public void setSex(String sex) {
        this.sex = sex;
    }
    public Date getBorn() {
        return born;
    }
    public void setBorn(Date born) {
        this.born = born;
    }
    @Override
    public String toString() {
        return "Student: " +
                "id=" + id +
                ", name='" + name + '\'' +
                ", sex='" + sex + '\'' +
                ", born=" + born ;
    }
}

接下來我們配置Spring的核心配置文件spring.xml，建立起數據庫和我們項目的連接

<?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"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xmlns:tx="http://www.springframework.org/schema/tx"
       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.xsd
    http://www.springframework.org/schema/aop
    http://www.springframework.org/schema/aop/spring-aop.xsd
    http://www.springframework.org/schema/tx
    http://www.springframework.org/schema/tx/spring-tx.xsd">


<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/selection_course?useUnicode=true&amp;characterEncoding=utf-8"/>
        <property name="username" value="root"/>
        <property name="password" value="root"/>
    </bean>

    <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
        <property name="dataSource" ref="dataSource"/>
<!--自動掃描-->
    </bean>
    <context:component-scan base-package="com.jjyu.src"/>
    </beans>

上面的準備工作終於結束啦。

再做這些項目的時候，測試永遠不是麻煩的，麻煩的永遠是配置和準備工作。

接下來便一塊看看測試我們JDBCTemplate的各種方法吧。ok！let’s go！！！

public class Test {
    //獲取到數據庫操作對象
   private JdbcTemplate jdbcTemplate;
    {
        ApplicationContext context=new ClassPathXmlApplicationContext("spring.xml");
         jdbcTemplate=(JdbcTemplate) context.getBean("jdbcTemplate");
    }
    //接下來的方法就是單個單個的了，如果你真的在coding的話，
    //就把下面的代碼插入到這行註釋之後即可，即可測試，如下圖

 }

JDBC Template基本使用測試代碼

execute方法執行DDL（數據定義語言：定義表名，標題，列名，及其結構）語句

 @org.junit.Test
    public void testExecute(){
      jdbcTemplate.execute("create table user2(id int,name VARCHAR (20))");
    }

你看多了個user2

update與batchUpdate方法更新方法
update 對數據進行增刪改操作
batchUpdate批量增刪改

 @org.junit.Test
    public void testUpdate(){
        String sql="insert into student(name,sex) values(?,?)";
        jdbcTemplate.update(sql,new Object[]{"apple","男"});
    }
    @org.junit.Test
    public void testUpdate2(){
        String sql="UPDATE  student set sex=? where id=?";
        jdbcTemplate.update(sql,"b",1);
    }
   @org.junit.Test
    public void testBatchUpdate(){
        String[] sql={
                "insert into student(name,sex) values('b','n')",
                "insert into student(name,sex) values('c','b')",
                "update  student set sex='n' where id=1"
        };
        jdbcTemplate.batchUpdate(sql);
    }
    @org.junit.Test
    public void testBatchUpdate2(){
        String sql="insert into selection(student,course) values(?,?)";
        List<Object[]> list=new ArrayList<Object[]>();
        list.add(new Object[]{1,1001});
        list.add(new Object[]{1,1003});

        jdbcTemplate.batchUpdate(sql,list);
    }

query和queryXXX方法查詢方法
查詢簡單數據項
獲取一個數據

 @org.junit.Test
    public void testQuerySimple(){
        String sql="select count(*) from student";

        int count=jdbcTemplate.queryForObject(sql,Integer.class);
        System.out.println(count);
    }
    @org.junit.Test
    public void testQuerySimple2(){
        String sql="select name from student where sex=?";

        List<String> count=jdbcTemplate.queryForList(sql,String.class,"n");
        System.out.println(count);
    }

獲取多個數據
獲取複雜對象（封裝爲Map）

@org.junit.Test
    public void testQueryMap(){
        String sql="select * from student where id=?";

        Map<String,Object> count=jdbcTemplate.queryForMap(sql,1);
        System.out.println(count);
    }
    @org.junit.Test
    public void testQueryMap2(){
        String sql="select * from student ";

       List< Map<String,Object>> count=jdbcTemplate.queryForList(sql);
        System.out.println(count);
    }

查詢複雜對象RowMapper接口
call方法調用存儲過程

  @org.junit.Test
    public void testQueryEnetity1(){
        String sql="select * from student where id=? ";
        Student student=jdbcTemplate.queryForObject(sql, new StudentRowMapper(), 1);

        System.out.println(student);
    }
    @org.junit.Test
    public void testQueryEnetity2(){
        String sql="select * from student  ";
       List<Student>  students=jdbcTemplate.query(sql, new StudentRowMapper());

        System.out.println(students);
    }
    private  class StudentRowMapper implements RowMapper<Student>{
        public Student mapRow(ResultSet resultSet, int i) throws SQLException {
            Student stu=new Student();
            stu.setId(resultSet.getInt("id"));
            stu.setName(resultSet.getString("name" ));
            stu.setSex(resultSet.getString("sex"));
            stu.setBorn(resultSet.getDate("born"));
            return stu;
        }
    }

接下來爲了方便加深理解，我們實現下模擬業務邏輯中的增刪改查

對應代碼

public interface CourseDao {
    void insert(Course stu);
    void update(Course stu);
    void delete(int id);
    Course select(int id);
    List<Course> selectAll();
}




@Repository
public class CourseDaoImpl implements CourseDao {
    @Autowired
    private JdbcTemplate jdbcTemplate;


    public void insert(Course course) {
        String sql ="insert into student(name,score) values(?,?)";
        jdbcTemplate.update(sql,course.getName(),course.getScore());
    }
    public void update(Course course) {
        String sql="update course set name=?,score where id=?";    jdbcTemplate.update(sql,course.getName(),course.getScore(),course.getId());

    }

    public void delete(int id) {
        String sql="delete from course where id=?";
        jdbcTemplate.update(sql,id);
    }

    public Course select(int id) {
        String sql ="select * from course where id=?";
        return jdbcTemplate.queryForObject(sql,new CourseRowMapper(),id);

    }

    public List<Course> selectAll() {
        String sql ="select * from course ";
        return jdbcTemplate.query(sql,new CourseRowMapper());
    }
    private  class CourseRowMapper implements RowMapper<Course> {
        public Course mapRow(ResultSet resultSet, int i) throws SQLException {
            Course course=new Course();
            course.setId(resultSet.getInt("id"));
            course.setName(resultSet.getString("name" ));
            course.setScore(resultSet.getInt("score"));

            return course;
        }
    }
}



public interface SeletcionDao {
    void insert(List<Selection> seles);
    void delete(int sid,int cid);
    List<Map<String,Object>> selectByStudent(int sid);
    List<Map<String,Object>> selectByCourse(int cid);
}




@Repository
public class SelectionDaoImpl implements SeletcionDao {
    @Autowired
    private JdbcTemplate jdbcTemplate;

    public void insert(List<Selection> seles) {
        String sql="insert into selection values(?,?,?,?)";
        List<Object[]> list=new ArrayList<Object[]>();
        for(Selection selection:seles){
            Object[] args=new Object[4];
            args[0]=selection.getSid();
            args[1]=selection.getCid();
            args[2]=selection.getSelTime();
            args[3]=selection.getScore();
            list.add(args);
        }
        jdbcTemplate.batchUpdate(sql,list);

    }


    public void delete(int sid,int cid) {
        String sql="delete from selection where student=? and course=?";
        jdbcTemplate.update(sql,sid,cid);

    }

    public List<Map<String, Object>> selectByStudent(int sid) {
        String sql="select se.* , stu.name sname ,cou.name cname" +
                "from selection se left join student stu on se.student=stu.id " +
                "left join course cou onse.course=cou.id"+
                "where student=?";
        return jdbcTemplate.queryForList(sql,sid);
    }

    public List<Map<String, Object>> selectByCourse(int cid) {
        String sql="select se.* , stu.name sname ,cou.name cname" +
                "from selection se left join student stu on se.student=stu.id " +
                "left join course cou onse.course=cou.id"+
                "where course=?";
        return jdbcTemplate.queryForList(sql,cid);
    }
}



public interface StudentDao {
    void insert(Student stu);
    void update(Student stu);
    void delete(int id);
    Student select(int id);
    List<Student> selectAll();
}





@Repository("studentDaoImpl")
public class StudentDaoImpl implements StudentDao {
    @Autowired
    private JdbcTemplate jdbcTemplate;

    public void insert(Student stu) {
       String sql ="insert into student(name,sex,born) values(?,?,?)";
        jdbcTemplate.update(sql,stu.getName(),stu.getSex(),stu.getBorn());
    }

    public void update(Student stu) {
        String sql="update student set name=?,sex=?, born=? where id=?";
        jdbcTemplate.update(sql,stu.getName(),stu.getSex(),stu.getBorn(),stu.getId());

    }

    public void delete(int id) {
       String sql="delete from student where id=?";
        jdbcTemplate.update(sql,id);
    }

    public Student select(int id) {
        String sql ="select * from student where id=?";
        return jdbcTemplate.queryForObject(sql,new StudentRowMapper(),id);
    }

    public List<Student> selectAll() {
        String sql ="select * from student ";
        return jdbcTemplate.query(sql,new StudentRowMapper());
    }
    private  class StudentRowMapper implements RowMapper<Student> {
        public Student mapRow(ResultSet resultSet, int i) throws SQLException {
            Student stu=new Student();
            stu.setId(resultSet.getInt("id"));
            stu.setName(resultSet.getString("name" ));
            stu.setSex(resultSet.getString("sex"));
            stu.setBorn(resultSet.getDate("born"));
            return stu;
        }
    }
  
}

此爲idea環境下配置項目數據庫

在此處選擇數據庫。

Spring菜鳥小白學習筆記---此節圖片特多，逐步講解Spring jdbcTemplate&&&&idea環境下配置項目數據庫

總體目錄在此

鏈接

上面的準備工作終於結束啦。

JDBC Template基本使用測試代碼

此爲idea環境下配置項目數據庫

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