标签:private 查询 apr return upd HERE ext password sql语句
1、Spring整合JDBC
(1)导包(共12个):
c3p0连接池、JDBC驱动(4个)
Spring-jdbc、Spring-tx事务(2个)
(2)JDBC模板对象(JDBCTemplate)
public class JDBCDemo { public void test() throws PropertyVetoException { ComboPooledDataSource comboPooledDataSource=new ComboPooledDataSource(); comboPooledDataSource.setDriverClass("com.mysql.jdbc.Driver"); comboPooledDataSource.setJdbcUrl("jdbc:mysql:///stu_mangement"); comboPooledDataSource.setPassword("root"); comboPooledDataSource.setUser("root"); JdbcTemplate jdbcTemplate=new JdbcTemplate(); jdbcTemplate.setDataSource(comboPooledDataSource); String sql="INSERT INTO student VALUES(‘201816‘,‘1998-11-11‘,‘tx101‘,‘19837372534‘,‘男‘,‘jiayou‘,‘892‘)"; jdbcTemplate.update(sql); } public static void main(String[] args) throws PropertyVetoException { JDBCDemo jdbcDemo=new JDBCDemo(); jdbcDemo.test(); } }
需要先创建连接池,获取comboPooledDataSource对象,将该对象给模板对象,最后,利用模板对象执行sql语句。但是,这种方法是手动创建对象的,没有体现Spring的IoC特性。
2、连接池、JDBC模板、Dao配置到Spring容器
(1)创建数据库(学生信息):
(2)创建一个接口,指定实现类的方法:
import java.util.List; public interface StudentDao { void add(Student student); void delete(Integer studentno); void update(Student student); Student getStudentByNum(Integer studentno); int getTotalCount(); List<Student> getAll(); }
(3)创建实现类,实现接口中的方法:
添加学生信息:
public void add(Student student) { String sql="INSERT INTO student VALUES(?,?,?,?,?,?,?)"; jdbcTemplate.update(sql, student.getStudentno(), student.getBirthday(), student.getClassno(), student.getPhone(), student.getSex(), student.getSname(), student.getPoint()); }
根据学生的学号删除学生信息:
public void delete(Integer studentno){ String sql="delete from student where studentno=?"; jdbcTemplate.update(sql,studentno); }
修改学生信息:
public void update(Student student) { String sql="update student set phone=? where studentno=?"; jdbcTemplate.update(sql,student.getPhone(),student.getStudentno()); }
public static void main(String [] args){ ApplicationContext applicationContext=new ClassPathXmlApplicationContext("applicationContext.xml");//创建容器对象 StudentDao studentDao =(StudentDao)applicationContext.getBean("studentDao"); Student student=new Student(); student.setStudentno(201811); student.setPhone("1234567890"); studentDao.update(student); }
根据学号查询学生信息:
public Student getStudentByNum(Integer studentno) { String sql="select * from student where studentno=?"; return jdbcTemplate.queryForObject(sql, new RowMapper<Student>() { @Override public Student mapRow(ResultSet resultSet, int i) throws SQLException { Student student=new Student(); student.setStudentno(resultSet.getInt("studentno")); student.setSname(resultSet.getString("sname")); return student; } }, studentno);//这个studentno是参数传过来的 }
利用匿名内部类创建一个RowMapper,并实现该内部类里面的方法,获取一个student的对象,通过传递参数(studentno)返回符合条件的Student。
Student{sname=‘jiayou‘, studentno=201816, birthday=‘null‘, classno=‘null‘, phone=‘null‘, sex=‘null‘, point=null}
获取学生的数量:
public int getTotalCount() { String sql="select count(*) from student"; Integer count =jdbcTemplate.queryForObject(sql,Integer.class); return count; }
传递参数的时候需要指明返回的结果的数据类型,用Integer.class。
获取全部学生信息:
public List<Student> getAll() { String sql="select * from student"; List<Student> list=jdbcTemplate.query(sql, new RowMapper<Student>() { @Override public Student mapRow(ResultSet resultSet, int i) throws SQLException { Student student=new Student(); student.setStudentno(resultSet.getInt("studentno")); student.setSname(resultSet.getString("sname")); student.setPhone(resultSet.getString("phone")); student.setSex(resultSet.getString("sex")); student.setPoint(resultSet.getFloat("point")); student.setClassno(resultSet.getString("classno")); student.setBirthday(resultSet.getString("birthday")); return student; } }); return list; }
与通过学号获取学生的信息不同,获取全部学生的信息的时候不需要传递参数,因此,query方法中参数的数量为2。
(4)配置文件:只有配置好了配置文件后才能获取到对象
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://www.springframework.org/schema/beans" xmlns:util="http://www.springframework.org/schema/util" xmlns:context="http://www.springframework.org/schema/context" xmlns:aop="http://www.springframework.org/schema/aop" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.2.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util.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"> <!--将连接池放入Spring容器--> <bean name="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"> <property name="driverClass" value="com.mysql.jdbc.Driver"></property> <property name="jdbcUrl" value="jdbc:mysql:///stu_mangement"></property> <property name="user" value="root"></property> <property name="password" value="root"></property> </bean> <!--将JDBCTemplate放入Spring容器--> <bean name="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate"> <property name="dataSource" ref="dataSource"></property> </bean> <!--将StudentDao放入Spring容器中--> <bean name="studentDao" class="pers.zhb.jdbc.StudentDaoImp"> <property name="jdbcTemplate" ref="jdbcTemplate"></property> </bean> </beans>
通过配置文件,将以前手动创建对象的方式变成了通过配置文件获取对象。在这里用到了属性的注入,要注意基本数据类型和引用数据类型属性的区别。
(5)测试类:
public class Test { public static void main(String [] args){ ApplicationContext applicationContext=new ClassPathXmlApplicationContext("applicationContext.xml");//创建容器对象 StudentDao studentDao =(StudentDao)applicationContext.getBean("studentDao"); List<Student> list =studentDao.getAll(); System.out.println(list); } }
(6)StudentDaoImp类:
public class StudentDaoImp implements StudentDao{ private JdbcTemplate jdbcTemplate; public void setJdbcTemplate(JdbcTemplate jdbcTemplate) { this.jdbcTemplate = jdbcTemplate; } @Override public void add(Student student) { String sql="INSERT INTO student VALUES(?,?,?,?,?,?,?)"; jdbcTemplate.update(sql, student.getStudentno(), student.getBirthday(), student.getClassno(), student.getPhone(), student.getSex(), student.getSname(), student.getPoint()); } @Override public void delete(Integer studentno){ String sql="delete from student where studentno=?"; jdbcTemplate.update(sql,studentno); } @Override public void update(Student student) { String sql="update student set phone=? where studentno=?"; jdbcTemplate.update(sql,student.getPhone(),student.getStudentno()); } @Override public Student getStudentByNum(Integer studentno) { String sql="select * from student where studentno=?"; return jdbcTemplate.queryForObject(sql, new RowMapper<Student>() { @Override public Student mapRow(ResultSet resultSet, int i) throws SQLException { Student student=new Student(); student.setStudentno(resultSet.getInt("studentno")); student.setSname(resultSet.getString("sname")); return student; } }, studentno);//这个studentno是参数传过来的 } @Override public int getTotalCount() { String sql="select count(*) from student"; Integer count =jdbcTemplate.queryForObject(sql,Integer.class); return count; } @Override public List<Student> getAll() { String sql="select * from student"; List<Student> list=jdbcTemplate.query(sql, new RowMapper<Student>() { @Override public Student mapRow(ResultSet resultSet, int i) throws SQLException { Student student=new Student(); student.setStudentno(resultSet.getInt("studentno")); student.setSname(resultSet.getString("sname")); student.setPhone(resultSet.getString("phone")); student.setSex(resultSet.getString("sex")); student.setPoint(resultSet.getFloat("point")); student.setClassno(resultSet.getString("classno")); student.setBirthday(resultSet.getString("birthday")); return student; } }); return list; } }
另外一种方法:不需要手动书写JDBC模板对象,直接从父类中获取即可:
public class StudentDaoImp extends JdbcDaoSupport implements StudentDao{ @Override public void add(Student student) { String sql="INSERT INTO student VALUES(?,?,?,?,?,?,?)"; super.getJdbcTemplate().update(sql, student.getStudentno(), student.getBirthday(), student.getClassno(), student.getPhone(), student.getSex(), student.getSname(), student.getPoint()); } @Override public void delete(Integer studentno){ String sql="delete from student where studentno=?"; super.getJdbcTemplate().update(sql,studentno); } @Override public void update(Student student) { String sql="update student set phone=? where studentno=?"; super.getJdbcTemplate().update(sql,student.getPhone(),student.getStudentno()); } @Override public Student getStudentByNum(Integer studentno) { String sql="select * from student where studentno=?"; return super.getJdbcTemplate().queryForObject(sql, new RowMapper<Student>() { @Override public Student mapRow(ResultSet resultSet, int i) throws SQLException { Student student=new Student(); student.setStudentno(resultSet.getInt("studentno")); student.setSname(resultSet.getString("sname")); return student; } }, studentno);//这个studentno是参数传过来的 } @Override public int getTotalCount() { String sql="select count(*) from student"; Integer count =super.getJdbcTemplate().queryForObject(sql,Integer.class); return count; } @Override public List<Student> getAll() { String sql="select * from student"; List<Student> list=super.getJdbcTemplate().query(sql, new RowMapper<Student>() { @Override public Student mapRow(ResultSet resultSet, int i) throws SQLException { Student student=new Student(); student.setStudentno(resultSet.getInt("studentno")); student.setSname(resultSet.getString("sname")); student.setPhone(resultSet.getString("phone")); student.setSex(resultSet.getString("sex")); student.setPoint(resultSet.getFloat("point")); student.setClassno(resultSet.getString("classno")); student.setBirthday(resultSet.getString("birthday")); return student; } }); return list; } }
此时的配置文件少了一个继承关系:
<!--将连接池放入Spring容器--> <bean name="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"> <property name="driverClass" value="com.mysql.jdbc.Driver"></property> <property name="jdbcUrl" value="jdbc:mysql:///stu_mangement"></property> <property name="user" value="root"></property> <property name="password" value="root"></property> </bean> <!--将StudentDao放入Spring容器中--> <bean name="studentDao" class="pers.zhb.jdbc.StudentDaoImp"> <property name="dataSource" ref="dataSource"></property> </bean>
因为JDBCDaoSupport是根据连接池创建的JDBC模板,不需要再手动获取了。
3、配置文件有关JDBC的优化
(1)创建db.properties配置文件:
jdbc.driverClass=com.mysql.jdbc.Driver jdbc.jdbcUrl=jdbc:mysql:///stu_mangement jdbc.user=root jdbc.password=root
(2)在spring的配置文件中读取db.properties配置文件的数据:
<!--指定要读取的配置文件的位置--> <context:property-placeholder location="classpath:db.properties"></context:property-placeholder> <!--将连接池放入Spring容器--> <bean name="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"> <property name="driverClass" value="${jdbc.driverClass}"></property> <property name="jdbcUrl" value="${jdbc.jdbcUrl}"></property> <property name="user" value="${jdbc.user}"></property> <property name="password" value="${jdbc.password}"></property> </bean> <!--将StudentDao放入Spring容器中--> <bean name="studentDao" class="pers.zhb.jdbc.StudentDaoImp"> <property name="dataSource" ref="dataSource"></property> </bean>
这种方式虽然创建了两个配置文件看上去比较繁琐,但是,这种方式是有利于后期的维护的:方便对JDBC有关参数的修改。
标签:private 查询 apr return upd HERE ext password sql语句
原文地址:https://www.cnblogs.com/zhai1997/p/12304072.html