Sprng4之JDBC--很原始的使用方法
\[www.dev1234.com]一头扎进Spring4视频教程\一头扎进Spring4源码\[www.java1234.com]《一头扎进Spring4》第九讲 源码\Spring404
此例子有对数据库的增删改查
CRUD
是指增加(Create)、读取查询(Retrieve)、更新(Update)和删除(Delete)
说它落后，因为到了
1、人人框架的xml里面根本上都看不到这些配置了：【但是比将数据库配置写在代码中要好】
2、在Dao 和Service的Impl实现中也不用在java代码里面写 SQL语句。sql语句写在xml里面
课件内容
：
bean.xml 文件：
<?xml version="1.0" encoding="UTF-8"?> <beansxmlns="http://www.springframework.org/schema/beans"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xmlns:aop="http://www.springframework.org/schema/aop"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/aop
http://www.springframework.org/schema/aop/spring-aop.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd"> <beanid="dataSource"class="org.apache.commons.dbcp.BasicDataSource"destroy-method="close"> <propertyname="driverClassName"value="${jdbc.driverClassName}"/> <propertyname="url"value="${jdbc.url}"/> <propertyname="username"value="${jdbc.username}"/> <propertyname="password"value="${jdbc.password}"/> </bean> <context:property-placeholderlocation="jdbc.properties"/>//加载本地的文件，文件如下下发 <beanid="jdbcTemplate"class="org.springframework.jdbc.core.JdbcTemplate"> <propertyname="dataSource"ref="dataSource"></property> </bean> <beanid="studentDao"class="com.java1234.dao.impl.StudentDaoImpl"> <propertyname="jdbcTemplate"ref="jdbcTemplate"></property>//注入属性，然后在StudentDaoImpl就可以用Jdbc了 </bean> <beanid="studentService"class="com.java1234.service.impl.StudentServiceImpl"> <propertyname="studentDao"ref="studentDao"></property>//StudentServiceImpl类中要有studentDao属性和get、set方法，在这里注入属性，同上 </bean> </beans>
jdbc.properties文件：
jdbc.driverClassName=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/db_spring
jdbc.username=root
jdbc.password=123456渐进式优化：
1、 直接用jdbc来链接，很麻烦try{
conn=dataSource.getConnection();
PreparedStatement ps=conn.prepareStatement(sql);
ps.setString(1, u.getName());
ps.setString(2, u.getPassword());
ps.executeUpdate();
ps.close();
}catch(SQLException e) {throw newRuntimeException(e);2、JdbcTemplatepublic voidinsert(User u) {
String sql= "insert into _user " + "values(null, ?, ?)";//普通的sql语句 JdbcTemplate template = newJdbcTemplate(dataSource);
template.update(sql,newObject[]{u.getName(), u.getPassword()});
}3、JdbcDaoSupport
这个更简单，不用new JdbcTemplate了。this.getJdbcTemplate().updatepublic voidinsert(User u) {
String sql= "insert into _user " + "values(null, ?, ?)";//普通的sql语句 this.getJdbcTemplate().update(sql, newObject[]{u.getName(), u.getPassword()});
}4、namedParameterJdbcTemplate 不用？好，用冒号加变量名
如：namedParameterJdbcTemplate= newNamedParameterJdbcTemplate(jdbcTemplate);
String selectSql= "select * from test where name=:name";
String deleteSql= "delete from test where name=:name";
Map<String, Object> paramMap = new HashMap<String, Object>();
paramMap.put("name", "name5");
namedParameterJdbcTemplate.update(insertSql, paramMap);//要传一个Map 进去。MapSqlparameterSource类型的也可以
=========例子结构==========
\src\jdbc.properties;//数据库配置
\src\beans.xml;//配置文件
\src\com\java1234\model\Student.java;//实体类
\src\com\java1234\dao\StudentDao.java;//dao接口
\src\com\java1234\dao\impl\StudentDaoImpl.java;//dao实现
\src\com\java1234\service\StudentService.java;//业务接口
\src\com\java1234\service\impl\StudentServiceImpl.java;//业务实现
\src\com\java1234\test\T.java;//调用层，可以当做UI展示层
packagecom.java1234.dao.impl;importjava.sql.ResultSet;importjava.sql.SQLException;importjava.util.ArrayList;importjava.util.List;importorg.springframework.jdbc.core.JdbcTemplate;importorg.springframework.jdbc.core.RowCallbackHandler;importcom.java1234.dao.StudentDao;importcom.java1234.model.Student;public class StudentDaoImpl implementsStudentDao{privateJdbcTemplate jdbcTemplate;public voidsetJdbcTemplate(JdbcTemplate jdbcTemplate) {this.jdbcTemplate =jdbcTemplate;
}
@Overridepublic intaddStudent(Student student) {
String sql="insert into t_student values(null,?,?)";
Object []params=newObject[]{student.getName(),student.getAge()};returnjdbcTemplate.update(sql,params);
}
@Overridepublic intupdateStudent(Student student) {
String sql="update t_student set name=?,age=? where id=?";
Object []params=newObject[]{student.getName(),student.getAge(),student.getId()};returnjdbcTemplate.update(sql,params);
}
@Overridepublic int deleteStudent(intid) {
String sql="delete from t_student where id=?";
Object []params=newObject[]{id};returnjdbcTemplate.update(sql,params);
}
@Overridepublic List<Student>findStudents() {
String sql="select * from t_student";final List<Student> studentList=new ArrayList<Student>();
jdbcTemplate.query(sql,newRowCallbackHandler(){
@Overridepublic void processRow(ResultSet rs) throwsSQLException {
Student student=newStudent();
student.setId(rs.getInt("id"));
student.setName(rs.getString("name"));
student.setAge(rs.getInt("age"));
studentList.add(student);
}
});returnstudentList;
}
}
StudentDaoImpl.java;
packagecom.java1234.test;importjava.util.List;importorg.junit.Before;importorg.junit.Test;importorg.springframework.context.ApplicationContext;importorg.springframework.context.support.ClassPathXmlApplicationContext;importcom.java1234.model.Student;importcom.java1234.service.StudentService;public classT {privateApplicationContext ac;
@Beforepublic void setUp() throwsException {
ac=new ClassPathXmlApplicationContext("beans.xml");
}
@Testpublic voidaddStudent() {
StudentService studentService=(StudentService)ac.getBean("studentService");int addNums=studentService.addStudent(new Student("����", 1));if(addNums==1){
System.out.println("��ӳɹ�");
}
}
@Testpublic voidupdateStudent() {
StudentService studentService=(StudentService)ac.getBean("studentService");int updateNums=studentService.updateStudent(new Student(8,"����2", 2));if(updateNums==1){
System.out.println("���³ɹ�");
}
}
@Testpublic voiddeleteStudent() {
StudentService studentService=(StudentService)ac.getBean("studentService");int deleteNums=studentService.deleteStudent(8);if(deleteNums==1){
System.out.println("ɾ���ɹ�");
}
}
@Testpublic voidfindStudents() {
StudentService studentService=(StudentService)ac.getBean("studentService");
List<Student> studentList=studentService.findStudents();for(Student student:studentList){
System.out.println(student);
}
}
}
T.java;//调用层