Java用C3P0、DBUtils连接操作数据库综合实例
编辑工具：Eclipse
数据库：MySQL
实例内容：操作数据库中的Student表
需要导入的jar包：
Student的属性文件：存放DbUtils连接数据库和C3P0配置连接池的信息：
C3P0.properties:
USER=root
PASSWORD=root
Driver=com.mysql.cj.jdbc.Driver
URL=jdbc:mysql://localhost:3306/mydb?useUnicode=true&characterEncoding=utf8&serverTimezone=GMT%2B8&useSSL=false
#当连接池中的连接耗尽的时候c3p0一次同时获取的连接数，default：3
c3p0.acquireIncrement=3
#没60秒检查所有连接池中的空闲 连接。default：0
c3p0.idleConnectionTestPeriod=60
c3p0.initialPoolSize=10
#最大空闲时间，60秒内未连接被丢弃，默认为0，永不丢弃，default：0
c3p0.maxIdleTime=60
c3p0.maxPoolSize=20
c3p0.minPoolSize=5Student的domain类：
private String stu_name;
private int stu_age;
private String stu_class;
private String stu_course;
private int stu_score;
public Student() {}
public Student(String stu_name, int stu_age, String stu_class, String stu_course, int stu_score) {
super();
this.stu_name = stu_name;
this.stu_age = stu_age;
this.stu_class = stu_class;
this.stu_course = stu_course;
this.stu_score = stu_score;
}
@Override
public String toString() {
return "Student [stu_name=" + stu_name + ", stu_age=" + stu_age + ", stu_class=" + stu_class + ", stu_course="
+ stu_course + ", stu_score=" + stu_score + "]";
}
public String getStu_name() {
return stu_name;
}
public void setStu_name(String stu_name) {
this.stu_name = stu_name;
}
public int getStu_age() {
return stu_age;
}
public void setStu_age(int stu_age) {
this.stu_age = stu_age;
}
public String getStu_class() {
return stu_class;
}
public void setStu_class(String stu_class) {
this.stu_class = stu_class;
}
public String getStu_course() {
return stu_course;
}
public void setStu_course(String stu_course) {
this.stu_course = stu_course;
}
public int getStu_score() {
return stu_score;
}
public void setStu_score(int stu_score) {
this.stu_score = stu_score;
}
}C3P0的配置工具类：
public class DBPoolUtils {
//取得属性文件中的信息
private static ResourceBundle bundle=ResourceBundle.getBundle("com/demo4/C3P0");
//数据库的连接池
private static ComboPooledDataSource dataSource=new ComboPooledDataSource();
static
{
try {
//配置数据库的驱动
dataSource.setDriverClass(bundle.getString("Driver"));
//设置数据库的url
dataSource.setJdbcUrl(bundle.getString("URL"));
//设置数据库的用户名
dataSource.setUser(bundle.getString("USER"));
//设置数据库的密码
dataSource.setPassword(bundle.getString("PASSWORD"));
//设置连接池中耗尽的时候c3p0一次同时获取的连接数
dataSource.setAcquireIncrement(Integer.parseInt(bundle.getString("c3p0.acquireIncrement")));
//设置检查连接池的空闲连接的时间
dataSource.setIdleConnectionTestPeriod(Integer.parseInt(bundle.getString("c3p0.idleConnectionTestPeriod")));
dataSource.setInitialPoolSize(Integer.parseInt(bundle.getString("c3p0.initialPoolSize")));
//设置最大的空闲时间
dataSource.setMaxIdleTime(Integer.parseInt(bundle.getString("c3p0.maxIdleTime")));
//设置最大的连接池数量
dataSource.setMaxPoolSize(Integer.parseInt(bundle.getString("c3p0.maxPoolSize")));
//设置最小的连接池数量
dataSource.setMinPoolSize(Integer.parseInt(bundle.getString("c3p0.minPoolSize")));
} catch (PropertyVetoException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public static Connection getConnection() throws SQLException
{
return dataSource.getConnection();
}
}数据操作Dao接口：用于规定操作的方法
public interface StudentDao {
//增加一个学生
boolean addStudent(Student student);
//更新一个学生
boolean updateStudent(Student student);
//删除一个学生
boolean deleteStudent(String name);
//查看一个学生
Student viewStudentByName(String name);
//得到一个学生的所有信息
Map viewMapBuName(String name);
//得到多个的学生
List queryMultiStudent(String name);
//得到多个学生的所有信息
List>queryMultiMapForStudent(int score);
} 数据操作DAO接口的实现类：用于具体的实现操作
public class StudentDaoImpl implements StudentDao{
public StudentDaoImpl() {}
@Override
public boolean addStudent(Student student) {
//使用DBUtils工具类，操作数据库
QueryRunner queryRunner=new QueryRunner();
Connection connection=null;
String sql="insert into student values(?,?,?,?,?)";
boolean flag=false;
//使用JDBC连接池
try {
connection=DBPoolUtils.getConnection();//得到数据库连接
int result=queryRunner.update(connection,sql,new Object[] {student.getStu_name(),student.getStu_age(),student.getStu_class(),student.getStu_course(),student.getStu_score()});//使用DButils工具执行更新操作
flag=result>0?true:false;
} catch (SQLException e) {
e.printStackTrace();
}finally
{
try {
DbUtils.close(connection);//关闭数据库连接
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
return flag;
}
@Override
public boolean updateStudent(Student student) {
QueryRunner queryRunner =new QueryRunner();
Connection connection=null;
String sql="update student set stu_age=?,stu_class=?,stu_course=?,stu_score=? where stu_name=?";
boolean flag=false;
try {
connection=DBPoolUtils.getConnection();
int result=queryRunner.update(connection,sql,new Object[] {student.getStu_age(),student.getStu_class(),student.getStu_course(),student.getStu_score(),student.getStu_name()});
flag=result>0?true:false;
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally
{
try {
DbUtils.close(connection);//关闭数据库连接
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
return flag;
}
@Override
public boolean deleteStudent(String name) {
QueryRunner queryRunner =new QueryRunner();
Connection connection=null;
String sql="delete from student where stu_name=?";
boolean flag=false;
try {
connection=DBPoolUtils.getConnection();
int result=queryRunner.update(connection,sql,new Object[] {name});
flag=result>0?true:false;
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally
{
try {
DbUtils.close(connection);//关闭数据库连接
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
return flag;
}
@Override
public Student viewStudentByName(String name) {
QueryRunner queryRunner =new QueryRunner();
Connection connection=null;
String sql="select * from student where stu_name=?";
try {
connection=DBPoolUtils.getConnection();
return (Student) queryRunner.query(connection,sql,new BeanHandler<>(Student.class),new Object[] {name});
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally
{
try {
DbUtils.close(connection);//关闭数据库连接
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
return null;
}
@Override
public Map viewMapBuName(String name) {
QueryRunner queryRunner =new QueryRunner();
Connection connection=null;
String sql="select * from student where stu_name=?";
try {
connection=DBPoolUtils.getConnection();
return queryRunner.query(connection,sql,new MapHandler(),new Object[] {name});
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally
{
try {
DbUtils.close(connection);//关闭数据库连接
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
return null;
}
@Override
public List queryMultiStudent(String name) {
QueryRunner queryRunner =new QueryRunner();
Connection connection=null;
String sql="select * from student where stu_name like ?";
try {
connection=DBPoolUtils.getConnection();
return queryRunner.query(connection,sql,new BeanListHandler<>(Student.class),new Object[] {"%"+name+"%"});
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally
{
try {
DbUtils.close(connection);//关闭数据库连接
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
return null;
}
@Override
public List> queryMultiMapForStudent(int score) {
QueryRunner queryRunner =new QueryRunner();
Connection connection=null;
String sql="select * from student where stu_score > ?";
try {
connection=DBPoolUtils.getConnection();
return queryRunner.query(connection,sql,new MapListHandler(),new Object[] {score});
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally
{
try {
DbUtils.close(connection);//关闭数据库连接
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
return null;
}
} 下面是简单的一个添加学生功能的测试：
public class TestStudent {
public static void main(String[] args) {
StudentDaoImpl test=new StudentDaoImpl();
Student student=new Student("李白",23,"B3","物理",89);
if(test.addStudent(student))
{
System.out.println("插入成功");
}else
{
System.out.println("插入失败");
}
}
}