Apache—DBUtils框架开发

private static ComboPooledDataSource ds;
//线程数据连接管理器
private static ThreadLocal<Connection> map = new ThreadLocal<Connection>();

static{
try{
//使用3cp0数据连接池获取数据资源
ds = new ComboPooledDataSource();
}catch (Exception e) {
throw new ExceptionInInitializerError(e);
}
}

public static Connection getConnection() throws SQLException{
Connection conn = map.get(); //获取到当前线程上绑定的链接
if(conn==null){
conn = ds.getConnection();
map.set(conn); //把链接绑定到当前线程上
}
return conn;
}
//开启事务
public static void startTransaction(){
try{
Connection conn = map.get(); //获取到当前线程上绑定的链接
if(conn==null){
conn = ds.getConnection();
map.set(conn);
}
conn.setAutoCommit(false);
}catch (Exception e) {
throw new RuntimeException(e);
}
}
//提交事务
public static void commitTransaction(){
try{
Connection conn = map.get(); //获取到当前线程上绑定的链接
if(conn!=null){
conn.commit();
}
}catch (Exception e) {
throw new RuntimeException(e);
}
}
//回滚事务
public static void rollbackTransaction(){
try{
Connection conn = map.get(); //获取到当前线程上绑定的链接
if(conn!=null){
conn.rollback();
conn.commit();
}
}catch (Exception e) {
throw new RuntimeException(e);
}
}
//关闭连接
public static void closeConnection(){
try{
Connection conn = map.get(); //获取到当前线程上绑定的链接
if(conn!=null){
try{
conn.close(); //求求大家，千万注意
}finally{
map.remove();//解除当前线程绑定的资源
}
}
}catch (Exception e) {
throw new RuntimeException(e);
}
}

public static DataSource getDataSource(){
return ds;
}

c3p0配置文件

<named-config name="mysql">
<property name="driverClass">com.mysql.jdbc.Driver</property>
<property name="jdbcUrl">jdbc:mysql://localhost:3306/day16</property>
<property name="user">root</property>
<property name="password">root</property>

<property name="acquireIncrement">5</property>
<property name="initialPoolSize">10</property>
<property name="minPoolSize">5</property>
<property name="maxPoolSize">30</property>
</named-config>