在独力的应用程序中创建和使用连接池
在独立的应用程序中创建和使用连接池
很多时候我们都需要独立开发应用程序来处理业务，这个时候也需要利用连接也来进行数据库的访问。这里我们用Apache的DBCP来构造连接池。
DBConnPool.java
package jead.chap4;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.Properties;
import org.apache.commons.dbcp.ConnectionFactory;
import org.apache.commons.dbcp.DriverManagerConnectionFactory;
import org.apache.commons.dbcp.PoolableConnectionFactory;
import org.apache.commons.dbcp.PoolingDriver;
import org.apache.commons.pool.ObjectPool;
import org.apache.commons.pool.impl.GenericObjectPool;
public class DBConnPool
{
static {
setupPool();
}
public static void setupPool()
{
System.out.println("初始化线程池");
String strDBConnUrl = "jdbc:mysql://localhost:3306/test";
// 连接名称
String strPoolName = "testPool";
String strJdbcDriverName = "com.mysql.jdbc.Driver";
String strPoolingDriverName = "org.apache.commons.dbcp.PoolingDriver";
// 接连数据库用户
String strUser = "root";
// 连接数据库密码
String strPassword = "111111";
String strUseUnicode = "true";
// 数据库使用编辑
String strCharacterEncoding = "utf-8";
// 最大活动连接
int intMaxAction = 10;
// 最大空闲连接数
int intMaxIdle = 5;
// 最大等待连接数
int intMaxWait = 100;
try {
// 加载JDBC到JVM
Class.forName(strJdbcDriverName);
// 创建通用对象池
GenericObjectPool connectionPool = new GenericObjectPool(null);
// 设置通用对象池参数
connectionPool.setMaxActive(intMaxAction);
connectionPool.setMaxIdle(intMaxIdle);
connectionPool.setMaxWait(intMaxWait);
// 接下来创建连接工厂池，对象会利用连接工产生成数据库连接
// 这里使用的是DriverManagerConnectionFactory连接工产，利用
// 连接参数来构造这个连接工产
Properties prop = new Properties();
prop.setProperty("user", strUser);
prop.setProperty("password", strPassword);
prop.setProperty("useUnicode", strUseUnicode);
prop.setProperty("characterEncoding", strCharacterEncoding);
ConnectionFactory connectionFactory = new DriverManagerConnectionFactory(
strDBConnUrl, prop);
// 现在创建PoolableConnectionFactory对象，安包装了连接工产创建 的连接 使用其池的功能
@SuppressWarnings("unused")
PoolableConnectionFactory poolableConnectionFactory = new PoolableConnectionFactory(
connectionFactory, connectionPool, null, null, false, true);
// 最后，创建连接也驱动
Class.forName(strPoolingDriverName);
PoolingDriver driver = (PoolingDriver) DriverManager
.getDriver("jdbc:apache:commons:dbcp:");
// 用连接池驱动注册连接池到JVM
driver.registerPool(strPoolName, connectionPool);
// 完成以上步骤以后就可以使用连接池了，我们利用getConnection从池是取得一个返回
} catch (Exception e) {
e.printStackTrace();
}
System.out.println("连接池：" + strPoolName + "建立成功！");
}
//获取连接
public static Connection getConnection(String strPoolName)
throws SQLException, ClassNotFoundException
{
Connection conn = null;
conn = DriverManager.getConnection("jdbc:apache:commons:dbcp:"
+ strPoolName);
return conn;
}
//关闭连接池
public static void closePool(String strPoolName)
{
try {
PoolingDriver driver=(PoolingDriver) DriverManager.getDriver("jdbc:apache:commons:dbcp:");
driver.closePool(strPoolName);
} catch (Exception e) {
e.printStackTrace();
}
System.out.println("连接池"+strPoolName+" 成功关闭");
}
//打印连接状态
public static void printDriverStats(String strPoolName)
{
try {
PoolingDriver driver=(PoolingDriver) DriverManager.getDriver("jdbc:apache:commons:dbcp:");
ObjectPool connectionPool= driver.getConnectionPool(strPoolName);
System.out.println("NumActive:"+connectionPool.getNumActive());
System.out.println("NumIdle:"+connectionPool.getNumIdle());
} catch (Exception e) {
e.printStackTrace();
}
}
}
TestConnPool.java
运行结果：
初始化线程池 连接池：testPool建立成功！ id:1 username:张三 password:111111 desc:一个人 id:2 username:李四 password:111111 desc:一个人 id:3 username:王五 password:111111 desc:一个人 id:4 username:马拉多纳 password:10 desc:阿根足球运动员 id:5 username:坎通纳 password:10 desc:法国足球运动员 id:6 username:罗马里奥 password:10 desc:法国足球运动员 id:7 username:古利特 password:10 desc:荷兰足球运动员package jead.chap4;
import java.sql.*;
public class TestConnPool
{
private boolean stop = false;
public void testQuery()
{
Connection conn = null;
Statement smt = null;
ResultSet rs = null;
try {
conn = DBConnPool.getConnection("testPool");
smt = conn.createStatement();
String sql = "select * from login";
rs = smt.executeQuery(sql);
while (rs.next()) {
System.out.println("id:" + rs.getInt("_id") + " username:"
+ rs.getString("_username") + " password:"
+ rs.getString("_password") + " desc:"
+ rs.getString("_desc"));
}
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
if (rs != null)
rs.close();
if (smt != null)
smt.close();
if (conn != null)
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
public static void main(String[] args)
{
try {
Class.forName("jead.chap4.DBConnPool");
} catch (Exception e) {
e.printStackTrace();
}
TestConnPool tcp = new TestConnPool();
tcp.testQuery();
}
}