c3p0 连接池配置

1、.3301000falsetestfalse100nullfalse60精品.360151003rootpasswordselect id from test where id=1300精品.falsetruerootfalse精品.acquireincrement - 5 acquireretryattempts - 30 acquireretrydelay - 1000 autocommitonclose - false automatictesttable - null breakafteracquirefailure - true checkouttimeout - 0 connect

2、ioncustomizerclassname - null connectiontesterclassname - com.mchange.v2.c3p0.impl.defaultconnectiontester datasourcename - 1bqp8hc8ezqxpjc1hp9gny|704baa debugunreturnedconnectionstacktraces - false description - null driverclass - com.mysql.jdbc.driver factoryclasslocation - null forceignoreunresol

3、vedtransactions - false identitytoken - 1bqp8hc8ezqxpjc1hp9gny|704baa idleconnectiontestperiod - 60 initialpoolsize - 5 jdbcurl - jdbc:mysql:/localhost:3306/db_temp?useunicode=true&characterencoding=utf-8 lastacquisitionfailuredefaultuser - null maxadministrativetasktime - 0 maxconnectionage - 0 max

4、idletime - 60 maxidletimeexcessconnections - 0 maxpoolsize - 30 maxstatements - 0 maxstatementsperconnection - 0 minpoolsize - 5 numhelperthreads - 3 numthreadsawaitingcheckoutdefaultuser - 0 preferredtestquery - null properties - user=*password=* propertycycle - 0 testconnectiononcheckin - false te

5、stconnectiononcheckout - false unreturnedconnectiontimeout - 0 usestraditionalreflectiveproxies - false精品.package com.paipaiestore.database.c3p0;import java.util.hashmap;import java.util.iterator;import java.util.map;import java.util.set;import javax.sql.datasource;import com.mchange.v2.c3p0.datasou

6、rces;/* 数据连接池工厂* author samland* version 1.0, 2006-11*/public class dbpoolfactory private static dbpoolfactory dbpoolfactory = new dbpoolfactory();/* 连接池列表*/private static map poollist = new hashmap();private dbpoolfactory()public static dbpoolfactory getinstance()return dbpoolfactory;/* 向连接池列表添加一个新

7、的池化（pooled）数据源* param key* param configfile 配置文件名。为了简化参数输入与便于外部维护，可以把配置好的文件传入这里分析*/public void add(string key, string configfile) /read config from file, and build a dbpool/* 向连接池列表添加一个新的池化（pooled）数据源* param key* param driver 数据连接驱动，如com.mysql.jdbc.driver* param url 连接串， 如jdbc:mysql:/localhost/samla

8、nd* param username 数据库连接用户名，如samland* param password 数据库连接用户密码* throws exception*/public void add(string key, string driver, string url, string username, string password)throws exceptionif (key=null) throw new exception(dbpool key cannot be null) ;class.forname(driver);datasource ds_unpooled = datas

9、ources.unpooleddatasource(url, username, password);datasource ds_pooled = datasources.pooleddatasource( ds_unpooled );if (poollist.containskey(key)poollist.remove(key);poollist.put(key, ds_pooled);/* 根据key字符串获取连接池* param key* return dbpool 连接池* throws exception*/public dbpool getdbpool(string key) t

10、hrows exceptionif (key=null) throw new exception(dbpool key cannot be null) ;datasource ds = (datasource)poollist.get(key);dbpool dbpool = new dbpool();dbpool.setds_pooled(ds);return dbpool;/四、连接池的使用通过dbpool来获取数据库连接 （jdbc connection）。4.1 由dbpoolfactory工厂产生一个dbpool4.2 同时，dbpoolfactory工厂根据传入的参数key向这个d

11、bpool注入数据源4.3 从dbpool产生线程内的connection/package com.paipaiestore.database.c3p0;import java.sql.connection;import java.sql.sqlexception;import javax.sql.datasource;public class dbpool /* 数据库连接。同一个线程使用同一个连接。*/protected static threadlocal connection = new threadlocal();/* 数据源，需由dbpoolfactory工厂注入*/private

12、 datasource ds_pooled;/* 不能独立构造，必须从dbpoolfactory工厂产生*/protected dbpool()/* get 数据源* return*/public datasource getds_pooled() return ds_pooled;/* 注入数据源* param ds_pooled*/public void setds_pooled(datasource ds_pooled) this.ds_pooled = ds_pooled;/* 获得数据库连接* 同一个线程只返回相同的一个连接。* return connection* throws s

13、qlexception*/public connection getconnection() throws sqlexceptionconnection con = (connection)connection.get();if (con=null) con = ds_pooled.getconnection();connection.set(con);return con;/五、改进线程内数据库连接的使用为了适应程序已经使用开的jdbc事务管理，因此需要改进dbpool成为transaction类，而原来的dbpool则缩减为如下代码：/public class dbpool private

14、 datasource ds_pooled;protected dbpool()public datasource getds_pooled() return ds_pooled;public void setds_pooled(datasource ds_pooled) this.ds_pooled = ds_pooled;/package com.paipaiestore.database.c3p0;import java.sql.connection;import java.sql.resultset;import java.sql.sqlexception;import java.sq

15、l.statement;import javax.sql.datasource;public class transaction /* 数据库连接。同一个线程使用同一个连接。*/protected static threadlocal connection = new threadlocal();protected static boolean isinused = false;/* 开始一个事务* 如果当前线程的数据库连接不存在，则会新获得一个数据库连接* param key* throws exception*/public static void begintransaction(str

16、ing key) throws exceptionconnection conn = (connection)connection.get();if (conn=null) conn = createconnection(key);setconnection(conn);conn.settransactionisolation(connection.transaction_read_committed);conn.setautocommit(false);isinused = true;/* 提交一个事务* throws sqlexception*/public static void com

17、mittransaction() throws sqlexception connection conn = (connection)connection.get();mit();/* 回滚一个事务* throws sqlexception*/public static void rollbacktransaction() throws sqlexception connection conn = (connection)connection.get();conn.rollback();public static boolean getisinused() return isi

18、nused;private static void closeconnection() try connection conn = (connection)connection.get();if (conn!=null) connection.set(null);conn.close();catch(sqlexception sqlexception) private static void close(resultset rs)trystatement st = rs.getstatement();connection conn = st.getconnection();rs.close()

19、;st.close();conn.close();catch(exception exception) /* 获得数据库连接* 同一个线程只返回相同的一个连接。* return* throws sqlexception*/public static connection getconnection() throws sqlexception connection conn = null;conn = (connection)connection.get();if(conn = null)throw new nullpointerexception();elsereturn conn;priva

20、te static void setconnection(connection conn)connection.set(conn);/* 获得一个新的数据库连接* param key* return connection* throws exception*/private static connection createconnection(string key)throws exception dbpoolfactory df = dbpoolfactory.getinstance();datasource ds_pooled = df.getdbpool(key).getds_pooled() ;connection conn = ds_pooled.getconnection();df = null;return conn;/六、测试/package samland;import java.sql.connection;import java.sql.resultset;import java.sql.statement;import com.paipaiestore.database.c3p0.dbpoolfactory;import com.