java – Tomcat JDBC连接池问题:“语句已关闭”
作者:互联网
我有一个使用Tomcat JDBC连接池的服务器应用程序.
这是我用来创建DataSource的代码:
PoolProperties connProperties = new PoolProperties();
connProperties.setUrl(resources.getProperty("db.url"));
connProperties.setDriverClassName(resources.getProperty("db.driver"));
connProperties.setUsername(resources.getProperty("db.user"));
connProperties.setPassword(resources.getProperty("db.password"));
connProperties.setJmxEnabled(true);
connProperties.setTestWhileIdle(false);
connProperties.setValidationQuery("SELECT 1");
connProperties.setTestOnReturn(false);
connProperties.setValidationInterval(30000);
connProperties.setTimeBetweenEvictionRunsMillis(30000);
connProperties.setMaxActive(500);
connProperties.setInitialSize(50);
connProperties.setMaxWait(10000);
connProperties.setRemoveAbandonedTimeout(60);
connProperties.setMinEvictableIdleTimeMillis(60000);
connProperties.setSuspectTimeout(60);
connProperties.setMaxIdle(50);
connProperties.setMinIdle(10);
connProperties.setLogAbandoned(false);
connProperties.setRemoveAbandoned(true);
connProperties.setJdbcInterceptors("org.apache.tomcat.jdbc.pool.interceptor.ConnectionState;"+
"org.apache.tomcat.jdbc.pool.interceptor.StatementFinalizer");
dataSource = new DataSource();
dataSource.setPoolProperties(connProperties);
然后我有一个从池中获取连接的方法
protected Connection getDbConnection() throws Exception
{
dbConn = dataSource.getConnection();
return dbConn;
}
每次我想执行一个语句我都会调用这段代码:
protected CallableStatement executeCSqlQuery(String sql) throws Exception
{
CallableStatement cstmt;
ResultSet rs = null;
try {
cstmt = getDbConnection().prepareCall(sql);
cstmt.execute();
} catch (SQLException e) {
throw e;
}
return cstmt;
}
这是对前一个代码的调用示例:
try {
cstmt = dbConnection.executeCSqlQuery(query);
rs = cstmt.getResultSet();
} catch (Exception e) {
// do smething
} finally {
try {
if (cstmt != null) {
cstmt.close();
}
dbConnection.shutdown();
} catch (Exception e) {
// do something
}
}
public void shutdown() {
if (this.dbConn != null)
this.dbConn.close();
}
我面临的问题是,当我每隔X秒在线程中执行一次调用时,我会偶尔得到一个异常“Statement is closed”.
我不确定为什么会这样.我认为它可能是驱动程序错误或与数据库连接失败的东西(在不同的服务器上运行).
我没有想法.我错过了什么?
我应该使用c3p0连接池吗?
解决方法:
我创造了赏金以帮助Reznik,但我最终通过查看他的代码来弄清楚问题是什么.
问题是每次从池中获取新连接时
protected Connection getDbConnection() throws Exception
{
dbConn = dataSource.getConnection();
return dbConn;
}
对象dbConn更新为新连接.
例:
T1调用getDbConnection()
T2调用getDbConnection()
T1执行查询,处理resultSet并调用shutdown()
public void shutdown() {
if (this.dbConn != null)
this.dbConn.close();
}
因为T2更新了对象,T2使用的连接将被T1关闭
T2尝试使用连接,但它已经关闭.
这样,不是总是更新连接,只需返回它,然后添加额外的逻辑来关闭从池中获取的连接.
标签:java,jdbc,tomcat,connection-pooling 来源: https://codeday.me/bug/20191008/1872127.html