javaweb服务MYSQL连接管理
我被web服务中的MySQL连接卡住了javaweb服务MYSQL连接管理,java,web-services,jdbc,jdbc-pool,Java,Web Services,Jdbc,Jdbc Pool,我被web服务中的MySQL连接卡住了 public class DBAccessLayer { private Connection connection = null; private Statement statement = null; private String DBFormatter = "'"; private String key; private static DataSource datasource = null; priv
public class DBAccessLayer
{
private Connection connection = null;
private Statement statement = null;
private String DBFormatter = "'";
private String key;
private static DataSource datasource = null;
private static boolean _isInitiated = false;
private static boolean _isInitializing = false;
public DBAccessLayer()
{
key = ConstantValues.getKey();
SetPoolSettings();
}
private void SetPoolSettings()
{
try
{
if (!_isInitiated && !_isInitializing)
{
_isInitializing = true;
PoolProperties p = new PoolProperties();
p.setUrl("jdbc:mysql://localhost:3306/DBName?autoReconnect=true");
p.setDriverClassName("com.mysql.jdbc.Driver");
p.setUsername("root");
p.setPassword("password");
p.setJmxEnabled(true);
p.setTestWhileIdle(false);
p.setTestOnBorrow(true);
p.setValidationQuery("SELECT 1");
p.setTestOnReturn(false);
p.setValidationInterval(30000);
p.setTimeBetweenEvictionRunsMillis(30000);
p.setMaxActive(100);
p.setInitialSize(10);
p.setMaxWait(10000);
p.setRemoveAbandonedTimeout(60);
p.setMinEvictableIdleTimeMillis(30000);
p.setMinIdle(10);
p.setLogAbandoned(true);
p.setRemoveAbandoned(true);
p.setFairQueue(true);
p
.setJdbcInterceptors("org.apache.tomcat.jdbc.pool.interceptor.ConnectionState;org.apache.tomcat.jdbc.pool.interceptor.StatementFinalizer");
datasource = new DataSource();
datasource.setPoolProperties(p);
_isInitiated = true;
}
}
finally
{
_isInitializing = false;
}
}
public void OpenConnection() throws SQLException
{
if (connection == null || connection.isClosed())
connection = datasource.getConnection();
if (statement == null || statement.isClosed())
statement = connection.createStatement();
}
public Statement getStatement() throws Exception
{
if (connection == null || connection.isClosed())
connection = datasource.getConnection();
statement = connection.createStatement();
return statement;
}
public void CloseConnection()
{
try
{
if (statement != null)
statement.close();
}
catch (Exception ignore)
{
ignore.printStackTrace();
}
try
{
if (connection != null)
connection.close();
}
catch (Exception ignore)
{
ignore.printStackTrace();
}
}
}
这是我用来连接web服务中数据库的类。。我有一些quartz计划的作业使用相同的web服务运行
我在每次web服务方法调用和每次作业启动时以及在finally block CloseConnection()中调用OpenConnection()方法
但我经常会遇到这个错误,而我在try-finally块中只关闭了一次连接
com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException:语句关闭后不允许执行任何操作
所以我的web服务方法看起来像
private DBAccessLayer _DBAccessLayer = null;
private DBAccessLayer getDBAccessLayer()
{
if (_DBAccessLayer == null)
_DBAccessLayer = new DBAccessLayer();
rerurn _DBAccessLayer;
}
public void dummyCall()
{
try
{
getDBAccessLayer.getStatement().executeQuery("Some query");
}
finally
{
getDBAccessLayer.CloseConnection();
}
}
运行时中存在多少个
DBAccessLayer
实例?希望每个电话一个。。。请记住,给定的连接不能在多个线程中并行使用。不使用标准连接池的具体原因是什么?此代码似乎不是线程安全的,正在web服务中使用。为每个调用创建一个新的“DBAccessLayer”对象。我删除了OpenConnection调用,并让它由TomcatApacheJDBC池处理@Vikdor这就是为什么我使用jdbc池,而我的web服务正在tomcat服务器上运行。又出现了一个错误:-com.mysql.jdbc.ResultSetImpl.next(ResultSetImpl.java:7008)上的java.lang.NullPointerException,错误消息为nullMore。情况更窄了,这两个错误来自一个方法,该方法是每个web服务方法调用的身份验证模块。其中,我们在两个查询中验证令牌和更新日期时间。