ORA-12516，TNS：监听器找不到可用的处理程序
我的错误：
java.sql.SQLException: Listener refused the connection with the following error: ORA-12516, TNS:listener could not find available handler with matching protocol stack The Connection descriptor used by the client was: //10.2.5.21:9001/XE at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java :112) at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java :261) at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:387) at oracle.jdbc.driver.PhysicalConnection.(PhysicalConnection.java: 414) at oracle.jdbc.driver.T4CConnection.(T4CConnection.java:165) at oracle.jdbc.driver.T4CDriverExtension.getConnection(T4CDriverExtensio n.java:35) at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:801) at oracle.jdbc.pool.OracleDataSource.getPhysicalConnection(OracleDataSou rce.java:297) at oracle.jdbc.pool.OracleDataSource.getConnection(OracleDataSource.java :221) at oracle.jdbc.pool.OracleDataSource.getConnection(OracleDataSource.java :165) at utilityService.DB_util.setOracleConnectionActive(DB_util.java:99) at utilityService.DB_util.getRecPreparedAuthentication(DB_util.java:124) 我的常见数据库连接类：
package utilityService; import java.sql.CallableStatement; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; import oracle.jdbc.pool.OracleDataSource; public class DB_util { String propValue = ""; ResultSet rec = null; Statement stm = null; PreparedStatement pre_stm = null; CallableStatement call_stm = null; Connection conn1 = null; /** * Constructure to get oracle connection */ public DB_util() { Util util=new Util(); propValue=util.getFilePathToSave(); //propValue = Util.propValue;// get oracle connection setOracleConnectionActive(); } /** * Close all oracle connections and result sets. */ public void setOracleConnectionClose() { try { if (conn1 != null || !conn1.isClosed()) { if (rec != null) { rec.close(); rec = null; } if (stm != null) { stm.close(); stm = null; } if (pre_stm != null) { pre_stm.close(); pre_stm = null; } if (call_stm != null) { call_stm.close(); call_stm = null; } conn1.commit(); conn1.close(); conn1 = null; } } catch (Exception ex) { ex.printStackTrace(); } } /** * return a result set according to sql sent * * @param SQL * @return */ public ResultSet getRec(String SQL) { try { setOracleConnectionActive(); stm = conn1.createStatement(); rec = stm.executeQuery(SQL); return rec; } catch (Exception ex) { ex.printStackTrace(); return rec; } } /** * Activate oracle connection */ private void setOracleConnectionActive() { try { if (conn1 == null || conn1.isClosed()) { OracleDataSource ods = new OracleDataSource(); if (propValue != null) { ods.setURL(propValue); } conn1 = ods.getConnection(); System.out.println("DB connection CONNECTED......"); conn1.setAutoCommit(false); } } catch (Exception ex) { //setOracleConnectionActive(); ex.printStackTrace(); System.out.println("DB connection FAILED......"); } } /** * send prepared result set with user authenticate * * @param SQL * @param strInputUserMobile * @param strInputUserName * @param strInputUserPassword * @return */ public ResultSet getRecPreparedAuthentication(String SQL, String strInputUserMobile, String strInputUserName, String strInputUserPassword) { try { setOracleConnectionActive(); pre_stm = conn1.prepareStatement(SQL); pre_stm.setString(1, strInputUserMobile); pre_stm.setString(2, strInputUserName); pre_stm.setString(3, strInputUserPassword); rec = pre_stm.executeQuery(); return rec; } catch (Exception ex) { ex.printStackTrace(); return rec; } } /** * insert sql to db which is send as a sql * * @param SQL * @return */ public int insertSQL(String SQL) { int output = 0; try { setOracleConnectionActive(); stm = conn1.createStatement(); output = stm.executeUpdate(SQL); conn1.commit(); output = 1; } catch (Exception ex) { try { conn1.rollback(); output = 0; } catch (SQLException e) { e.printStackTrace(); output = 0; } ex.printStackTrace(); } return output; } /** * Send a callable statement according to sent sql * * @param SQL * @return */ public CallableStatement callableStatementSQL(String SQL) { int output = 0; try { setOracleConnectionActive(); call_stm = conn1.prepareCall(SQL); } catch (Exception ex) { try { conn1.rollback(); output = 0; } catch (SQLException e) { e.printStackTrace(); output = 0; } ex.printStackTrace(); } return call_stm; } }
我引用此类的每个事务都执行我的获取和CRUD操作。 我的代码有问题吗？
你打开了很多联系，这就是问题所在。 我认为在您的代码中，您没有关闭打开的连接。
数据库跳出可以暂时解决，但在连续执行时会重新出现。 此外，还应validation与数据库的并发连接数。 如果已达到最大DB进程参数，则这是常见症状。
由这个主题提供： https ： //community.oracle.com/thread/362226？tstart = -1
我用sql命令行修复了这个问题：
connect system/ alter system set processes=300 scope=spfile; alter system set sessions=300 scope=spfile;
重启数据库。