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Trouble with MySQL+TOMCAT Resultset

 
toum toum
Greenhorn
Posts: 1
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I'm programming applets & servlets on Tomcat and MySQL with my desktop (PIII500 - Win2000 - 512Mo).
- jakarta-tomcat-4.1.27-LE-jdk14
- mysql-4.0.14b
- j2sdk1.4.2
- mysql-connector-java-3.0.9-stable
- Tomcat DBCP (collections-2.1 dbcp-1.0 pool-1.0.1)
But ! I can not have stable behaviour with ResultSet :
- Sometimes all records are returned. Fine !!!
- Sometimes, 0 (Zero) record is returned. Too bad !
- Sometimes, some (but not all) records are returned. Bad !
And, When all records are not returned, one of the two following exception types is raised :
java.sql.SQLException: Operation not allowed after ResultSet closed
at com.mysql.jdbc.ResultSet.checkClosed(ResultSet.java:3601)
at com.mysql.jdbc.ResultSet.checkRowPos(ResultSet.java:3614)
....
OR
java.lang.NullPointerException
at com.mysql.jdbc.ResultSet.checkRowPos(ResultSet.java:3625)
at com.mysql.jdbc.ResultSet.getString(ResultSet.java:1772)
at org.apache.commons.dbcp.DelegatingResultSet.getString(DelegatingResultSet.java:137)
....
What my application does :
- Inserting rows in a table (strings, dates, integers).
- And the, selecting table in a Resultset for gettind data
- I use ResultSet.getString() for getting all fields.
Database Pooling configuration in server.xml file :
<parameter>
<name>maxActive</name>
<value>10</value>
</parameter>
<parameter>
<name>maxIdle</name>
<value>0</value>
</parameter>
<parameter>
<name>maxWait</name>
<value>15000</value>
</parameter>
What I DO NOT suspect :
- Having not closed connection, statement or cursor.
- Doing some computation with null variables.
Thanks in advance for your help.
Toum.
 
Mark Spritzler
ranger
Sheriff
Posts: 17278
6
IntelliJ IDE Mac Spring
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Is MySQL transactional? Meaning if you have one session and you insert records, but don't commit, then wouldn't a sepertae session not see those records yet. Not much help, but an idea. Maybe it has to do with closing or not closing Connections correctly. But not much else to help since we don't see your code.
Mark
 
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