Compiling with mysql

Wed Sep 3 16:24:00 GMT 2008

3) i discovered how to use the second solution:
conn =
DriverManager.getConnection("jdbc:mysql://localhost:3306/mysql?user=root&password=root&useJvmCharsetConverters=true");
with that you can stay de my.conf unmodified.
Now i am still dont know the performance diference, its not should to run
faster?
ezer wrote:
>> 1) I found whats going on, its an incompatibility in the character
> conversion between the gcj and mysql. Here is the explanation and the
> workaround :
>> http://dev.mysql.com/doc/refman/5.0/en/connector-j-usagenotes-troubleshooting.html#qandaitem-28-4-5-3-9
>> http://bugs.mysql.com/bug.php?id=29636
> (go to the post [9 Jul 2007 17:05])
>> 2) I added 
> default-character-set=utf8
> under [client] and [mysqld] sections of the my.cnf file of mysql
>> 3) The other solution of using useJvmCharsetConverters=true i didnt tested
> because i dont know where to use that string.
>> 4) Now i get the test program runing fine with the following output:
> MySQL Connect Example.
> Connected to the database
> Disconnected from database
>> But one thing is that the connection executing under the gcj program runs
> considerable slower than the same test runing with java MysqlConnect. Its
> normal for connections ? 
>>>>> Andrew Haley wrote:
>>>> ezer wrote:
>>> Andrew, i dont understand what do you mean with exactly, I will try to
>>> explain again, i isolated the problem only compiling a short code that
>>> only
>>> conects to the database and exit. 
>>>>>> 1) The code is the following
>>>>>> import java.sql.*;
>>>>>> public class MysqlConnect{
>>> public static void main(String[] args) {
>>> System.out.println("MySQL Connect Example.");
>>> Connection conn = null;
>>> String url = "jdbc:mysql://localhost:3306/";
>>> String dbName = "myDatabase";
>>> String driver = "com.mysql.jdbc.Driver";
>>> String userName = "root";
>>> String password = "root";
>>> try {
>>> Class.forName(driver).newInstance();
>>> conn = DriverManager.getConnection(url+dbName,userName,password);
>>> System.out.println("Connected to the database");
>>> conn.close();
>>> System.out.println("Disconnected from database");
>>> } catch (Exception e) {
>>> e.printStackTrace();
>>> }
>>> }
>>> }
>>>> As far as I can tell the error message is not coming from gcj,
>> but from mysql. It's quite possible that this is caused by
>> a bug in gcj, but I'd have to debug it to know for sure. Is
>> there a log from mysql?
>>>> Andrew.
>>>>> 2) I compile
>>> gcj --main=MysqlConnect -o mysqlconnect MysqlConnect.java
>>>>>> (gcj version : 4.3.1)
>>>>>> 3) Execution:
>>>>>> ./mysqlconnect
>>>>>> 4) Output:
>>>>>> MySQL Connect Example.
>>> com.mysql.jdbc.exceptions.MySQLSyntaxErrorException: You have an error
>>> in
>>> your SQL syntax; check the manual that corresponds to your MySQL server
>>> version for the right syntax to use near
>>> '????????????????????????????????'
>>> at line 1
>>> at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:936)
>>> at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2985)
>>> at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1631)
>>> at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:1723)
>>> at com.mysql.jdbc.Connection.execSQL(Connection.java:3277)
>>> at
>>> com.mysql.jdbc.Connection.configureClientCharacterSet(Connection.java:2525)
>>> at
>>> com.mysql.jdbc.Connection.initializePropsFromServer(Connection.java:4139)
>>> at com.mysql.jdbc.Connection.createNewIO(Connection.java:2789)
>>> at com.mysql.jdbc.Connection.<init>(Connection.java:1555)
>>> at
>>> com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:285)
>>> at java.sql.DriverManager.getConnection(libgcj.so.90)
>>> at java.sql.DriverManager.getConnection(libgcj.so.90)
>>> at MysqlConnect.main(MysqlConnect.java:14)
>>>>>> 5) I installed a previous version of gcj 4.2 and repetead the
>>> compilation
>>> and execution, and the result was the following:
>>>>>> MySQL Connect Example.
>>> java.sql.SQLException: Error during query: Unexpected Exception:
>>> java.io.CharConversionException message given: null
>>>>>> Nested Stack Trace:
>>>>>>>>> ** BEGIN NESTED EXCEPTION ** 
>>>>>> java.io.CharConversionException
>>>>>> STACKTRACE:
>>>>>> java.io.CharConversionException
>>> at gnu.gcj.convert.Input_iconv.read(libgcj.so.81)
>>> at java.lang.String.init(libgcj.so.81)
>>> at java.lang.String.<init>(libgcj.so.81)
>>> at
>>> com.mysql.jdbc.SingleByteCharsetConverter.<init>(SingleByteCharsetConverter.java:153)
>>> at
>>> com.mysql.jdbc.SingleByteCharsetConverter.initCharset(SingleByteCharsetConverter.java:108)
>>> at
>>> com.mysql.jdbc.SingleByteCharsetConverter.getInstance(SingleByteCharsetConverter.java:86)
>>> at
>>> com.mysql.jdbc.Connection.getCharsetConverter(Connection.java:3505)
>>> at com.mysql.jdbc.StringUtils.getBytes(StringUtils.java:615)
>>> at com.mysql.jdbc.Buffer.writeStringNoNull(Buffer.java:655)
>>> at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:1686)
>>> at com.mysql.jdbc.Connection.execSQL(Connection.java:3277)
>>> at
>>> com.mysql.jdbc.Connection.configureClientCharacterSet(Connection.java:2525)
>>> at
>>> com.mysql.jdbc.Connection.initializePropsFromServer(Connection.java:4139)
>>> at com.mysql.jdbc.Connection.createNewIO(Connection.java:2789)
>>> at com.mysql.jdbc.Connection.<init>(Connection.java:1555)
>>> at
>>> com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:285)
>>> at java.sql.DriverManager.getConnection(libgcj.so.81)
>>> at java.sql.DriverManager.getConnection(libgcj.so.81)
>>> at MysqlConnect.main(mysqlconnect)
>>>>>>>>> ** END NESTED EXCEPTION **
>>>>>>>>> at com.mysql.jdbc.Connection.execSQL(Connection.java:3330)
>>> at
>>> com.mysql.jdbc.Connection.configureClientCharacterSet(Connection.java:2525)
>>> at
>>> com.mysql.jdbc.Connection.initializePropsFromServer(Connection.java:4139)
>>> at com.mysql.jdbc.Connection.createNewIO(Connection.java:2789)
>>> at com.mysql.jdbc.Connection.<init>(Connection.java:1555)
>>> at
>>> com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:285)
>>> at java.sql.DriverManager.getConnection(libgcj.so.81)
>>> at java.sql.DriverManager.getConnection(libgcj.so.81)
>>> at MysqlConnect.main(mysqlconnect)
>>>>>> 6) It seems it cant execute the line conn =
>>> DriverManager.getConnection(url+dbName,userName,password);
>>> From the same machine executing with java sun, it did well, but not with
>>> the
>>> java version from the gcj.. 
>>>>>> It was exactly what i did.. dont know what else could i add.
>>>>>>>>>>>>>>>>>>>>>>>> Andrew Haley wrote:
>>>> ezer wrote:
>>>>> New try:
>>>>>>>>>> I generated mysql-connector-java-5.0.8-bin.o
>>>>> and used it in the compilation of the program
>>>>> gcj --main=Search --classpath=mysql-connector-java-5.0.8-bin.o 
>>>>> Searcher.jar
>>>>> -o search
>>>>>>>>>> It compiles without errors, but when i execute ./search i get
>>>>> segmentation
>>>>> fault
>>>>>>>>>> I dont know what to do.. help please...
>>>> the key problem here is that you haven't told us *exactly* what you are
>>>> doing. We need to know if we can help you.
>>>>>>>> http://www.catb.org/~esr/faqs/smart-questions.html
>>>>>>>> Andrew.
>>>>>>>>>>>>>>>>>>>>>>>>>>>
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