JRResultSetDataSource read data error, help!!

[2001 JI Open Discussion]

By: zhangyuxiang - zhangyuxang

JRResultSetDataSource read data error, help!!

2002-06-04 19:09

Result set columns within each row should be read in left-to-right order, but my jasper read column random, so there is a sql exception.

Can any one tell me why?

 

 

By: Teodor Danciu - teodord

RE: JRResultSetDataSource read data error, help!!

2002-06-05 01:03

 

Hi,

 

In the API documentation for the ResultSet

interface, they say:

 

"For maximum portability, result set columns

within each row should be read in left-to-right order,

and each column should be read only once."

 

The provided JRResultSetDataSource

implementation does not follow this

recommendation and retrieves the fields values

in no particular order and repeatedly.

 

A solution would be to create a different

implementation of this class or to improve it such

as that it would read all the fields values in the

correct order and only once and keep them in

some sort of a cache to supply them from there

when required.

 

It is not too difficult to do that.

 

I'll consider it for a future version.

 

Thank you,

Teodor

 

 

 

By: zhangyuxiang - zhangyuxang

RE: JRResultSetDataSource read data error, he

2002-06-05 19:32

HI.

 

Thanks.

 

I have create a implementation of JRDatasource to

solve this problem.

 

Does JasperReprt will support JDK1.4?

 

 

 

By: zhangyuxiang - zhangyuxang

Another way fix this problem

2002-06-05 23:15

Modify JRBaseFiller.java can fix this problem.

 

 

public JasperPrint fill(

Map parameters,

Connection conn

) throws JRException

{

if (parameters == null)

{

parameters = new HashMap();

}

parameters.put("REPORT_CONNECTION", conn);

 

ResultSet rs =JRQueryExecuter.executeQuery(

query,

parametersMap,

parameters,

conn

);

 

//add these code to sort fields

try{

java.sql.ResultSetMetaData meta = rs.getMetaData();

 

JRFillField[] newFields = new JRFillField[fields.length];

 

for(int i=0; i<meta.getColumnCount(); i++){

for(int m=0; m<fields.length; m++){

if(fields[m].getName().equals(meta.getColumnName(i+1)))

newFields = fields[m];

}

}

 

fields = newFields;

}

catch(SQLException exception){

throw new JRException("Error sort fileds : " + name, exception);

}

//end modify code

 

JRDataSource ds = new JRResultSetDataSource(rs);

 

JasperPrint jasperPrint = this.fill(parameters, ds);

 

try

{

rs.close();

}

catch (SQLException e)

{

throw new JRException("Error closing ResultSet for report data source : " + name, e);

}

 

return jasperPrint;

}

 

 

By: Teodor Danciu - teodord

JDK 1.4

2002-06-05 23:59

 

Hi,

 

JasperReports already supports JDK1.4 as far as

I have tested it.

 

Thanks,

Teodor