Convert string to double

[nealhudson]

Hi

I'd like to convert a string to a double. The issue is that sometimes the string does not contain numeric data.

 

I was thinking of placing a try catch block in the value expression for a variable.

Something like this:

 

try{

new java.lang.Double(java.lang.Double.parseDouble($F{Time}));

}

catch(NumberFormatException e){

new java.lang.Double(0);

}

 

where $F{Time} is a string field returned from the database.

 

However, I keep getting the following errors when trying to compile the report:

Syntax error on token "(", ; expected

Syntax error on token ")", delete this token

[nealhudson]

This code works fine through a java compiler, stumped as to why it won't in iReports:

 

try{

return new java.lang.Double(java.lang.Double.parseDouble($F{Time}));

}

catch(NumberFormatException e){

return new java.lang.Double(0);

}

[svenn]

Straight java code is not supported in the expession box. If you want to write straight java code you can to do it in a Scriptlet or in your own class that you then point to in the report.

[nealhudson]

hmmm.. ok.

 

So if straight java is not supported, is there any way in the expression box of doing what I want? (i.e. check to see if a string value contains a double, if it does then return it, if not then return 0).

[svenn]

Try the following expession in your expession variable box

 

($F{Time}.isNaN() ? do something : do something else )

[csbac]

Hi!

If you are using SQL ... any way of converting the string field into a double field in the SQL query already?

 

Otherwise, the only way I see is writing a scriptlet that contains a "non-throwing" conversion function, and deploy the scriptlet together with the report, as svenn already mentioned ...

 

Sebastian

[nealhudson]

[deleted]

Post edited by: nealhudson, at: 2007/09/20 15:38

[nealhudson]

[deleted]

Post edited by: nealhudson, at: 2007/09/20 15:38

[margaret]

In the text field expression try entering

new Double($F{Time})

and then changed the expression class to

java.lang.double

[neruv]

Works with...

Set " Text Field Expression " : Double.parseDouble($F{PARAM})
Set " Expression Class " : java.lang.Double

Add rt.jar (from java runtime) to classpath [ Tools >> Options >> Classpath]

And Compile