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JAsper Report 3.0 issue :

I am using jasper Reoprt Ireport 3.0 for Generating excel. my problem is I have One text field in that i want to keep below data which is coming from my database.
**Disclaimer: Please note that in case of disease conditions which can have both Acute and Chronic manifestations, they are considered as Chronic illness for analysis keeping in view the objective of the report.
Actually in jasper reoprt summary area i have given one text field but it is too small too keep this above line data. but still I want to keep whole data in small field in excel .
because normaly when we are typing in excel cell anything and when it become overflows then also it's looking like it has been typed in next cell but ,when we are clicking in another cell it will show in that cell only.whole data will come in that small cell without wrapping text filed.
just like it i want also through I-report 3.0 . I tried so much but I didn't find solution so i am posting here . please suggest if you faced same problem and got solution too. it will be helpful.
I don't want to merge it in multiple columns because if it will merge multiple columns then for calculating value through Excel column selection will be a problem. and V lookup we cant do so.
if the data in any cell is greater than 2 rows, then the remaining data just gets cut off and not displayed.

Maybe it is time to update. At this time JasperReports 6.x is the version to go, but ...
From my expierience JasperReports is the wrong tool to generate "clean" Excel documents. You get always layout informations in it that result in the behaviour you describe.
To get a clean Excel document I would suggest to go with Apache-Poi (https://poi.apache.org/) and generate it directly or simply to generate a CSV - file which can be easily opened using Excel.

How to find a specific string in 1 or 2 sheets of a excel file using Apache POI?

I need to find an specific string (id, name for example) in 1 sheet of excel.
this is a basic need.
Later on we need to find a user on several excel sheets and copy the whole record identified with that code and send it to a JTable in the frame.

Are you looking for a high-level search function or something? I don't think that exists.
As you load the sheets, you might consider just adding the interesting columns to a HashMap if you can use exact matches, otherwise just iterate over the sheets/columns/rows and search manually.
You could create some mid-level tooling to do this. A "Sheet Indexer" perhaps, that takes a sheet and a list of columns then lets you do lookups. Even if you have to write code to iterate over everything manually you shouldn't worry too much about speed--the number of sheets/rows are very unlikely to get large enough to effect performance or anything.
We actually have a lot of tooling built around poi including a ORM layer that lets us load from spreadsheets using annotations just like hibernate. We called it "son of poi" aka "poison".

Using Apache POI can I stop users copying formatting?

I have made an excel sheet which is generated by Java. The cells can only accept certain values, depending on data validation done against lists on a separate sheet.
This all works great, but if a user copies some values from another cell and pastes it into the cell it avoids validation... is there any way to prevent this?

You can do this by setting data format for that cell.
style = wb.createCellStyle();
style.setDataFormat(wb.createDataFormat().getFormat("0.000%"));
which will percentage value.
For documentation goto:
Apache HSSF Doc

File size issue. while poi read write

I am using apache poi api to deal with my spread sheet files.
I have observed, if we try to edit an existing .xls file it size is not the same as if that same file (same data ) is written in one go.

It is normal for an Excel spreadsheet to grow after being opened or edited. When a spreadsheet is opened in Microsoft Excel the formulas are automatically calculated, so this increases the size of the file. If a spreadsheet is opened by Apache POI it is up to the developer to call the (FormulaEvaluator) to update all the values. When a spreadsheet is read by Apache POI and the formulas have not been evaluated, formula answers may be invalid.

POI will always write out one record per cell
Excel, however, will sometimes bunch several similar sequential cells up into a single record. For example, if you have 3 cells in a row that are blank but styled, then excel will generate a MulBlankRecord which holds all of them. For several cells in a row with simple numbers in them, excel uses a MulRKRecord
When POI reads in a file, it expands all the Mul* records out. At write time, the individual cell records are written, so the file gets slightly bigger. I think there's an entry in the POI bugzilla for the enhancement to get POI to coalesce cells into Mul records, but no-one seems to have volunteered to work on it yet...

How to update an excel dynamically in java

I am designing stock market predictor wherein the user is supposed to update his database of historical indexes through the web. I want to just add the new data to the TOP of my excel file. not Bottom but on Top of my file. Now i know i can make a copy and modify that copy and the regular stuff.
How to do i avoid this complicated steps and do in few steps instead?
is it possible to do this without making a copy

Apache POI's Sheet objects have a shiftRows method you could use to do this. Here's an example from the Busy Developers' Guide to HSSF and XSSF Features:
Shift rows up or down on a sheet
shiftRows API documentation
Here's an answer with some sample code:
How to create new rows in apache poi 3.6?

Why not update a .csv (which is easier) and at the end after all updates are done, convert it to .xls