The open source community has created many open source Java projects, which range from charting software to game frameworks to word processors. In this post, I introduce an open source library project for reading and writing Microsoft Excel spreadsheets. Q: I've been asked to extend my company's Java-based spreadsheet software to read and write Excel spreadsheets. Can you recommend an open source Java library that will help me with this task? Here are a few of its many features:.
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For most recent default installations of Office, Windows, and IE, it is enough. However, for some older installations of Office, Windows, and IE, many of us have seen that Excel still opens in a separate window outside of IE. The other thing which must be done is to edit the advanced MIME type settings on the Windows computers which will be hitting your web site. In other words, your customers must do this next step: there is nothing you can do from your response stream or anywhere else on your web site to enforce this advanced MIME setting.
I will give the directions for Windows Click OK and Close. Thanks go out to Dermot Balson and the microsoft. Assuming your class is named MyClass with no package: Windows: javac -classpath jxl.
MyClass Unix: javac -classpath jxl. Yes How can I copy a worksheet in one workbook to a new worksheet in another workbook? This can be done, but requires a little work. Firstly, you have to copy it cell within a couple of nested for loops. For each cell you need to invoke the copyTo method, which will produce a deep copy.
However the format is only shallow copied, so you will need to get the cell format and use the copy constructor of that, and then call setCellFormat on the cell you have just copied. Also make sure to turn on cell wrapping with WritableCellFormat. How do I force Excel to open inside Internet Explorer instead of a separate window? That's it. The JVM places an upper limit on the amount of memory available to the current process in order to prevent runaway processes gobbling system resources and making the machine grind to a halt.
When reading or writing large spreadsheets, the JVM may require more memory than has been allocated to the JVM by default - this normally manifests itself as a java. OutOfMemory exception. By default, each workbook allocates 5MB when created and allocates more memory in 5MB increments. These values can be changed by using class WorkbookSettings.
Often the OutOfMemory exception can be removed by lowering these values note that performance may suffer as a result. Oftentimes, as is the case with Tomcat and WebLogic, a simple change to a startup script is all that's necessary. Charts that already exist in a spreadsheet can be copied to another spreadsheet.
New charts can't yet be inserted into a spreadsheet, but by using a chart in an pre-existing spreadsheet as a template, you can create new spreadsheets that use that template chart but plug-in new data values at runtime.
Adam Caldwell has written a patch that allows the insertion of BMPs. The patch for JExcelApi version 2. Patches for other versions are also available. Version 2. You can insert PNG files into a spreadsheet using sheet. I create a very large Excel file using JExcelApi. If I open the file in Excel and save it without making any changes, the files shrinks to about half its original size.
Excel performs optimizations to reduce file size when possible, but JExcelApi does not. This can halve the size of all stored strings. If many cells use the same formula, Excel will only write this formula to the underlying file once, whereas JExcelApi writes the formula once for each cell. I get the exception "reference to Number is ambiguous; both class jxl. Number in package jxl. Number in package java.
Number at the top of the source file, or fully-qualify each reference to Number with jxl. Number in the source code. I'm getting the error message 'too many different cell formats' You need to reuse old formats rather than create a new one for each cell.
BOLD ; boldRed. As a cell format is added to a sheet, it gets assigned an internal index number. If you have two threads such as in a Web environment writing two different spreadsheets, the format numbers will get confused and the resulting sheet could either be corrupted or incorrect. Why do dates appear one day less that is stored in Excel?
This is because java automatically adjusts for your local timezone information. As Excel dates are not concerned with timezone information, any hours java subtracts for timezone adjustments make it look as if the date has been adjusted by a whole day, instead of a couple of hours.
This is explained in more detail on Andy's Page. How do I set the width of Columns and the height of Rows? See the javadoc for: WritableSheet. There is no API function to do this for you. You'll need to write code that scans the cells in each column, calculates the maximum length, and then calls setColumnView accordingly. This will get you close to what Excel does but not exactly. Since most fonts have variable width characters, to get the exact same value, you would need to use FontMetrics to calculate the maximum width of each string in the column.
No one has posted code on how to do this yet. Feel free to post code to the Yahoo! There is no API function to do this for you, however you can simulate it under most conditions. If you do not explicitly set a row's size, Excel will re-size it on load if any of the cells in the row are set to auto-wrap format. Excel will then resize the row to be large enough to handle the biggest cell of data. The only exception to this rule I've found is when the auto-wrap format is set on a merged cell.
Like this: import java. IOException; import java. OutputStream; import javax. ServletException; import javax. HttpServlet; import javax. HttpServletRequest; import javax. HttpServletResponse; import jxl. Workbook; import jxl. Label; import jxl.
WritableSheet; import jxl. How do I do this? If you are using Java 1. BufferedImage; import java. ByteArrayOutputStream; import javax. If you want to avoid the 1. JXL supports some things on copy that it doesn't support via the WritableSheet interface. For example, you can copy macros from a template to an output file, but you can't create a macro.
Jung grimholtz yahoo. How can I copy a worksheet in one workbook to a new worksheet in another workbook? You can either import jxl.
You need to reuse old formats rather than create a new one for each cell.
JExcel API – Reading and Writing Excel file in Java
The information presented in this tutorial is intended as a brief overview as to how JExcelApi may be used to read and write data in Excel format. The tutorial is by no means exhaustive, and if something is not described here, it does not mean that it cannot be done. The reader is encouraged to examine the API documentation and the sample code particularly Write. Reading Spreadsheets. JExcelApi can read an Excel spreadsheet from a file stored on the local filesystem or from some input stream. The first step when reading a spreadsheet from a file or input stream is to create a Workbook.
In this article, we will discuss about how to read and write an excel file using JExcel API, a simple library and widely used for simple operations which do not involve a high level of formatting and complex formulas based operations. Or download directly at this location. The above code is nearly self-understandable. Each cell or sheet is mapped as an object in Java.
Reading and writing Excel spreadsheets
To use this library in your Java program add the lib jxl. See Changing classpath in Eclipse. Create a new Java project called de. Create the de. I assume that the code is pretty much self-explaining. I tried to add lots of comments to make it easier to understand. For more complex examples have a look at the excellent documentation of the Java Excel API which is also part of the distribution.
For most recent default installations of Office, Windows, and IE, it is enough. However, for some older installations of Office, Windows, and IE, many of us have seen that Excel still opens in a separate window outside of IE. The other thing which must be done is to edit the advanced MIME type settings on the Windows computers which will be hitting your web site. In other words, your customers must do this next step: there is nothing you can do from your response stream or anywhere else on your web site to enforce this advanced MIME setting. I will give the directions for Windows Click OK and Close.