org.apache.poi.xssf.model

Class SharedStringsTable

java.lang.Object

org.apache.poi.POIXMLDocumentPart

org.apache.poi.xssf.model.SharedStringsTable

public class SharedStringsTable
extends POIXMLDocumentPart

Table of strings shared across all sheets in a workbook.

A workbook may contain thousands of cells containing string (non-numeric) data. Furthermore this data is very likely to be repeated across many rows or columns. The goal of implementing a single string table that is shared across the workbook is to improve performance in opening and saving the file by only reading and writing the repetitive information once.

Consider for example a workbook summarizing information for cities within various countries. There may be a column for the name of the country, a column for the name of each city in that country, and a column containing the data for each city. In this case the country name is repetitive, being duplicated in many cells. In many cases the repetition is extensive, and a tremendous savings is realized by making use of a shared string table when saving the workbook. When displaying text in the spreadsheet, the cell table will just contain an index into the string table as the value of a cell, instead of the full string.

The shared string table contains all the necessary information for displaying the string: the text, formatting properties, and phonetic properties (for East Asian languages).

Author:

Nick Birch, Yegor Kozlov

Field Summary

Fields inherited from class org.apache.poi.POIXMLDocumentPart

DEFAULT_XML_OPTIONS

Constructor Summary

Constructors

Constructor and Description
SharedStringsTable()
SharedStringsTable(PackagePart part, PackageRelationship rel)

Method Summary

Methods

Modifier and Type	Method and Description
int	addEntry(org.openxmlformats.schemas.spreadsheetml.x2006.main.CTRst st) Add an entry to this Shared String table (a new value is appened to the end).
protected void	commit() Save the content in the underlying package part.
int	getCount() Return an integer representing the total count of strings in the workbook.
org.openxmlformats.schemas.spreadsheetml.x2006.main.CTRst	getEntryAt(int idx) Return a string item by index
List<org.openxmlformats.schemas.spreadsheetml.x2006.main.CTRst>	getItems() Provide low-level access to the underlying array of CTRst beans
int	getUniqueCount() Returns an integer representing the total count of unique strings in the Shared String Table.
void	readFrom(InputStream is) Read this shared strings table from an XML file.
void	writeTo(OutputStream out) Write this table out as XML.

Methods inherited from class org.apache.poi.POIXMLDocumentPart

addRelation, createRelationship, createRelationship, createRelationship, getPackagePart, getPackageRelationship, getParent, getRelationById, getRelationId, getRelations, getTargetPart, onDocumentCreate, onDocumentRead, onDocumentRemove, onSave, prepareForCommit, read, rebase, removeRelation, removeRelation, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

SharedStringsTable

public SharedStringsTable()

SharedStringsTable

public SharedStringsTable(PackagePart part,
                  PackageRelationship rel)
                   throws IOException

Throws:

IOException

Method Detail

readFrom

public void readFrom(InputStream is)
              throws IOException

Read this shared strings table from an XML file.

Parameters:

is - The input stream containing the XML document.

Throws:

IOException - if an error occurs while reading.

getEntryAt

public org.openxmlformats.schemas.spreadsheetml.x2006.main.CTRst getEntryAt(int idx)

Return a string item by index

Parameters:

idx - index of item to return.

Returns:

the item at the specified position in this Shared String table.

getCount

public int getCount()

Return an integer representing the total count of strings in the workbook. This count does not include any numbers, it counts only the total of text strings in the workbook.

Returns:

the total count of strings in the workbook

getUniqueCount

public int getUniqueCount()

Returns an integer representing the total count of unique strings in the Shared String Table. A string is unique even if it is a copy of another string, but has different formatting applied at the character level.

Returns:

the total count of unique strings in the workbook

addEntry

public int addEntry(org.openxmlformats.schemas.spreadsheetml.x2006.main.CTRst st)

Add an entry to this Shared String table (a new value is appened to the end).

If the Shared String table already contains this CTRst bean, its index is returned. Otherwise a new entry is aded.

Parameters:

st - the entry to add

Returns:

index the index of added entry

getItems

public List<org.openxmlformats.schemas.spreadsheetml.x2006.main.CTRst> getItems()

Provide low-level access to the underlying array of CTRst beans

Returns:

array of CTRst beans

writeTo

public void writeTo(OutputStream out)
             throws IOException

Write this table out as XML.

Parameters:

out - The stream to write to.

Throws:

IOException - if an error occurs while writing.

commit

protected void commit()
               throws IOException

Description copied from class: POIXMLDocumentPart

Save the content in the underlying package part. Default implementation is empty meaning that the package part is left unmodified. Sub-classes should override and add logic to marshal the "model" into Ooxml4J. For example, the code saving a generic XML entry may look as follows:

 protected void commit() throws IOException {
   PackagePart part = getPackagePart();
   OutputStream out = part.getOutputStream();
   XmlObject bean = getXmlBean(); //the "model" which holds changes in memory
   bean.save(out, DEFAULT_XML_OPTIONS);
   out.close();
 }
  

Overrides:

commit in class POIXMLDocumentPart

Throws:

IOException