Class SharedStringsTable
- java.lang.Object
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- org.apache.poi.ooxml.POIXMLDocumentPart
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- org.apache.poi.xssf.model.SharedStringsTable
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- All Implemented Interfaces:
java.io.Closeable
,java.lang.AutoCloseable
,SharedStrings
public class SharedStringsTable extends POIXMLDocumentPart implements SharedStrings, java.io.Closeable
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).
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Nested Class Summary
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Nested classes/interfaces inherited from class org.apache.poi.ooxml.POIXMLDocumentPart
POIXMLDocumentPart.RelationPart
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Constructor Summary
Constructors Constructor Description SharedStringsTable()
SharedStringsTable(PackagePart part)
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description int
addSharedStringItem(RichTextString string)
Add an entry to this Shared String table (a new value is appended to the end).void
close()
Close any open resources, like temp files.int
getCount()
Return an integer representing the total count of strings in the workbook.RichTextString
getItemAt(int idx)
Return a string item by indexjava.util.List<RichTextString>
getSharedStringItems()
Provide access to the strings in the SharedStringsTableint
getUniqueCount()
Returns an integer representing the total count of unique strings in the Shared String Table.void
readFrom(java.io.InputStream is)
Read this shared strings table from an XML file.void
writeTo(java.io.OutputStream out)
Write this table out as XML.-
Methods inherited from class org.apache.poi.ooxml.POIXMLDocumentPart
_invokeOnDocumentRead, addRelation, createRelationship, createRelationship, createRelationship, getNextPartNumber, getPackagePart, getParent, getRelationById, getRelationId, getRelationPartById, getRelationParts, getRelations, isCommitted, setCommitted, toString
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Constructor Detail
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SharedStringsTable
public SharedStringsTable()
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SharedStringsTable
public SharedStringsTable(PackagePart part) throws java.io.IOException
- Throws:
java.io.IOException
- Since:
- POI 3.14-Beta1
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Method Detail
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readFrom
public void readFrom(java.io.InputStream is) throws java.io.IOException
Read this shared strings table from an XML file.- Parameters:
is
- The input stream containing the XML document.- Throws:
java.io.IOException
- if an error occurs while reading.
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getItemAt
public RichTextString getItemAt(int idx)
Return a string item by index- Specified by:
getItemAt
in interfaceSharedStrings
- Parameters:
idx
- index of item to return.- Returns:
- the item at the specified position in this Shared String table.
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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.- Specified by:
getCount
in interfaceSharedStrings
- Returns:
- the total count of strings in the workbook
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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.- Specified by:
getUniqueCount
in interfaceSharedStrings
- Returns:
- the total count of unique strings in the workbook
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addSharedStringItem
public int addSharedStringItem(RichTextString string)
Add an entry to this Shared String table (a new value is appended to the end).If the Shared String table already contains this string entry, its index is returned. Otherwise a new entry is added.
- Parameters:
string
- the entry to add- Returns:
- index the index of added entry
- Since:
- POI 4.0.0
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getSharedStringItems
public java.util.List<RichTextString> getSharedStringItems()
Provide access to the strings in the SharedStringsTable- Returns:
- list of shared string instances
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writeTo
public void writeTo(java.io.OutputStream out) throws java.io.IOException
Write this table out as XML.- Parameters:
out
- The stream to write to.- Throws:
java.io.IOException
- if an error occurs while writing.
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close
public void close() throws java.io.IOException
Close any open resources, like temp files. This method is called byXSSFWorkbook#close()
.This implementation is empty but subclasses may need to implement some logic.
- Specified by:
close
in interfacejava.lang.AutoCloseable
- Specified by:
close
in interfacejava.io.Closeable
- Throws:
java.io.IOException
- if an error occurs while closing.- Since:
- 4.0.0
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