com.github.pjfanning.poi.xssf.streaming

Class SharedStringsTableBase

java.lang.Object

org.apache.poi.ooxml.POIXMLDocumentPart

org.apache.poi.xssf.model.SharedStringsTable

com.github.pjfanning.poi.xssf.streaming.SharedStringsTableBase

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable, org.apache.poi.xssf.model.SharedStrings

Direct Known Subclasses:

MapBackedSharedStringsTable, TempFileSharedStringsTable

public abstract class SharedStringsTableBase
extends org.apache.poi.xssf.model.SharedStringsTable

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).

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.poi.ooxml.POIXMLDocumentPart

org.apache.poi.ooxml.POIXMLDocumentPart.RelationPart

Field Summary

Fields

Modifier and Type	Field and Description
protected boolean	fullFormat
protected java.util.concurrent.ConcurrentMap<java.lang.String,java.lang.Integer>	stmap Maps strings and their indexes in the strings arrays
protected java.util.concurrent.ConcurrentMap<java.lang.Integer,java.lang.String>	strings Array of individual string items in the Shared String table.

Fields inherited from class org.apache.poi.xssf.model.SharedStringsTable

count, uniqueCount

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	SharedStringsTableBase(boolean fullFormat)

Method Summary

Modifier and Type	Method and Description
int	addSharedStringItem(org.apache.poi.ss.usermodel.RichTextString string) Add an entry to this Shared String table (a new value is appended to the end).
int	getCount() Return an integer representing the total count of strings in the workbook.
org.apache.poi.ss.usermodel.RichTextString	getItemAt(int idx) Return a (rich text) string item by index
protected abstract org.slf4j.Logger	getLogger()
java.lang.String	getString(int idx) Return a string item by index
int	getUniqueCount() Returns an integer representing the total count of unique strings in the Shared String Table.
protected abstract java.util.Iterator<java.lang.Integer>	keyIterator()
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.xssf.model.SharedStringsTable

close, commit, getSharedStringItems, xmlText

Methods inherited from class org.apache.poi.ooxml.POIXMLDocumentPart

_invokeOnDocumentRead, addRelation, createRelationship, createRelationship, createRelationship, getNextPartNumber, getPackagePart, getParent, getRelationById, getRelationId, getRelationPartById, getRelationParts, getRelations, getTargetPart, isCommitted, onDocumentCreate, onDocumentRead, onDocumentRemove, onSave, prepareForCommit, read, rebase, removeRelation, removeRelation, removeRelation, setCommitted, toString

Methods inherited from class java.lang.Object

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

Field Detail

fullFormat

protected final boolean fullFormat

strings

protected java.util.concurrent.ConcurrentMap<java.lang.Integer,java.lang.String> strings

Array of individual string items in the Shared String table.

stmap

protected java.util.concurrent.ConcurrentMap<java.lang.String,java.lang.Integer> stmap

Maps strings and their indexes in the strings arrays

Constructor Detail

SharedStringsTableBase

protected SharedStringsTableBase(boolean fullFormat)

Method Detail

getLogger

protected abstract org.slf4j.Logger getLogger()

keyIterator

protected abstract java.util.Iterator<java.lang.Integer> keyIterator()

readFrom

public void readFrom(java.io.InputStream is)
              throws java.io.IOException

Read this shared strings table from an XML file.

Overrides:

readFrom in class org.apache.poi.xssf.model.SharedStringsTable

Parameters:

is - The input stream containing the XML document.

Throws:

java.io.IOException - if an error occurs while reading.

getItemAt

public org.apache.poi.ss.usermodel.RichTextString getItemAt(int idx)

Return a (rich text) string item by index

Specified by:

getItemAt in interface org.apache.poi.xssf.model.SharedStrings

Overrides:

getItemAt in class org.apache.poi.xssf.model.SharedStringsTable

Parameters:

idx - index of item to return.

Returns:

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

Throws:

java.util.NoSuchElementException - if no item exists for this index

org.apache.poi.ooxml.POIXMLException - if the item cannot be parsed

getString

public java.lang.String getString(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.

Throws:

java.util.NoSuchElementException - if no item exists for this index

org.apache.poi.ooxml.POIXMLException - if the item cannot be parsed

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 interface org.apache.poi.xssf.model.SharedStrings

Overrides:

getCount in class org.apache.poi.xssf.model.SharedStringsTable

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.

Specified by:

getUniqueCount in interface org.apache.poi.xssf.model.SharedStrings

Overrides:

getUniqueCount in class org.apache.poi.xssf.model.SharedStringsTable

Returns:

the total count of unique strings in the workbook

addSharedStringItem

public int addSharedStringItem(org.apache.poi.ss.usermodel.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.

Overrides:

addSharedStringItem in class org.apache.poi.xssf.model.SharedStringsTable

Parameters:

string - the entry to add

Returns:

index the index of added entry

writeTo

public void writeTo(java.io.OutputStream out)
             throws java.io.IOException

Write this table out as XML.

Overrides:

writeTo in class org.apache.poi.xssf.model.SharedStringsTable

Parameters:

out - The stream to write to.

Throws:

java.io.IOException - if an error occurs while writing.