public class SharedStringsTable extends POIXMLDocumentPart implements SharedStrings, java.io.Closeable
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).
POIXMLDocumentPart.RelationPart| Modifier and Type | Field and Description |
|---|---|
protected int |
count
An integer representing the total count of strings in the workbook.
|
protected int |
uniqueCount
An integer representing the total count of unique strings in the Shared String Table.
|
| Constructor and Description |
|---|
SharedStringsTable() |
SharedStringsTable(PackagePart part) |
| Modifier and Type | Method and 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.
|
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.
|
RichTextString |
getItemAt(int idx)
Return a string item by index
|
java.util.List<RichTextString> |
getSharedStringItems()
Provide access to the strings in the SharedStringsTable
|
int |
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.
|
protected java.lang.String |
xmlText(org.openxmlformats.schemas.spreadsheetml.x2006.main.CTRst st) |
_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, toStringprotected int count
protected int uniqueCount
public SharedStringsTable()
public SharedStringsTable(PackagePart part) throws java.io.IOException
java.io.IOExceptionpublic void readFrom(java.io.InputStream is)
throws java.io.IOException
is - The input stream containing the XML document.java.io.IOException - if an error occurs while reading.protected java.lang.String xmlText(org.openxmlformats.schemas.spreadsheetml.x2006.main.CTRst st)
public RichTextString getItemAt(int idx)
getItemAt in interface SharedStringsidx - index of item to return.public int getCount()
getCount in interface SharedStringspublic int getUniqueCount()
getUniqueCount in interface SharedStringspublic int addSharedStringItem(RichTextString string)
If the Shared String table already contains this string entry, its index is returned. Otherwise a new entry is added.
string - the entry to addpublic java.util.List<RichTextString> getSharedStringItems()
public void writeTo(java.io.OutputStream out)
throws java.io.IOException
out - The stream to write to.java.io.IOException - if an error occurs while writing.protected void commit()
throws java.io.IOException
POIXMLDocumentPartSub-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();
}
commit in class POIXMLDocumentPartjava.io.IOException - a subclass may throw an IOException if the changes can't be committedpublic void close()
throws java.io.IOException
XSSFWorkbook#close().
This implementation is empty but subclasses may need to implement some logic.
close in interface java.io.Closeableclose in interface java.lang.AutoCloseablejava.io.IOException - if an error occurs while closing.Copyright 2021 The Apache Software Foundation or its licensors, as applicable.