org.apache.poi.xssf.eventusermodel.examples.FromHowTo Maven / Gradle / Ivy
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package org.apache.poi.xssf.eventusermodel.examples;
import java.io.InputStream;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.Map;
import javax.xml.parsers.ParserConfigurationException;
import org.apache.poi.openxml4j.opc.PackageAccess;
import org.apache.poi.ooxml.util.SAXHelper;
import org.apache.poi.xssf.eventusermodel.XLSX2CSV;
import org.apache.poi.xssf.eventusermodel.XSSFReader;
import org.apache.poi.xssf.model.SharedStringsTable;
import org.apache.poi.xssf.usermodel.XSSFRichTextString;
import org.apache.poi.openxml4j.opc.OPCPackage;
import org.xml.sax.Attributes;
import org.xml.sax.ContentHandler;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.XMLReader;
import org.xml.sax.helpers.DefaultHandler;
/**
* XSSF and SAX (Event API) basic example.
* See {@link XLSX2CSV} for a fuller example of doing
* XSLX processing with the XSSF Event code.
*/
public class FromHowTo {
public void processFirstSheet(String filename) throws Exception {
try (OPCPackage pkg = OPCPackage.open(filename, PackageAccess.READ)) {
XSSFReader r = new XSSFReader(pkg);
SharedStringsTable sst = r.getSharedStringsTable();
XMLReader parser = fetchSheetParser(sst);
// process the first sheet
try (InputStream sheet = r.getSheetsData().next()) {
InputSource sheetSource = new InputSource(sheet);
parser.parse(sheetSource);
}
}
}
public void processAllSheets(String filename) throws Exception {
try (OPCPackage pkg = OPCPackage.open(filename, PackageAccess.READ)) {
XSSFReader r = new XSSFReader(pkg);
SharedStringsTable sst = r.getSharedStringsTable();
XMLReader parser = fetchSheetParser(sst);
Iterator sheets = r.getSheetsData();
while (sheets.hasNext()) {
System.out.println("Processing new sheet:\n");
try (InputStream sheet = sheets.next()) {
InputSource sheetSource = new InputSource(sheet);
parser.parse(sheetSource);
}
System.out.println();
}
}
}
public XMLReader fetchSheetParser(SharedStringsTable sst) throws SAXException, ParserConfigurationException {
XMLReader parser = SAXHelper.newXMLReader();
ContentHandler handler = new SheetHandler(sst);
parser.setContentHandler(handler);
return parser;
}
/**
* See org.xml.sax.helpers.DefaultHandler javadocs
*/
private static class SheetHandler extends DefaultHandler {
private final SharedStringsTable sst;
private String lastContents;
private boolean nextIsString;
private boolean inlineStr;
private final LruCache lruCache = new LruCache<>(50);
private static class LruCache extends LinkedHashMap {
private final int maxEntries;
public LruCache(final int maxEntries) {
super(maxEntries + 1, 1.0f, true);
this.maxEntries = maxEntries;
}
@Override
protected boolean removeEldestEntry(final Map.Entry eldest) {
return super.size() > maxEntries;
}
}
private SheetHandler(SharedStringsTable sst) {
this.sst = sst;
}
@Override
public void startElement(String uri, String localName, String name,
Attributes attributes) throws SAXException {
// c => cell
if(name.equals("c")) {
// Print the cell reference
System.out.print(attributes.getValue("r") + " - ");
// Figure out if the value is an index in the SST
String cellType = attributes.getValue("t");
nextIsString = cellType != null && cellType.equals("s");
inlineStr = cellType != null && cellType.equals("inlineStr");
}
// Clear contents cache
lastContents = "";
}
@Override
public void endElement(String uri, String localName, String name)
throws SAXException {
// Process the last contents as required.
// Do now, as characters() may be called more than once
if(nextIsString) {
Integer idx = Integer.valueOf(lastContents);
lastContents = lruCache.get(idx);
if (lastContents == null && !lruCache.containsKey(idx)) {
lastContents = new XSSFRichTextString(sst.getEntryAt(idx)).toString();
lruCache.put(idx, lastContents);
}
nextIsString = false;
}
// v => contents of a cell
// Output after we've seen the string contents
if(name.equals("v") || (inlineStr && name.equals("c"))) {
System.out.println(lastContents);
}
}
@Override
public void characters(char[] ch, int start, int length) throws SAXException { // NOSONAR
lastContents += new String(ch, start, length);
}
}
public static void main(String[] args) throws Exception {
FromHowTo howto = new FromHowTo();
howto.processFirstSheet(args[0]);
howto.processAllSheets(args[0]);
}
}