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NanoXLSX4j is a small Java library to create and read XLSX files (Microsoft Excel 2007 or newer) in an
easy and native way. The library is originated form PicoXLSX4j and has basic support of reading spreadsheets
/*
* NanoXLSX4j is a small Java library to write and read XLSX (Microsoft Excel 2007 or newer) files in an easy and native way
* Copyright Raphael Stoeckli © 2018
* This library is licensed under the MIT License.
* You find a copy of the license in project folder or on: http://opensource.org/licenses/MIT
*/
package ch.rabanti.nanoxlsx4j.lowLevel;
import org.w3c.dom.Document;
import java.io.BufferedOutputStream;
import java.io.OutputStream;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.List;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;
/**
* Class representing a packer to compile XLSX files
* @author Raphael Stoeckli
*/
public class Packer {
// ### C O N S T A N T S ###
/**
* Path of the main content type file (MSXML)
*/
private static final String CONTENT_TYPE_DOCUMENT = "[Content_Types].xml";
// ### P R I V A T E F I E L D S ###
private final List contentTypeList;
private final List dataList;
private final List includeContentType;
private final List pathList;
private final List relationships;
private final LowLevel lowLevelReference;
// ### C O N S T R U C T O R S ###
/**
* Default constructor with parameter
* @param reference Reference to the low level instance
*/
public Packer(LowLevel reference)
{
dataList = new ArrayList<>();
pathList = new ArrayList<>();
contentTypeList = new ArrayList<>();
relationships = new ArrayList<>();
includeContentType = new ArrayList<>();
this.lowLevelReference = reference;
}
// ### M E T H O D S ###
/**
* Adds a Part to the file
* @param name Filename with relative path
* @param contentType URL with information about the content type (MSXML).
This information is used in the main content type file
* @param document XML document to add
* @throws ch.rabanti.nanoxlsx4j.exception.IOException Thrown if the document could not be converted to a byte array
*/
public void addPart(String name, String contentType, Document document) throws ch.rabanti.nanoxlsx4j.exception.IOException
{
dataList.add(LowLevel.createBytesFromDocument(document));
pathList.add(name);
contentTypeList.add(contentType);
includeContentType.add(true);
}
/**
* Adds a Part to the file
* @param name Filename with relative path
* @param contentType URL with information about the content type (MSXML).
This information is used in the main content type file
* @param document XML document to add
* @param includeInContentType If true, the content type will be added in the main content type file, otherwise not
* @throws ch.rabanti.nanoxlsx4j.exception.IOException Thrown if the document could not be converted to a byte array
*/
public void addPart(String name, String contentType, Document document, boolean includeInContentType) throws ch.rabanti.nanoxlsx4j.exception.IOException
{
dataList.add(LowLevel.createBytesFromDocument(document));
pathList.add(name);
contentTypeList.add(contentType);
includeContentType.add(includeInContentType);
}
/**
* Creates the main content type file (MSXML)
* @return Returns the byte array to add into the compilation
* @throws ch.rabanti.nanoxlsx4j.exception.IOException Thrown if the document could not be converted to a byte array
*/
private byte[] createContentTypeDocument() throws ch.rabanti.nanoxlsx4j.exception.IOException
{
StringBuilder sb = new StringBuilder();
sb.append("\r\n");
sb.append(" ");
Document d = this.lowLevelReference.createXMLDocument(sb.toString(), "CONTENTTYPE");
return LowLevel.createBytesFromDocument(d);
}
/**
* Creates a relationship. This will be used to generate a .rels file in the compilation (MSXML)
* @param path relative path and filename to rels file (e.g. _rels/.rels)
* @return Returns the object reference to add relationship entries
*/
public Relationship createRelationship(String path)
{
Relationship r = new Relationship(path);
this.relationships.add(r);
return r;
}
/**
* Creates a relationship file (MSXML)
* @param rel Relationship object to process
* @return Returns the byte array to add into the compilation
* @throws ch.rabanti.nanoxlsx4j.exception.IOException Thrown if the document could not be converted to a byte array
*/
private byte[] createRelationshipDocument(Relationship rel) throws ch.rabanti.nanoxlsx4j.exception.IOException
{
StringBuilder sb = new StringBuilder();
sb.append("\r\n");
for (int i = 0; i < rel.getIdList().size(); i++)
{
sb.append(" ");
Document d = this.lowLevelReference.createXMLDocument(sb.toString(), "REL: " + rel.currentId);
return LowLevel.createBytesFromDocument(d);
}
/**
* Method to pack the data into a XLSX file. This is the actual compiling and writing method (to a OutputStream)
* @param stream OutputStream to save the data into
* @throws ch.rabanti.nanoxlsx4j.exception.IOException Thrown in case of a error while packing or writing
*/
public void pack(OutputStream stream) throws ch.rabanti.nanoxlsx4j.exception.IOException
{
try
{
byte[] contentTypes = createContentTypeDocument();
ZipOutputStream out = new ZipOutputStream(new BufferedOutputStream(stream), Charset.forName("UTF-8"));
out.setMethod(ZipOutputStream.DEFLATED);
ZipEntry entry = new ZipEntry(CONTENT_TYPE_DOCUMENT);
out.putNextEntry(entry);
out.write(contentTypes, 0, contentTypes.length);
byte[] data;
for (int i = 0; i < this.relationships.size(); i++)
{
data = createRelationshipDocument(this.relationships.get(i));
entry = new ZipEntry(this.relationships.get(i).getRootFolder());
out.putNextEntry(entry);
out.write(data, 0, data.length);
}
for (int i = 0; i < this.dataList.size(); i++)
{
data = this.dataList.get(i);
entry = new ZipEntry(this.pathList.get(i));
out.putNextEntry(entry);
out.write(data, 0, data.length);
}
out.flush();
out.close();
}
catch(Exception e)
{
throw new ch.rabanti.nanoxlsx4j.exception.IOException("PackingException","There was an error while packing the file. Please see the inner exception.", e);
}
}
// ### S U B C L A S S E S ###
/**
* Nested class representing a relationship (MSXML)
*/
public class Relationship
{
private final String rootFolder;
private final List targetList;
private final List typeList;
private final List idList;
private int currentId;
/**
* Gets the root folder of the relationship
* @return Root folder of the relationship
*/
String getRootFolder() {
return rootFolder;
}
/**
* Gets the list of targets
* @return ArrayList of targets as strings
*/
List getTargetList() {
return targetList;
}
/**
* Gets the list of types
* @return ArrayList of types as strings
*/
List getTypeList() {
return typeList;
}
/**
* Gets the list of IDs (rId...)
* @return ArrayList of IDs as strings
*/
List getIdList() {
return idList;
}
/**
* Constructor with definition of the root folder
* @param path Root folder of the relationship
*/
Relationship(String path)
{
this.idList = new ArrayList<>();
this.targetList = new ArrayList<>();
this.typeList = new ArrayList<>();
this.rootFolder = path;
this.currentId = 1;
}
/**
* Adds a relationship entry to the relationship
* @param target Target of the entry
* @param type Type of the entry
*/
public void addRelationshipEntry(String target, String type)
{
this.targetList.add(target);
this.typeList.add(type);
String id = "rId" + Integer.toString(this.currentId);
this.idList.add(id);
this.currentId++;
}
}
}