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Showing posts from August, 2017

Read Images from a xlsx file using Apache POI

This article is all about how to read and download images inside a file in xlsx format. We will use Apache POI using java.

1. Maven dependencies
commons-logging-1.2.jar commons-collections4-4.1.jaropenxml4j-1.0-betapoi-3.16.jarpoi-ooxml-3.16.jarpoi-ooxml-schemas-3.16.jarxmlbeans-2.6.0.jarservlet-api 2. Sharing java code


import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;

import org.apache.poi.ss.usermodel.PictureData;
import org.apache.poi.xssf.usermodel.XSSFCell;
import org.apache.poi.xssf.usermodel.XSSFDrawing;
import org.apache.poi.xssf.usermodel.XSSFPicture;
import org.apache.poi.xssf.usermodel.XSSFRow;
import org.apache.poi.xssf.usermodel.XSSFShape;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWork…

Read Excel using Apache POI - Exception in thread "main" org.apache.poi.poifs.filesystem.OfficeXmlFileException:

Read Excel using Apache POI - Challenges ------------------------------------------------ 1) Exception in thread "main" org.apache.poi.poifs.filesystem.OfficeXmlFileException: The supplied data appears to be in the Office 2007+ XML. You are calling the part of POI that deals with OLE2 Office Documents. You need to call a different part of POI to process this data (eg XSSF instead of HSSF)

Add following maven dependency
-- Use poi-ooxml from xlsx files while poi for xls <!-- POI : Excel library --> <dependency> <groupId>org.apache.poi</groupId> <artifactId>poi</artifactId> <version>${poi.version}</version> </dependency> <dependency>        < groupId>org.apache.poi</groupId>         <artifactId>poi-ooxml</artifactId> <version>${poi.version}</version> </dependency
2)Caused by: java.lang.ClassNotFoundException: org.apache.xmlbeans.XmlException -- Reading excel using apache POI – Add library xml…

Create and write Excel file using Google App Engine

This article explains how you can export data in excel using Google App Engine.

1. Apache POI library -- Here is maven dependency
        <dependency>
        <groupId>org.apache.poi</groupId>
        <artifactId>poi</artifactId>
    <version>3.16</version>
2. Download Servlet

import java.io.FileOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;




public class ExcelServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;

     private static final String F…

Git Commands : How to remove all files deleted from index

Remove all deleted files from git index

git ls-files --deleted -z | xargs -0 git rm