I have checked every possible question on here with a similar problem, and none of the solutions have worked. I feel like I am missing something really obvious, but I just can't see it.
I am on Windows 10, using Eclipse 2019, and the newest Apache POI jar files (not maven) with xmlbeans version 3.1.0. I want to read an xlsx file, but every time I run my code (Which is a basic example I've seen used and run successfully on multiple websites and videos), I receive a "NullPointerException" at the line where I create my workbook:
import java.io.File;
//import java.io.FileInputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import org.apache.poi.openxml4j.exceptions.InvalidFormatException;
//import org.apache.poi.openxml4j.opc.OPCPackage;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
public class excelImportTest {
public static void main (String args[]) throws IOException, InvalidFormatException {
// Linking file to Workbook
// ****Where exception is called every time****
XSSFWorkbook wb = new XSSFWorkbook(new File("C:\\Users\\Owner\\Downloads\\TestData.xlsx"));
// Pulling sheet from Workbook
XSSFSheet sheet = wb.getSheetAt(0);
// Get iterator to all the rows in current sheet
Iterator rowIterator = sheet.iterator();
// Traversing over each row of XLSX file
while (rowIterator.hasNext()) {
Row row = rowIterator.next();
// For each row, iterate through each columns
Iterator cellIterator = row.cellIterator();
while (cellIterator.hasNext()) {
Cell cell = cellIterator.next();
switch(cell.getCellType()) {
case STRING:
System.out.print(cell.getStringCellValue() + "\t");
break;
case NUMERIC:
System.out.print(cell.getNumericCellValue() + "\t");
break;
case BOOLEAN:
System.out.print(cell.getBooleanCellValue() + "\t");
break;
default :
}
}
}
wb.close();
Here is the exception I receive:
Exception in thread "main" java.lang.ExceptionInInitializerError
at sun.misc.Unsafe.ensureClassInitialized(Native Method)
at sun.reflect.UnsafeFieldAccessorFactory.newFieldAccessor(Unknown Source)
at sun.reflect.ReflectionFactory.newFieldAccessor(Unknown Source)
at java.lang.reflect.Field.acquireFieldAccessor(Unknown Source)
at java.lang.reflect.Field.getFieldAccessor(Unknown Source)
at java.lang.reflect.Field.get(Unknown Source)
at org.apache.xmlbeans.XmlBeans.typeSystemForClassLoader(XmlBeans.java:775)
at org.openxmlformats.schemas.drawingml.x2006.main.ThemeDocument.(Unknown Source)
at org.openxmlformats.schemas.drawingml.x2006.main.ThemeDocument$Factory.parse(Unknown Source)
at org.apache.poi.xssf.model.ThemesTable.(ThemesTable.java:86)
at org.apache.poi.ooxml.POIXMLFactory.createDocumentPart(POIXMLFactory.java:61)
at org.apache.poi.ooxml.POIXMLDocumentPart.read(POIXMLDocumentPart.java:684)
at org.apache.poi.ooxml.POIXMLDocument.load(POIXMLDocument.java:180)
at org.apache.poi.xssf.usermodel.XSSFWorkbook.(XSSFWorkbook.java:288)
at org.apache.poi.xssf.usermodel.XSSFWorkbook.(XSSFWorkbook.java:325)
at excelImportTest.main(excelImportTest.java:62)
Caused by: java.lang.RuntimeException: Could not instantiate SchemaTypeSystemImpl (java.lang.reflect.InvocationTargetException): is the version of xbean.jar correct?
at schemaorg_apache_xmlbeans.system.sD023D6490046BA0250A839A9AD24C443.TypeSystemHolder.loadTypeSystem(Unknown Source)
at schemaorg_apache_xmlbeans.system.sD023D6490046BA0250A839A9AD24C443.TypeSystemHolder.(Unknown Source)
... 16 more
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
... 18 more
Caused by: java.lang.NullPointerException
at org.apache.xmlbeans.impl.schema.ClassLoaderResourceLoader.getResourceAsStream(ClassLoaderResourceLoader.java:33)
at org.apache.xmlbeans.impl.schema.SchemaTypeSystemImpl$XsbReader.getLoaderStream(SchemaTypeSystemImpl.java:2249)
at org.apache.xmlbeans.impl.schema.SchemaTypeSystemImpl$XsbReader.(SchemaTypeSystemImpl.java:1522)
at org.apache.xmlbeans.impl.schema.SchemaTypeSystemImpl.initFromHeader(SchemaTypeSystemImpl.java:273)
at org.apache.xmlbeans.impl.schema.SchemaTypeSystemImpl.(SchemaTypeSystemImpl.java:185)
... 22 more
I have tried every combination of options I can think of and suggestions I have found online:
I created a separate FileInputStream(new File(...)), and ran an if statement to see if it was null. This returned "not null", but I still got the exception when it got to the line above
I tried running the line with a nested new FileInputStream(new File(...)) format, and received the same error
I have been using a try-catch block for the exception, but it does not seem to flag the exception before aborting the program
I have tried using the Apache-POI-included OCPPackage.open(new File(...)) approach, and get the same error
Is there any obvious approach I am missing, or does this stem from some other issue in my setup?
Edit
Since it seems my problem may be in the .jar files I am referencing, here is what I have as part of the file's build path:
解决方案
I think you have not added the jars properly.
First go to this url : https://archive.apache.org/dist/poi/release/bin/ and download poi-bin-4.1.2-20200217.zip from there.
Now extract the zip and add this jars to your project marked with red.
I have tested your code and its working.
import java.io.File;
import java.io.IOException;
import java.util.Iterator;
import org.apache.poi.openxml4j.exceptions.InvalidFormatException;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
public class Testing {
public static void main(String args[]) throws IOException, InvalidFormatException {
// Linking file to Workbook
// ****Where exception is called every time****
XSSFWorkbook wb = new XSSFWorkbook(new File("C:\\Users\\Anish\\Downloads\\TestData.xlsx"));
System.out.println("Workbook loaded");
// Pulling sheet from Workbook
XSSFSheet sheet = wb.getSheetAt(0);
// Get iterator to all the rows in current sheet
Iterator rowIterator = sheet.iterator();
// Traversing over each row of XLSX file
while (rowIterator.hasNext()) {
Row row = rowIterator.next();
// For each row, iterate through each columns
Iterator cellIterator = row.cellIterator();
while (cellIterator.hasNext()) {
Cell cell = cellIterator.next();
switch (cell.getCellType()) {
case STRING:
System.out.print(cell.getStringCellValue() + "\t");
break;
case NUMERIC:
System.out.print(cell.getNumericCellValue() + "\t");
break;
case BOOLEAN:
System.out.print(cell.getBooleanCellValue() + "\t");
break;
default:
}
}
}
wb.close();
}
}
Output :
Now, if you are using maven in the project.Then, you don't need to add jars on the classpath.
Simply, add this dependency in the pom.xml.
org.apache.poi
poi
4.1.2
org.apache.poi
poi-ooxml
4.1.2