What Is poi-5.2.3.jar?

What Is poi-5.2.3.jar?

✍: FYIcenter.com

poi-5.2.3.jar is one of the JAR files for Apache POI 5.2.3, which provides an API for Microsoft document files of Word, Excel, PowerPoint, and Visio.

poi-5.2.3.jar supports Apache POI components that read and write Microsoft's OLE 2 Compound document format, which is used in early versions of Microsoft Office tools like Word 97, Excel 97, PowerPoint 97, etc.

poi-5.2.3.jar is distributed as part of the poi-bin-5.2.3-20220909.zip download file.

JAR File Size and Download Location:

JAR name: poi-5.2.3.jar
Target JDK version: 9

File name: poi.jar, poi-5.2.3.jar
File size: 2964641 bytes
Release date: 09-09-2022
Download: Apache POI Website

Here are Java Source Code files for poi-5.2.3.jar:


/* ====================================================================
   Licensed to the Apache Software Foundation (ASF) under one or more
   contributor license agreements.  See the NOTICE file distributed with
   this work for additional information regarding copyright ownership.
   The ASF licenses this file to You under the Apache License, Version 2.0
   (the "License"); you may not use this file except in compliance with
   the License.  You may obtain a copy of the License at


   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   See the License for the specific language governing permissions and
   limitations under the License.
==================================================================== */

package org.apache.poi.poifs.nio;

import org.apache.poi.util.SuppressForbidden;

import java.io.IOException;
import java.lang.invoke.MethodHandle;
import java.lang.invoke.MethodHandles;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.nio.ByteBuffer;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.Objects;

import static java.lang.invoke.MethodHandles.constant;
import static java.lang.invoke.MethodHandles.dropArguments;
import static java.lang.invoke.MethodHandles.filterReturnValue;
import static java.lang.invoke.MethodHandles.guardWithTest;
import static java.lang.invoke.MethodType.methodType;

 * This is taken from Hadoop at https://issues.apache.org/jira/browse/HADOOP-12760 and
 * https://github.com/apache/hadoop/blob/trunk/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/CleanerUtil.java
 * Unfortunately this is not available in some general utility library yet, but hopefully will be at some point.
 * sun.misc.Cleaner has moved in OpenJDK 9 and
 * sun.misc.Unsafe#invokeCleaner(ByteBuffer) is the replacement.
 * This class is a hack to use sun.misc.Cleaner in Java 8 and
 * use the replacement in Java 9+.
 * This implementation is inspired by LUCENE-6989.
@SuppressForbidden("uses java.security features deprecated in java 17 - no other option though")
public final class CleanerUtil {

    // Prevent instantiation
    private CleanerUtil(){}

     * <code>true</code>, if this platform supports unmapping mmapped files.
    public static final boolean UNMAP_SUPPORTED;

     * if {@link #UNMAP_SUPPORTED} is {@code false}, this contains the reason
     * why unmapping is not supported.
    public static final String UNMAP_NOT_SUPPORTED_REASON;

    private static final BufferCleaner CLEANER;

     * Reference to a BufferCleaner that does unmapping.
     * @return {@code null} if not supported.
    public static BufferCleaner getCleaner() {
        return CLEANER;

    static {
        final Object hack = AccessController.doPrivileged(
                (PrivilegedAction<Object>) CleanerUtil::unmapHackImpl);
        if (hack instanceof BufferCleaner) {
            CLEANER = (BufferCleaner) hack;
            UNMAP_SUPPORTED = true;
            UNMAP_NOT_SUPPORTED_REASON = null;
        } else {
            CLEANER = null;
            UNMAP_SUPPORTED = false;
            UNMAP_NOT_SUPPORTED_REASON = hack.toString();

    @SuppressForbidden("Java 9 Jigsaw allows access to sun.misc.Cleaner, so setAccessible works")
    private static Object unmapHackImpl() {
        final MethodHandles.Lookup lookup = MethodHandles.lookup();
        try {
            try {
                // *** sun.misc.Unsafe unmapping (Java 9+) ***
                final Class<?> unsafeClass = Class.forName("sun.misc.Unsafe");
                // first check if Unsafe has the right method, otherwise we can
                // give up without doing any security critical stuff:
                final MethodHandle unmapper = lookup.findVirtual(unsafeClass,
                        "invokeCleaner", methodType(void.class, ByteBuffer.class));
                // fetch the unsafe instance and bind it to the virtual MH:
                final Field f = unsafeClass.getDeclaredField("theUnsafe");
                final Object theUnsafe = f.get(null);
                return newBufferCleaner(ByteBuffer.class, unmapper.bindTo(theUnsafe));
            } catch (SecurityException se) {
                // rethrow to report errors correctly (we need to catch it here,
                // as we also catch RuntimeException below!):
                throw se;
            } catch (ReflectiveOperationException | RuntimeException e) {
                // *** sun.misc.Cleaner unmapping (Java 8) ***
                final Class<?> directBufferClass =

                final Method m = directBufferClass.getMethod("cleaner");
                final MethodHandle directBufferCleanerMethod = lookup.unreflect(m);
                final Class<?> cleanerClass =

                 * "Compile" a MethodHandle that basically is equivalent
                 * to the following code:
                 * void unmapper(ByteBuffer byteBuffer) {
                 *   sun.misc.Cleaner cleaner =
                 *       ((java.nio.DirectByteBuffer) byteBuffer).cleaner();
                 *   if (Objects.nonNull(cleaner)) {
                 *     cleaner.clean();
                 *   } else {
                 *     // the noop is needed because MethodHandles#guardWithTest
                 *     // always needs ELSE
                 *     noop(cleaner);
                 *   }
                 * }
                final MethodHandle cleanMethod = lookup.findVirtual(
                        cleanerClass, "clean", methodType(void.class));
                final MethodHandle nonNullTest = lookup.findStatic(Objects.class,
                        "nonNull", methodType(boolean.class, Object.class))
                        .asType(methodType(boolean.class, cleanerClass));
                final MethodHandle noop = dropArguments(
                        constant(Void.class, null).asType(methodType(void.class)),
                        0, cleanerClass);
                final MethodHandle unmapper = filterReturnValue(
                        guardWithTest(nonNullTest, cleanMethod, noop))
                        .asType(methodType(void.class, ByteBuffer.class));
                return newBufferCleaner(directBufferClass, unmapper);
        } catch (SecurityException se) {
            return "Unmapping is not supported, because not all required " +
                    "permissions are given to the Hadoop JAR file: " + se +
                    " [Please grant at least the following permissions: " +
                    "RuntimePermission(\"accessClassInPackage.sun.misc\") " +
                    " and ReflectPermission(\"suppressAccessChecks\")]";
        } catch (ReflectiveOperationException | RuntimeException e) {
            return "Unmapping is not supported on this platform, " +
                    "because internal Java APIs are not compatible with " +
                    "this Hadoop version: " + e;

    private static BufferCleaner newBufferCleaner(
            final Class<?> unmappableBufferClass, final MethodHandle unmapper) {
        assert Objects.equals(
                methodType(void.class, ByteBuffer.class), unmapper.type());
        return buffer -> {
            if (!buffer.isDirect()) {
                throw new IllegalArgumentException(
                        "unmapping only works with direct buffers");
            if (!unmappableBufferClass.isInstance(buffer)) {
                throw new IllegalArgumentException("buffer is not an instance of " +
            final Throwable error = AccessController.doPrivileged(
                    (PrivilegedAction<Throwable>) () -> {
                        try {
                            return null;
                        } catch (Throwable t) {
                            return t;
            if (error != null) {
                throw new IOException("Unable to unmap the mapped buffer", error);

     * Pass in an implementation of this interface to cleanup ByteBuffers.
     * CleanerUtil implements this to allow unmapping of bytebuffers
     * with private Java APIs.
    public interface BufferCleaner {
        void freeBuffer(ByteBuffer b) throws IOException;


Or download all of them as a single archive file:

File name: poi-5.2.3-src.zip
File size: 2479830 bytes
Release date: 2022-09-09


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