{"id":2347,"date":"2025-05-12T02:13:53","date_gmt":"2025-05-12T02:13:53","guid":{"rendered":"https:\/\/techtrendfeed.com\/?p=2347"},"modified":"2025-05-12T02:13:53","modified_gmt":"2025-05-12T02:13:53","slug":"the-right-way-to-convert-xls-to-xlsx-in-java","status":"publish","type":"post","link":"https:\/\/techtrendfeed.com\/?p=2347","title":{"rendered":"The right way to Convert XLS to XLSX in Java"},"content":{"rendered":"<p> <br \/>\n<\/p>\n<div>\n<h2><strong>Why Upgrading XLS to XLSX Is Price Your Time<\/strong><\/h2>\n<p>Ask any seasoned Java developer who&#8217;s labored with Excel recordsdata lengthy sufficient, and also you\u2019ll most likely hear an analogous chorus: the outdated XLS Excel format is clunky and annoying. It\u2019s been round because the late \u201980s, and whereas it\u2019s nonetheless supported in a variety of techniques, it isn&#8217;t doing us many favors at present. \u00a0It was, in any case, changed with XLSX for a cause.<\/p>\n<p>Sadly, there\u2019s nonetheless a variety of vital knowledge packed in these outdated binary XLS containers, and a few builders are tasked with making clear conversions to XLSX to enhance the usability (and safety) of that knowledge for the long term.<\/p>\n<p>On this article, we&#8217;re taking a detailed take a look at why changing legacy XLS recordsdata to the <a rel=\"nofollow\" target=\"_blank\" href=\"https:\/\/dzone.com\/articles\/go-language-library-for-reading-and-writing-micros\">newer XLSX format<\/a> is vital. We&#8217;ll dig into what modifications below the hood throughout that conversion, why XLSX is clearly a lot better suited to trendy workflows, and what your greatest choices are to effectively construct out programmatic XLS to XLSX conversions in a Java utility.<\/p>\n<h2><strong>Why Individuals Nonetheless Use XLS \u2014 And Why It\u2019s a Headache<\/strong><\/h2>\n<p>The older XLS format makes use of a binary file construction. That alone units it aside from virtually each main doc format we use at present, which are likely to favor XML or JSON-based requirements. When you&#8217;ve stumbled throughout an outdated finance export or been compelled to inherit reporting logic from 2006, there is a good likelihood you&#8217;ve got handled binary Excel knowledge, and also you most likely haven\u2019t been excited to try this once more.<\/p>\n<p>XLS format has some exhausting limits baked in that do not make a ton of sense at present. It\u2019s capped at simply over 65,000 rows and 256 columns per sheet (a staggering 983,576 rows and 16,128 columns wanting trendy XLSX capabilities), and discovering clear interoperability for XLS with newer APIs or cloud providers might be hit-or-miss.<\/p>\n<p>Much more frustratingly, as a result of XLS is a binary container, you possibly can&#8217;t simply crack it open to see what&#8217;s flawed internally. You\u2019re caught counting on some library to parse XLS contents appropriately \u2014 and good luck in case you hit one thing nonstandard throughout that course of. Compared, in search of errors within the Open XML file construction that XLSX (and all trendy MS Workplace) recordsdata use is like trying to find typos in a child\u2019s ebook.<\/p>\n<p>After which there&#8217;s the tooling: in style open-source Java conversion libraries like <a rel=\"nofollow\" target=\"_blank\" href=\"https:\/\/dzone.com\/articles\/introduction-to-apache-poi-library\">Apache POI<\/a> <em>can<\/em> deal with XLS recordsdata, however that possibility requires a distinct code path, totally different lessons, and customarily extra brittle habits in comparison with working with XLSX and different Open XML recordsdata. \u00a0We\u2019ll cowl this specific problem in some extra element in a while on this article.<\/p>\n<h2><strong>What\u2019s So Nice About XLSX Anyway?<\/strong><\/h2>\n<p>Trendy Excel\u2019s XLSX format is a part of Microsoft\u2019s Open Workplace XML commonplace. Meaning it\u2019s only a ZIP archive filled with plain, neatly organized XML recordsdata at its most elementary degree. XML is each human-readable and machine-friendly: the most effective of each worlds.\u00a0<\/p>\n<p>As a substitute of being one big binary blob, every a part of the XLSX spreadsheet \u2014 the worksheets, the shared string desk, the fashion definitions \u2014 is damaged out into neatly right into a sequence of structured XML paperwork.\u00a0<\/p>\n<p>For instance, if we constructed a easy spreadsheet with the next content material:<\/p>\n<p><img decoding=\"async\" style=\"width: 538px;\" class=\"fr-fic fr-dib lazyload\" data-image=\"true\" data-new=\"false\" data-sizeformatted=\"8.2 kB\" data-mimetype=\"image\/png\" data-creationdate=\"1746727110572\" data-creationdateformatted=\"05\/08\/2025 05:58 PM\" data-type=\"temp\" data-url=\"https:\/\/dz2cdn1.dzone.com\/storage\/temp\/18391740-1746727110056.png\" data-modificationdate=\"null\" data-size=\"8221\" data-name=\"1746727110056.png\" data-id=\"18391740\" src=\"https:\/\/dz2cdn1.dzone.com\/storage\/temp\/18391740-1746727110056.png\" alt=\"Spreadsheet\"\/><\/p>\n<p>We&#8217;d discover this actual knowledge represented within the worksheet XML file like so:<\/p>\n<p>The column show settings are outlined within the <code><cols\/><\/code> tag, and the precise cell knowledge (which carries shared string references on this case) is represented within the <code><sheetdata\/><\/code> tag. You do not want a sophisticated diploma in any computational subject to determine what is going on on right here, and that is a fantastic factor.<\/p>\n<p>This construction actually does matter. It makes debugging simpler, model management extra wise, the format extensible, and the whole file extra future-proof. And, after all, it performs far, much more properly with open-source instruments, cloud APIs, and Java libraries, which usually want a weight loss plan of well-defined transportable codecs.<\/p>\n<p>So, in case you\u2019re engaged on something that entails remodeling spreadsheet knowledge, exposing it by way of APIs, or piping it by means of cloud platforms, XLSX is by far the safer and extra scalable selection. There are quite a few the reason why binary containers have been eradicated in favor of compressed XML to start with, and every thing we\u2019ve talked about here&#8217;s a contributing issue.<\/p>\n<h2><strong>What Truly Occurs Throughout the XLS to XLSX Improve<\/strong><\/h2>\n<p>Upgrading XLS to XLSX programmatically is a little more advanced than the straightforward \u201cSave As\u201d operation Excel permits you to do manually inside the Excel desktop utility. \u00a0<\/p>\n<p>Beneath the hood, binary to compressed XML conversion entails some heavy lifting. The outdated binary workbook have to be unpacked and rewritten totally into an XML-based construction. Meaning all of the cells, rows, and sheets get redefined as the suitable set of XML components. Every fashion, font, and border from the XLS binary container will get transformed into an XML equal, too, and the formulation get reserialized.<\/p>\n<p>If XLS recordsdata carry legacy macros or embedded objects (which, by the way in which, it is best to by no means implicitly belief the safety of in ANY spreadsheet handler), the story will get a bit messier. Outdated macros and objects don\u2019t at all times translate cleanly into trendy Excel, and you&#8217;ll simply lose constancy relying on the conversion library you\u2019re utilizing. <a rel=\"nofollow\" target=\"_blank\" href=\"https:\/\/dzone.com\/articles\/how-to-merge-excel-xlsx-files-in-java\">Excel XLSX<\/a> additionally doesn\u2019t help macros straight the way in which XLS does; macros will both be cleansed from the XLSX file robotically, or the Excel utility will counsel redefining the file as an XLSM (macro-enabled XLSX) doc.<\/p>\n<p>Fortunately, although, the overwhelming majority of XLS spreadsheet conversions will retailer little greater than tabular knowledge, fundamental formatting, and easy formulation. The conversion for these recordsdata to XLSX tends to be a lot smoother.<\/p>\n<h2><strong>Open-Supply Libraries That Get the Job Accomplished<\/strong><\/h2>\n<p>Apache POI continues to be the most effective open-source default for Excel work in Java, and it helps each XLS and XLSX.<\/p>\n<p>That mentioned, there\u2019s a big catch on this occasion: you\u2019re working with two separate APIs to deal with XLS and XLSX paperwork. For XLS recordsdata, you\u2019ll be utilizing the HSSF API (which accurately stands for \u201cHorrible Spreadsheet Format\u201d), and for XLSX, you\u2019ll be utilizing the XSSF API (which merely stands for \u201cXML Spreadsheet Format\u201d).<\/p>\n<p>In apply, constructing a conversion workflow by way of Apache POI means you\u2019ll have to <strong>1)<\/strong> load the XLS file with HSSFWorkbook, <strong>2)<\/strong> construct a brand new XSSFWorkbook, and <strong>3)<\/strong> (tragically) manually copy every sheet, row, and cell from one to the opposite. It\u2019s actually doable \u2014 nevertheless it\u2019s additionally extraordinarily tedious. On this case, POI sadly doesn\u2019t provide the magic methodology you most likely need for file format conversions. You\u2019ll want to put in writing that translation logic your self.<\/p>\n<p>Nonetheless, in case you&#8217;re already utilizing POI in your mission for an additional objective, or in case you simply need most management over the workbook construction, it is a stable possibility. Simply don\u2019t count on it to be elegant.<\/p>\n<h2><strong>Dealing with XLS to XLSX With a Third-Get together Net API<\/strong><\/h2>\n<p>A less complicated possibility for dealing with XLS to XLSX conversions entails utilizing a totally realized internet API answer. \u00a0This abstracts the complexity away out of your setting. \u00a0 The choice we&#8217;ll reveal right here isn\u2019t open supply, and it does require an API key, nevertheless it\u2019ll plug straight into your Java mission, and it\u2019ll use very minimal code in comparison with patchwork open-source options. Beneath, we\u2019ll stroll by means of code examples you need to use to construction your API name for XLS to XLSX conversions.<\/p>\n<p>If we&#8217;re working with Maven, we&#8217;ll first add the next reference to our <code>pom.xml<\/code> repository:<\/p>\n<div class=\"codeMirror-wrapper\" contenteditable=\"false\">\n<div contenteditable=\"false\">\n<div class=\"codeMirror-code--wrapper\" data-code=\"&lt;repositories&gt;&#10;    &lt;repository&gt;&#10;        &lt;id&gt;jitpack.io&lt;\/id&gt;&#10;        &lt;url&gt;https:\/\/jitpack.io&lt;\/url&gt;&#10;    &lt;\/repository&gt;&#10;&lt;\/repositories&gt;&#10;\" data-lang=\"application\/xml\">\n<pre><code lang=\"application\/xml\"><repositories>\n    <repository>\n        <id>jitpack.io<\/id>\n        <url>https:\/\/jitpack.io<\/url>\n    <\/repository>\n<\/repositories>\n<\/code><\/pre>\n<\/p><\/div><\/div>\n<\/div>\n<p>And we&#8217;ll then add a reference to our <code>pom.xml<\/code> dependency:<\/p>\n<div class=\"codeMirror-wrapper\" contenteditable=\"false\">\n<div contenteditable=\"false\">\n<div class=\"codeMirror-code--wrapper\" data-code=\"&lt;dependencies&gt;&#10;&lt;dependency&gt;&#10;    &lt;groupId&gt;com.github.Cloudmersive&lt;\/groupId&gt;&#10;    &lt;artifactId&gt;Cloudmersive.APIClient.Java&lt;\/artifactId&gt;&#10;    &lt;version&gt;v4.25&lt;\/version&gt;&#10;&lt;\/dependency&gt;&#10;&lt;\/dependencies&gt;\" data-lang=\"application\/xml\">\n<pre><code lang=\"application\/xml\"><dependencies>\n<dependency>\n    <groupid>com.github.Cloudmersive<\/groupid>\n    <artifactid>Cloudmersive.APIClient.Java<\/artifactid>\n    <version>v4.25<\/version>\n<\/dependency>\n<\/dependencies><\/code><\/pre>\n<\/p><\/div><\/div>\n<\/div>\n<p>If we&#8217;re working with Gradle, we&#8217;ll want so as to add it in our root <code>construct.gradle<\/code> (on the finish of repositories):<\/p>\n<div class=\"codeMirror-wrapper\" contenteditable=\"false\">\n<div contenteditable=\"false\">\n<div class=\"codeMirror-code--wrapper\" data-code=\"allprojects {&#10;&#9;repositories {&#10;&#9;&#9;...&#10;&#9;&#9;maven { url 'https:\/\/jitpack.io' }&#10;&#9;}&#10;}\" data-lang=\"text\/x-groovy\">\n<pre><code lang=\"text\/x-groovy\">allprojects {\n\trepositories {\n\t\t...\n\t\tmaven { url 'https:\/\/jitpack.io' }\n\t}\n}<\/code><\/pre>\n<\/p><\/div><\/div>\n<\/div>\n<p>After which add the dependency in <code>construct.gradle<\/code>:<\/p>\n<div class=\"codeMirror-wrapper\" contenteditable=\"false\">\n<div contenteditable=\"false\">\n<div class=\"codeMirror-code--wrapper\" data-code=\"dependencies {&#10;        implementation 'com.github.Cloudmersive:Cloudmersive.APIClient.Java:v4.25'&#10;}\" data-lang=\"text\/x-groovy\">\n<pre><code lang=\"text\/x-groovy\">dependencies {\n        implementation 'com.github.Cloudmersive:Cloudmersive.APIClient.Java:v4.25'\n}<\/code><\/pre>\n<\/p><\/div><\/div>\n<\/div>\n<p>After we have put in the SDK, we&#8217;ll place the Import lessons on the prime of our file (commented out for now):<\/p>\n<div class=\"codeMirror-wrapper\" contenteditable=\"false\">\n<div contenteditable=\"false\">\n<div class=\"codeMirror-code--wrapper\" data-code=\"\/\/ Import classes:&#10;\/\/import com.cloudmersive.client.invoker.ApiClient;&#10;\/\/import com.cloudmersive.client.invoker.ApiException;&#10;\/\/import com.cloudmersive.client.invoker.Configuration;&#10;\/\/import com.cloudmersive.client.invoker.auth.*;&#10;\/\/import com.cloudmersive.client.ConvertDocumentApi;\" data-lang=\"text\/x-java\">\n<pre><code lang=\"text\/x-java\">\/\/ Import lessons:\n\/\/import com.cloudmersive.consumer.invoker.ApiClient;\n\/\/import com.cloudmersive.consumer.invoker.ApiException;\n\/\/import com.cloudmersive.consumer.invoker.Configuration;\n\/\/import com.cloudmersive.consumer.invoker.auth.*;\n\/\/import com.cloudmersive.consumer.ConvertDocumentApi;<\/code><\/pre>\n<\/p><\/div><\/div>\n<\/div>\n<p>Lastly, we&#8217;ll configure the API consumer, set our API key within the authorization snippet, and make our XLS to XLSX conversion:<\/p>\n<div class=\"codeMirror-wrapper\" contenteditable=\"false\">\n<div contenteditable=\"false\">\n<div class=\"codeMirror-code--wrapper\" data-code=\"ApiClient defaultClient = Configuration.getDefaultApiClient();&#10;&#10;\/\/ Configure API key authorization: Apikey&#10;ApiKeyAuth Apikey = (ApiKeyAuth) defaultClient.getAuthentication(&quot;Apikey&quot;);&#10;Apikey.setApiKey(&quot;YOUR API KEY&quot;);&#10;\/\/ Uncomment the following line to set a prefix for the API key, e.g. &quot;Token&quot; (defaults to null)&#10;\/\/Apikey.setApiKeyPrefix(&quot;Token&quot;);&#10;&#10;ConvertDocumentApi apiInstance = new ConvertDocumentApi();&#10;File inputFile = new File(&quot;\/path\/to\/inputfile&quot;); \/\/ File | Input file to perform the operation on.&#10;try {&#10;    byte[] result = apiInstance.convertDocumentXlsToXlsx(inputFile);&#10;    System.out.println(result);&#10;} catch (ApiException e) {&#10;    System.err.println(&quot;Exception when calling ConvertDocumentApi#convertDocumentXlsToXlsx&quot;);&#10;    e.printStackTrace();&#10;}\" data-lang=\"text\/x-java\">\n<pre><code lang=\"text\/x-java\">ApiClient defaultClient = Configuration.getDefaultApiClient();\n\n\/\/ Configure API key authorization: Apikey\nApiKeyAuth Apikey = (ApiKeyAuth) defaultClient.getAuthentication(\"Apikey\");\nApikey.setApiKey(\"YOUR API KEY\");\n\/\/ Uncomment the next line to set a prefix for the API key, e.g. \"Token\" (defaults to null)\n\/\/Apikey.setApiKeyPrefix(\"Token\");\n\nConvertDocumentApi apiInstance = new ConvertDocumentApi();\nFile inputFile = new File(\"\/path\/to\/inputfile\"); \/\/ File | Enter file to carry out the operation on.\nattempt {\n    byte[] end result = apiInstance.convertDocumentXlsToXlsx(inputFile);\n    System.out.println(end result);\n} catch (ApiException e) {\n    System.err.println(\"Exception when calling ConvertDocumentApi#convertDocumentXlsToXlsx\");\n    e.printStackTrace();\n}<\/code><\/pre>\n<\/p><\/div><\/div>\n<\/div>\n<p>We&#8217;ll get our XLSX file content material as a byte array (<code>byte[] end result<\/code>), and we are able to write that content material to a brand new file with the <code>.xlsx<\/code> extension. This simplifies automated XLS to XLSX conversion workflows significantly.<\/p>\n<h2><strong>Conclusion<\/strong><\/h2>\n<p>On this article, we realized in regards to the variations between XLS and XLSX codecs and mentioned the the reason why XLSX is clearly the superior trendy format. We urged a preferred open-source library as one possibility for constructing automated XLS to XLSX conversion logic in Java and a totally realized internet API answer to summary the whole course of away from our surroundings.<\/p>\n<\/div>\n\n","protected":false},"excerpt":{"rendered":"<p>Why Upgrading XLS to XLSX Is Price Your Time Ask any seasoned Java developer who&#8217;s labored with Excel recordsdata lengthy sufficient, and also you\u2019ll most likely hear an analogous chorus: the outdated XLS Excel format is clunky and annoying. It\u2019s been round because the late \u201980s, and whereas it\u2019s nonetheless supported in a variety of [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":2349,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[56],"tags":[2311,2314,2312,2313],"class_list":["post-2347","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-software","tag-convert","tag-java","tag-xls","tag-xlsx"],"_links":{"self":[{"href":"https:\/\/techtrendfeed.com\/index.php?rest_route=\/wp\/v2\/posts\/2347","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/techtrendfeed.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/techtrendfeed.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/techtrendfeed.com\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/techtrendfeed.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2347"}],"version-history":[{"count":1,"href":"https:\/\/techtrendfeed.com\/index.php?rest_route=\/wp\/v2\/posts\/2347\/revisions"}],"predecessor-version":[{"id":2348,"href":"https:\/\/techtrendfeed.com\/index.php?rest_route=\/wp\/v2\/posts\/2347\/revisions\/2348"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/techtrendfeed.com\/index.php?rest_route=\/wp\/v2\/media\/2349"}],"wp:attachment":[{"href":"https:\/\/techtrendfeed.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2347"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/techtrendfeed.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2347"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/techtrendfeed.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2347"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}<!-- This website is optimized by Airlift. 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