The full source code for this tutorial is available on Github<\/a>.<\/p>\n Jericho is a java library<\/a> that allows analysis and manipulation of parts of an HTML document, including server-side tags, while reproducing verbatim any unrecognized or invalid HTML. It also provides high-level HTML form manipulation functions.\u00a0It is an open source library released under the following licenses:\u00a0Eclipse Public License (EPL)<\/a>,\u00a0GNU Lesser General Public License (LGPL)<\/a>, and\u00a0Apache License<\/a>.<\/p>\n I found Jericho to be very easy to use for achieving my goal of converting HTML to RichText.<\/p>\n Here are the required dependencies for the application we are building. Please take note that for this application we have to use Java 9<\/strong>. This is because of a java.util.regex appendReplacement method<\/a> we use that has only been available since Java 9.<\/p>\n We use Thymeleaf to create a basic webpage that has a form with a textarea. The source code for Thymeleaf page is available here on Github<\/a>. This textarea could be replaced with a RichText Editor if we like, such as CKEditor. We just must be mindful to make the data<\/em> for AJAX correct, using an appropriate setData<\/em> method. There is a previous tutorial about CKeditor titled AJAX with CKEditor in Spring Boot<\/a>.<\/p>\n In our controller, we Autowire JobLauncher<\/em> and a Spring Batch job we are going to create called GenerateExcel<\/em>. Autowiring these two classes allow us to run the Spring Batch Job GenerateExcel<\/em> on demand when a POST request is sent to \u201c\/export\u201d<\/em>.<\/p>\n Another thing to note is that to ensure that the Spring Batch job will run more than once we include unique parameters with this code: addLong(\u201cuniqueness\u201d, System.nanoTime()).toJobParameters()<\/em>. An error may occur if we do not include unique parameters because only unique JobInstances<\/em> may be created and executed, and Spring Batch has no way of distinguishing between the first and second JobInstance <\/em>otherwise.<\/p>\n In Step1 of our Batch job, we call the getCurrentContent() method to get the content that was passed into the Thymeleaf form, create a new XSSFWorkbook, specify an arbitrary Microsoft Excel Sheet tab name, and then pass all three variables into the createWorksheet method that we will be making in the next step of our tutorial : We have covered Spring Batch in other tutorials such as Converting XML to JSON + Spring Batch<\/a> and Spring Batch CSV Processing<\/a>.<\/p>\n We use a variety of classes to create our Microsoft Excel file. Order matters when dealing with converting HTML to RichText, so this will be a focus.<\/p>\n A class with two parameters: a String that will have our contents that will become RichText and a font map.<\/p>\n A POJO that will keep track of the location of the RichText and what not:<\/p>\n A enum to contains HTML tags that we want to process. We can add to this as necessary:<\/p>\n A POJO to keep track of tag info:<\/p>\n This is not a small class, so let\u2019s break it down by method.<\/p>\n Essentially, we are surrounding any arbitrary HTML with a div<\/em> tag, so we know what we are looking for. Then we look for all elements within the div<\/em> tag, add each to an ArrayList of RichTextDetails , and then pass the whole ArrayList to the mergeTextDetails method. mergeTextDetails returns RichtextString, which is what we need to set a cell value:<\/p>\n As we saw above, we pass an ArrayList of RichTextDetails in this method. Jericho has a setting that takes boolean value to recognize empty tag elements such as As mentioned above, we are using Java 9 in order to use StringBuilder with the java.util.regex.Matcher.appendReplacement<\/em>. Why? Well that\u2019s because StringBuffer slower than StringBuilder for operations. StringBuffer functions are synchronized for thread safety and thus slower.<\/p>\n We are using Deque instead of Stack because a more complete and consistent set of LIFO stack operations is provided by the Deque interface:<\/p>\n We can see where RichTextInfo comes in to use here:<\/p>\n Where we use STYLES enum:<\/p>\n We are making use of the TagInfo class to track the current tag:<\/p>\n We process the HTML tags:<\/p>\n Using StringBuilder, I create a String that is going to written to FileOutPutStream. In a real application this should be user defined. I appended my folder path and filename on two different lines. Please change the file path to your own.<\/p>\n sheet.createRow(0)<\/em> creates a row on the very first line and dataRow.createCell(0)<\/em> creates a cell in column A of the row.<\/p>\n We visit localhost:8080<\/em>.<\/p>\n We input some text with some HTML: We open up our excel file and see the RichText we created: We can see it is not trivial to convert HTML to Apache POI\u2019s RichTextString class; however, for business applications converting HTML to RichTextString can be essential because readability is important in Microsoft Excel files. There\u2019s likely room to improve upon the performance of the application we build, but we covered the foundation of building such an application .<\/p>\n The full source code is available on Github.<\/a><\/p>\n2. What is Jericho?<\/h2>\n
3. pom.xml<\/h2>\n
<parent>\r\n\t<groupId>org.springframework.boot<\/groupId>\r\n\t<artifactId>spring-boot-starter-parent<\/artifactId>\r\n\t<version>1.5.9.RELEASE<\/version>\r\n\t<relativePath \/> <!-- lookup parent from repository -->\r\n<\/parent>\r\n\r\n<properties>\r\n\t<project.build.sourceEncoding>UTF-8<\/project.build.sourceEncoding>\r\n\t<project.reporting.outputEncoding>UTF-8<\/project.reporting.outputEncoding>\r\n\t<java.version>9<\/java.version>\r\n<\/properties>\r\n\r\n<dependencies>\r\n\t<dependency>\r\n\t\t<groupId>org.springframework.boot<\/groupId>\r\n\t\t<artifactId>spring-boot-starter-batch<\/artifactId>\r\n\t<\/dependency>\r\n\t<dependency>\r\n\t\t<groupId>org.springframework.boot<\/groupId>\r\n\t\t<artifactId>spring-boot-starter-thymeleaf<\/artifactId>\r\n\t<\/dependency>\r\n\r\n\t<dependency>\r\n\t\t<groupId>com.h2database<\/groupId>\r\n\t\t<artifactId>h2<\/artifactId>\r\n\t\t<scope>runtime<\/scope>\r\n\t<\/dependency>\r\n\t<dependency>\r\n\t\t<groupId>org.springframework.boot<\/groupId>\r\n\t\t<artifactId>spring-boot-starter-test<\/artifactId>\r\n\t\t<scope>test<\/scope>\r\n\t<\/dependency>\r\n\t<!-- https:\/\/mvnrepository.com\/artifact\/org.apache.commons\/commons-lang3 -->\r\n\t<dependency>\r\n\t\t<groupId>org.apache.commons<\/groupId>\r\n\t\t<artifactId>commons-lang3<\/artifactId>\r\n\t\t<version>3.7<\/version>\r\n\t<\/dependency>\r\n\t<dependency>\r\n\t\t<groupId>org.springframework.batch<\/groupId>\r\n\t\t<artifactId>spring-batch-test<\/artifactId>\r\n\t\t<scope>test<\/scope>\r\n\t<\/dependency>\r\n\t<dependency>\r\n\t\t<groupId>org.apache.poi<\/groupId>\r\n\t\t<artifactId>poi<\/artifactId>\r\n\t\t<version>3.15<\/version>\r\n\t<\/dependency>\r\n\r\n\t<dependency>\r\n\t\t<groupId>org.apache.poi<\/groupId>\r\n\t\t<artifactId>poi-ooxml<\/artifactId>\r\n\t\t<version>3.15<\/version>\r\n\t<\/dependency>\r\n\t<!-- https:\/\/mvnrepository.com\/artifact\/net.htmlparser.jericho\/jericho-html -->\r\n\t<dependency>\r\n\t\t<groupId>net.htmlparser.jericho<\/groupId>\r\n\t\t<artifactId>jericho-html<\/artifactId>\r\n\t\t<version>3.4<\/version>\r\n\t<\/dependency>\r\n\t<dependency>\r\n\t\t<groupId>org.springframework.boot<\/groupId>\r\n\t\t<artifactId>spring-boot-configuration-processor<\/artifactId>\r\n\t\t<optional>true<\/optional>\r\n\t<\/dependency>\r\n\t<!-- legacy html allow -->\r\n\t<dependency>\r\n\t\t<groupId>net.sourceforge.nekohtml<\/groupId>\r\n\t\t<artifactId>nekohtml<\/artifactId>\r\n\t<\/dependency>\r\n<\/dependencies><\/pre>\n
4. Web page \u2013 Thymeleaf<\/h2>\n
5. Controller<\/h2>\n
@Controller\r\npublic class WebController {\r\n\r\n private String currentContent;\r\n\r\n @Autowired\r\n JobLauncher jobLauncher;\r\n \r\n @Autowired\r\n GenerateExcel exceljob; \r\n\r\n @GetMapping(\"\/\")\r\n public ModelAndView getHome() {\r\n ModelAndView modelAndView = new ModelAndView(\"index\");\r\n return modelAndView;\r\n\r\n }\r\n \r\n\r\n @PostMapping(\"\/export\")\r\n public String postTheFile(@RequestBody String body, RedirectAttributes redirectAttributes, Model model)\r\n throws IOException, JobExecutionAlreadyRunningException, JobRestartException, JobInstanceAlreadyCompleteException, JobParametersInvalidException {\r\n\r\n\r\n setCurrentContent(body);\r\n\r\n Job job = exceljob.ExcelGenerator();\r\n jobLauncher.run(job, new JobParametersBuilder().addLong(\"uniqueness\", System.nanoTime()).toJobParameters()\r\n );\r\n\r\n return \"redirect:\/\";\r\n }\r\n\r\n \/\/standard getters and setters\r\n\r\n}<\/pre>\n6. Batch Job<\/h2>\n
@Configuration\r\n@EnableBatchProcessing\r\n@Lazy\r\npublic class GenerateExcel {\r\n \r\n List<String> docIds = new ArrayList<String>();\r\n\r\n @Autowired\r\n private JobBuilderFactory jobBuilderFactory;\r\n\r\n @Autowired\r\n private StepBuilderFactory stepBuilderFactory;\r\n\r\n @Autowired\r\n WebController webcontroller;\r\n \r\n @Autowired\r\n CreateWorksheet createexcel;\r\n\r\n @Bean\r\n public Step step1() {\r\n return stepBuilderFactory.get(\"step1\")\r\n .tasklet(new Tasklet() {\r\n @Override\r\n public RepeatStatus execute(StepContribution stepContribution, ChunkContext chunkContext) throws Exception, JSONException {\r\n\r\n String content = webcontroller.getCurrentContent();\r\n \r\n System.out.println(\"content is ::\" + content);\r\n Workbook wb = new XSSFWorkbook();\r\n String tabName = \"some\";\r\n createexcel.createWorkSheet(wb, content, tabName);\r\n\r\n return RepeatStatus.FINISHED;\r\n }\r\n })\r\n .build();\r\n }\r\n\r\n @Bean\r\n public Job ExcelGenerator() {\r\n return jobBuilderFactory.get(\"ExcelGenerator\")\r\n .start(step1())\r\n .build();\r\n\r\n }\r\n\r\n}<\/pre>\n7. Excel Creation Service<\/h2>\n
7.1 RichTextDetails<\/h3>\n
public class RichTextDetails {\r\n private String richText;\r\n private Map<Integer, Font> fontMap;\r\n \/\/standard getters and setters\r\n @Override\r\n public int hashCode() {\r\n \r\n \/\/ The goal is to have a more efficient hashcode than standard one.\r\n return richText.hashCode();\r\n }<\/pre>\n7.2 RichTextInfo<\/h3>\n
public class RichTextInfo {\r\n private int startIndex;\r\n private int endIndex;\r\n private STYLES fontStyle;\r\n private String fontValue;\r\n \/\/ standard getters and setters, and the like<\/pre>\n7.3 Styles<\/h3>\n
public enum STYLES {\r\n BOLD(\"b\"), \r\n EM(\"em\"), \r\n STRONG(\"strong\"), \r\n COLOR(\"color\"), \r\n UNDERLINE(\"u\"), \r\n SPAN(\"span\"), \r\n ITALLICS(\"i\"), \r\n UNKNOWN(\"unknown\"),\r\n PRE(\"pre\");\r\n \/\/ standard getters and setters<\/pre>\n7.4 TagInfo<\/h3>\n
public class TagInfo {\r\n private String tagName;\r\n private String style;\r\n private int tagType;\r\n \/\/ standard getters and setters<\/pre>\n7.5 HTML to RichText<\/h3>\n
public RichTextString fromHtmlToCellValue(String html, Workbook workBook){\r\n Config.IsHTMLEmptyElementTagRecognised = true;\r\n \r\n Matcher m = HEAVY_REGEX.matcher(html);\r\n String replacedhtml = m.replaceAll(\"\");\r\n StringBuilder sb = new StringBuilder();\r\n sb.insert(0, \"<div>\");\r\n sb.append(replacedhtml);\r\n sb.append(\"<\/div>\");\r\n String newhtml = sb.toString();\r\n Source source = new Source(newhtml);\r\n List<RichTextDetails> cellValues = new ArrayList<RichTextDetails>();\r\n for(Element el : source.getAllElements(\"div\")){\r\n cellValues.add(createCellValue(el.toString(), workBook));\r\n }\r\n RichTextString cellValue = mergeTextDetails(cellValues);\r\n\r\n \r\n return cellValue;\r\n }<\/pre>\n
\n: Config.IsHTMLEmptyElementTagRecognised. This can be important when dealing with online rich text editors, so we set this to true. Because we need to keep track of the order of the elements, we use a LinkedHashMap instead of a HashMap.<\/p>\nprivate static RichTextString mergeTextDetails(List<RichTextDetails> cellValues) {\r\n Config.IsHTMLEmptyElementTagRecognised = true;\r\n StringBuilder textBuffer = new StringBuilder();\r\n Map<Integer, Font> mergedMap = new LinkedHashMap<Integer, Font>(550, .95f);\r\n int currentIndex = 0;\r\n for (RichTextDetails richTextDetail : cellValues) {\r\n \/\/textBuffer.append(BULLET_CHARACTER + \" \");\r\n currentIndex = textBuffer.length();\r\n for (Entry<Integer, Font> entry : richTextDetail.getFontMap()\r\n .entrySet()) {\r\n mergedMap.put(entry.getKey() + currentIndex, entry.getValue());\r\n }\r\n textBuffer.append(richTextDetail.getRichText())\r\n .append(NEW_LINE);\r\n }\r\n\r\n RichTextString richText = new XSSFRichTextString(textBuffer.toString());\r\n for (int i = 0; i < textBuffer.length(); i++) {\r\n Font currentFont = mergedMap.get(i);\r\n if (currentFont != null) {\r\n richText.applyFont(i, i + 1, currentFont);\r\n }\r\n }\r\n return richText;\r\n }<\/pre>\nstatic RichTextDetails createCellValue(String html, Workbook workBook) {\r\n Config.IsHTMLEmptyElementTagRecognised = true;\r\n Source source = new Source(html);\r\n Map<String, TagInfo> tagMap = new LinkedHashMap<String, TagInfo>(550, .95f);\r\n for (Element e : source.getChildElements()) {\r\n getInfo(e, tagMap);\r\n }\r\n\r\n StringBuilder sbPatt = new StringBuilder();\r\n sbPatt.append(\"(\").append(StringUtils.join(tagMap.keySet(), \"|\")).append(\")\");\r\n String patternString = sbPatt.toString();\r\n Pattern pattern = Pattern.compile(patternString);\r\n Matcher matcher = pattern.matcher(html);\r\n\r\n StringBuilder textBuffer = new StringBuilder();\r\n List<RichTextInfo> textInfos = new ArrayList<RichTextInfo>();\r\n ArrayDeque<RichTextInfo> richTextBuffer = new ArrayDeque<RichTextInfo>();\r\n while (matcher.find()) {\r\n matcher.appendReplacement(textBuffer, \"\");\r\n TagInfo currentTag = tagMap.get(matcher.group(1));\r\n if (START_TAG == currentTag.getTagType()) {\r\n richTextBuffer.push(getRichTextInfo(currentTag, textBuffer.length(), workBook));\r\n } else {\r\n if (!richTextBuffer.isEmpty()) {\r\n RichTextInfo info = richTextBuffer.pop();\r\n if (info != null) {\r\n info.setEndIndex(textBuffer.length());\r\n textInfos.add(info);\r\n }\r\n }\r\n }\r\n }\r\n matcher.appendTail(textBuffer);\r\n Map<Integer, Font> fontMap = buildFontMap(textInfos, workBook);\r\n\r\n return new RichTextDetails(textBuffer.toString(), fontMap);\r\n }<\/pre>\nprivate static Map<Integer, Font> buildFontMap(List<RichTextInfo> textInfos, Workbook workBook) {\r\n Map<Integer, Font> fontMap = new LinkedHashMap<Integer, Font>(550, .95f);\r\n\r\n for (RichTextInfo richTextInfo : textInfos) {\r\n if (richTextInfo.isValid()) {\r\n for (int i = richTextInfo.getStartIndex(); i < richTextInfo.getEndIndex(); i++) {\r\n fontMap.put(i, mergeFont(fontMap.get(i), richTextInfo.getFontStyle(), richTextInfo.getFontValue(), workBook));\r\n }\r\n }\r\n }\r\n\r\n return fontMap;\r\n }<\/pre>\nprivate static Font mergeFont(Font font, STYLES fontStyle, String fontValue, Workbook workBook) {\r\n if (font == null) {\r\n font = workBook.createFont();\r\n }\r\n\r\n switch (fontStyle) {\r\n case BOLD:\r\n case EM:\r\n case STRONG:\r\n font.setBoldweight(Font.BOLDWEIGHT_BOLD);\r\n break;\r\n case UNDERLINE:\r\n font.setUnderline(Font.U_SINGLE);\r\n break;\r\n case ITALLICS:\r\n font.setItalic(true);\r\n break;\r\n case PRE:\r\n font.setFontName(\"Courier New\");\r\n case COLOR:\r\n if (!isEmpty(fontValue)) {\r\n\r\n font.setColor(IndexedColors.BLACK.getIndex());\r\n }\r\n break;\r\n default:\r\n break;\r\n }\r\n\r\n return font;\r\n }<\/pre>\nprivate static RichTextInfo getRichTextInfo(TagInfo currentTag, int startIndex, Workbook workBook) {\r\n RichTextInfo info = null;\r\n switch (STYLES.fromValue(currentTag.getTagName())) {\r\n case SPAN:\r\n if (!isEmpty(currentTag.getStyle())) {\r\n for (String style : currentTag.getStyle()\r\n .split(\";\")) {\r\n String[] styleDetails = style.split(\":\");\r\n if (styleDetails != null && styleDetails.length > 1) {\r\n if (\"COLOR\".equalsIgnoreCase(styleDetails[0].trim())) {\r\n info = new RichTextInfo(startIndex, -1, STYLES.COLOR, styleDetails[1]);\r\n }\r\n }\r\n }\r\n }\r\n break;\r\n default:\r\n info = new RichTextInfo(startIndex, -1, STYLES.fromValue(currentTag.getTagName()));\r\n break;\r\n }\r\n return info;\r\n }<\/pre>\nprivate static void getInfo(Element e, Map<String, TagInfo> tagMap) {\r\n tagMap.put(e.getStartTag()\r\n .toString(),\r\n new TagInfo(e.getStartTag()\r\n .getName(), e.getAttributeValue(\"style\"), START_TAG));\r\n if (e.getChildElements()\r\n .size() > 0) {\r\n List<Element> children = e.getChildElements();\r\n for (Element child : children) {\r\n getInfo(child, tagMap);\r\n }\r\n }\r\n if (e.getEndTag() != null) {\r\n tagMap.put(e.getEndTag()\r\n .toString(),\r\n new TagInfo(e.getEndTag()\r\n .getName(), END_TAG));\r\n } else {\r\n \/\/ Handling self closing tags\r\n tagMap.put(e.getStartTag()\r\n .toString(),\r\n new TagInfo(e.getStartTag()\r\n .getName(), END_TAG));\r\n }\r\n }<\/pre>\n7.6 Create Worksheet<\/h3>\n
public void createWorkSheet(Workbook wb, String content, String tabName) {\r\n StringBuilder sbFileName = new StringBuilder();\r\n sbFileName.append(\"\/Users\/mike\/javaSTS\/michaelcgood-apache-poi-richtext\/\");\r\n sbFileName.append(\"myfile.xlsx\");\r\n String fileMacTest = sbFileName.toString();\r\n try {\r\n this.fileOut = new FileOutputStream(fileMacTest);\r\n } catch (FileNotFoundException ex) {\r\n Logger.getLogger(CreateWorksheet.class.getName())\r\n .log(Level.SEVERE, null, ex);\r\n }\r\n\r\n Sheet sheet = wb.createSheet(tabName); \/\/ Create new sheet w\/ Tab name\r\n\r\n sheet.setZoom(85); \/\/ Set sheet zoom: 85%\r\n \r\n\r\n \/\/ content rich text\r\n RichTextString contentRich = null;\r\n if (content != null) {\r\n contentRich = htmlToExcel.fromHtmlToCellValue(content, wb);\r\n }\r\n\r\n\r\n \/\/ begin insertion of values into cells\r\n Row dataRow = sheet.createRow(0);\r\n Cell A = dataRow.createCell(0); \/\/ Row Number\r\n A.setCellValue(contentRich);\r\n sheet.autoSizeColumn(0);\r\n \r\n \r\n try {\r\n \/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\r\n \/\/ Write the output to a file\r\n wb.write(fileOut);\r\n fileOut.close();\r\n } catch (IOException ex) {\r\n Logger.getLogger(CreateWorksheet.class.getName())\r\n .log(Level.SEVERE, null, ex);\r\n }\r\n\r\n\r\n }<\/pre>\n8. Demo<\/h2>\n
\n![\"\"](\"http:\/\/www.javacodegeeks.com\/wp-content\/uploads\/2018\/01\/apache-poi-richtext-example-1024x420.png\")
<\/a><\/p>\n
\n![\"\"](\"http:\/\/www.javacodegeeks.com\/wp-content\/uploads\/2018\/01\/excel-apache-poi-screenshot.png\")
<\/a><\/p>\n9. Conclusion<\/h2>\n