Java中字符串根据宽度(像素)换行的问题 Java中字符串根据宽度(像素)换

Java 字符串根据宽度(像素)换行

根据像素宽度进行换行

Java字符串根据宽度(像素)进行换行及Pdf合并

1、工具类最终版前奏
2、工具类最终版
3、项目中具体使用

3.1 controller层
3.2 serviceImpl层

4、工具类补充

Java 字符串根据宽度(像素)换行在一些场景下，我们经常会通过判断字符串的长度，比如个数来实现换行，但是中文、英文、数字、其实在展示的时候同样长度的字符串，其实它的宽度是不一样的，这也是们我通俗意义上说的宽度(像素)

根据像素宽度进行换行
需求：

文章图片

/*** 10、自己做图片，根据文本宽度进行换行*/@Testpublic void creatMyImage(){//整体图合成BufferedImage bufferedImage = new BufferedImage(500, 500, BufferedImage.TYPE_INT_RGB); //设置图片的背景色Graphics2D main = bufferedImage.createGraphics(); main.fillRect(0, 0, 500, 500); String text = "111122223所以比传统纸巾更环保3334441比传统纸巾更环11111111111111122223所以比传统纸巾更环保3334441比传统纸巾更环11111111111111122223所以比传统纸巾更环保3334441比传统纸巾更环11111111111111122223所以比传统纸巾更环保3334441比传统纸巾更环11111111111"; Graphics2D textG = bufferedImage.createGraphics() ; textG.setColor(new Color(37,37,37)); Font hualaoContentFont = new Font("PingFang SC", Font.PLAIN, 20); textG.setFont(hualaoContentFont); textG.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_GASP); drawString(textG,text,30,100,4,10,50,true,false); //存储到本地String saveFilePath = "/Users/healerjean/Desktop/new.png"; saveImageToLocalDir(bufferedImage, saveFilePath); }/**** @param g* @param text 文本* @param lineHeight 行高（注意字体大小的控制哦）* @param maxWidth 行宽* @param maxLine 最大行数* @param left 左边距 //整段文字的左边距* @param top 上边距 //整顿文字的上边距* @param trim 是否修剪文本（1、去除首尾空格，2、将多个换行符替换为一个）* @param lineIndent 是否首行缩进*/public static void drawString(Graphics2D g, String text, float lineHeight, float maxWidth, int maxLine, float left,float top, boolean trim, boolean lineIndent) {if (text == null || text.length() == 0) return; if(trim) {text = text.replaceAll("\\n+", "\n").trim(); }if(lineIndent) {text = "" + text.replaceAll("\\n", "\n"); }drawString(g, text, lineHeight, maxWidth, maxLine, left, top); }/**** @param g* @param text 文本* @param lineHeight 行高* @param maxWidth 行宽* @param maxLine 最大行数* @param left 左边距* @param top 上边距*/private static void drawString(Graphics2D g, String text, float lineHeight, float maxWidth, int maxLine, float left,float top) {if (text == null || text.length() == 0) return; FontMetrics fm = g.getFontMetrics(); StringBuilder sb = new StringBuilder(); for (int i = 0; i < text.length(); i++) {char c = text.charAt(i); sb.append(c); int stringWidth = fm.stringWidth(sb.toString()); if (c == '\n' || stringWidth > maxWidth) {if(c == '\n') {i += 1; }if (maxLine > 1) {g.drawString(text.substring(0, i), left, top); drawString(g, text.substring(i), lineHeight, maxWidth, maxLine - 1, left, top + lineHeight); } else {g.drawString(text.substring(0, i - 1) + "…", left, top); }return; }}g.drawString(text, left, top); }

Java字符串根据宽度(像素)进行换行及Pdf合并实际开发中，我们经常会通过判断字符串的长度，比如个数来实现换行，但是中文、英文、数字在展示的时候同样长度的字符串，其实它的宽度是不一样的，这也是们我通俗意义上说的宽度(像素)。
下面结合jasper套打打印业务来说明。

1、工具类最终版前奏

package main; import java.awt.Color; import java.awt.Font; import java.awt.FontMetrics; import java.awt.Graphics2D; import java.awt.RenderingHints; import java.awt.image.BufferedImage; import java.io.ByteArrayInputStream; import java.io.ByteArrayOutputStream; import java.io.FileOutputStream; import java.io.InputStream; import java.io.OutputStream; import javax.imageio.ImageIO; import javax.imageio.stream.ImageOutputStream; public class SubstringStr { /*** 1、自己做图片，根据文本宽度进行换行*/ public void creatMyImage(String text) {// 整体图合成BufferedImage bufferedImage = new BufferedImage(595, 842, BufferedImage.TYPE_INT_RGB); // 设置图片的背景色Graphics2D main = bufferedImage.createGraphics(); main.fillRect(0, 0, 1500, 2600); Graphics2D graphics2d = bufferedImage.createGraphics(); graphics2d.setColor(new Color(37, 37, 37)); Font hualaoContentFont = new Font("宋体", Font.PLAIN, 20); graphics2d.setFont(hualaoContentFont); graphics2d.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_GASP); drawString1(graphics2d, text, 30, 500, 28, 71, 20, false, false, 0); // 存储到本地String saveFilePath = "D:\\new.png"; saveImageToLocalDir(bufferedImage, saveFilePath); } private void saveImageToLocalDir(BufferedImage img, String saveFilePath) { try {//bufferedimage 转换成 inputstreamByteArrayOutputStream bs = new ByteArrayOutputStream(); ImageOutputStream imOut = ImageIO.createImageOutputStream(bs); ImageIO.write(img, "jpg", imOut); InputStream inputStream = new ByteArrayInputStream(bs.toByteArray()); long length = imOut.length(); OutputStream outStream = new FileOutputStream(saveFilePath); //输出流byte[] bytes = new byte[1024]; long count = 0; while(count < length){int len = inputStream.read(bytes, 0, 1024); count +=len; outStream.write(bytes, 0, len); }outStream.flush(); inputStream.close(); outStream.close(); } catch (Exception e) {e.printStackTrace(); } } /*** @param graphics2d* @param text文本* @param lineHeight 行高（注意字体大小的控制哦）* @param maxWidth 行宽* @param maxLine最大行数* @param left 左边距 //整段文字的左边距* @param top 上边距 //整段文字的上边距* @param trim是否修剪文本（1、去除首尾空格，2、将多个换行符替换为一个）* @param lineIndent 是否首行缩进*/ public static void drawString1(Graphics2D graphics2d, String text, float lineHeight, float maxWidth, int maxLine, float left,float top, boolean trim, boolean lineIndent, int resultLine) {if (text == null || text.length() == 0)return; if (trim) {text = text.replaceAll("\\n+", "\n").trim(); System.err.println("执行了。。。。"); }if (lineIndent) {text = "" + text.replaceAll("\\n", "\n"); System.err.println("执行了====="); }drawString2(graphics2d, text, lineHeight, maxWidth, maxLine, left, top, resultLine); } /**** @param graphics2d* @param text 文本* @param lineHeight 行高* @param maxWidth 行宽* @param maxLine 最大行数* @param left 左边距* @param top 上边距*/ private static void drawString2(Graphics2D graphics2d, String text, float lineHeight, float maxWidth, int maxLine,float left, float top, int resultLine) {if (text == null || text.length() == 0) {return; } FontMetrics fm = graphics2d.getFontMetrics(); StringBuilder sb = new StringBuilder(); for (int i = 0; i < text.length(); i++) {char strChar = text.charAt(i); sb.append(strChar); int stringWidth = fm.stringWidth(sb.toString()); if (strChar == '\n' || stringWidth > maxWidth) {if (strChar == '\n') {i += 1; System.out.println("\n字符串内容为：" + text.substring(0, i)); }if (maxLine > 1) {resultLine = resultLine + 1; System.err.println("\nif中字符串内容为：" + text.substring(0, i)); graphics2d.drawString(text.substring(0, i), left, top); drawString2(graphics2d, text.substring(i), lineHeight, maxWidth, maxLine - 1, left, top + lineHeight, resultLine); } else {System.err.println("\nelse中字符串内容为：" + text.substring(0, i)); graphics2d.drawString(text.substring(0, i - 1) + "…", left, top); }return; }}System.err.println("最后字符串内容为：" + text + "===行数为：" + resultLine); graphics2d.drawString(text, left, top); } public static void main(String[] args) {String text = "111122223所以比传统纸巾更环保3334441比传统纸巾更环11111111111111122223所以比传统纸巾更环保3334441比传统纸巾"+ System.getProperty("line.separator") + "更环66666666"+ System.getProperty("line.separator") + "所以比传统纸巾更环保3334441比传统纸巾更环。。。。。。。"+ "111111122223所以比传统纸巾更环保3334441比传统纸巾更环11111111111"; SubstringStr test = new SubstringStr(); test.creatMyImage(text); System.out.println("输入图片完成：D:/new.png"); } }

2、工具类最终版

package com.sinosoft.emr.util; import java.awt.Color; import java.awt.Font; import java.awt.FontMetrics; import java.awt.Graphics2D; import java.awt.RenderingHints; import java.awt.image.BufferedImage; import java.util.LinkedHashMap; import java.util.Map; import java.util.regex.Matcher; import java.util.regex.Pattern; public class SubstrUtil { private static int index = 0; /*** 1、自己做图片，根据文本宽度进行换行*/ public static Map creatMyImage(String text, Font font, int appointRow, Map map, int rows) {index = 0; // 整体图合成BufferedImage bufferedImage = new BufferedImage(595, 842, BufferedImage.TYPE_INT_RGB); Graphics2D graphics2d = bufferedImage.createGraphics(); graphics2d.setColor(new Color(37, 37, 37)); graphics2d.setFont(font); graphics2d.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_GASP); map = myDrawString(graphics2d, text, 30, 500, appointRow, 71, 20, map, rows); return map; } /*** 2、根据宽度截取字符串* @param graphics2d* @param text 文本* @param lineHeight 行高* @param maxWidth 行宽* @param maxLine 最大行数* @param left 左边距* @param top 上边距*/ private static Map myDrawString(Graphics2D graphics2d, String text, int lineHeight, int maxWidth,int maxLine, int left, int top, Map map, int rows) {if (text == null || text.length() == 0) {return map; } FontMetrics fm = graphics2d.getFontMetrics(); StringBuilder sb = new StringBuilder(); for (int i = 0; i < text.length(); i++) {char strChar = text.charAt(i); sb.append(strChar); int stringWidth = fm.stringWidth(sb.toString()); int strLength = text.substring(0, i).length(); if (strLength >= 53 || strChar == '\n' || stringWidth >= maxWidth) {if (strChar == '\n') {i += 1; //System.out.println("字符串内容为：" + text.substring(0, i)); }if (maxLine > 1) {rows = rows + 1; //System.err.println("if中字符串内容为：" + text.substring(0, i)); char valuehttps://www.it610.com/article/= ' ', value1 = ' '; try {value = https://www.it610.com/article/text.substring(i).charAt(0); value1 = text.substring(i - 1).charAt(0); } catch (Exception e) {/*e.printStackTrace(); */System.err.println("----" + e.getMessage()); } if (isChinesePunctuation(value) && checkCharCN(value1)) {map.put("row" + rows, text.substring(0, i - 1)); myDrawString(graphics2d, text.substring(i - 1), lineHeight, maxWidth, maxLine - 1, left, top + lineHeight, map, rows); } else {map.put("row" + rows, text.substring(0, i)); myDrawString(graphics2d, text.substring(i), lineHeight, maxWidth, maxLine - 1, left, top + lineHeight, map, rows); } index = index + i; map.put("index", index); //System.err.println("---下标" + index); } else {rows = rows + 1; map.put("row" + rows, text.substring(0, i)); //System.err.println("else中字符串内容为：" + text.substring(0, i)); index = index + i; map.put("index", index); }return map; }}return map; } // 2.1 判断字符是否是中文 public static boolean checkCharCN(char c) {String s = String.valueOf(c); String regex = "[\u4e00-\u9fa5]"; Pattern p = Pattern.compile(regex); Matcher m = p.matcher(s); return m.matches(); } // 2.2 判断字符是否是中文标点符号 public static boolean isChinesePunctuation(char c) {Character.UnicodeBlock ub = Character.UnicodeBlock.of(c); if (ub == Character.UnicodeBlock.GENERAL_PUNCTUATION || ub == Character.UnicodeBlock.CJK_SYMBOLS_AND_PUNCTUATION|| ub == Character.UnicodeBlock.HALFWIDTH_AND_FULLWIDTH_FORMS|| ub == Character.UnicodeBlock.CJK_COMPATIBILITY_FORMS|| ub == Character.UnicodeBlock.VERTICAL_FORMS) {return true; } else {return false; } } /*** 3、针对jasper中宽度较短的文本* @author wanglong* @date2020年11月10日下午7:12:14*/ public static Map creatShortImage(String text, Font font, int appointRow, Map map, int rows) {index = 0; // 整体图合成BufferedImage bufferedImage = new BufferedImage(595, 842, BufferedImage.TYPE_INT_RGB); // 设置图片的背景色Graphics2D main = bufferedImage.createGraphics(); main.fillRect(0, 0, 595, 842); Graphics2D graphics2d = bufferedImage.createGraphics(); graphics2d.setColor(new Color(37, 37, 37)); graphics2d.setFont(font); graphics2d.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_GASP); map = myDrawShortString(graphics2d, text, 30, 230, appointRow, 71, 20, map, rows); return map; } // 3.1 private static Map myDrawShortString(Graphics2D graphics2d, String text, int lineHeight, int maxWidth, int maxLine, int left, int top, Map map, int rows) {if (text == null || text.length() == 0) {return map; } FontMetrics fm = graphics2d.getFontMetrics(); StringBuilder sb = new StringBuilder(); for (int i = 0; i < text.length(); i++) {char strChar = text.charAt(i); sb.append(strChar); int stringWidth = fm.stringWidth(sb.toString()); if (strChar == '\n' || stringWidth > maxWidth) {if (strChar == '\n') {i += 1; //System.out.println("字符串内容为：" + text.substring(0, i)); }if (maxLine > 1) {rows = rows + 1; //System.err.println("if中字符串内容为：" + text.substring(0, i)); map.put("row" + rows, text.substring(0, i)); map.put("row_len" + rows, stringWidth); myDrawShortString(graphics2d, text.substring(i), lineHeight, maxWidth, maxLine - 1, left, top + lineHeight, map, rows); } else {rows = rows + 1; map.put("row" + rows, text.substring(0, i)); map.put("row_len" + rows, stringWidth); //System.err.println("else中字符串内容为：" + text.substring(0, i)); }return map; }}return map; } public static void main(String[] args) {Map map = new LinkedHashMap<>(); int rows = 0; int appointRow = 4; Font font = new Font("宋体", Font.PLAIN, 12); String text = "111122223所以比传统纸巾更环保3334441比传统纸巾更环11111111111111122223所以比传统纸巾更环保3334441测试数据"+ System.getProperty("line.separator") + "在仿苹果官网垃圾桶时，设计出的UI使用PingFang SC 字体"+ System.getProperty("line.separator") + "天津市防控指挥部消息称,经排查,滨海新区中新天津纸巾更环保3334441比传统纸巾更环666所以比传统纸巾更环保3334441比传统纸巾更环8888"; int length = text.length(); map = creatMyImage(text, font, appointRow, map, rows); if (length > index) {System.out.println("还剩余文本：" + text.substring(index)); }System.out.println("\n<<--->>>rows=" + rows + ", map="+map); } }

说明：此工具类我们经理进行了改造，生成的文本内容符合中国人的书写习惯：行首不能是标点符号。如果行首是标点符号，上一行的最后一个文字会挪至本行。

3、项目中具体使用

3.1 controller层

/** * 4、打印病程记录 * @author wanglong * @date 2020年3月4日下午5:22:57 */@RequestMapping(value = "https://www.it610.com/article/printEmrCourse", method = RequestMethod.GET, produces = MediaType.APPLICATION_PDF_VALUE)public void printEmrCourse(@RequestParam(value = "https://www.it610.com/article/id", required = true) String id,@RequestParam(value = "https://www.it610.com/article/courseType", required = true) String courseType,@RequestParam(value = "https://www.it610.com/article/token", required = true) String token, HttpServletResponse response) { List filePathList = new ArrayList(); Map> map = iEmrCourseSelectBusi.selectEmrCourseData(id, courseType, token); try {if (map.size() > 0) {for (int i = 0, len = map.size(); i < len; i++) {if (i % 2 == 0) {String path1 = iEmrCourseSelectBusi.getCoursePdf(map.get("map" + i), "emrCourseLeft.jasper"); if (!"".equals(path1)) {filePathList.add(path1); }} else {String path2 = iEmrCourseSelectBusi.getCoursePdf(map.get("map" + i), "emrCourseRight.jasper"); if (!"".equals(path2)) {filePathList.add(path2); }}}iEmrCourseSelectBusi.printEmrCoursePdf(filePathList, response); } } catch (Exception e) {e.printStackTrace(); }}

3.2 serviceImpl层

@Service("iEmrCourseSelectBusi")public class EmrCourseBusiSelectImpl extends EmrCourseSelectServiceImpl implements IEmrCourseSelectBusi{ private static final long serialVersionUID = 1L; private Font font = new Font("宋体", Font.PLAIN, 12); // 读取配置文件里的jasper路径@Value("${jasperPath}")private String jasperPath; /*** 4、打印病程记录* @author wanglong* @date2020年11月9日下午3:49:23*/@Overridepublic Map> selectEmrCourseData(String id, String courseType, String token) {Map> resultMap = new LinkedHashMap<>(); Map map = new LinkedHashMap<>(); int rows = 0, appointRow = 28; StringBuffer bufferStr = new StringBuffer(); String lineBreak = System.getProperty("line.separator"); // 换行符try {EmrCourse record = emrCourseMapper.selectByPrimaryKey(id); if (record != null) {map.put("patientName", record.getPatientName()); map.put("fkHosRegisterHosNo", record.getFkHosRegisterHosNo()); String recordTime = DateUtil.dateToString(record.getCourseRecordTime(), "yyyy-MM-dd HH:mm"); String doctorName = record.getDoctorRealName(); if ("1".equals(courseType)) {bufferStr.append(recordTime + lineBreak); String tempStr = record.getGeneralRecords() == null ? "" : record.getGeneralRecords(); String blankStr = ""; if (!"".equals(tempStr)) {blankStr = StringDealUtil.getSubString(blankStr, tempStr); }String generalRecords = record.getGeneralRecords() == null ? "" : (blankStr + lineBreak); bufferStr.append(generalRecords); } String updateName = record.getUpdateOprName(); String opraterName = updateName == null ? record.getAddOprName() : updateName; bufferStr.append("\t\t\t\t\t\t\t\t\t签名：" + opraterName + lineBreak); String text = bufferStr.toString(); int length = text.length(); map = SubstrUtil.creatMyImage(text, font, appointRow, map, rows); map.put("pageNum", "1"); resultMap.put("map0", map); int index = (int) map.get("index"); if (length > index) {String _text = StringDealUtil.getSurplusText(text, index); resultMap = this.getOtherMap(_text, appointRow, resultMap, 1); }}} catch (Exception e) {e.printStackTrace(); }return resultMap; } // 4.1 截取文本获取其余mapprivate Map> getOtherMap(String text, int appointRow,Map> resultMap, int i) {int length = text.length(); Map map = new LinkedHashMap<>(); map = SubstrUtil.creatMyImage(text, font, appointRow, map, 0); map.put("pageNum", i + 1 + ""); resultMap.put("map"+ i, map); int index = (int) map.get("index"); if (length > index) {String _text = StringDealUtil.getSurplusText(text, index); resultMap = this.getOtherMap(_text, appointRow, resultMap, i+1); }return resultMap; } /*** 5、生成pdf* @author wanglong* @date2020年11月9日下午1:52:42*/@Overridepublic String getCoursePdf(Map map, String jasperName) {String fileInfo = ""; Instant timestamp = Instant.now(); try {JRDataSource jrDataSource = new JRBeanCollectionDataSource(null); File reportFile = new File(jasperPath + jasperName); String exportFileName = timestamp.toEpochMilli() + ".pdf"; fileInfo = jasperPath + exportFileName; //调用工具类JasperHelper.exportPdf2File(jasperPath + exportFileName, reportFile, map, jrDataSource); } catch (Exception e) {e.printStackTrace(); }return fileInfo; } /*** 5.1合成pdf进行打印* @author wanglong* @date2020年11月9日下午1:52:58*/@Overridepublic void printEmrCoursePdf(List filePathList, HttpServletResponse response) {List files = new ArrayList(); try {if (filePathList != null && filePathList.size() > 0) {for (int i = 0, length = filePathList.size(); i < length; i++) {String pathName = filePathList.get(i); files.add(new File(pathName)); }String newFileName = Instant.now().toEpochMilli() + "病程记录mul2one.pdf"; String targetPath = jasperPath + newFileName; File newFile = PdfMergeUtil.mulFile2One(files, targetPath); if (newFile.exists()) {// 先将单个的pdf文件删除for (File file : files) {if (file.exists() && file.isFile()) {file.delete(); }}newFile.getName(); PdfUtil.downloadFile(response, targetPath, newFileName); }}} catch (Exception e) {e.printStackTrace(); }}}

4、工具类补充

package utils; import net.sf.jasperreports.engine.*; import net.sf.jasperreports.engine.util.JRLoader; import java.io.*; import java.util.Map; public class JasperHelper { /*** 1、直接导出pdf文件* @author wanglong* @date2020年10月31日下午9:10:41*/ public static void exportPdf2File(String defaultFilename, File is, Map parameters, JRDataSource conn) {try {JasperReport jasperReport = (JasperReport) JRLoader.loadObject(is); JasperPrint jasperPrint = JasperFillManager.fillReport(jasperReport, parameters, conn); exportPdfToFile(jasperPrint, defaultFilename); } catch (Exception e) {e.printStackTrace(); } } // 1.1 导出Pdf private static void exportPdfToFile(JasperPrint jasperPrint, String defaultFilename) throws IOException, JRException {FileOutputStream ouputStream = new FileOutputStream(new File(defaultFilename)); JasperExportManager.exportReportToPdfStream(jasperPrint, ouputStream); ouputStream.flush(); ouputStream.close(); } }

package utils; import java.io.File; import java.io.IOException; import java.util.List; import org.apache.pdfbox.io.MemoryUsageSetting; import org.apache.pdfbox.multipdf.PDFMergerUtility; /** * @name: PdfMergeUtil * @Description: pdf合并拼接工具类 * @author wanglong * @date2020年2月25日下午4:33:13 * @version 1.0 */public class PdfMergeUtil { /*** @Description: pdf合并拼接* @param files 文件列表* @param targetPath 合并到* @throws IOException*/public static File mulFile2One(List files,String targetPath) throws IOException{// pdf合并工具类PDFMergerUtility mergePdf = new PDFMergerUtility(); for (File f : files) {if(f.exists() && f.isFile()){// 循环添加要合并的pdfmergePdf.addSource(f); }}// 设置合并生成pdf文件名称mergePdf.setDestinationFileName(targetPath); // 合并pdfmergePdf.mergeDocuments(MemoryUsageSetting.setupMainMemoryOnly()); return new File(targetPath); }}

package utils; import javax.servlet.http.HttpServletResponse; import java.io.*; /** * 导出PDF */public class PdfUtil {// 下载public static void downloadFile(HttpServletResponse response, String filePath, String fileName) {if (fileName != null) {response.reset(); response.setContentType("application/pdf"); // 设置文件路径File file = new File(filePath); if (file.exists()) {byte[] buffer = new byte[1024]; FileInputStream fis = null; BufferedInputStream bis = null; try {fis = new FileInputStream(file); bis = new BufferedInputStream(fis); OutputStream os = response.getOutputStream(); int i = bis.read(buffer); while (i != -1) {os.write(buffer, 0, i); i = bis.read(buffer); }System.out.println("download success!"); } catch (Exception e) {e.printStackTrace(); } finally {if (bis != null) {try {bis.close(); } catch (IOException e) {e.printStackTrace(); }}if (fis != null) {try {fis.close(); } catch (IOException e) {e.printStackTrace(); }}}file.delete(); }}}}

【Java中字符串根据宽度(像素)换行的问题】以上为个人经验，希望能给大家一个参考，也希望大家多多支持脚本之家。