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XLSXCovertCSVReader 工具类(XML )

运维开发网 https://www.qedev.com 2020-10-29 09:43 出处:51CTO 作者:IT达仁
importcn.com.amway.msgcenter.console.util.StringUtil;importorg.apache.poi.hssf.usermodel.HSSFDateUtil;importorg.apache.poi.openxml4j.exceptions.OpenXML4JException;importorg.apache.poi.openxml4j.opc.OP

import cn.com.amway.msgcenter.console.util.StringUtil;

import org.apache.poi.hssf.usermodel.HSSFDateUtil;

import org.apache.poi.openxml4j.exceptions.OpenXML4JException;

import org.apache.poi.openxml4j.opc.OPCPackage;

import org.apache.poi.openxml4j.opc.PackageAccess;

import org.apache.poi.ss.usermodel.BuiltinFormats;

import org.apache.poi.ss.usermodel.DataFormatter;

import org.apache.poi.xssf.eventusermodel.ReadOnlySharedStringsTable;

import org.apache.poi.xssf.eventusermodel.XSSFReader;

import org.apache.poi.xssf.model.StylesTable;

import org.apache.poi.xssf.usermodel.XSSFCellStyle;

import org.apache.poi.xssf.usermodel.XSSFRichTextString;

import org.xml.sax.Attributes;

import org.xml.sax.InputSource;

import org.xml.sax.SAXException;

import org.xml.sax.XMLReader;

import org.xml.sax.helpers.DefaultHandler;

import javax.xml.parsers.ParserConfigurationException;

import javax.xml.parsers.SAXParser;

import javax.xml.parsers.SAXParserFactory;

import java.io.File;

import java.io.IOException;

import java.io.InputStream;

import java.io.PrintStream;

import java.text.SimpleDateFormat;

import java.util.ArrayList;

import java.util.Date;

import java.util.List;

/**

  • 使用CVS模式解决XLSX文件,可以有效解决用户模式内存溢出的问题 该模式是POI官方推荐的读取大数据的模式,在用户模式下,数据量较大、Sheet较多、或者是有很多无用的空行的情况
  • ,容易出现内存溢出,用户模式读取Excel的典型代码如下: FileInputStream file=new FileInputStream("c:\test.xlsx"); Workbook
  • wb=new XSSFWorkbook(file);
  • @author 山人

    */

    public class XLSXCovertCSVReader {

    /**

    • The type of the data value is indicated by an attribute on the cell. The value is usually in
    • a "v" element within the cell.

      */

      enum xssfDataType {

      BOOL, ERROR, FORMULA, INLINESTR, SSTINDEX, NUMBER,

      }

    /**

    • 使用xssf_sax_API处理Excel,请参考: http://poi.apache.org/spreadsheet/how-to.html#xssf_sax_api
    • <p/>
    • Also see Standard ECMA-376, 1st edition, part 4, pages 1928ff, at
    • http://www.ecma-international.org/publications/standards/Ecma-376.htm
    • <p/>
    • A web-friendly version is http://openiso.org/Ecma/376/Part4

      */

      class MyXSSFSheetHandler extends DefaultHandler {

      /**

      • Table with styles

        */

        private StylesTable stylesTable;

      /**

      • Table with unique strings

        */

        private ReadOnlySharedStringsTable sharedStringsTable;

      /**

      • Destination for data

        */

        private final PrintStream output;

      /**

      • Number of columns to read starting with leftmost

        */

        private final int minColumnCount;

      // Set when V start element is seen

      private boolean vIsOpen;

      // Set when cell start element is seen;

      // used when cell close element is seen.

      private xssfDataType nextDataType;

      // Used to format numeric cell values.

      private short formatIndex;

      private String formatString;

      private final DataFormatter formatter;

      private int thisColumn = -1;

      // The last column printed to the output stream

      private int lastColumnNumber = -1;

      // Gathers characters as they are seen.

      private StringBuffer value;

      private String[] record;

      private List<String[]> rows = new ArrayList<String[]>();

      private boolean isCellNull = false;

      /**

      • Accepts objects needed while parsing.
      • @param styles Table of styles
      • @param strings Table of shared strings
      • @param cols Minimum number of columns to show
      • @param target Sink for output

        */

        public MyXSSFSheetHandler(StylesTable styles, ReadOnlySharedStringsTable strings, int cols, PrintStream target) {

        this.stylesTable = styles;

        this.sharedStringsTable = strings;

        this.minColumnCount = cols;

        this.output = target;

        this.value = new StringBuffer();

        this.nextDataType = xssfDataType.NUMBER;

        this.formatter = new DataFormatter();

        record = new String[this.minColumnCount];

        rows.clear();// 每次读取都清空行集合

        }

      /*

      • (non-Javadoc)
      • @see org.xml.sax.helpers.DefaultHandler#startElement(java.lang.String, java.lang.String,
      • java.lang.String, org.xml.sax.Attributes)

        */

        public void startElement(String uri, String localName, String name, Attributes attributes) throws SAXException {

        if ("inlineStr".equals(name) || "v".equals(name)) {

        vIsOpen = true;

        // Clear contents cache

        value.setLength(0);

        }

        // c => cell

        else if ("c".equals(name)) {

        // Get the cell reference

        String r = attributes.getValue("r");

        int firstDigit = -1;

        for (int c = 0; c < r.length(); ++c) {

        if (Character.isDigit(r.charAt(c))) {

        firstDigit = c;

        break;

        }

        }

        thisColumn = nameToColumn(r.substring(0, firstDigit));

        // Set up defaults.
        this.nextDataType = xssfDataType.NUMBER;
        this.formatIndex = -1;
        this.formatString = null;
        String cellType = attributes.getValue("t");
        String cellStyleStr = attributes.getValue("s");
        if ("b".equals(cellType))
            nextDataType = xssfDataType.BOOL;
        else if ("e".equals(cellType))
            nextDataType = xssfDataType.ERROR;
        else if ("inlineStr".equals(cellType))
            nextDataType = xssfDataType.INLINESTR;
        else if ("s".equals(cellType))
            nextDataType = xssfDataType.SSTINDEX;
        else if ("str".equals(cellType))
            nextDataType = xssfDataType.FORMULA;
        else if (cellStyleStr != null) {
            // It's a number, but almost certainly one
            // with a special style or format
            int styleIndex = Integer.parseInt(cellStyleStr);
            XSSFCellStyle style = stylesTable.getStyleAt(styleIndex);
            this.formatIndex = style.getDataFormat();
            this.formatString = style.getDataFormatString();
            if (this.formatString == null)
                this.formatString = BuiltinFormats.getBuiltinFormat(this.formatIndex);
        }

        }

      }

      /*

      • (non-Javadoc)
      • @see org.xml.sax.helpers.DefaultHandler#endElement(java.lang.String, java.lang.String,
      • java.lang.String)

        */

        public void endElement(String uri, String localName, String name) throws SAXException {

        String thisStr = null;

        // v => contents of a cell

        if ("v".equals(name)) {

        // Process the value contents as required.

        // Do now, as characters() may be called more than once

        switch (nextDataType) {

            case BOOL:
                char first = value.charAt(0);
                thisStr = first == '0' ? "FALSE" : "TRUE";
                break;
        
            case ERROR:
                thisStr = "\"ERROR:" + value.toString() + '"';
                break;
        
            case FORMULA:
                // A formula could result in a string value,
                // so always add double-quote characters.
                thisStr = value.toString();
                break;
        
            case INLINESTR:
                // TODO: have seen an example of this, so it's untested.
                XSSFRichTextString rtsi = new XSSFRichTextString(value.toString());
                thisStr = rtsi.toString();
                break;
        
            case SSTINDEX:
                String sstIndex = value.toString();
                try {
                    int idx = Integer.parseInt(sstIndex);
                    XSSFRichTextString rtss = new XSSFRichTextString(sharedStringsTable.getEntryAt(idx));
                    thisStr = rtss.toString();
                } catch (NumberFormatException ex) {
                    output.println("Failed to parse SST index '" + sstIndex + "': " + ex.toString());
                }
                break;
        
            case NUMBER:
                String n = value.toString();
                // 判断是否是日期格式
                if (HSSFDateUtil.isADateFormat(this.formatIndex, n)) {
                    Double d = Double.parseDouble(n);
                    Date date = HSSFDateUtil.getJavaDate(d);
                    thisStr = formateDateToString(date);
                } else if (this.formatString != null)
                    thisStr =
                            formatter.formatRawCellContents(Double.parseDouble(n), this.formatIndex,
                                    this.formatString);
                else
                    thisStr = n;
                break;
        
            default:
                thisStr = "(TODO: Unexpected type: " + nextDataType + ")";
                break;
        }
        
        // Output after we've seen the string contents
        // Emit commas for any fields that were missing on this row
        if (lastColumnNumber == -1) {
            lastColumnNumber = 0;
        }
        // 判断单元格的值是否为空
        if (thisStr == null || "".equals(isCellNull)) {
            isCellNull = true;// 设置单元格是否为空值
        }
        record[thisColumn] = thisStr;
        // Update column
        if (thisColumn > -1) lastColumnNumber = thisColumn;

        } else if ("row".equals(name)) {

        // Print out any missing commas if needed
        if (minColumns > 0) {
            // Columns are 0 based
            if (lastColumnNumber == -1) {
                lastColumnNumber = 0;
            }
            if (isCellNull == false)// 判断是否空行
            {
                rows.add(record.clone());
                isCellNull = false;
                for (int i = 0; i < record.length; i++) {
                    record[i] = null;
                }
            }
        }
        lastColumnNumber = -1;

        }

      }

      public List<String[]> getRows() {

      return rows;

      }

      public void setRows(List<String[]> rows) {

      this.rows = rows;

      }

      /**

      • Captures characters only if a suitable element is open. Originally was just "v"; extended
      • for inlineStr also.

        */

        public void characters(char[] ch, int start, int length) throws SAXException {

        if (vIsOpen) value.append(ch, start, length);

        }

      /**

      • Converts an Excel column name like "C" to a zero-based index.
      • @param name
      • @return Index corresponding to the specified name

        /

        private int nameToColumn(String name) {

        int column = -1;

        for (int i = 0; i < name.length(); ++i) {

        int c = name.charAt(i);

        column = (column + 1) 26 + c - 'A';

        }

        return column;

        }

      private String formateDateToString(Date date) {

      SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");// 格式化日期

      return sdf.format(date);

      }

    }

    // /////////////////////////////////////

    private OPCPackage xlsxPackage;

    private int minColumns;

    private PrintStream output;

    /**

    • Creates a new XLSX -> CSV converter
    • @param pkg The XLSX package to process
    • @param output The PrintStream to output the CSV to
    • @param minColumns The minimum number of columns to output, or -1 for no minimum

      */

      public XLSXCovertCSVReader(OPCPackage pkg, PrintStream output, int minColumns) {

      this.xlsxPackage = pkg;

      this.output = output;

      this.minColumns = minColumns;

      }

    /**

    • Parses and shows the content of one sheet using the specified styles and shared-strings
    • tables.
    • @param styles
    • @param strings
    • @param sheetInputStream

      */

      public List<String[]> processSheet(StylesTable styles, ReadOnlySharedStringsTable strings,

      InputStream sheetInputStream) throws IOException, ParserConfigurationException, SAXException {

      InputSource sheetSource = new InputSource(sheetInputStream);

      SAXParserFactory saxFactory = SAXParserFactory.newInstance();

      SAXParser saxParser = saxFactory.newSAXParser();

      XMLReader sheetParser = saxParser.getXMLReader();

      MyXSSFSheetHandler handler = new MyXSSFSheetHandler(styles, strings, this.minColumns, this.output);

      sheetParser.setContentHandler(handler);

      sheetParser.parse(sheetSource);

      return handler.getRows();

      }

    /**

    • 初始化这个处理程序 将
    • @throws IOException
    • @throws OpenXML4JException
    • @throws ParserConfigurationException
    • @throws SAXException

      */

      public List<String[]> process() throws IOException, OpenXML4JException, ParserConfigurationException, SAXException {

      ReadOnlySharedStringsTable strings = new ReadOnlySharedStringsTable(this.xlsxPackage);

      XSSFReader xssfReader = new XSSFReader(this.xlsxPackage);

      List<String[]> list = null;

      StylesTable styles = xssfReader.getStylesTable();

      XSSFReader.SheetIterator iter = (XSSFReader.SheetIterator) xssfReader.getSheetsData();

      while (iter.hasNext()) {

      InputStream stream = iter.next();

      list = processSheet(styles, strings, stream);

      stream.close();

      break;

      }

      return list;

      }

    /**

    • 读取Excel
    • @param path 文件路径
    • @param sheetName sheet名称
    • @param minColumns 列总数
    • @return
    • @throws SAXException
    • @throws ParserConfigurationException
    • @throws OpenXML4JException
    • @throws IOException

      */

      public static List<String[]> readerExcel(String path, int minColumns) throws IOException, OpenXML4JException,

      ParserConfigurationException, SAXException {

      OPCPackage p = OPCPackage.open(path, PackageAccess.READ);

      XLSXCovertCSVReader xlsx2csv = new XLSXCovertCSVReader(p, System.out, minColumns);

      List<String[]> list = xlsx2csv.process();

      p.close();

      return list;

      }

    /**

    • @param file
    • @param minColumns
    • @return
    • @throws IOException
    • @throws OpenXML4JException
    • @throws ParserConfigurationException
    • @throws SAXException

      */

      public static List<String[]> readerExcel(File file, int minColumns) throws IOException, OpenXML4JException,

      ParserConfigurationException, SAXException {

      OPCPackage p = OPCPackage.open(file, PackageAccess.READ);

      XLSXCovertCSVReader xlsx2csv = new XLSXCovertCSVReader(p, System.out, minColumns);

      List<String[]> list = xlsx2csv.process();

      p.close();

      return list;

      }

    /**

    • 读取Excel
    • @param path 文件路径
    • @param sheetName sheet名称
    • @param minColumns 列总数
    • @return
    • @throws SAXException
    • @throws ParserConfigurationException
    • @throws OpenXML4JException
    • @throws IOException

      */

      public static List<String[]> readerExcel(InputStream in, int minColumns) throws IOException, OpenXML4JException,

      ParserConfigurationException, SAXException {

      OPCPackage p = OPCPackage.open(in);

      XLSXCovertCSVReader xlsx2csv = new XLSXCovertCSVReader(p, System.out, minColumns);

      List<String[]> list = xlsx2csv.process();

      List<String[]> newlist=new ArrayList<>();

      p.close();

      for(String [] str:list){

      //判断excle 集合里是否有 All elements are null引起的异常

      if(!StringUtil.isEmpty(str[0])){

      newlist.add(str);

      }

      }

      return newlist;

      }

}

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