【utils】XLSXCovertCSVReader

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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.FileInputStream;
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模式解決XLSX文件，可以有效解決用戶模式內存溢出的問題
 * 該模式是POI官方推薦的讀取大數據的模式，在用戶模式下，數據量較大、Sheet較多、或者是有很多無用的空行的情況
 * ClassName: XLSXCovertCSVReader 
 * @author liweiyan
 * @date 2015年12月24日
 * @version V1.0
 */
public class XLSXCovertCSVReader {
    /**
     * 定義枚舉類excel數據類型
     * ClassName: xssfDataType 
     * @author 王茂
     * @date 2015年12月24日
     * @version V1.0
     */
    enum xssfDataType {
        BOOL, ERROR, FORMULA, INLINESTR, SSTINDEX, NUMBER,
    }

    /**
     * xssf_sax_API處理Excel
     * ClassName: MyXSSFSheetHandler 
     * @author 王茂
     * @date 2015年12月24日
     * @version V1.0
     */
    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;

        /**
         * 構造器初始化自定義類型
         * <p>Description: </p>

         * @param styles
         * @param strings
         * @param cols
         * @param target
         */
        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();// 每次讀取都清空行集合
        }

        /**
         * 讀取excel行
         */
        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);
                }
            }
        }

        /**
         * 行讀取完成後將數據存入數組
         */
        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();
                    // 判斷是否是日期格式
                    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;
                }
                // 判斷單元格的值是否爲空
                if (thisStr == null || "".equals(isCellNull)) {
                    isCellNull = true;// 設置單元格是否爲空值
                }
                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 && record[0] != null
                            && record[1] != null)// 判斷是否空行
                    {
                        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;

    /**
     * Cew 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();
    }

    /**
     * 
     * @Description: 讀取excel返回對應集合
     * @param @return
     * @param @throws IOException
     * @param @throws OpenXML4JException
     * @param @throws ParserConfigurationException
     * @param @throws SAXException   
     * @return List<String[]> 
     * @throws
     * @author 王茂
     * @date 2015年12月24日
     */
    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();
        int index = 0;
        // 獲取sheetIter迭代,並遍歷
        while (iter.hasNext()) {
            InputStream stream = iter.next();
            // 判斷如果爲需要獲取的sheet則執行
            if (0 == index) {
                list = processSheet(styles, strings, stream);
                stream.close();
                ++index;
            }
        }
        return list;
    }

    /**
     * 
     * @Description: 讀取Excel
     * @param @param path   文件地址
     * @param @param minColumns excel行數
     * @param @return
     * @param @throws IOException
     * @param @throws OpenXML4JException
     * @param @throws ParserConfigurationException
     * @param @throws SAXException   
     * @return List<String[]> 
     * @throws
     * @author 王茂
     * @date 2015年12月24日
     */
    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;
    }

    public static List<String[]> readerExcel(InputStream inputStream, int minColumns) throws IOException, OpenXML4JException, ParserConfigurationException, SAXException{
        OPCPackage p = OPCPackage.open(inputStream);
        XLSXCovertCSVReader xlsx2csv = new XLSXCovertCSVReader(p, System.out,
                minColumns);
        List<String[]> list = xlsx2csv.process();
        p.close();
        return list;
    }

    public static void main(String[] args) throws IOException, OpenXML4JException, ParserConfigurationException, SAXException {
        //String path  = "C:\\Users\\keith\\AppData\\Local\\VcreditChatData\\MessageFile\\推薦碼.xlsx";
        String path = "C:\\Users\\keith\\Desktop\\用戶.xlsx";
        File file = new File(path);
        InputStream inputStream = new FileInputStream(file);
        List<String[]> list = readerExcel(inputStream, 10);
        print(list);
    }

    public static void print(List<String[]> list) {
        if(list == null){
            return ;
        }
        int i = 0;
        for(String[] strings : list){
            StringBuilder stringBuilder = new StringBuilder();
            for(String string : strings){
                stringBuilder.append(string).append(",");
            }
            stringBuilder.append(i++);
            System.out.println(stringBuilder);
        }
    }
}