XLSXCovertCSVReader 工具类（XML ）

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;
  }

}

XLSXCovertCSVReader 工具类（XML ）

猜你喜欢