超大excel读取 43万记录 26M文件

maven:

 

<dependency>
        <groupId>org.apache.poi</groupId>
        <artifactId>poi-ooxml</artifactId>
        <version>3.8</version>
</dependency>
<dependency>
        <groupId>xerces</groupId>
        <artifactId>xercesImpl</artifactId>
        <version>2.10.0</version>
</dependency>

 

代码：读取26M excel 2007 xlsx，43万记录，耗时25s (jvm: -Xmx1024M)

 

import java.io.BufferedInputStream;
import java.io.FileInputStream;
import java.io.InputStream;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Random;

import org.apache.poi.hssf.usermodel.HSSFDateUtil;
import org.apache.poi.openxml4j.opc.OPCPackage;
import org.apache.poi.xssf.eventusermodel.XSSFReader;
import org.apache.poi.xssf.model.SharedStringsTable;
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 org.xml.sax.helpers.XMLReaderFactory;

public class XSSFProcess {
        public static void main1(String[] args) throws Exception {
                System.out.println();
                long end, start = System.currentTimeMillis();
//              Path file = Paths.get("/home/skzrorg/tmp/2007.xlsx");
                Path file = Paths.get("/home/skzrorg/tmp/xlsx/IPTABLE.xlsx");
                SheetDatasHandler handler = UtilPoi.read(file);
                end = System.currentTimeMillis();
                System.out.println("耗时：" + (end - start) / 1000f + "s");
                List<List<Object>> sheet = handler.getSheetData(0);
                System.out.println("sheet 大小：" + sheet.size());
                System.out.println("sheet[0]" + sheet.get(0));
                int i = new Random().nextInt(sheet.size());
                System.out.println("sheet[" + i + "]" + sheet.get(i));
                System.out.println("sheet[" + (sheet.size() - 1) + "]" + sheet.get(sheet.size() - 1));
        }
        
        private static int rowCount;
        public static void main(String[] args) throws Exception {
                System.out.println();
                long end, start = System.currentTimeMillis();
                Path file = Paths.get("/home/skzrorg/tmp/xlsx/IPTABLE.xlsx");
                UtilPoi.read(file, new RowMapper() {
                        @Override
                        void mapRow(int sheetIndex, int rowIndex, List<Object> row) {
                                rowCount++;
                        }
                });
                end = System.currentTimeMillis();
                System.out.println("耗时：" + (end - start) / 1000f + "s");
                System.out.println("sheet 大小：" + rowCount);
        }
}

class UtilPoi {
        public static SheetDatasHandler read(Path file) throws Exception {
                SheetDatasHandler handler = new SheetDatasHandler((int) (Files.size(file) / 50));
                read(file, handler);
                return handler;
        }
        public static void read(Path file, RowMapper mapper) throws Exception {
                final long size = Files.size(file);
                try (InputStream in = new BufferedInputStream(new FileInputStream(file.toFile()), size > Integer.MAX_VALUE ? 1024 * 1024 * 10 : (int) size)) {
                        read(in, mapper);
                }
        }
        public static void read(InputStream in, RowMapper mapper) throws Exception {
                XSSFReader reader = new XSSFReader(OPCPackage.open(in));
                XMLReader parser = XMLReaderFactory.createXMLReader("org.apache.xerces.parsers.SAXParser");
                
                mapper.setSharedStringsTable(reader.getSharedStringsTable());
                parser.setContentHandler(mapper);
                
                for (Iterator<InputStream> iter = reader.getSheetsData(); iter.hasNext();) {
                        try (InputStream sheetIn = iter.next()) {
                                parser.parse(new InputSource(sheetIn));
                        }
                }
        }
}

class SheetDatasHandler extends RowMapper {
        private int bufRowSize, curSheetIndex = -1;
        private List<List<List<Object>>> sheetDatas = new ArrayList<>();
        private List<List<Object>> sheetData;
        
        public List<List<List<Object>>> getSheetDatas() {
                return sheetDatas;
        }
        public List<List<Object>> getSheetData(int sheetIndex) {
                return sheetDatas.get(sheetIndex);
        }
        
        SheetDatasHandler(int bufRowSize) {
                this.bufRowSize = bufRowSize;
        }
        
        @Override
        void mapRow(int sheetIndex, int rowIndex, List<Object> row) {
                if (curSheetIndex != sheetIndex) {
                        sheetData = new ArrayList<>(sheetIndex == 0 ? bufRowSize : sheetData.size() / 2);
                        sheetDatas.add(sheetData);
                        curSheetIndex = sheetIndex;
                }
                
                sheetData.add(row);
        }
}

abstract class RowMapper extends DefaultHandler {
        private SharedStringsTable sst;
        private Map<Integer, String> strMap;
        private int sheetIndex = -1, rowIndex = -1;
        private List<Object> row;
        private String cellS;
        private String cellType;
        private boolean valueFlag;
        private StringBuilder value;
        
        public void setSharedStringsTable(SharedStringsTable sst) {
                this.sst = sst;
                strMap = new HashMap<>(sst.getCount());
        }
        
        private void clearSheet() {
                sst = null;
                strMap = null;
                row = null;
                cellS = null;
                cellType = null;
                value = null;
                rowIndex = 0;
        }
        
        private Object convertCellValue() {
                String tmp = value.toString();
                Object result = tmp;
                
                if ("s".equals(cellType)) {     //字符串
                        Integer key = Integer.parseInt(tmp);
                        result = strMap.get(key);
                        if (result == null) strMap.put(key, (String) (result = new XSSFRichTextString(sst.getEntryAt(key)).toString()));
                } else if ("n".equals(cellType)) {
                        if ("2".equals(cellS)) {        //日期
                                result = HSSFDateUtil.getJavaDate(Double.valueOf(tmp));
                        }
                }
                return result;
        }
        
        @Override
        public void startElement(String uri, String localName, String name, Attributes attributes) throws SAXException {
                if ("sheetData".equals(name)) {
                        sheetIndex++;
                } else if ("row".equals(name)) {
                        rowIndex++;
                        row = new ArrayList<>();
                } else if ("c".equals(name)) {
                        cellS = attributes.getValue("s");
                        cellType = attributes.getValue("t");
                } else if ("v".equals(name)) {
                        valueFlag = true;
                        value = new StringBuilder();
                }
        }
        
        @Override
        public void endElement(String uri, String localName, String name) throws SAXException {
                if ("sheetData".equals(name)) {
                        clearSheet();
                } else if ("row".equals(name)) {
                        mapRow(sheetIndex, rowIndex, row);
                } else if ("v".equals(name)) {
                        row.add(convertCellValue());
                        valueFlag = false;
                }
        }

        @Override
        public void characters(char[] ch, int start, int length) throws SAXException {
                if (valueFlag) value.append(ch, start, length);
        }
        
        abstract void mapRow(int sheetIndex, int rowIndex, List<Object> row);
}

 

 

如果采用dom解析，需要配置2G内存