之前写过一篇《JAVA操作Excel》，介绍了jxl和poi读写Excel的实现，今天为大家介绍一下使用easyexcel对Excel进行读写，项目主页地址：https://github.com/alibaba/easyexcel

作者对easyexcel的介绍是：

Java解析、生成Excel比较有名的框架有Apache poi、jxl。但他们都存在一个严重的问题就是非常的耗内存，poi有一套SAX模式的API可以一定程度的解决一些内存溢出的问题，但POI还是有一些缺陷，比如07版Excel解压缩以及解压后存储都是在内存中完成的，内存消耗依然很大。easyexcel重写了poi对07版Excel的解析，能够原本一个3M的excel用POI sax依然需要100M左右内存降低到KB级别，并且再大的excel不会出现内存溢出，03版依赖POI的sax模式。在上层做了模型转换的封装，让使用者更加简单方便

使用easyexcel，首先我们需要添加maven依赖：

<dependency>
   <groupId>com.alibaba</groupId>
   <artifactId>easyexcel</artifactId>
   <version>1.0.1</version>
</dependency>

首先，我们先来看看如何写Excel，写入Excel，我们可以通过com.alibaba.excel.ExcelWriter类实现，下面我们来看一下最简单的无表头的实现

package test;

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.List;

import org.junit.Test;

import com.alibaba.excel.ExcelWriter;
import com.alibaba.excel.metadata.Sheet;
import com.alibaba.excel.support.ExcelTypeEnum;

public class ExcelWriteTest {

   /**
    * 每行数据是List<String>无表头
    * 
    * @throws IOException
    */
   @Test
   public void writeWithoutHead() throws IOException {
      try (OutputStream out = new FileOutputStream("withoutHead.xlsx");) {
         ExcelWriter writer = new ExcelWriter(out, ExcelTypeEnum.XLSX, false);
         Sheet sheet1 = new Sheet(1, 0);
         sheet1.setSheetName("sheet1");
         List<List<String>> data = new ArrayList<>();
         for (int i = 0; i < 100; i++) {
            List<String> item = new ArrayList<>();
            item.add("item0" + i);
            item.add("item1" + i);
            item.add("item2" + i);
            data.add(item);
         }
         writer.write0(data, sheet1);
         writer.finish();
      }
   }
}

生成的Excel样式如下：

很多时候，我们在生成Excel的时候都是需要添加表头的，使用easyexcel可以很容易的实现，我们可以对上面的例子进行简单的改造，为其添加表头

package test;

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.List;

import org.junit.Test;

import com.alibaba.excel.ExcelWriter;
import com.alibaba.excel.metadata.Sheet;
import com.alibaba.excel.metadata.Table;
import com.alibaba.excel.support.ExcelTypeEnum;

public class ExcelWriteTest {

   @Test
   public void writeWithoutHead() throws IOException {
      try (OutputStream out = new FileOutputStream("withHead.xlsx");) {
         ExcelWriter writer = new ExcelWriter(out, ExcelTypeEnum.XLSX);
         Sheet sheet1 = new Sheet(1, 0);
         sheet1.setSheetName("sheet1");
         List<List<String>> data = new ArrayList<>();
         for (int i = 0; i < 100; i++) {
            List<String> item = new ArrayList<>();
            item.add("item0" + i);
            item.add("item1" + i);
            item.add("item2" + i);
            data.add(item);
         }
         List<List<String>> head = new ArrayList<List<String>>();
         List<String> headCoulumn1 = new ArrayList<String>();
         List<String> headCoulumn2 = new ArrayList<String>();
         List<String> headCoulumn3 = new ArrayList<String>();
         headCoulumn1.add("第一列");
         headCoulumn2.add("第二列");
         headCoulumn3.add("第三列");
         head.add(headCoulumn1);
         head.add(headCoulumn2);
         head.add(headCoulumn3);
         Table table = new Table(1);
         table.setHead(head);
         writer.write0(data, sheet1, table);
         writer.finish();
      }
   }
}

效果如下：

除了上面添加表头的方式，我们还可以使用实体类，为其添加com.alibaba.excel.annotation.ExcelProperty注解来生成表头，实体类数据作为Excel数据

package test;

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.List;

import org.junit.Test;

import com.alibaba.excel.ExcelWriter;
import com.alibaba.excel.annotation.ExcelProperty;
import com.alibaba.excel.metadata.BaseRowModel;
import com.alibaba.excel.metadata.Sheet;
import com.alibaba.excel.metadata.Table;
import com.alibaba.excel.support.ExcelTypeEnum;

public class ExcelWriteTest {

   @Test
   public void writeWithHead() throws IOException {
      try (OutputStream out = new FileOutputStream("withHead.xlsx");) {
         ExcelWriter writer = new ExcelWriter(out, ExcelTypeEnum.XLSX);
         Sheet sheet1 = new Sheet(1, 0, ExcelPropertyIndexModel.class);
         sheet1.setSheetName("sheet1");
         List<ExcelPropertyIndexModel> data = new ArrayList<>();
         for (int i = 0; i < 100; i++) {
            ExcelPropertyIndexModel item = new ExcelPropertyIndexModel();
            item.name = "name" + i;
            item.age = "age" + i;
            item.email = "email" + i;
            item.address = "address" + i;
            item.sax = "sax" + i;
            item.heigh = "heigh" + i;
            item.last = "last" + i;
            data.add(item);
         }
         writer.write(data, sheet1);
         writer.finish();
      }
   }

   public static class ExcelPropertyIndexModel extends BaseRowModel {

      @ExcelProperty(value = "姓名", index = 0)
      private String name;

      @ExcelProperty(value = "年龄", index = 1)
      private String age;

      @ExcelProperty(value = "邮箱", index = 2)
      private String email;

      @ExcelProperty(value = "地址", index = 3)
      private String address;

      @ExcelProperty(value = "性别", index = 4)
      private String sax;

      @ExcelProperty(value = "高度", index = 5)
      private String heigh;

      @ExcelProperty(value = "备注", index = 6)
      private String last;

      public String getName() {
         return name;
      }

      public void setName(String name) {
         this.name = name;
      }

      public String getAge() {
         return age;
      }

      public void setAge(String age) {
         this.age = age;
      }

      public String getEmail() {
         return email;
      }

      public void setEmail(String email) {
         this.email = email;
      }

      public String getAddress() {
         return address;
      }

      public void setAddress(String address) {
         this.address = address;
      }

      public String getSax() {
         return sax;
      }

      public void setSax(String sax) {
         this.sax = sax;
      }

      public String getHeigh() {
         return heigh;
      }

      public void setHeigh(String heigh) {
         this.heigh = heigh;
      }

      public String getLast() {
         return last;
      }

      public void setLast(String last) {
         this.last = last;
      }
   }
}

效果如下：

如果单行表头表头还不满足需求，没关系，还可以使用多行复杂的表头

package test;

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.List;

import org.junit.Test;

import com.alibaba.excel.ExcelWriter;
import com.alibaba.excel.annotation.ExcelProperty;
import com.alibaba.excel.metadata.BaseRowModel;
import com.alibaba.excel.metadata.Sheet;
import com.alibaba.excel.metadata.Table;
import com.alibaba.excel.support.ExcelTypeEnum;

public class ExcelWriteTest {
   @Test
   public void writeWithMultiHead() throws IOException {
      try (OutputStream out = new FileOutputStream("withMultiHead.xlsx");) {
         ExcelWriter writer = new ExcelWriter(out, ExcelTypeEnum.XLSX);
         Sheet sheet1 = new Sheet(1, 0, MultiLineHeadExcelModel.class);
         sheet1.setSheetName("sheet1");
         List<MultiLineHeadExcelModel> data = new ArrayList<>();
         for (int i = 0; i < 100; i++) {
            MultiLineHeadExcelModel item = new MultiLineHeadExcelModel();
            item.p1 = "p1" + i;
            item.p2 = "p2" + i;
            item.p3 = "p3" + i;
            item.p4 = "p4" + i;
            item.p5 = "p5" + i;
            item.p6 = "p6" + i;
            item.p7 = "p7" + i;
            item.p8 = "p8" + i;
            item.p9 = "p9" + i;
            data.add(item);
         }
         writer.write(data, sheet1);
         writer.finish();
      }
   }

   public static class MultiLineHeadExcelModel extends BaseRowModel {

      @ExcelProperty(value = { "表头1", "表头1", "表头31" }, index = 0)
      private String p1;

      @ExcelProperty(value = { "表头1", "表头1", "表头32" }, index = 1)
      private String p2;

      @ExcelProperty(value = { "表头3", "表头3", "表头3" }, index = 2)
      private String p3;

      @ExcelProperty(value = { "表头4", "表头4", "表头4" }, index = 3)
      private String p4;

      @ExcelProperty(value = { "表头5", "表头51", "表头52" }, index = 4)
      private String p5;

      @ExcelProperty(value = { "表头6", "表头61", "表头611" }, index = 5)
      private String p6;

      @ExcelProperty(value = { "表头6", "表头61", "表头612" }, index = 6)
      private String p7;

      @ExcelProperty(value = { "表头6", "表头62", "表头621" }, index = 7)
      private String p8;

      @ExcelProperty(value = { "表头6", "表头62", "表头622" }, index = 8)
      private String p9;

      public String getP1() {
         return p1;
      }

      public void setP1(String p1) {
         this.p1 = p1;
      }

      public String getP2() {
         return p2;
      }

      public void setP2(String p2) {
         this.p2 = p2;
      }

      public String getP3() {
         return p3;
      }

      public void setP3(String p3) {
         this.p3 = p3;
      }

      public String getP4() {
         return p4;
      }

      public void setP4(String p4) {
         this.p4 = p4;
      }

      public String getP5() {
         return p5;
      }

      public void setP5(String p5) {
         this.p5 = p5;
      }

      public String getP6() {
         return p6;
      }

      public void setP6(String p6) {
         this.p6 = p6;
      }

      public String getP7() {
         return p7;
      }

      public void setP7(String p7) {
         this.p7 = p7;
      }

      public String getP8() {
         return p8;
      }

      public void setP8(String p8) {
         this.p8 = p8;
      }

      public String getP9() {
         return p9;
      }

      public void setP9(String p9) {
         this.p9 = p9;
      }
   }
}

效果如下：

怎么样，这些已经基本满足我们的日常需求了，easyexcel不仅支持上述几种形式，还支持在一个sheet中添加多个表

package test;

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.List;

import org.junit.Test;

import com.alibaba.excel.ExcelWriter;
import com.alibaba.excel.annotation.ExcelProperty;
import com.alibaba.excel.metadata.BaseRowModel;
import com.alibaba.excel.metadata.Sheet;
import com.alibaba.excel.metadata.Table;
import com.alibaba.excel.support.ExcelTypeEnum;

public class ExcelWriteTest {
   @Test
   public void writeWithMultiTable() throws IOException {
      try (OutputStream out = new FileOutputStream("withMultiTable.xlsx");) {
         ExcelWriter writer = new ExcelWriter(out, ExcelTypeEnum.XLSX);
         Sheet sheet1 = new Sheet(1, 0);
         sheet1.setSheetName("sheet1");

         // 数据全是List<String> 无模型映射关系
         Table table1 = new Table(1);
         List<List<String>> data1 = new ArrayList<>();
         for (int i = 0; i < 5; i++) {
            List<String> item = new ArrayList<>();
            item.add("item0" + i);
            item.add("item1" + i);
            item.add("item2" + i);
            data1.add(item);
         }
         writer.write0(data1, sheet1, table1);

         // 模型上有表头的注解
         Table table2 = new Table(2);
         table2.setClazz(MultiLineHeadExcelModel.class);
         List<MultiLineHeadExcelModel> data2 = new ArrayList<>();
         for (int i = 0; i < 5; i++) {
            MultiLineHeadExcelModel item = new MultiLineHeadExcelModel();
            item.p1 = "p1" + i;
            item.p2 = "p2" + i;
            item.p3 = "p3" + i;
            item.p4 = "p4" + i;
            item.p5 = "p5" + i;
            item.p6 = "p6" + i;
            item.p7 = "p7" + i;
            item.p8 = "p8" + i;
            item.p9 = "p9" + i;
            data2.add(item);
         }
         writer.write(data2, sheet1, table2);

         // 模型上没有注解，表头数据动态传入,此情况下模型field顺序与excel现实顺序一致
         List<List<String>> head = new ArrayList<List<String>>();
         List<String> headCoulumn1 = new ArrayList<String>();
         List<String> headCoulumn2 = new ArrayList<String>();
         List<String> headCoulumn3 = new ArrayList<String>();
         headCoulumn1.add("第一列");
         headCoulumn2.add("第二列");
         headCoulumn3.add("第三列");
         head.add(headCoulumn1);
         head.add(headCoulumn2);
         head.add(headCoulumn3);
         Table table3 = new Table(3);
         table3.setHead(head);
         writer.write0(data1, sheet1, table3);

         writer.finish();
      }
   }

   public static class MultiLineHeadExcelModel extends BaseRowModel {

      @ExcelProperty(value = { "表头1", "表头1", "表头31" }, index = 0)
      private String p1;

      @ExcelProperty(value = { "表头1", "表头1", "表头32" }, index = 1)
      private String p2;

      @ExcelProperty(value = { "表头3", "表头3", "表头3" }, index = 2)
      private String p3;

      @ExcelProperty(value = { "表头4", "表头4", "表头4" }, index = 3)
      private String p4;

      @ExcelProperty(value = { "表头5", "表头51", "表头52" }, index = 4)
      private String p5;

      @ExcelProperty(value = { "表头6", "表头61", "表头611" }, index = 5)
      private String p6;

      @ExcelProperty(value = { "表头6", "表头61", "表头612" }, index = 6)
      private String p7;

      @ExcelProperty(value = { "表头6", "表头62", "表头621" }, index = 7)
      private String p8;

      @ExcelProperty(value = { "表头6", "表头62", "表头622" }, index = 8)
      private String p9;

      public String getP1() {
         return p1;
      }

      public void setP1(String p1) {
         this.p1 = p1;
      }

      public String getP2() {
         return p2;
      }

      public void setP2(String p2) {
         this.p2 = p2;
      }

      public String getP3() {
         return p3;
      }

      public void setP3(String p3) {
         this.p3 = p3;
      }

      public String getP4() {
         return p4;
      }

      public void setP4(String p4) {
         this.p4 = p4;
      }

      public String getP5() {
         return p5;
      }

      public void setP5(String p5) {
         this.p5 = p5;
      }

      public String getP6() {
         return p6;
      }

      public void setP6(String p6) {
         this.p6 = p6;
      }

      public String getP7() {
         return p7;
      }

      public void setP7(String p7) {
         this.p7 = p7;
      }

      public String getP8() {
         return p8;
      }

      public void setP8(String p8) {
         this.p8 = p8;
      }

      public String getP9() {
         return p9;
      }

      public void setP9(String p9) {
         this.p9 = p9;
      }
   }
}

效果如下：

如果表头的样式不满足我们的需求，需要调整，我们可以使用com.alibaba.excel.metadata.TableStyle定义我们需要的样式，然后调用table对象的setTableStyle方法进行设置。

好了，到这里写入excel就基本介绍完了，下面我们就来看看如何读取excel，实际上现在的这个版本(1.0.1)在读取的时候是有BUG的，读取03版的.xls格式的excel正常，但是读取07版的.xlsx版的excel就会出异常，原因是在解析的时候sheet临时文件路径拼装有误，下面是我针对这个版本修复后的实现，大家可以替换掉原包中的实现

package com.alibaba.excel.read;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.LinkedList;
import java.util.List;
import java.util.Locale;

import javax.xml.parsers.ParserConfigurationException;

import com.alibaba.excel.read.v07.RowHandler;
import com.alibaba.excel.read.v07.XmlParserFactory;
import com.alibaba.excel.read.v07.XMLTempFile;
import com.alibaba.excel.read.context.AnalysisContext;
import com.alibaba.excel.read.exception.ExcelAnalysisException;
import com.alibaba.excel.metadata.Sheet;
import com.alibaba.excel.util.FileUtil;

import org.apache.poi.xssf.model.SharedStringsTable;
import org.apache.xmlbeans.XmlException;
import org.openxmlformats.schemas.spreadsheetml.x2006.main.CTWorkbook;
import org.openxmlformats.schemas.spreadsheetml.x2006.main.CTWorkbookPr;
import org.openxmlformats.schemas.spreadsheetml.x2006.main.WorkbookDocument;
import org.xml.sax.Attributes;
import org.xml.sax.ContentHandler;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

public class SaxAnalyserV07 extends BaseSaxAnalyser {

    private SharedStringsTable sharedStringsTable;

    private List<String> sharedStringList = new LinkedList<String>();

    private List<SheetSource> sheetSourceList = new ArrayList<SheetSource>();

    private boolean use1904WindowDate = false;

    private final String path;

    private File tmpFile;

    private String workBookXMLFilePath;

    private String sharedStringXMLFilePath;

    public SaxAnalyserV07(AnalysisContext analysisContext) throws Exception {
        this.analysisContext = analysisContext;
        this.path = XMLTempFile.createPath();
        this.tmpFile = new File(XMLTempFile.getTmpFilePath(path));
        this.workBookXMLFilePath = XMLTempFile.getWorkBookFilePath(path);
        this.sharedStringXMLFilePath = XMLTempFile.getSharedStringFilePath(path);
        start();
    }

    @Override
    protected void execute() {
        try {
            Sheet sheet = analysisContext.getCurrentSheet();
            if (!isAnalysisAllSheets(sheet)) {
                if (this.sheetSourceList.size() < sheet.getSheetNo() || sheet.getSheetNo() == 0) {
                    return;
                }
                InputStream sheetInputStream = this.sheetSourceList.get(sheet.getSheetNo() - 1).getInputStream();
                parseXmlSource(sheetInputStream);
                return;
            }
            int i = 0;
            for (SheetSource sheetSource : this.sheetSourceList) {
                i++;
                this.analysisContext.setCurrentSheet(new Sheet(i));
                parseXmlSource(sheetSource.getInputStream());
            }

        } catch (Exception e) {
            stop();
            throw new ExcelAnalysisException(e);
        } finally {
        }

    }

    private boolean isAnalysisAllSheets(Sheet sheet) {
        if (sheet == null) {
            return true;
        }
        if (sheet.getSheetNo() < 0) {
            return true;
        }
        return false;
    }

    public void stop() {
        FileUtil.deletefile(path);
    }

    private void parseXmlSource(InputStream inputStream) {
        try {
            ContentHandler handler = new RowHandler(this, this.sharedStringsTable, this.analysisContext,
                sharedStringList);
            XmlParserFactory.parse(inputStream, handler);
            inputStream.close();
        } catch (Exception e) {
            try {
                inputStream.close();
            } catch (IOException e1) {
                e1.printStackTrace();
            }
            throw new ExcelAnalysisException(e);
        }
    }

    public List<Sheet> getSheets() {
        List<Sheet> sheets = new ArrayList<Sheet>();
        try {
            int i = 1;
            for (SheetSource sheetSource : this.sheetSourceList) {
                Sheet sheet = new Sheet(i, 0);
                sheet.setSheetName(sheetSource.getSheetName());
                i++;
                sheets.add(sheet);
            }
        } catch (Exception e) {
            stop();
            throw new ExcelAnalysisException(e);
        } finally {

        }

        return sheets;
    }

    private void start() throws IOException, XmlException, ParserConfigurationException, SAXException {

        createTmpFile();

        unZipTempFile();

        initSharedStringsTable();

        initUse1904WindowDate();

        initSheetSourceList();

    }

    private void createTmpFile() throws FileNotFoundException {
        FileUtil.writeFile(tmpFile, analysisContext.getInputStream());
    }

    private void unZipTempFile() throws IOException {
        FileUtil.doUnZip(path, tmpFile);
    }

    private void initSheetSourceList() throws IOException, ParserConfigurationException, SAXException {
        this.sheetSourceList = new ArrayList<SheetSource>();
        InputStream workbookXml = new FileInputStream(this.workBookXMLFilePath);
        XmlParserFactory.parse(workbookXml, new DefaultHandler() {
            @Override
            public void startElement(String uri, String localName, String qName, Attributes attrs) throws SAXException {
                if (qName.toLowerCase(Locale.US).equals("sheet")) {
                    String name = null;
                    int id = 0;
                    for (int i = 0; i < attrs.getLength(); i++) {
                        if (attrs.getLocalName(i).toLowerCase(Locale.US).equals("name")) {
                            name = attrs.getValue(i);
                        }/** else if (attrs.getLocalName(i).toLowerCase(Locale.US).equals("r:id")) {
                            id = Integer.parseInt(attrs.getValue(i).replaceAll("rId", ""));
                            try {
                                InputStream inputStream = new FileInputStream(XMLTempFile.getSheetFilePath(path, id));
                                sheetSourceList.add(new SheetSource(id, name, inputStream));
                            } catch (FileNotFoundException e) {
                                e.printStackTrace();
                            }
                        } **/
                        //应该使用sheetId属性
                        else if (attrs.getLocalName(i).toLowerCase(Locale.US).equals("sheetid")) {
                            id = Integer.parseInt(attrs.getValue(i));
                            try {
                                InputStream inputStream = new FileInputStream(XMLTempFile.getSheetFilePath(path, id));
                                sheetSourceList.add(new SheetSource(id, name, inputStream));
                            } catch (FileNotFoundException e) {
                                e.printStackTrace();
                            }
                       }
                    }

                }
            }

        });
        workbookXml.close();
        // 排序后是倒序，不符合实际要求
        // Collections.sort(sheetSourceList);
        Collections.sort(sheetSourceList, new Comparator<SheetSource>() {
           @Override
           public int compare(SheetSource o1, SheetSource o2) {
              return o1.id - o2.id;
           }
        });
    }

    private void initUse1904WindowDate() throws IOException, XmlException {
        InputStream workbookXml = new FileInputStream(workBookXMLFilePath);
        WorkbookDocument ctWorkbook = WorkbookDocument.Factory.parse(workbookXml);
        CTWorkbook wb = ctWorkbook.getWorkbook();
        CTWorkbookPr prefix = wb.getWorkbookPr();
        if (prefix != null) {
            this.use1904WindowDate = prefix.getDate1904();
        }
        this.analysisContext.setUse1904WindowDate(use1904WindowDate);
        workbookXml.close();
    }

    private void initSharedStringsTable() throws IOException, ParserConfigurationException, SAXException {
        //因为sharedStrings.xml文件不一定存在，所以在处理之前增加判断
        File sharedStringXMLFile = new File(this.sharedStringXMLFilePath);
        if (!sharedStringXMLFile.exists()) {
            return;
        }
        InputStream inputStream = new FileInputStream(this.sharedStringXMLFilePath);
        //this.sharedStringsTable = new SharedStringsTable();
        //this.sharedStringsTable.readFrom(inputStream);

        XmlParserFactory.parse(inputStream, new DefaultHandler() {
            @Override
            public void characters(char[] ch, int start, int length) {
                sharedStringList.add(new String(ch, start, length));
            }

        });
        inputStream.close();
    }

    private class SheetSource implements Comparable<SheetSource> {

        private int id;

        private String sheetName;

        private InputStream inputStream;

        public SheetSource(int id, String sheetName, InputStream inputStream) {
            this.id = id;
            this.sheetName = sheetName;
            this.inputStream = inputStream;
        }

        public String getSheetName() {
            return sheetName;
        }

        public void setSheetName(String sheetName) {
            this.sheetName = sheetName;
        }

        public InputStream getInputStream() {
            return inputStream;
        }

        public void setInputStream(InputStream inputStream) {
            this.inputStream = inputStream;
        }

        public int getId() {
            return id;
        }

        public void setId(int id) {
            this.id = id;
        }

        public int compareTo(SheetSource o) {
            if (o.id == this.id) {
                return 0;
            } else if (o.id > this.id) {
                return 1;
            } else {
                return -1;
            }
        }
    }

}

另外，使用easyexcel读取excel的时候需要设置excel的版本，但是有些时候我们无法预知excel的版本，所以个人感觉这样不是太好，所以模仿poi写了一个用于获取com.alibaba.excel.ExcelReader对象的工具类

package com.alibaba.excel.read;

import java.io.IOException;
import java.io.InputStream;
import java.io.PushbackInputStream;

import org.apache.poi.EmptyFileException;
import org.apache.poi.openxml4j.exceptions.InvalidFormatException;
import org.apache.poi.poifs.filesystem.DocumentFactoryHelper;
import org.apache.poi.poifs.filesystem.NPOIFSFileSystem;
import org.apache.poi.util.IOUtils;

import com.alibaba.excel.ExcelReader;
import com.alibaba.excel.read.context.AnalysisContext;
import com.alibaba.excel.read.event.AnalysisEventListener;
import com.alibaba.excel.support.ExcelTypeEnum;

public class ExcelReaderFactory {
   /**
    * @param in
    *           文件输入流
    * @param customContent
    *           自定义模型可以在
    *           {@link AnalysisEventListener#invoke(Object, AnalysisContext) }
    *           AnalysisContext中获取用于监听者回调使用
    * @param eventListener
    *           用户监听
    * @throws IOException
    * @throws EmptyFileException
    * @throws InvalidFormatException
    */
   public static ExcelReader getExcelReader(InputStream in, Object customContent,
         AnalysisEventListener<?> eventListener) throws EmptyFileException, IOException, InvalidFormatException {
      // 如果输入流不支持mark/reset，需要对其进行包裹
      if (!in.markSupported()) {
         in = new PushbackInputStream(in, 8);
      }

      // 确保至少有一些数据
      byte[] header8 = IOUtils.peekFirst8Bytes(in);
      ExcelTypeEnum excelTypeEnum = null;
      if (NPOIFSFileSystem.hasPOIFSHeader(header8)) {
         excelTypeEnum = ExcelTypeEnum.XLS;
      }
      if (DocumentFactoryHelper.hasOOXMLHeader(in)) {
         excelTypeEnum = ExcelTypeEnum.XLSX;
      }
      if (excelTypeEnum != null) {
         return new ExcelReader(in, excelTypeEnum, customContent, eventListener);
      }
      throw new InvalidFormatException("Your InputStream was neither an OLE2 stream, nor an OOXML stream");

   }

   /**
    * @param in
    *           文件输入流
    * @param customContent
    *           自定义模型可以在
    *           {@link AnalysisEventListener#invoke(Object, AnalysisContext) }
    *           AnalysisContext中获取用于监听者回调使用
    * @param eventListener
    *           用户监听
    * @param trim
    *           是否对解析的String做trim()默认true,用于防止 excel中空格引起的装换报错。
    * @throws IOException
    * @throws EmptyFileException
    * @throws InvalidFormatException
    */
   public static ExcelReader getExcelReader(InputStream in, Object customContent,
         AnalysisEventListener<?> eventListener, boolean trim)
         throws EmptyFileException, IOException, InvalidFormatException {
      // 如果输入流不支持mark/reset，需要对其进行包裹
      if (!in.markSupported()) {
         in = new PushbackInputStream(in, 8);
      }

      // 确保至少有一些数据
      byte[] header8 = IOUtils.peekFirst8Bytes(in);
      ExcelTypeEnum excelTypeEnum = null;
      if (NPOIFSFileSystem.hasPOIFSHeader(header8)) {
         excelTypeEnum = ExcelTypeEnum.XLS;
      }
      if (DocumentFactoryHelper.hasOOXMLHeader(in)) {
         excelTypeEnum = ExcelTypeEnum.XLSX;
      }
      if (excelTypeEnum != null) {
         return new ExcelReader(in, excelTypeEnum, customContent, eventListener, trim);
      }
      throw new InvalidFormatException("Your InputStream was neither an OLE2 stream, nor an OOXML stream");
   }
}

下面我们就来写一个简单的读取Excel的示例：

package test;

import java.io.FileInputStream;
import java.io.InputStream;
import java.util.List;

import org.junit.Test;

import com.alibaba.excel.ExcelReader;
import com.alibaba.excel.annotation.ExcelProperty;
import com.alibaba.excel.metadata.BaseRowModel;
import com.alibaba.excel.metadata.Sheet;
import com.alibaba.excel.read.ExcelReaderFactory;
import com.alibaba.excel.read.context.AnalysisContext;
import com.alibaba.excel.read.event.AnalysisEventListener;

public class ExcelReadTest {
   @Test
   public void read() throws Exception {
      try (InputStream in = new FileInputStream("withoutHead.xlsx");) {
         AnalysisEventListener<List<String>> listener = new AnalysisEventListener<List<String>>() {

            @Override
            public void invoke(List<String> object, AnalysisContext context) {
               System.err.println("Row:" + context.getCurrentRowNum() + " Data:" + object);
            }

            @Override
            public void doAfterAllAnalysed(AnalysisContext context) {
               System.err.println("doAfterAllAnalysed...");
            }
         };
         ExcelReader excelReader = ExcelReaderFactory.getExcelReader(in, null, listener);
         excelReader.read();
      }
   }
}

正如写入Excel的时候可以使用数据模型一样，在读取Excel的时候也可以直接将数据映射为模型对象，区别在于要使用ExcelReader #read的重载方法。

package test;

import java.io.FileInputStream;
import java.io.InputStream;
import java.util.List;

import org.junit.Test;

import com.alibaba.excel.ExcelReader;
import com.alibaba.excel.annotation.ExcelProperty;
import com.alibaba.excel.metadata.BaseRowModel;
import com.alibaba.excel.metadata.Sheet;
import com.alibaba.excel.read.ExcelReaderFactory;
import com.alibaba.excel.read.context.AnalysisContext;
import com.alibaba.excel.read.event.AnalysisEventListener;

public class ExcelReadTest {
   @Test
   public void read() throws Exception {
      try (InputStream in = new FileInputStream("withHead.xlsx");) {
         AnalysisEventListener<ExcelPropertyIndexModel> listener = new AnalysisEventListener<ExcelPropertyIndexModel>() {

            @Override
            public void invoke(ExcelPropertyIndexModel object, AnalysisContext context) {
               System.err.println("Row:" + context.getCurrentRowNum() + " Data:" + object);
            }

            @Override
            public void doAfterAllAnalysed(AnalysisContext context) {
               System.err.println("doAfterAllAnalysed...");
            }
         };
         ExcelReader excelReader = ExcelReaderFactory.getExcelReader(in, null, listener);
         // 第二个参数为表头行数，按照实际设置
         excelReader.read(new Sheet(1, 1, ExcelPropertyIndexModel.class));
      }
   }

   public static class ExcelPropertyIndexModel extends BaseRowModel {

      @ExcelProperty(value = "姓名", index = 0)
      private String name;

      @ExcelProperty(value = "年龄", index = 1)
      private String age;

      @ExcelProperty(value = "邮箱", index = 2)
      private String email;

      @ExcelProperty(value = "地址", index = 3)
      private String address;

      @ExcelProperty(value = "性别", index = 4)
      private String sax;

      @ExcelProperty(value = "高度", index = 5)
      private String heigh;

      @ExcelProperty(value = "备注", index = 6)
      private String last;

      public String getName() {
         return name;
      }

      public void setName(String name) {
         this.name = name;
      }

      public String getAge() {
         return age;
      }

      public void setAge(String age) {
         this.age = age;
      }

      public String getEmail() {
         return email;
      }

      public void setEmail(String email) {
         this.email = email;
      }

      public String getAddress() {
         return address;
      }

      public void setAddress(String address) {
         this.address = address;
      }

      public String getSax() {
         return sax;
      }

      public void setSax(String sax) {
         this.sax = sax;
      }

      public String getHeigh() {
         return heigh;
      }

      public void setHeigh(String heigh) {
         this.heigh = heigh;
      }

      public String getLast() {
         return last;
      }

      public void setLast(String last) {
         this.last = last;
      }

      @Override
      public String toString() {
         return "ExcelPropertyIndexModel [name=" + name + ", age=" + age + ", email=" + email + ", address=" + address
               + ", sax=" + sax + ", heigh=" + heigh + ", last=" + last + "]";
      }
   }
}

以上就是关于easyexcel的使用方法介绍，如有疑问，欢迎交流指正。