* 读csv会忽略BOM数据 [Issue #3137](https://github.com/alibaba/easyexcel/issues/3137)

* 解决csv用office打开乱码的问题，写csv默认带上BOM数据

easyexcel-core/pom.xml

@@ -40,5 +40,9 @@
             <groupId>org.ehcache</groupId>
             <artifactId>ehcache</artifactId>
         </dependency>
+        <dependency>
+            <groupId>commons-io</groupId>
+            <artifactId>commons-io</artifactId>
+        </dependency>
     </dependencies>
 </project>

easyexcel-core/src/main/java/com/alibaba/excel/analysis/csv/BomBufferedInputStream.java

@@ -1,90 +0,0 @@
-package com.alibaba.excel.analysis.csv;
-
-
-import java.io.BufferedInputStream;
-import java.io.IOException;
-import java.io.InputStream;
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.List;
-
-/**
- * This class is used to wrap a stream that includes an encoded {@link ByteOrderMark} as its first bytes.
- *
- * @author supalle
- * @see <a href="http://unicode.org/faq/utf_bom.html#BOM">Byte Order Mark (BOM) FAQ</a>
- * @see <a href="https://commons.apache.org/proper/commons-io/apidocs/org/apache/commons/io/ByteOrderMark.html">Apache CommonsIO BOMInputStream</a>
- */
-public class BomBufferedInputStream extends BufferedInputStream {
-    public final static List<ByteOrderMark> DEFAULT_BYTE_ORDER_MARKS = new ArrayList<>();
-
-    static {
-        DEFAULT_BYTE_ORDER_MARKS.add(ByteOrderMark.UTF_8);
-        DEFAULT_BYTE_ORDER_MARKS.add(ByteOrderMark.UTF_16BE);
-        DEFAULT_BYTE_ORDER_MARKS.add(ByteOrderMark.UTF_16LE);
-        DEFAULT_BYTE_ORDER_MARKS.add(ByteOrderMark.UTF_32BE);
-        DEFAULT_BYTE_ORDER_MARKS.add(ByteOrderMark.UTF_32LE);
-    }
-
-    private boolean initialized;
-    private ByteOrderMark byteOrderMark;
-    private final List<ByteOrderMark> byteOrderMarks;
-
-    public BomBufferedInputStream(InputStream in, final ByteOrderMark... byteOrderMarks) {
-        super(in);
-        this.byteOrderMarks = applyByteOrderMarks(byteOrderMarks);
-    }
-
-    public BomBufferedInputStream(InputStream in, int size, final ByteOrderMark... byteOrderMarks) {
-        super(in, size);
-        this.byteOrderMarks = applyByteOrderMarks(byteOrderMarks);
-    }
-
-    private static List<ByteOrderMark> applyByteOrderMarks(ByteOrderMark[] byteOrderMarks) {
-        return byteOrderMarks == null || byteOrderMarks.length == 0 ? DEFAULT_BYTE_ORDER_MARKS : Arrays.asList(byteOrderMarks);
-    }
-
-    public boolean hasByteOrderMark() throws IOException {
-        return getByteOrderMark() != null;
-    }
-
-    public ByteOrderMark getByteOrderMark() throws IOException {
-        if (initialized) {
-            return byteOrderMark;
-        }
-        this.byteOrderMarks.sort(ByteOrderMark::compareTo);
-        int maxBomLength = byteOrderMarks.get(0).length();
-        mark(maxBomLength);
-        int[] firstBytes = new int[maxBomLength];
-        for (int i = 0; i < maxBomLength; i++) {
-            firstBytes[i] = read();
-            if (firstBytes[i] < 0) {
-                break;
-            }
-        }
-        byteOrderMark = matchByteOrderMark(this.byteOrderMarks, firstBytes);
-
-        reset();
-        if (byteOrderMark != null) {
-            skip(byteOrderMark.length());
-        }
-        initialized = true;
-        return byteOrderMark;
-    }
-
-    private ByteOrderMark matchByteOrderMark(final List<ByteOrderMark> byteOrderMarks, final int[] firstBytes) {
-        loop:
-        for (ByteOrderMark item : byteOrderMarks) {
-            int[] bytes = item.getBytes();
-            int length = bytes.length;
-            for (int i = 0; i < length; i++) {
-                if (firstBytes[i] != bytes[i]) {
-                    continue loop;
-                }
-            }
-            return item;
-        }
-        return null;
-    }
-
-}

easyexcel-core/src/main/java/com/alibaba/excel/analysis/csv/ByteOrderMark.java

@@ -1,108 +0,0 @@
-package com.alibaba.excel.analysis.csv;
-
-import java.nio.charset.Charset;
-import java.nio.charset.StandardCharsets;
-import java.util.Arrays;
-import java.util.Objects;
-import java.util.stream.Collectors;
-
-/**
- * Byte Order Mark (BOM)
- * <br/>
- * User in {@link BomBufferedInputStream}
- *
- * @author supalle
- * @see <a href="http://unicode.org/faq/utf_bom.html#BOM">Byte Order Mark (BOM) FAQ</a>
- * @see <a href="https://commons.apache.org/proper/commons-io/apidocs/org/apache/commons/io/ByteOrderMark.html">Apache CommonsIO ByteOrderMark</a>
- */
-public class ByteOrderMark implements Comparable<ByteOrderMark> {
-
-    /**
-     * UTF-8 BOM.
-     */
-    public static final ByteOrderMark UTF_8 = new ByteOrderMark(StandardCharsets.UTF_8, 0xEF, 0xBB, 0xBF);
-
-    /**
-     * UTF-16BE BOM (Big-Endian).
-     */
-    public static final ByteOrderMark UTF_16BE = new ByteOrderMark(StandardCharsets.UTF_16BE, 0xFE, 0xFF);
-
-    /**
-     * UTF-16LE BOM (Little-Endian).
-     */
-    public static final ByteOrderMark UTF_16LE = new ByteOrderMark(StandardCharsets.UTF_16LE, 0xFF, 0xFE);
-
-    /**
-     * UTF-32BE BOM (Big-Endian).
-     *
-     * @since 2.2
-     */
-    public static final ByteOrderMark UTF_32BE = new ByteOrderMark(Charset.forName("UTF-32BE"), 0x00, 0x00, 0xFE, 0xFF);
-
-    /**
-     * UTF-32LE BOM (Little-Endian).
-     *
-     * @since 2.2
-     */
-    public static final ByteOrderMark UTF_32LE = new ByteOrderMark(Charset.forName("UTF-32LE"), 0xFF, 0xFE, 0x00, 0x00);
-
-    private final Charset charset;
-    private final int[] bytes;
-
-    public ByteOrderMark(final Charset charset, final int... bytes) {
-        this.charset = Objects.requireNonNull(charset, "charset must be not null");
-        if (bytes == null || bytes.length == 0) {
-            throw new IllegalArgumentException("bytes must be not empty");
-        }
-        this.bytes = bytes;
-    }
-
-    public Charset getCharset() {
-        return charset;
-    }
-
-    public int[] getBytes() {
-        return bytes;
-    }
-
-    public int length() {
-        return bytes.length;
-    }
-
-    @Override
-    public boolean equals(Object o) {
-        if (this == o) {
-            return true;
-        }
-        if (o == null || getClass() != o.getClass()) {
-            return false;
-        }
-        ByteOrderMark that = (ByteOrderMark) o;
-        return Objects.equals(charset, that.charset) && Arrays.equals(bytes, that.bytes);
-    }
-
-    @Override
-    public int hashCode() {
-        int result = Objects.hash(charset);
-        result = 31 * result + Arrays.hashCode(bytes);
-        return result;
-    }
-
-    @Override
-    public String toString() {
-        return "ByteOrderMark{" +
-            "charset=" + charset +
-            ", bytes=["
-            + Arrays.stream(bytes)
-            .mapToObj(Integer::toHexString)
-            .map(String::toUpperCase)
-            .map("0x"::concat)
-            .collect(Collectors.joining(",")) +
-            "]}";
-    }
-
-    @Override
-    public int compareTo(ByteOrderMark o) {
-        return o.length() - length();
-    }
-}

easyexcel-core/src/main/java/com/alibaba/excel/analysis/csv/CsvExcelReadExecutor.java

@@ -1,6 +1,7 @@
 package com.alibaba.excel.analysis.csv;
 
 import java.io.IOException;
+import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.nio.file.Files;
 import java.util.ArrayList;
@@ -11,6 +12,7 @@ import java.util.Map;
 
 import com.alibaba.excel.analysis.ExcelReadExecutor;
 import com.alibaba.excel.context.csv.CsvReadContext;
+import com.alibaba.excel.enums.ByteOrderMarkEnum;
 import com.alibaba.excel.enums.CellDataTypeEnum;
 import com.alibaba.excel.enums.RowTypeEnum;
 import com.alibaba.excel.exception.ExcelAnalysisException;
@@ -27,6 +29,7 @@ import org.apache.commons.collections4.MapUtils;
 import org.apache.commons.csv.CSVFormat;
 import org.apache.commons.csv.CSVParser;
 import org.apache.commons.csv.CSVRecord;
+import org.apache.commons.io.input.BOMInputStream;
 
 /**
  * read executor
@@ -82,17 +85,26 @@ public class CsvExcelReadExecutor implements ExcelReadExecutor {
     private CSVParser csvParser() throws IOException {
         CsvReadWorkbookHolder csvReadWorkbookHolder = csvReadContext.csvReadWorkbookHolder();
         CSVFormat csvFormat = csvReadWorkbookHolder.getCsvFormat();
-
+        ByteOrderMarkEnum byteOrderMark = ByteOrderMarkEnum.valueOfByCharsetName(
+            csvReadContext.csvReadWorkbookHolder().getCharset().name());
         if (csvReadWorkbookHolder.getMandatoryUseInputStream()) {
-            return csvFormat.parse(
-                new InputStreamReader(csvReadWorkbookHolder.getInputStream(), csvReadWorkbookHolder.getCharset()));
+            return buildCsvParser(csvFormat, csvReadWorkbookHolder.getInputStream(), byteOrderMark);
         }
         if (csvReadWorkbookHolder.getFile() != null) {
-            return csvFormat.parse(new InputStreamReader(Files.newInputStream(csvReadWorkbookHolder.getFile().toPath()),
-                csvReadWorkbookHolder.getCharset()));
+            return buildCsvParser(csvFormat, Files.newInputStream(csvReadWorkbookHolder.getFile().toPath()),
+                byteOrderMark);
         }
-        return csvFormat.parse(
-            new InputStreamReader(csvReadWorkbookHolder.getInputStream(), csvReadWorkbookHolder.getCharset()));
+        return buildCsvParser(csvFormat, csvReadWorkbookHolder.getInputStream(), byteOrderMark);
+    }
+
+    private CSVParser buildCsvParser(CSVFormat csvFormat, InputStream inputStream, ByteOrderMarkEnum byteOrderMark)
+        throws IOException {
+        if (byteOrderMark == null) {
+            return csvFormat.parse(
+                new InputStreamReader(inputStream, csvReadContext.csvReadWorkbookHolder().getCharset()));
+        }
+        return csvFormat.parse(new InputStreamReader(new BOMInputStream(inputStream, byteOrderMark.getByteOrderMark()),
+            csvReadContext.csvReadWorkbookHolder().getCharset()));
     }
 
     private void dealRecord(CSVRecord record, int rowIndex) {

easyexcel-core/src/main/java/com/alibaba/excel/enums/ByteOrderMarkEnum.java

@@ -0,0 +1,51 @@
+package com.alibaba.excel.enums;
+
+import java.nio.charset.Charset;
+import java.util.Map;
+
+import com.alibaba.excel.util.MapUtils;
+
+import lombok.Getter;
+import org.apache.commons.io.ByteOrderMark;
+
+/**
+ * byte order mark
+ *
+ * @author Jiaju Zhuang
+ */
+@Getter
+public enum ByteOrderMarkEnum {
+
+    UTF_8(ByteOrderMark.UTF_8),
+    UTF_16BE(ByteOrderMark.UTF_16BE),
+    UTF_16LE(ByteOrderMark.UTF_16LE),
+    UTF_32BE(ByteOrderMark.UTF_32BE),
+    UTF_32LE(ByteOrderMark.UTF_32LE),
+
+    ;
+
+    final ByteOrderMark byteOrderMark;
+    final String stringPrefix;
+
+    ByteOrderMarkEnum(ByteOrderMark byteOrderMark) {
+        this.byteOrderMark = byteOrderMark;
+        Charset charset = Charset.forName(byteOrderMark.getCharsetName());
+        this.stringPrefix = new String(byteOrderMark.getBytes(), charset);
+    }
+
+    /**
+     * store character aliases corresponding to `ByteOrderMark` prefix
+     */
+    private static final Map<String, ByteOrderMarkEnum> CHARSET_BYTE_ORDER_MARK_MAP = MapUtils.newHashMap();
+
+    static {
+        for (ByteOrderMarkEnum value : ByteOrderMarkEnum.values()) {
+            CHARSET_BYTE_ORDER_MARK_MAP.put(value.getByteOrderMark().getCharsetName(), value);
+        }
+    }
+
+    public static ByteOrderMarkEnum valueOfByCharsetName(String charsetName) {
+        return CHARSET_BYTE_ORDER_MARK_MAP.get(charsetName);
+    }
+
+}

easyexcel-core/src/main/java/com/alibaba/excel/metadata/csv/CsvSheet.java

@@ -3,24 +3,30 @@ package com.alibaba.excel.metadata.csv;
 import java.io.Closeable;
 import java.io.IOException;
 import java.math.BigDecimal;
+import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 import java.util.Collection;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 
 import com.alibaba.excel.constant.BuiltinFormats;
+import com.alibaba.excel.enums.ByteOrderMarkEnum;
 import com.alibaba.excel.enums.NumericCellTypeEnum;
 import com.alibaba.excel.exception.ExcelGenerateException;
 import com.alibaba.excel.util.DateUtils;
 import com.alibaba.excel.util.ListUtils;
+import com.alibaba.excel.util.MapUtils;
 import com.alibaba.excel.util.NumberDataFormatterUtils;
 import com.alibaba.excel.util.StringUtils;
 
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
 import lombok.Setter;
+import org.apache.commons.collections4.CollectionUtils;
 import org.apache.commons.csv.CSVFormat;
 import org.apache.commons.csv.CSVPrinter;
+import org.apache.commons.io.ByteOrderMark;
 import org.apache.poi.ss.usermodel.AutoFilter;
 import org.apache.poi.ss.usermodel.Cell;
 import org.apache.poi.ss.usermodel.CellRange;
@@ -51,6 +57,7 @@ import org.apache.poi.ss.util.PaneInformation;
 @Setter
 @EqualsAndHashCode
 public class CsvSheet implements Sheet, Closeable {
+
     /**
      * workbook
      */
@@ -109,6 +116,13 @@ public class CsvSheet implements Sheet, Closeable {
         }
         rowCache = ListUtils.newArrayListWithExpectedSize(rowCacheCount);
         try {
+            if (csvWorkbook.getWithBom()) {
+                ByteOrderMarkEnum byteOrderMark = ByteOrderMarkEnum.valueOfByCharsetName(
+                    csvWorkbook.getCharset().name());
+                if (byteOrderMark != null) {
+                    out.append(byteOrderMark.getStringPrefix());
+                }
+            }
             csvPrinter = csvFormat.print(out);
         } catch (IOException e) {
             throw new ExcelGenerateException(e);

easyexcel-core/src/main/java/com/alibaba/excel/metadata/csv/CsvWorkbook.java

@@ -2,6 +2,7 @@ package com.alibaba.excel.metadata.csv;
 
 import java.io.IOException;
 import java.io.OutputStream;
+import java.nio.charset.Charset;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Locale;
@@ -71,11 +72,25 @@ public class CsvWorkbook implements Workbook {
      */
     private List<CsvCellStyle> csvCellStyleList;
 
-    public CsvWorkbook(Appendable out, Locale locale, Boolean use1904windowing, Boolean useScientificFormat) {
+    /**
+     * charset.
+     */
+    private Charset charset;
+
+    /**
+     * Set the encoding prefix in the csv file, otherwise the office may open garbled characters.
+     * Default true.
+     */
+    private Boolean withBom;
+
+    public CsvWorkbook(Appendable out, Locale locale, Boolean use1904windowing, Boolean useScientificFormat,
+        Charset charset, Boolean withBom) {
         this.out = out;
         this.locale = locale;
         this.use1904windowing = use1904windowing;
         this.useScientificFormat = useScientificFormat;
+        this.charset = charset;
+        this.withBom = withBom;
     }
 
     @Override

easyexcel-core/src/main/java/com/alibaba/excel/read/metadata/holder/csv/CsvReadWorkbookHolder.java

@@ -1,9 +1,9 @@
 package com.alibaba.excel.read.metadata.holder.csv;
 
-import com.alibaba.excel.analysis.csv.BomBufferedInputStream;
 import com.alibaba.excel.read.metadata.ReadWorkbook;
 import com.alibaba.excel.read.metadata.holder.ReadWorkbookHolder;
 import com.alibaba.excel.support.ExcelTypeEnum;
+
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
 import lombok.Setter;
@@ -30,34 +30,5 @@ public class CsvReadWorkbookHolder extends ReadWorkbookHolder {
         super(readWorkbook);
         setExcelType(ExcelTypeEnum.CSV);
         this.csvFormat = CSVFormat.DEFAULT;
-        // CSV BOM
-        if (readWorkbook.getCharset() == null) {
-            BomBufferedInputStream bomBufferedInputStream = buildBomBufferedInputStream();
-            setInputStream(bomBufferedInputStream);
-            setMandatoryUseInputStream(Boolean.TRUE);
-            try {
-                if (bomBufferedInputStream.hasByteOrderMark()) {
-                    setCharset(bomBufferedInputStream.getByteOrderMark().getCharset());
-                }
-            } catch (IOException e) {
-                throw new RuntimeException(e);
-            }
-        }
-    }
-
-    private BomBufferedInputStream buildBomBufferedInputStream() {
-        BomBufferedInputStream bomBufferedInputStream;
-        try {
-            if (Boolean.TRUE.equals(getMandatoryUseInputStream())) {
-                bomBufferedInputStream = new BomBufferedInputStream(getInputStream());
-            } else if (getFile() != null) {
-                bomBufferedInputStream = new BomBufferedInputStream(Files.newInputStream(getFile().toPath()));
-            } else {
-                bomBufferedInputStream = new BomBufferedInputStream(getInputStream());
-            }
-        } catch (IOException e) {
-            throw new RuntimeException(e.getMessage());
-        }
-        return bomBufferedInputStream;
     }
 }

easyexcel-core/src/main/java/com/alibaba/excel/util/WorkBookUtil.java

@@ -70,7 +70,9 @@ public class WorkBookUtil {
                     new OutputStreamWriter(writeWorkbookHolder.getOutputStream(), writeWorkbookHolder.getCharset())),
                     writeWorkbookHolder.getGlobalConfiguration().getLocale(),
                     writeWorkbookHolder.getGlobalConfiguration().getUse1904windowing(),
-                    writeWorkbookHolder.getGlobalConfiguration().getUseScientificFormat());
+                    writeWorkbookHolder.getGlobalConfiguration().getUseScientificFormat(),
+                    writeWorkbookHolder.getCharset(),
+                    writeWorkbookHolder.getWithBom());
                 writeWorkbookHolder.setCachedWorkbook(csvWorkbook);
                 writeWorkbookHolder.setWorkbook(csvWorkbook);
                 return;

easyexcel-core/src/main/java/com/alibaba/excel/write/builder/ExcelWriterBuilder.java

@@ -94,6 +94,15 @@ public class ExcelWriterBuilder extends AbstractExcelWriterParameterBuilder<Exce
         return this;
     }
 
+    /**
+     * Set the encoding prefix in the csv file, otherwise the office may open garbled characters.
+     * Default true.
+     */
+    public ExcelWriterBuilder withBom(Boolean withBom) {
+        writeWorkbook.setWithBom(withBom);
+        return this;
+    }
+
     /**
      * Template file.
      * This file is read into memory, excessive cases can lead to OOM.

easyexcel-core/src/main/java/com/alibaba/excel/write/metadata/WriteWorkbook.java

@@ -41,6 +41,13 @@ public class WriteWorkbook extends WriteBasicParameter {
      * Only work on the CSV file
      */
     private Charset charset;
+
+    /**
+     * Set the encoding prefix in the csv file, otherwise the office may open garbled characters.
+     * Default true.
+     */
+    private Boolean withBom;
+
     /**
      * Template input stream
      * <p>

easyexcel-core/src/main/java/com/alibaba/excel/write/metadata/holder/WriteWorkbookHolder.java

@@ -84,6 +84,13 @@ public class WriteWorkbookHolder extends AbstractWriteHolder {
      * Only work on the CSV file
      */
     private Charset charset;
+
+    /**
+     * Set the encoding prefix in the csv file, otherwise the office may open garbled characters.
+     * Default true.
+     */
+    private Boolean withBom;
+
     /**
      * Template input stream
      * <p>
@@ -176,6 +183,12 @@ public class WriteWorkbookHolder extends AbstractWriteHolder {
             this.charset = writeWorkbook.getCharset();
         }
 
+        if (writeWorkbook.getWithBom() == null) {
+            this.withBom = Boolean.TRUE;
+        } else {
+            this.withBom = writeWorkbook.getWithBom();
+        }
+
         if (writeWorkbook.getAutoCloseStream() == null) {
             this.autoCloseStream = Boolean.TRUE;
         } else {

easyexcel-test/src/test/java/com/alibaba/easyexcel/test/core/bom/BomData.java

@@ -1,6 +1,7 @@
 package com.alibaba.easyexcel.test.core.bom;
 
 import com.alibaba.excel.annotation.ExcelProperty;
+
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
 import lombok.Setter;
@@ -12,5 +13,5 @@ public class BomData {
     @ExcelProperty("姓名")
     private String name;
     @ExcelProperty("年纪")
-    private Integer age;
+    private Long age;
 }

easyexcel-test/src/test/java/com/alibaba/easyexcel/test/core/bom/BomDataTest.java

@@ -1,10 +1,18 @@
 package com.alibaba.easyexcel.test.core.bom;
 
+import com.alibaba.easyexcel.test.core.simple.SimpleData;
+import com.alibaba.easyexcel.test.demo.read.DemoData;
 import com.alibaba.easyexcel.test.util.TestFileUtil;
 import com.alibaba.excel.EasyExcel;
 import com.alibaba.excel.context.AnalysisContext;
 import com.alibaba.excel.metadata.data.ReadCellData;
+import com.alibaba.excel.read.listener.PageReadListener;
 import com.alibaba.excel.read.listener.ReadListener;
+import com.alibaba.excel.support.ExcelTypeEnum;
+import com.alibaba.excel.util.ListUtils;
+import com.alibaba.fastjson2.JSON;
+
+import lombok.extern.slf4j.Slf4j;
 import org.apache.commons.compress.utils.Lists;
 import org.junit.Assert;
 import org.junit.FixMethodOrder;
@@ -12,17 +20,76 @@ import org.junit.Test;
 import org.junit.runners.MethodSorters;
 
 import java.io.File;
+import java.io.FileOutputStream;
+import java.nio.charset.Charset;
+import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 
+/**
+ * bom test
+ *
+ * @author Jiaju Zhuang
+ */
 @FixMethodOrder(MethodSorters.NAME_ASCENDING)
+@Slf4j
 public class BomDataTest {
+
     @Test
-    public void t01ReadAndWriteCsv() {
-        readCsv(TestFileUtil.readFile("bom" + File.separator + "bom_none.csv"));
-        readCsv(TestFileUtil.readFile("bom" + File.separator + "bom_utf8.csv"));
-        readCsv(TestFileUtil.readFile("bom" + File.separator + "bom_utf16be.csv"));
-        readCsv(TestFileUtil.readFile("bom" + File.separator + "bom_utf16le.csv"));
+    public void t01ReadCsv() {
+        readCsv(TestFileUtil.readFile("bom" + File.separator + "no_bom.csv"));
+        readCsv(TestFileUtil.readFile("bom" + File.separator + "office_bom.csv"));
+    }
+
+    @Test
+    public void t02ReadAndWriteCsv() throws Exception {
+        readAndWriteCsv(TestFileUtil.createNewFile("bom" + File.separator + "bom_default.csv"), null, null);
+        readAndWriteCsv(TestFileUtil.createNewFile("bom" + File.separator + "bom_utf_8.csv"), "UTF-8", null);
+        readAndWriteCsv(TestFileUtil.createNewFile("bom" + File.separator + "bom_utf_8_lower_case.csv"), "utf-8", null);
+        readAndWriteCsv(TestFileUtil.createNewFile("bom" + File.separator + "bom_gbk.csv"), "GBK", null);
+        readAndWriteCsv(TestFileUtil.createNewFile("bom" + File.separator + "bom_gbk_lower_case.csv"), "gbk", null);
+        readAndWriteCsv(TestFileUtil.createNewFile("bom" + File.separator + "bom_utf_16be.csv"), "UTF-16BE", null);
+        readAndWriteCsv(TestFileUtil.createNewFile("bom" + File.separator + "bom_utf_8_not_with_bom.csv"), "UTF-8",
+            Boolean.FALSE);
+    }
+
+    private void readAndWriteCsv(File file, String charsetName, Boolean withBom) throws Exception {
+        Charset charset = null;
+        if (charsetName != null) {
+            charset = Charset.forName(charsetName);
+        }
+        EasyExcel.write(new FileOutputStream(file), BomData.class)
+            .charset(charset)
+            .withBom(withBom)
+            .excelType(ExcelTypeEnum.CSV)
+            .sheet()
+            .doWrite(data());
+
+        EasyExcel.read(file, BomData.class, new ReadListener<BomData>() {
+
+                private final List<BomData> dataList = Lists.newArrayList();
+
+                @Override
+                public void invokeHead(Map<Integer, ReadCellData<?>> headMap, AnalysisContext context) {
+                    String head = headMap.get(0).getStringValue();
+                    Assert.assertEquals("姓名", head);
+                }
+
+                @Override
+                public void invoke(BomData data, AnalysisContext context) {
+                    dataList.add(data);
+                }
+
+                @Override
+                public void doAfterAllAnalysed(AnalysisContext context) {
+                    Assert.assertEquals(dataList.size(), 10);
+                    BomData bomData = dataList.get(0);
+                    Assert.assertEquals("姓名0", bomData.getName());
+                    Assert.assertEquals(20, (long)bomData.getAge());
+                }
+            })
+            .charset(charset)
+            .sheet().doRead();
     }
 
     private void readCsv(File file) {
@@ -46,8 +113,19 @@ public class BomDataTest {
                 Assert.assertEquals(dataList.size(), 10);
                 BomData bomData = dataList.get(0);
                 Assert.assertEquals("姓名0", bomData.getName());
-                Assert.assertEquals(0, (long) bomData.getAge());
+                Assert.assertEquals(20L, (long)bomData.getAge());
             }
         }).sheet().doRead();
     }
+
+    private List<BomData> data() {
+        List<BomData> list = ListUtils.newArrayList();
+        for (int i = 0; i < 10; i++) {
+            BomData data = new BomData();
+            data.setName("姓名" + i);
+            data.setAge(20L);
+            list.add(data);
+        }
+        return list;
+    }
 }

easyexcel-test/src/test/resources/bom/bom_none.csv

@@ -1,11 +0,0 @@
-姓名,年纪
-姓名0,0
-姓名1,1
-姓名2,2
-姓名3,3
-姓名4,4
-姓名5,5
-姓名6,6
-姓名7,7
-姓名8,8
-姓名9,9

easyexcel-test/src/test/resources/bom/bom_utf8.csv

@@ -1,11 +0,0 @@
-姓名,年纪
-姓名0,0
-姓名1,1
-姓名2,2
-姓名3,3
-姓名4,4
-姓名5,5
-姓名6,6
-姓名7,7
-姓名8,8
-姓名9,9

easyexcel-test/src/test/resources/bom/no_bom.csv

@@ -0,0 +1,11 @@
+姓名,年纪
+姓名0,20
+姓名1,20
+姓名2,20
+姓名3,20
+姓名4,20
+姓名5,20
+姓名6,20
+姓名7,20
+姓名8,20
+姓名9,20

easyexcel-test/src/test/resources/bom/office_bom.csv

@@ -0,0 +1,11 @@
+姓名,年纪
+姓名0,20
+姓名1,20
+姓名2,20
+姓名3,20
+姓名4,20
+姓名5,20
+姓名6,20
+姓名7,20
+姓名8,20
+姓名9,20

pom.xml

@@ -20,7 +20,7 @@
 
 
     <properties>
-        <revision>3.2.1</revision>
+        <revision>3.3.0</revision>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <jdk.version>1.8</jdk.version>
         <gpg.skip>true</gpg.skip>
@@ -128,6 +128,11 @@
                 <artifactId>lombok</artifactId>
                 <version>1.18.20</version>
             </dependency>
+            <dependency>
+                <groupId>commons-io</groupId>
+                <artifactId>commons-io</artifactId>
+                <version>2.11.0</version>
+            </dependency>
 
 
             <dependency>

update.md

@@ -1,3 +1,8 @@
+# 3.3.0
+
+* 读csv会忽略BOM数据 [Issue #3137](https://github.com/alibaba/easyexcel/issues/3137)
+* 解决csv用office打开乱码的问题，写csv默认带上BOM数据
+
 # 3.2.1
 
 * 兼容`LocalDate` [Issue #2908](https://github.com/alibaba/easyexcel/issues/2908)