修复无法根据文件流判断csv的bug [Issue #2297]

easyexcel-core/src/main/java/com/alibaba/excel/support/ExcelTypeEnum.java

@@ -4,37 +4,46 @@ import java.io.BufferedInputStream;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.InputStream;
+import java.util.Arrays;
 
 import com.alibaba.excel.exception.ExcelAnalysisException;
 import com.alibaba.excel.exception.ExcelCommonException;
 import com.alibaba.excel.read.metadata.ReadWorkbook;
 import com.alibaba.excel.util.StringUtils;
 
+import lombok.Getter;
 import org.apache.poi.poifs.filesystem.FileMagic;
+import org.apache.poi.util.IOUtils;
 
 /**
  * @author jipengfei
  */
+@Getter
 public enum ExcelTypeEnum {
+
     /**
      * csv
      */
-    CSV(".csv"),
+    CSV(".csv", new byte[] {-27, -89, -109, -27}),
     /**
      * xls
      */
-    XLS(".xls"),
+    XLS(".xls", new byte[] {-48, -49, 17, -32, -95, -79, 26, -31}),
     /**
      * xlsx
      */
-    XLSX(".xlsx");
+    XLSX(".xlsx", new byte[] {80, 75, 3, 4});
 
-    private String value;
+    final String value;
+    final byte[] magic;
 
-    ExcelTypeEnum(String value) {
-        this.setValue(value);
+    ExcelTypeEnum(String value, byte[] magic) {
+        this.value = value;
+        this.magic = magic;
     }
 
+    final static int MAX_PATTERN_LENGTH = 8;
+
     public static ExcelTypeEnum valueOf(ReadWorkbook readWorkbook) {
         ExcelTypeEnum excelType = readWorkbook.getExcelType();
         if (excelType != null) {
@@ -85,22 +94,27 @@ public enum ExcelTypeEnum {
     }
 
     private static ExcelTypeEnum recognitionExcelType(InputStream inputStream) throws Exception {
-        FileMagic fileMagic = FileMagic.valueOf(inputStream);
-        if (FileMagic.OLE2.equals(fileMagic)) {
-            return XLS;
-        }
-        if (FileMagic.OOXML.equals(fileMagic)) {
+        // Grab the first bytes of this stream
+        byte[] data = IOUtils.peekFirstNBytes(inputStream, MAX_PATTERN_LENGTH);
+        if (findMagic(XLSX.magic, data)) {
             return XLSX;
+        } else if (findMagic(CSV.magic, data)) {
+            return CSV;
+        } else if (findMagic(XLS.magic, data)) {
+            return XLS;
         }
         throw new ExcelCommonException(
             "Convert excel format exception.You can try specifying the 'excelType' yourself");
     }
 
-    public String getValue() {
-        return value;
+    private static boolean findMagic(byte[] expected, byte[] actual) {
+        int i = 0;
+        for (byte expectedByte : expected) {
+            if (actual[i++] != expectedByte && expectedByte != '?') {
+                return false;
+            }
+        }
+        return true;
     }
 
-    public void setValue(String value) {
-        this.value = value;
-    }
 }

easyexcel-core/src/test/java/com/alibaba/easyexcel/test/core/simple/SimpleDataTest.java

@@ -1,11 +1,16 @@
 package com.alibaba.easyexcel.test.core.simple;
 
 import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+import java.io.InputStream;
 import java.util.ArrayList;
 import java.util.List;
 
 import com.alibaba.easyexcel.test.util.TestFileUtil;
 import com.alibaba.excel.EasyExcel;
+import com.alibaba.excel.support.ExcelTypeEnum;
 
 import org.junit.Assert;
 import org.junit.BeforeClass;
@@ -50,6 +55,26 @@ public class SimpleDataTest {
         EasyExcel.read(file, SimpleData.class, new SimpleDataListener()).sheet().doRead();
     }
 
+    @Test
+    public void t04ReadAndWrite07() throws Exception {
+        readAndWriteInputStream(file07, ExcelTypeEnum.XLSX);
+    }
+
+    @Test
+    public void t05ReadAndWrite03() throws Exception {
+        readAndWriteInputStream(file03, ExcelTypeEnum.XLS);
+    }
+
+    @Test
+    public void t06ReadAndWriteCsv() throws Exception {
+        readAndWriteInputStream(fileCsv, ExcelTypeEnum.CSV);
+    }
+
+    private void readAndWriteInputStream(File file, ExcelTypeEnum excelTypeEnum) throws Exception {
+        EasyExcel.write(new FileOutputStream(file), SimpleData.class).excelType(excelTypeEnum).sheet().doWrite(data());
+        EasyExcel.read(new FileInputStream(file), SimpleData.class, new SimpleDataListener()).sheet().doRead();
+    }
+
     @Test
     public void t11SynchronousRead07() {
         synchronousRead(file07);
@@ -66,7 +91,7 @@ public class SimpleDataTest {
     }
 
     @Test
-    public void t05SheetNameRead07() {
+    public void t21SheetNameRead07() {
         EasyExcel.read(TestFileUtil.readFile("simple" + File.separator + "simple07.xlsx"), SimpleData.class,
             new SimpleDataSheetNameListener()).sheet("simple").doRead();
     }

update.md

@@ -1,6 +1,7 @@
 # 3.1.0
 * 支持jdk17,去除cglib&asm依赖，改成重新拷贝一份 [Issue #2240](https://github.com/alibaba/easyexcel/issues/2240)
-* 有样式没有数据的情况下也算空行 [Issue #2294](https://github.com/alibaba/easyexcel/issues/2294)
+* 在有样式没有数据的情况下也算空行 [Issue #2294](https://github.com/alibaba/easyexcel/issues/2294)
+* 修复无法根据文件流判断csv的bug [Issue #2297](https://github.com/alibaba/easyexcel/issues/2297)
 
 # 3.0.5
 * 修复`ReadListener` 转换异常不抛出的问题