Pre Merge pull request !1369 from xy/v5-master

hutool-core/src/main/java/cn/hutool/core/io/FileSplitUtil.java

@@ -0,0 +1,83 @@
+package cn.hutool.core.io;
+
+import cn.hutool.core.util.StrUtil;
+
+import java.io.*;
+import java.nio.file.Files;
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * 大文件分片处理工具
+ */
+public class FileSplitUtil {
+
+    /**
+     * 将大文件分割为多个小文件
+     * @param sourceFile 源文件
+     * @param chunkSize 每个分片的大小(字节)
+     * @param targetDir 目标目录
+     * @return 分片文件列表
+     */
+    public static List<File> split(File sourceFile, long chunkSize, String targetDir) {
+        if (!sourceFile.exists()) {
+            throw new IORuntimeException("Source file not exists: " + sourceFile.getAbsolutePath());
+        }
+
+        if (chunkSize <= 0) {
+            throw new IllegalArgumentException("Chunk size must be positive");
+        }
+
+        List<File> chunkFiles = new ArrayList<>();
+        String baseName = FileUtil.getPrefix(sourceFile);
+        String extension = FileUtil.getSuffix(sourceFile);
+
+        try (InputStream in = Files.newInputStream(sourceFile.toPath())) {
+            byte[] buffer = new byte[(int) Math.min(chunkSize, 8192)];
+            int bytesRead;
+            int chunkIndex = 0;
+            long totalBytesRead = 0;
+            
+            while ((bytesRead = in.read(buffer)) != -1) {
+                if (totalBytesRead % chunkSize == 0) {
+                    // 开始新的分片
+                    String chunkName = StrUtil.format("{}/{}-{}.{}", 
+                            targetDir, baseName, chunkIndex, extension);
+                    File chunkFile = new File(chunkName);
+                    try (OutputStream out = Files.newOutputStream(chunkFile.toPath())) {
+                        out.write(buffer, 0, bytesRead);
+                    }
+                    chunkFiles.add(chunkFile);
+                    chunkIndex++;
+                } else {
+                    // 继续写入当前分片
+                    File currentChunk = chunkFiles.get(chunkFiles.size() - 1);
+                    try (OutputStream out = new FileOutputStream(currentChunk, true)) {
+                        out.write(buffer, 0, bytesRead);
+                    }
+                }
+                totalBytesRead += bytesRead;
+            }
+        } catch (IOException e) {
+            throw new IORuntimeException(e);
+        }
+
+        return chunkFiles;
+    }
+
+    /**
+     * 合并分片文件
+     * @param chunkFiles 分片文件列表
+     * @param targetFile 目标文件
+     */
+    public static void merge(List<File> chunkFiles, File targetFile) {
+        try (OutputStream out = Files.newOutputStream(targetFile.toPath())) {
+            for (File chunk : chunkFiles) {
+                Files.copy(chunk.toPath(), out);
+            }
+        } catch (IOException e) {
+            throw new IORuntimeException(e);
+        }
+    }
+
+}

hutool-core/src/test/java/cn/hutool/core/io/FileSplitUtilTest.java

@@ -0,0 +1,34 @@
+package cn.hutool.core.io;
+
+import cn.hutool.core.collection.ListUtil;
+import cn.hutool.core.io.file.LineSeparator;
+import cn.hutool.core.lang.Console;
+import cn.hutool.core.util.CharsetUtil;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Disabled;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.condition.EnabledOnOs;
+import org.junit.jupiter.api.condition.OS;
+
+import java.io.File;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+/**
+ * {@link FileUtil} 单元测试类
+ *
+ * @author Looly
+ */
+public class FileSplitUtilTest {
+
+	@Test
+	public void fileSplitTest1() {
+		final File file = FileUtil.file("d:/aaa/123.docx");
+		List<File> splitFiles = FileSplitUtil.split(file,3072,"d:/bbb");
+		FileSplitUtil.merge(splitFiles,FileUtil.newFile("d:/ccc/456.docx"));
+	}
+
+}