Fix a potential fd leak in AbstractDiskHttpData.setContent (#10198)

Motivation:

`RandomAccessFile.setLength` may throw an IOException. We must deal with this in case of the occurrence of `I/O` error.

Modification:

Place the `RandomAccessFile.setLength` method call in the `try-finally` block.

Result:

Avoid fd leak.

codec-http/src/main/java/io/netty/handler/codec/http/multipart/AbstractDiskHttpData.java

@@ -124,8 +124,8 @@ public abstract class AbstractDiskHttpData extends AbstractHttpData {
                 return;
             }
             RandomAccessFile accessFile = new RandomAccessFile(file, "rw");
-            accessFile.setLength(0);
             try {
+                accessFile.setLength(0);
                 FileChannel localfileChannel = accessFile.getChannel();
                 ByteBuffer byteBuffer = buffer.nioBuffer();
                 int written = 0;
@@ -216,9 +216,9 @@ public abstract class AbstractDiskHttpData extends AbstractHttpData {
         }
         file = tempFile();
         RandomAccessFile accessFile = new RandomAccessFile(file, "rw");
-        accessFile.setLength(0);
         int written = 0;
         try {
+            accessFile.setLength(0);
             FileChannel localfileChannel = accessFile.getChannel();
             byte[] bytes = new byte[4096 * 4];
             ByteBuffer byteBuffer = ByteBuffer.wrap(bytes);

codec-http/src/test/java/io/netty/handler/codec/http/multipart/DiskFileUploadTest.java

@@ -15,6 +15,8 @@
  */
 package io.netty.handler.codec.http.multipart;
 
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.ByteBufInputStream;
 import io.netty.buffer.Unpooled;
 import io.netty.util.CharsetUtil;
 
@@ -23,6 +25,7 @@ import org.junit.Test;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.IOException;
+import java.io.InputStream;
 
 import static org.junit.Assert.assertArrayEquals;
 import static org.junit.Assert.assertEquals;
@@ -130,4 +133,65 @@ public class DiskFileUploadTest {
             f1.delete();
         }
     }
+
+    @Test
+    public void testSetContentFromByteBuf() throws Exception {
+        DiskFileUpload f1 = new DiskFileUpload("file2", "file2", "application/json", null, null, 0);
+        try {
+            String json = "{\"hello\":\"world\"}";
+            byte[] bytes = json.getBytes(CharsetUtil.UTF_8);
+            f1.setContent(Unpooled.wrappedBuffer(bytes));
+            assertEquals(json, f1.getString());
+            assertArrayEquals(bytes, f1.get());
+            File file = f1.getFile();
+            assertEquals((long) bytes.length, file.length());
+            assertArrayEquals(bytes, doReadFile(file, bytes.length));
+        } finally {
+            f1.delete();
+        }
+    }
+
+    @Test
+    public void testSetContentFromInputStream() throws Exception {
+        String json = "{\"hello\":\"world\",\"foo\":\"bar\"}";
+        DiskFileUpload f1 = new DiskFileUpload("file3", "file3", "application/json", null, null, 0);
+        try {
+            byte[] bytes = json.getBytes(CharsetUtil.UTF_8);
+            ByteBuf buf = Unpooled.wrappedBuffer(bytes);
+            InputStream is = new ByteBufInputStream(buf);
+            try {
+                f1.setContent(is);
+                assertEquals(json, f1.getString());
+                assertArrayEquals(bytes, f1.get());
+                File file = f1.getFile();
+                assertEquals((long) bytes.length, file.length());
+                assertArrayEquals(bytes, doReadFile(file, bytes.length));
+            } finally {
+                buf.release();
+                is.close();
+            }
+        } finally {
+            f1.delete();
+        }
+    }
+
+    private static byte[] doReadFile(File file, int maxRead) throws Exception {
+        FileInputStream fis = new FileInputStream(file);
+        try {
+            byte[] buf = new byte[maxRead];
+            int offset = 0;
+            int read = 0;
+            int len = buf.length;
+            while ((read = fis.read(buf, offset, len)) > 0) {
+                len -= read;
+                offset += read;
+                if (len <= 0 || offset >= buf.length) {
+                    break;
+                }
+            }
+            return buf;
+        } finally {
+            fis.close();
+        }
+    }
 }