Socket Client UI 기본 골격 작성

src/main/java/com/eactive/testmaster/client/service/internal/FixedLengthFrameDecoder.java

@@ -0,0 +1,25 @@
+package com.eactive.testmaster.client.service.internal;
+
+import io.netty.buffer.ByteBuf;
+import io.netty.channel.ChannelHandlerContext;
+import io.netty.handler.codec.ByteToMessageDecoder;
+import java.util.List;
+
+public class FixedLengthFrameDecoder extends ByteToMessageDecoder {
+    private final int frameLength;
+
+    public FixedLengthFrameDecoder(int frameLength) {
+        if (frameLength <= 0) {
+            throw new IllegalArgumentException("frameLength must be a positive integer: " + frameLength);
+        }
+        this.frameLength = frameLength;
+    }
+
+    @Override
+    protected void decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out) {
+        while (in.readableBytes() >= frameLength) {
+            ByteBuf buf = in.readBytes(frameLength);
+            out.add(buf);
+        }
+    }
+}