\ud83d\udc49\ud83c\udffb \ucf54\ub4dc \uc124\uba85 \/ Code Explanation<\/p>\n\n\n\n
\u2714\ufe0f Client.java<\/p>\n\n\n\n
— nodejs \uc11c\ubc84\ub791 \ud638\uc2a4\ud2b8\uc640 \ud3ec\ud2b8\ub97c \ub3d9\uc77c\ud558\uac8c \ub9de\ucda5\ub2c8\ub2e4.
Match the host and port to those of the Node.js server.<\/p>\n\n\n\n
String serverAddress = \"localhost\";\n int serverPort = 3000;<\/code><\/pre>\n\n\n\n— \uc2a4\ub808\ub4dc\ub97c \uc0ac\uc6a9\ud558\uc5ec \ucc44\ud305 \ud0c0\uc774\ud551\uacfc \ud654\uba74\uc5d0 \ucd9c\ub825\ud558\ub294 \ubd80\ubd84\uc744 \ubd84\ub9ac\uc2dc\ud0b5\ub2c8\ub2e4.
Use threads to separate the chat typing process from the screen output.<\/p>\n\n\n\n
Thread receiveThread = new Thread(() -> {\n\n try (BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()))) {\n String serverResponse;\n\n while ((serverResponse = in.readLine()) != null) {\n \/\/ ANSI \uc774\uc2a4\ucf00\uc774\ud504 \ucf54\ub4dc \ud2b8\ub9ad \/ ANSI Escape Code Trick\n \/\/ \\r: \ucee4\uc11c\ub97c \uc904 \ub9e8 \uc55e\uc73c\ub85c \uc774\ub3d9 \/ Move cursor to start of line\n \/\/ \\033[K: \ud604\uc7ac \ucee4\uc11c\uac00 \uc788\ub294 \uc904 \uc9c0\uc6b0\uae30 \/ Clear current line\n System.out.print(\"\\r\\033[K\"); \n \n \/\/ \uc11c\ubc84 \uba54\uc2dc\uc9c0 \ucd9c\ub825 \/ Print server message\n System.out.println(\"[\uc11c\ubc84 \uc751\ub2f5 \/ Server Response]: \" + serverResponse);\n \n \/\/ \uc9c0\uc6cc\uc9c4 \uc785\ub825 \ud504\ub86c\ud504\ud2b8\ub97c \ub9e8 \uc544\ub798\uc5d0 \ub2e4\uc2dc \ubcf5\uad6c\n \/\/ Restore the cleared input prompt at the bottom\n System.out.print(\"\ubcf4\ub0bc \uba54\uc2dc\uc9c0 \/ Send message: \");\n System.out.flush();\n }\n \n } catch (IOException e) {\n System.out.println(\"\\n\uc218\uc2e0 \uc2a4\ub808\ub4dc \uc885\ub8cc \/ Receive thread terminated.\");\n }\n\n });\n receiveThread.start();<\/code><\/pre>\n\n\n\n1)\uc11c\ubc84\ub85c \ubd80\ud130 \uba54\uc138\uc9c0\ub97c \uc2e4\uc2dc\uac04\uc73c\ub85c \ubc1b\ub294 \uc2a4\ub808\ub4dc\uc785\ub2c8\ub2e4.
This is a thread that receives messages from the server in real time.<\/p>\n\n\n\n
2)\uc2a4\ub808\ub4dc\ub85c \ubd84\ub9ac\uc2dc\ud0a4\uc9c0 \uc54a\uc73c\uba74 \ud654\uba74\uc774 \uc0ac\uc6a9\uc790 \uc785\ub825\ub9cc \ubc1b\ub294 \ubd80\ubd84\uc5d0\uc11c \uba48\ucdb0\uc838 \uc788\uc2b5\ub2c8\ub2e4.
If you don’t separate it into a thread, the screen freezes while waiting for user input.<\/p>\n\n\n\n
3) \uc544\ub798\uc758 \ucf54\ub4dc\ub294 \ud574\ub2f9\ucee4\uc11c\uac00\uc704\uce58\ud55c \uc904\uc744 \uc0ad\uc81c\ud558\uace0 \ucee4\uc11c\ub97c \uac00\uc7a5 \uc67c\ucabd\uc73c\ub85c \uc62e\uae41\ub2c8\ub2e4.
The code below deletes the line where the cursor is currently located and moves the cursor to the far left.<\/p>\n\n\n\n
System.out.print(\"\\r\\033[K\"); <\/code><\/pre>\n\n\n\n4)\uc704\uc758 ANSI \uc774\uc2a4\ucf00\uc774\ud504 \ucf54\ub4dc \ud2b8\ub9ad\uc774 \ud544\uc694\ud55c \uc774\uc720\ub294 \uc774 \ucc44\ud305 \ud074\ub77c\uc774\uc5b8\ud2b8\uc5d0\uc11c \ud654\uba74\uc5d0 “\ubcf4\ub0bc \uba54\uc2dc\uc9c0 \/ Send message:” \ucd9c\ub825\ud558\ub294 \ubd80\ubd84\uc774 \ub450\uad70\ub370 \uc788\uc2b5\ub2c8\ub2e4.
The reason the ANSI escape code trick mentioned above is necessary is that this chat client outputs the text “Send message:” to the screen in two different places.<\/p>\n\n\n\n
5)\uc11c\ubc84\uc5d0\uc11c \uba54\uc138\uc9c0\uac00 \ub3c4\ucc29\ud558\uba74 “\ubcf4\ub0bc \uba54\uc2dc\uc9c0 \/ Send message:”\uac00 \ud654\uba74\uc5d0 \ucd9c\ub825\ub418\uace0 \ub0b4\uac00 \ucc44\ud305\ubb38\uc790\ub97c \uc785\ub825\ud558\uace0 \uc5d4\ud130\uce58\uba74 “\ubcf4\ub0bc \uba54\uc2dc\uc9c0 \/ Send message:”\uac00 \ub610 \ucd9c\ub825\ub429\ub2c8\ub2e4.
When a message arrives from the server, “Send message:” is displayed on the screen; after I type a chat message and press Enter, “Send message:” appears again.<\/p>\n\n\n\n
6)\uadf8\ub798\uc11c \uc704\uc758 \ucf54\ub4dc\uc5d0\uc11c\uc640 \uba54\uc778\uc2a4\ub808\ub4dc\uc5d0\uc11c System.out.print(“\\r\\033[K\ubcf4\ub0bc \uba54\uc2dc\uc9c0 \/ Send message: “); \uc774 \ucf54\ub4dc\ub294 \ud654\uba74\uc5d0 \uc911\ubcf5\ub418\ub294 \ubb38\uc790\uac00 \ubc1c\uc0dd\ud558\uc9c0 \uc54a\uac8c \uc815\ub9ac\ud558\ub294 \uc5ed\ud560\uc744 \ud569\ub2c8\ub2e4.
Therefore, in the code above, the line System.out.print(\"\\r\\033[K\ubcf4\ub0bc \uba54\uc2dc\uc9c0 \/ Send message: \");<\/code> executed on the main thread serves to ensure that duplicate characters do not appear on the screen.<\/p>\n\n\n\n7)\ub2e4\uc74c\ucf54\ub4dc\ub294 \uc5d4\ud130\uc785\ub825\uc774 \uc5c6\uc5b4\ub3c4 \ubc84\ud37c\uc5d0 \uc800\uc7a5\ub418\uc5b4 \uc788\ub294 \ubb38\uc790\ub97c \ud654\uba74\uc5d0 \ud45c\uc2dc\ud558\ub77c\ub294 \uc758\ubbf8\uc785\ub2c8\ub2e4
The following code instructs the system to display the characters stored in the buffer on the screen without requiring the Enter key to be pressed.<\/p>\n\n\n\n
System.out.flush();<\/code><\/pre>\n\n\n\n— \uba54\uc778\uc2a4\ub808\ub4dc\ub85c \uc0ac\uc6a9\uc790\uc758 \uc785\ub825\uc744 \ubc1b\uc544\uc11c \uc11c\ubc84\ub85c \uc804\uc1a1\ud569\ub2c8\ub2e4.
The main thread receives user input and transmits it to the server.<\/p>\n\n\n\n
try (\n PrintWriter out = new PrintWriter(socket.getOutputStream(), true);\n Scanner scanner = new Scanner(System.in)\n ) {\n while (true) {\n String userInput = scanner.nextLine();\n \n if (\"exit\".equalsIgnoreCase(userInput)) {\n break;\n }\n out.println(userInput);\n \n \/\/ \ub0b4\uac00 \uc5d4\ud130\ub97c \ucce4\uc744 \ub54c \ud654\uba74\uc5d0 \ub0a8\uc544\uc788\ub294 \ud504\ub86c\ud504\ud2b8\ub97c \uc9c0\uc6b0\uace0 \ub2e4\uc2dc \uae54\ub054\ud558\uac8c \ucd9c\ub825\ud558\uac8c \ub9cc\ub4e6\n \/\/ Clears the lingering prompt when Enter is pressed and cleanly reprints it\n System.out.print(\"\\r\\033[K\ubcf4\ub0bc \uba54\uc2dc\uc9c0 \/ Send message: \");\n System.out.flush();\n }\n }<\/code><\/pre>\n\n\n\n1)\ub370\uc774\ud130\ub97c \uc11c\ubc84\ub85c \ubcf4\ub0bc \uc218 \uc788\ub294 \uae30\ubcf8\uc801\uc778 ‘\ub124\ud2b8\uc6cc\ud06c \ucd9c\ub825 \ud1b5\ub85c(\uc2a4\ud2b8\ub9bc)’\ub97c \uc18c\ucf13\uc73c\ub85c\ubd80\ud130 \uc5bb\uc5b4\uc635\ub2c8\ub2e4.
You obtain a basic ‘network output channel (stream)’ from the socket that allows you to send data to the server.<\/p>\n\n\n\n
PrintWriter out = new PrintWriter(socket.getOutputStream(), true);<\/code><\/pre>\n\n\n\n1) \uc0ac\uc6a9\uc790\uc758 \ud0a4\ubcf4\ub4dc \uc785\ub825\uc744 \ubc1b\uc744 \uc2a4\uce90\ub108\ub97c \uc900\ube44\ud569\ub2c8\ub2e4.
Prepare a scanner to receive keyboard input from the user.<\/p>\n\n\n\n
Scanner scanner = new Scanner(System.in);<\/code><\/pre>\n\n\n\n2)while(true){ … }\ub294 \ub8e8\ud504\ubb38\uc744 \ubb34\ud55c \ubc18\ubcf5\ud558\uba74\uc11c \ub8e8\ud504 \ube14\ub85d\uc744 \uacc4\uc18d \uc2e4\ud589\ud569\ub2c8\ub2e4.
while(true){ ... }<\/code> repeatedly executes the loop block in an infinite loop.<\/p>\n\n\n\n3)\uc0ac\uc6a9\uc790\uac00 \uae00\uc790 \uc785\ub825\ud6c4 \uc5d4\ud130\ub97c \ub204\ub974\uba74 userInput\ubcc0\uc218\uc5d0 \uac12\uc744 \ub2f4\uace0 \ub2e4\uc74c\uc904\ub85c \ub118\uc5b4\uac11\ub2c8\ub2e4.
When the user presses Enter after typing, the value is stored in the userInput<\/code> variable, and the cursor moves to the next line.<\/p>\n\n\n\nString userInput = scanner.nextLine();<\/code><\/pre>\n\n\n\n4)\uc2e4\uc81c \uc18c\ucf13\uc744 \ud1b5\ud574 \ub124\ud2b8\uc6cc\ud06c\ub85c \ub370\uc774\ud130\ub97c \uc804\ub2ec\ud569\ub2c8\ub2e4.
It transmits data over the network via an actual socket.<\/p>\n\n\n\n
out.println(userInput);<\/code><\/pre>\n\n\n\n5)exit\ub97c \uc785\ub825\ud558\uba74 \ub8e8\ud504 \uad6c\ubb38\uc744 \ube60\uc838\ub098\uac11\ub2c8\ub2e4.
Entering ‘exit’ exits the loop.<\/p>\n\n\n\n
if (\"exit\".equalsIgnoreCase(userInput)) { break; }<\/code><\/pre>\n\n\n\n<\/p>\n","protected":false},"excerpt":{"rendered":"
\ud83d\udc49\ud83c\udffb \ucf54\ub4dc \uc124\uba85 \/ Code Explanation \u2714\ufe0f Client.java — nodejs \uc11c\ubc84\ub791 \ud638\uc2a4\ud2b8\uc640 \ud3ec\ud2b8\ub97c \ub3d9\uc77c\ud558\uac8c \ub9de\ucda5\ub2c8\ub2e4.Match the host and port to those of the Node.js server. — \uc2a4\ub808\ub4dc\ub97c \uc0ac\uc6a9\ud558\uc5ec \ucc44\ud305 \ud0c0\uc774\ud551\uacfc \ud654\uba74\uc5d0 \ucd9c\ub825\ud558\ub294 \ubd80\ubd84\uc744 \ubd84\ub9ac\uc2dc\ud0b5\ub2c8\ub2e4.Use threads to separate the chat typing process from the screen output. 1)\uc11c\ubc84\ub85c \ubd80\ud130 \uba54\uc138\uc9c0\ub97c \uc2e4\uc2dc\uac04\uc73c\ub85c \ubc1b\ub294 \uc2a4\ub808\ub4dc\uc785\ub2c8\ub2e4.This is a thread that […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[9,1],"tags":[],"class_list":["post-6550","post","type-post","status-publish","format-standard","hentry","category-nodejs","category-uncategorized","missing-thumbnail"],"_links":{"self":[{"href":"https:\/\/www.freelifemakers.org\/wordpress\/index.php\/wp-json\/wp\/v2\/posts\/6550","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.freelifemakers.org\/wordpress\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.freelifemakers.org\/wordpress\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.freelifemakers.org\/wordpress\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.freelifemakers.org\/wordpress\/index.php\/wp-json\/wp\/v2\/comments?post=6550"}],"version-history":[{"count":19,"href":"https:\/\/www.freelifemakers.org\/wordpress\/index.php\/wp-json\/wp\/v2\/posts\/6550\/revisions"}],"predecessor-version":[{"id":6572,"href":"https:\/\/www.freelifemakers.org\/wordpress\/index.php\/wp-json\/wp\/v2\/posts\/6550\/revisions\/6572"}],"wp:attachment":[{"href":"https:\/\/www.freelifemakers.org\/wordpress\/index.php\/wp-json\/wp\/v2\/media?parent=6550"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.freelifemakers.org\/wordpress\/index.php\/wp-json\/wp\/v2\/categories?post=6550"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.freelifemakers.org\/wordpress\/index.php\/wp-json\/wp\/v2\/tags?post=6550"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}