TCP_ECHO.rar_ECHO JAVA_echo server_java tcp server

import java.net.*; import java.io.*; public class TCP_ECHO { //ip位置 String hostname; //port number int portnumber; //client端的socket Socket clientSocket; //存放user輸入的字串 String sentence; //存放server回傳的字串 String modifiedSentence; //讓user輸入資料的buffer BufferedReader inFromUser; // DataOutputStream outToServer; //server傳過來的資料,所暫放的buffer BufferedReader inFromServer; TCP_ECHO() { hostname = "140.136.149.242"; portnumber = 7; } TCP_ECHO(String newHostname,int newPortnumber) { hostname = newHostname; portnumber = newPortnumber; } public void connectionstart()throws Exception { //此變數檢查輸入資料是否有'.' boolean end = false; try { //連結server clientSocket= new Socket(hostname,portnumber); } catch (Exception ex) { //如果連結錯誤,出現錯誤訊息 System.out.println("連結失敗 time out"); } //user開始輸入資料 userinput(); while(true) { //檢查user輸入的資料是否有'.',有的話end為true for(int i=0;i<sentence.length();i++) { if(sentence.charAt(i) == '.') { System.out.println("結束輸入"); //關閉socket clientSocket.close(); end = true; } } //如果end為false(代表輸入的字串沒有'.'字元),就繼續輸入 if(!end) { userinput(); } //否則跳出此迴圈(也代表tcp echo結束) else { break; } } } public void userinput()throws Exception { System.out.println("請輸入您想要輸入的文字"); //user輸入字串給inFromUser這個buffer inFromUser = new BufferedReader(new InputStreamReader(System.in)); //建立一個附屬於socket的output stream outToServer = new DataOutputStream(clientSocket.getOutputStream()); //建立一個input stream 將未來接收到的封包,放到inFormServer這個buffer inFromServer = new BufferedReader(new InputStreamReader(clientSocket.getInputStream())); //讀取inFromUser這個buffer的資料(一行) sentence = inFromUser.readLine(); //將sentence的字串 傳給server outToServer.writeBytes(sentence + "\n"); //將在inFromServer這個buffer 讀取字串 modifiedSentence = inFromServer.readLine(); //將server傳回的資料印出 System.out.println("FROM SERVER: " + modifiedSentence); } }