無法初始化線程構造函數中的PrintWriter字段

需要爲每個連接創建一個新線程。線程應該有函數寫入套接字，即使它在run（）等待客戶端輸入：String clientCommand = in.readLine()。函數update應該符合此要求，並且能夠使用PrintWriter outWr寫入套接字，但它似乎是null，即使將它設置爲線程構造函數。無法在構造函數中初始化PrintWriter outWr。在try之後建造outWr仍然是null。如何解決它？無法初始化線程構造函數中的PrintWriter字段

public class Server { 
    public static void main(String[] args) { 
     ... 
     ClientServiceThread cliThread = new ClientServiceThread(clientSocket, id++, auction); 
     ... 
}

public class ClientServiceThread extends Thread { 
private PrintWriter outWr; 

ClientServiceThread(Socket s, int clientID, Auction a) { 
     try { 
      PrintWriter outWr = new PrintWriter(new OutputStreamWriter(
        m_clientSocket.getOutputStream())); 
     } catch (IOException e) { 
      e.printStackTrace(); 
     } 
    } 
public void run() {....; String clientCommand = in.readLine(); ... } 
public void update(String msg){outWr.println(msg);}

來源

2012-06-02 J.Olufsen

看看這段代碼

public class ClientServiceThread extends Thread { 
private PrintWriter outWr; 

ClientServiceThread(Socket s, int clientID, Auction a) { 
     try { 
      PrintWriter outWr = new PrintWriter(new OutputStreamWriter(

在構造函數中你沒有一流的領域，但本地參考PrintWriter outWr

更改它初始化爲

 try { 
      outWr = new PrintWriter(new OutputStreamWriter(

來源

2012-06-02 23:50:23 Pshemo

無法初始化線程構造函數中的PrintWriter字段

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