java - 多种方法或一种(但很长)方法

Question

我正在做一个学校项目，其中包含客户端服务器游戏。

Java 代码可以像示例 1 和示例 2 中演示的那样编写:

在示例 2 中，我看到可以通过创建 3 个私有(private)方法并在构造函数内调用它们来缩短构造函数(恕我直言，这看起来更简洁)。

哪个示例是 Java 中的最佳实践/推荐？

示例 1:

public ServerConnection()
{
    private Socket serverSocket = null;
    private SSLSocket sslServerSocket = null;

    private DataOutputStream dos;
    private DataInputStream dis;
    private ObjectOutputStream oos;
    private ObjectInputStream ois;

    private DataOutputStream ssldos;
    private DataInputStream ssldis;
    private ObjectOutputStream ssloos;
    private ObjectInputStream sslois;

    try
    {
        serverSocket = new Socket("localhost", 9000);

        String password = "password";

        KeyStore trustStore = KeyStore.getInstance("JKS");
        trustStore.load(ClassLoader.getSystemResourceAsStream("SSL/mykey.jks"), password.toCharArray());
        TrustManagerFactory trustManagerFactory = TrustManagerFactory.getInstance("SunX509");
        trustManagerFactory.init(trustStore);

        SSLContext context = SSLContext.getInstance("TLS");
        context.init(null, trustManagerFactory.getTrustManagers(), new SecureRandom());

        SSLSocketFactory sslSocketFactory = (SSLSocketFactory)context.getSocketFactory();
        sslServerSocket = (SSLSocket) sslSocketFactory.createSocket("localhost", 9001);

        sslServerSocket.startHandshake();


        dos = new DataOutputStream(serverSocket.getOutputStream());
        dis = new DataInputStream(serverSocket.getInputStream()); 
        oos = new ObjectOutputStream(serverSocket.getOutputStream());
        ois = new ObjectInputStream(serverSocket.getInputStream()); 

        ssldos = new DataOutputStream(sslServerSocket.getOutputStream()); 
        ssldis = new DataInputStream(sslServerSocket.getInputStream()); 
        ssloos = new ObjectOutputStream(sslServerSocket.getOutputStream()); 
        sslois = new ObjectInputStream(sslServerSocket.getInputStream()); 

    }
    catch (IOException | KeyStoreException | NoSuchAlgorithmException | CertificateException | KeyManagementException e)
    {
        System.out.println("ServerConnection 2 " + e.getMessage());
    }
}

示例 2:

public ServerConnection()
{
    private Socket serverSocket = null;
    private SSLSocket sslServerSocket = null;

    private DataOutputStream dos;
    private DataInputStream dis;
    private ObjectOutputStream oos;
    private ObjectInputStream ois;

    private DataOutputStream ssldos;
    private DataInputStream ssldis;
    private ObjectOutputStream ssloos;
    private ObjectInputStream sslois;

    try
    {
        serverSocket = new Socket("localhost", 9000);

        keyMethod();           

        SSLContext context = SSLContext.getInstance("TLS");
        context.init(null, trustManagerFactory.getTrustManagers(), new SecureRandom());           
        SSLSocketFactory sslSocketFactory = (SSLSocketFactory)context.getSocketFactory();
        sslServerSocket = (SSLSocket) sslSocketFactory.createSocket("localhost", 9001);  
        sslServerSocket.startHandshake();

        setStreams();

        setSSLStreams();            
    }
    catch (IOException | KeyStoreException | NoSuchAlgorithmException | CertificateException | KeyManagementException e)
    {
        System.out.println("ServerConnection 2 " + e.getMessage());
    }

    private void keyMethod()
    {
        String password = "password";
        KeyStore trustStore = KeyStore.getInstance("JKS");
        trustStore.load(ClassLoader.getSystemResourceAsStream("SSL/mykey.jks"), password.toCharArray());
        TrustManagerFactory trustManagerFactory = TrustManagerFactory.getInstance("SunX509");
        trustManagerFactory.init(trustStore);
    }

    private void setStreams()
    {
        dos = new DataOutputStream(serverSocket.getOutputStream());
        dis = new DataInputStream(serverSocket.getInputStream()); 
        oos = new ObjectOutputStream(serverSocket.getOutputStream());
        ois = new ObjectInputStream(serverSocket.getInputStream()); 
    }

    private void setSSLStreams()
    {
        ssldos = new DataOutputStream(sslServerSocket.getOutputStream()); 
        ssldis = new DataInputStream(sslServerSocket.getInputStream()); 
        ssloos = new ObjectOutputStream(sslServerSocket.getOutputStream()); 
        sslois = new ObjectInputStream(sslServerSocket.getInputStream());  
    }
}

Answer 1

示例 2 将是您的最佳选择，因为它遵循最佳实践指南，更易于阅读，进而使您的代码更加清晰。将代码片段转换为一个方法(其名称解释了该方法的用途)也是理想的选择。您需要简短且命名良好的方法有几个原因:

1. 首先，当方法细粒度时，它增加了其他方法可以使用该方法的机会。

2. 其次，它允许更高级别的方法更像一系列注释。当方法细粒度时，覆盖也更容易。

以 Martin Fowler 在他的博客上给出的例子:

代码碎片:

void printOwing() {
  printBanner();

  //print details
  System.out.println ("name:  " + _name);
  System.out.println ("amount " + getOutstanding());
}

重构代码:

void printOwing() {
  printBanner();
  printDetails(getOutstanding());
}

void printDetails (double outstanding) {
  System.out.println ("name:  " + _name);
  System.out.println ("amount " + outstanding);
}

这还可以帮助其他可能查看您代码的人快速了解发生了什么。

您可以查看 Fowler 先生的更多博客:Refactoring 。另请参阅SourceMaking关于为什么应该提取方法的博客。