如何自定義compareTo方法同時考慮方向流動

Question

，如果我需要自定義代碼才能使用這個邏輯

if this.srcAddr=other.srcAddr or 
this.src.Addr = other.sdstAddr 
this.srcPort=other.srcPort 
this.srcPort=other.dstPort 

，因爲我要考慮的雙向流動，從源數據包的目的地和分組從目的地到源頭屬於一個流程。

我該如何更改我的代碼？

package myclassifier; 
public class Flows implements Comparable<Flows> { 

    String srcAddr, dstAddr, srcPort, dstPort, protocol; 

    public Flows(String sIP, String dIP){ 
     this.srcAddr = sIP; 
     this.dstAddr = dIP; 
    } 

    public int compareTo(Flows other) { 
      int res = (this.srcAddr.compareTo(other.srcAddr)); 
      if (res != 0) { 
       return res; 
      } 
      res = this.dstAddr.compareTo(other.dstAddr); 
      if (res != 0) { 
       return res; 
      } 
      res = this.srcPort.compareTo(other.srcPort); 
      if (res != 0) { 
       return res; 
      } 
      res = this.dstPort.compareTo(other.dstPort); 
      if (res != 0) { 
       return res; 
      } 
      return this.protocol.compareTo(other.protocol); 
    } 

    @Override 
    public int hashCode() { 

     final int prime = 31; 
     int result = 1; 
     result = prime * result + ((dstAddr == null) ? 0 : dstAddr.hashCode()); 
     result = prime * result + ((dstPort == null) ? 0 : dstPort.hashCode()); 
     result = prime * result + ((srcAddr == null) ? 0 : srcAddr.hashCode()); 
     result = prime * result + ((srcPort == null) ? 0 : srcPort.hashCode()); 
     return result; 

    } 

    @Override 
    public boolean equals(Object obj) { 
     if (this == obj) 
      return true; 
     if (obj == null) 
      return false; 

     if (getClass() != obj.getClass()) 
      return false; 

     Flows other = (Flows) obj; 

     if (dstAddr == null) { 
      if (other.dstAddr != null) 
       return false; 
     } else if (!dstAddr.equals(other.dstAddr)) 
      return false; 

     if (dstPort == null) { 
      if (other.dstPort != null) 
       return false; 
     } else if (!dstPort.equals(other.dstPort)) 
      return false; 

     if (srcAddr == null) { 
      if (other.srcAddr != null) 
       return false; 
     } else if (!srcAddr.equals(other.srcAddr)) 
      return false; 

     if (srcPort == null) { 
      if (other.srcPort != null) 
       return false; 
     } else if (!srcPort.equals(other.srcPort)) 
      return false; 

     return true; 
    } 

} 

Answer 1

只是一個猜測，但我認爲你要尋找的是沿着以下線的東西（空檢查，類型檢查和錯誤處理作爲練習留給用戶）：

return ((this.srcAddr.equals(other.srcAddr) && this.srcPort.equals(other.srcPort) || 
     (this.srcAddr.equals(other.dstAddr) && this.srcPort.equals(other.dstPort)); 

請注意，這是基於以下假設：從機器1端口b到機器2端口a的連接與從機器1端口a到機器2端口b的連接不相同。

Answer 2

您可以大大簡化compareTo方法。你只是比較字符串，如果你只是連接所有的字符串和一個單一的比較，你會得到相同的結果。下面的示例添加一個toString（）實現作爲獎金：

@Override 
public String toString() { 
    return String.format("[%s, %s, %s, %s, %s]", srcAddr, dstAddr, srcPort, dstPort, protocol); 
} 

public int compareTo(Flows other) { 
    if (other == null) 
    return 0; // the necessary null check was missing in your code 

    return toString().compareTo(other.toString()); 
} 

如果您需要更多的性能，可以考慮構建連接字符串，而你構建一個流並將其存儲在私有字段。