Java - ajout d'éléments dans arraylist - Stack Overflow

Please consider the following code:

while(rs.next()){    
    String ipAddress = rs.getString("IP_vch");                    
    System.out.println("The value of ipAddress is:"+ipAddress); 
    MainConnection[i] = DriverManager.getConnection("jdbc:mysql://" + ipAddress + ":3306/test",RemoteUser,RemotePass); 
}// END Of WHILE (rs.next())  

I am defining an arraylist of String after the line System.out.println("The value of ipAddress is:"+ipAddress); as follows:

List AddressList = new ArrayList;

AddressList.add(ipAddress);

1. So, does above step will add all the values that are in the string variable ipAddress?




2. I want to establish connection in my next step something like as shown in above code as follows:

   MainConnection[i] = DriverManager.getConnection("jdbc:mysql://" + ipAddress + ":3306/test",RemoteUser,RemotePass);

For that I don't see nay put method in the ArrayList API description here.

yes. it will add all the values of arraylist ipAddress. use ipAddress.get(index) to access an ipaddress in a list.

I am not sure what is that you are trying to so. But if you are trying to store all the ip address in the list then you should define

List<String>  AddressList = new ArrayList<String>();

Outside your while loop and add ip address to list inside the loop. Defining ArrayList inside the loop is creating a new list for each iteration.

I would really expect something like this:

// Create array list
List<String> AddressList = new ArrayList<String>();

// Connect to database
Connection = 
  DriverManager.getConnection("jdbc:mysql://" +  ipAddress + ":3306/test",RemoteUser,RemotePass); 

// Make Query
...

// Fetch results and add them to the list
while(rs.next()){    
    String ipAddress = rs.getString("IP_vch");                    
    System.out.println("The value of ipAddress is:"+ipAddress); 
    AddressList.add(ipAddress);
    ...

List<String> addressList = new ArrayList<String>(); // will do it.. using Generics is always better.

Please consider the following code:

while(rs.next()){    
    String ipAddress = rs.getString("IP_vch");                    
    System.out.println("The value of ipAddress is:"+ipAddress); 
    MainConnection[i] = DriverManager.getConnection("jdbc:mysql://" + ipAddress + ":3306/test",RemoteUser,RemotePass); 
}// END Of WHILE (rs.next())  

I am defining an arraylist of String after the line System.out.println("The value of ipAddress is:"+ipAddress); as follows:

List AddressList = new ArrayList;

AddressList.add(ipAddress);

1. So, does above step will add all the values that are in the string variable ipAddress?




2. I want to establish connection in my next step something like as shown in above code as follows:

   MainConnection[i] = DriverManager.getConnection("jdbc:mysql://" + ipAddress + ":3306/test",RemoteUser,RemotePass);

For that I don't see nay put method in the ArrayList API description here.

yes. it will add all the values of arraylist ipAddress. use ipAddress.get(index) to access an ipaddress in a list.

I am not sure what is that you are trying to so. But if you are trying to store all the ip address in the list then you should define

List<String>  AddressList = new ArrayList<String>();

Outside your while loop and add ip address to list inside the loop. Defining ArrayList inside the loop is creating a new list for each iteration.

I would really expect something like this:

// Create array list
List<String> AddressList = new ArrayList<String>();

// Connect to database
Connection = 
  DriverManager.getConnection("jdbc:mysql://" +  ipAddress + ":3306/test",RemoteUser,RemotePass); 

// Make Query
...

// Fetch results and add them to the list
while(rs.next()){    
    String ipAddress = rs.getString("IP_vch");                    
    System.out.println("The value of ipAddress is:"+ipAddress); 
    AddressList.add(ipAddress);
    ...

List<String> addressList = new ArrayList<String>(); // will do it.. using Generics is always better.

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