如何将两个数组列表组合为一个数组列表并将其传递给过程

Question

I need your help and assistant in combining two arraylists into a new arraylist to be passed to a procedure. Once the user selected certificates from Type A list, they will be stored in:

private List<String> selectedTypeACertificates = new ArrayList<String>();

And once the user selected certificates from Type B, they will be stored in:

private List<String> selectedTypeBCertificates = new ArrayList<String>();

Now in the procedure I need to pass only two String variables. One is the Staff Code and the other is the selectedTypes for both Types A & B.

CallableStatement callableStatement =
    connection.prepareCall("{call processCertificates(?, ?)}");

callableStatement.setInt(1, Staff_Code);
callableStatement.setString   (2, ); //I need to pass selectedTypeBCertificates & selectedTypeACertificates

Answer 1

You can add all elements from both lists to a newly created one, and then use a StringBuilder to build a string in order to pass it to the procedure:

List<String> selectedCertificates = new ArrayList<String>();
selectedCertificates.addAll(selectedTypeACertificates);
selectedCertificates.addAll(selectedTypeBCertificates);

StringBuilder sb = new StringBuilder();
for (String cert : selectedCertificates)
{
    sb.append(cert);
    sb.append("','");
}

String certificatesString = sb.toString();
if(!certificatesString.isEmpty()) {
    certificatesString = "'" + certificatesString.substring(0, certificatesString.lastIndexOf(",")) + "'";
}

The last couple of lines are there to remove the trailing comma. Of course you might need to change this if the procedure expects the string in a different format.