Question

I have an hashmap declared as
private HashMap testMessages = null;

I will be storing string values in both key and value part of the hashmap retrieved from oracle table.

I am not concerned about the hashmap keys. I want to retrieve the hashmap values alone and check whether string variable filename is prefixed with one of the hash map value and return true if it’s same. I want to ensure that hash map values are not null and empty.

function (string filename)
{..

loop thru hashmap values

check whether the variable file name is prefixed with one of the hashmap values if so
return true
otherwise
return false
}

hashmap example:
key1,prod
key2,test
key3,dummy
filename example:
test123_20012010.csv

should return true since the file name is prefixed with one of the hashmap values

How can i do it?

Answer 1

Here’s a brute force approach to iterate over the hash map values and check whether filename begins with the value.

// generics version
private HashMap<String, String> testMessages = buildMap();

for (String v : testMessages.values()) {
  if (filename.startsWith(v) {
    // found a map value that starts the file name
  }
}

// alternative non-generics version
private HashMap testMessages; // assigned somewhere

for (Object v : testMessages.values()) {
  if (filename.startsWith((String) v) {
    // found a map value that starts the file name
  }
}