In Java 8 or later:

String listString = String.join(", ", list);

In case the list is not of type String, a joining collector can be used:

String listString = list.stream().map(Object::toString)
                        .collect(Collectors.joining(", "));

List<String> list = ..;
String[] array = list.toArray(new String[0]);

For example:

List<String> list = new ArrayList<String>();
//add some stuff
list.add("android");
list.add("apple");
String[] stringArray = list.toArray(new String[0]);

The toArray() method without passing any argument returns Object[]. So you have to pass an array as an argument, which will be filled with the data from the list, and returned. You can pass an empty array as well, but you can also pass an array with the desired size.

Important update: Originally the code above used new String[list.size()]. However, this blogpost reveals that due to JVM optimizations, using new String[0] is better now.

Use like this.

List<String> stockList = new ArrayList<String>();
stockList.add("stock1");
stockList.add("stock2");

String[] stockArr = new String[stockList.size()];
stockArr = stockList.toArray(stockArr);

for(String s : stockArr)
    System.out.println(s);

First of all, this is more a use case for a map, where your code is the key and the string is the value. See http://docs.oracle.com/javase/7/docs/api/java/util/Map.html.

Map<Integer, String> map = new HashMap<Integer, String>();
map.put(1, "string1");
map.put(2, "string2");
map.get(1)
...

Second approach is to create a new object holding the code as an Integer and the String, like

public class StringHolder {
int code;
String string;

// constructor
// setter and getter
}

then use a for-each loop to iterate trough your array list and compare the code of the object with the given one.

Or, the rude, not recommended way: do some crazy string operations to figure out where your code is in the string. Acutally, do not do this.