How to iterate map in a list best way

Question

The spring JDBC template returns me a list which looks like below:

[{CODE_C=CSC, DESC_C=CSC}, {CODE_C=PG1, DESC_C=PG1}] 

I want the above list to printed in jsp as below:

CSC-CSC
PG1-PG1

Can you tell me the best way to do this?

Answer 1

That appears to be a List of Maps.

Assume you've assigned it to a List<Map<?,?>> named rows:

for (Map<?,?> row : rows)
  out.format("%s-%s ",row.get("CODE_C"),row.get("DESC_C"));

Answer 2

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

for (Map<String, String> map : someList) {
    StringBuilder sb = new StringBuilder();
    for (String s : map.values()) {
        sb.append(s).append('-');
    }
    String result = sb.toString();
    results.add(result.substring(0, result.length() - 1); // To cut the trailing '-'
}
// Do whatever with the results.

Answer 3

<c:forEach var="map" items="${list_with_maps_inside}">
  ${map['CODE_C']} ${map['DESC_C']}
</c:forEach>

Answer 4

Although not really your question, I think it is best to use a Mapper to retrieve the results. If you do so, you will get a list of objects, which you can easily iterate using a for-loop.

Example from http://static.springsource.org/spring/docs/2.0.x/reference/jdbc.html:

public Collection findAllActors() {
    return this.jdbcTemplate.query( "select first_name, surname from t_actor", new ActorMapper());
}

private static final class ActorMapper implements RowMapper {

    public Object mapRow(ResultSet rs, int rowNum) throws SQLException {
        Actor actor = new Actor();
        actor.setFirstName(rs.getString("first_name"));
        actor.setSurname(rs.getString("surname"));
        return actor;
    }
}

Answer 5

${map['CODE_C']} ${map['DESC_C']}

is not working