private void getNotNullConstraintsInformation(StringBuilder constraintsInfo, NotNullConstraint constraint) {
    formatOutput("Table:", constraint.getDatabaseName() + "." + constraint.getTableName(), constraintsInfo);
    Map<String, String> notNullConstraints = constraint.getNotNullConstraints();
    if (MapUtils.isNotEmpty(notNullConstraints)) {
      for (Map.Entry<String, String> entry : notNullConstraints.entrySet()) {
        formatOutput("Constraint Name:", entry.getKey(), constraintsInfo);
        formatOutput("Column Name:", entry.getValue(), constraintsInfo);
        constraintsInfo.append(LINE_DELIM);
      }
    }
  }
Formats DESC TABLE results to text format.
ql/src/java/org/apache/hadoop/hive/ql/ddl/table/info/desc/formatter/TextDescTableFormatter.java