Example usage for org.hibernate.hql.internal.classic ParserHelper HQL_VARIABLE_PREFIX

Introduction

In this page you can find the example usage for org.hibernate.hql.internal.classic ParserHelper HQL_VARIABLE_PREFIX.

Prototype

String HQL_VARIABLE_PREFIX

To view the source code for org.hibernate.hql.internal.classic ParserHelper HQL_VARIABLE_PREFIX.

Click Source Link

Usage

From source file:com.blazebit.persistence.integration.hibernate.Hibernate43Access.java

License:Apache License

private String expandParameterList(SessionImplementor session, ParameterMetadata parameterMetadata,
        String query, String name, TypedValue typedList, Map<String, TypedValue> namedParamsCopy) {
    Collection<?> vals = (Collection<?>) typedList.getValue();

    // HHH-1123/*from  w ww.  j a v  a2s. co  m*/
    // Some DBs limit number of IN expressions.  For now, warn...
    final Dialect dialect = session.getFactory().getDialect();
    final int inExprLimit = dialect.getInExpressionCountLimit();
    if (inExprLimit > 0 && vals.size() > inExprLimit) {
        LOG.warning(String.format(
                "Dialect [%s] limits the number of elements in an IN predicate to %s entries.  "
                        + "However, the given parameter list [%s] contained %s entries, which will likely cause failures "
                        + "to execute the query in the database",
                dialect.getClass().getName(), inExprLimit, name, vals.size()));
    }

    Type type = typedList.getType();

    boolean isJpaPositionalParam = parameterMetadata.getNamedParameterDescriptor(name).isJpaStyle();
    String paramPrefix = isJpaPositionalParam ? "?" : ParserHelper.HQL_VARIABLE_PREFIX;
    String placeholder = new StringBuilder(paramPrefix.length() + name.length()).append(paramPrefix)
            .append(name).toString();

    if (query == null) {
        return query;
    }
    int loc = query.indexOf(placeholder);

    if (loc < 0) {
        return query;
    }

    String beforePlaceholder = query.substring(0, loc);
    String afterPlaceholder = query.substring(loc + placeholder.length());

    // check if placeholder is already immediately enclosed in parentheses
    // (ignoring whitespace)
    boolean isEnclosedInParens = StringHelper.getLastNonWhitespaceCharacter(beforePlaceholder) == '('
            && StringHelper.getFirstNonWhitespaceCharacter(afterPlaceholder) == ')';

    if (vals.size() == 1 && isEnclosedInParens) {
        // short-circuit for performance when only 1 value and the
        // placeholder is already enclosed in parentheses...
        namedParamsCopy.put(name, new TypedValue(type, vals.iterator().next()));
        return query;
    }

    StringBuilder list = new StringBuilder(16);
    Iterator<?> iter = vals.iterator();
    int i = 0;
    while (iter.hasNext()) {
        // Variable 'name' can represent a number or contain digit at the end. Surrounding it with
        // characters to avoid ambiguous definition after concatenating value of 'i' counter.
        String alias = (isJpaPositionalParam ? 'x' + name : name) + '_' + i++ + '_';
        if (namedParamsCopy.put(alias, new TypedValue(type, iter.next())) != null) {
            throw new HibernateException(
                    "Repeated usage of alias '" + alias + "' while expanding list parameter.");
        }
        list.append(ParserHelper.HQL_VARIABLE_PREFIX).append(alias);
        if (iter.hasNext()) {
            list.append(", ");
        }
    }
    return StringHelper.replace(beforePlaceholder, afterPlaceholder, placeholder.toString(), list.toString(),
            true, true);
}

---