DefaultMBeanServerInterceptor.java 文件源码

/**
 * Applies the specified queries to the set of ObjectInstances.
 */
private Set<ObjectInstance>
        filterListOfObjectInstances(Set<ObjectInstance> list,
                                    QueryExp query) {
    // Null query.
    //
    if (query == null) {
        return list;
    } else {
        Set<ObjectInstance> result = new HashSet<ObjectInstance>();
        // Access the filter.
        //
        for (ObjectInstance oi : list) {
            boolean res = false;
            MBeanServer oldServer = QueryEval.getMBeanServer();
            query.setMBeanServer(server);
            try {
                res = query.apply(oi.getObjectName());
            } catch (Exception e) {
                res = false;
            } finally {
                /*
                 * query.setMBeanServer is probably
                 * QueryEval.setMBeanServer so put back the old
                 * value.  Since that method uses a ThreadLocal
                 * variable, this code is only needed for the
                 * unusual case where the user creates a custom
                 * QueryExp that calls a nested query on another
                 * MBeanServer.
                 */
                query.setMBeanServer(oldServer);
            }
            if (res) {
                result.add(oi);
            }
        }
        return result;
    }
}