public String resolvePlaceholders(String str) {
        return ConfigUtils.replaceProperty(str, getConfiguration());
    }
@Test
    void testResolvePlaceholders() {
        Environment environment = ApplicationModel.defaultModel().modelEnvironment();

        Map<String, String> externalMap = new LinkedHashMap<>();
        externalMap.put("zookeeper.address", "127.0.0.1");
        externalMap.put("zookeeper.port", "2181");
        environment.updateAppExternalConfigMap(externalMap);

        Map<String, String> sysprops = new LinkedHashMap<>();
        sysprops.put("zookeeper.address", "192.168.10.1");
        System.getProperties().putAll(sysprops);

        try {
            String s = environment.resolvePlaceholders("zookeeper://${zookeeper.address}:${zookeeper.port}");
            assertEquals("zookeeper://192.168.10.1:2181", s);
        } finally {
            for (String key : sysprops.keySet()) {
                System.clearProperty(key);
            }
        }
    }