1. non-simplify mode:
```
dubbo://120.0.0.1:20880/org.apache.dubbo.demo.DemoService?key=value
```
the store path of ZK will be: `/dubbo/porg.apache.dubbo.demo.DemoService/url`

2. simplify mode:
```
dubbo://120.0.0.1:20880/org.apache.dubbo.demo.DemoService?key=value
```
the store path of ZK will be: `/dubbo/porg.apache.dubbo.demo.DemoService/url`

3. simplify mode with path specified:
```
dubbo://120.0.0.1:20880/path-value?key=value
```
the store path of ZK will be: `/dubbo/path-value/url`
class URL implements Serializable {
    private static final long serialVersionUID = -1985165475234910535L;
    private final String protocol;
    private final String username;
    private final String password;
    
    private final String host;
    
    private final int port;
    private final String path;
    private final Map<String, String> parameters;
    
    private volatile transient Map<String, Number> numbers;
    private volatile transient Map<String, URL> urls;
    private volatile transient String ip;
    private volatile transient String full;
    private volatile transient String identity;
    private volatile transient String parameter;
    private volatile transient String string;
    protected URL() {
        this.protocol = null;
        this.username = null;
        this.password = null;