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`
}
        if (host != null) {
            map.put(Constants.HOST_KEY, host);
        }
        if (port > 0) {
            map.put(Constants.PORT_KEY, String.valueOf(port));
        }
        if (path != null) {
            map.put(Constants.PATH_KEY, path);
        }
        return map;
    }
    @Override
    public String toString() {
        if (string != null) {
            return string;
        }
        return string = buildString(false, true); 
    }
    public String toString(String... parameters) {
        return buildString(false, true, parameters); 
    }
    public String toIdentityString() {
        if (identity != null) {
            return identity;
        }
        return identity = buildString(true, false); 
    }
    public String toIdentityString(String... parameters) {
        return buildString(true, false, parameters);