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`
public int getPort() {
        return port;
    }
    public URL setPort(int port) {
        return new URL(protocol, username, password, host, port, path, getParameters());
    }
    public int getPort(int defaultPort) {
        return port <= 0 ? defaultPort : port;
    }
    public String getAddress() {
        return port <= 0 ? host : host + ":" + port;
    }
    public URL setAddress(String address) {
        int i = address.lastIndexOf(':');
        String host;
        int port = this.port;
        if (i >= 0) {
            host = address.substring(0, i);
            port = Integer.parseInt(address.substring(i + 1));
        } else {
            host = address;
        }
        return new URL(protocol, username, password, host, port, path, getParameters());
    }
    public String getBackupAddress() {
        return getBackupAddress(0);
    }
    public String getBackupAddress(int defaultPort) {
        StringBuilder address = new StringBuilder(appendDefaultPort(getAddress(), defaultPort));
        String[] backups = getParameter(Constants.BACKUP_KEY, new String[0]);