- [x] I have searched the [issues](https://github.com/apache/dubbo/issues) of this repository and believe that this is not a duplicate.
- [x] I have checked the [FAQ](https://github.com/apache/dubbo/blob/master/FAQ.md) of this repository and believe that this is not a duplicate.

### Environment

* Dubbo version: 2.7.3
* Operating System version: Mac
* Java version: 1.8

### Steps to reproduce this issue

1.  `org/apache/dubbo/registry/support/ProviderConsumerRegTable.java:65` Type 'ProviderInvokerWrapper<>' does not define hashCode(), but is used in a hashing data-structure.
2. Class overrides equals but not hashCode.
* org.apache.dubbo.config.AbstractConfig
* org.apache.dubbo.registry.support.ProviderInvokerWrapper
* org.apache.dubbo.remoting.buffer.AbstractChannelBuffer

Pls. provide [GitHub address] to reproduce this issue.

### Expected Result

Whether the above suggestions can be fixed or have other considerations

### Actual Result

Is it considered a bug? Will it fix?

}
    /**
     * Should be called after Config was fully initialized.
     * // FIXME: this method should be completely replaced by appendParameters
     *
     * @return
     * @see AbstractConfig#appendParameters(Map, Object, String)
     * <p>
     * Notice! This method should include all properties in the returning map, treat @Parameter differently compared to appendParameters.
     */
    public Map<String, String> getMetaData() {
        Map<String, String> metaData = new HashMap<>();
        Method[] methods = this.getClass().getMethods();
        for (Method method : methods) {
            try {
                String name = method.getName();
                if (MethodUtils.isMetaMethod(method)) {
                    String key;
                    Parameter parameter = method.getAnnotation(Parameter.class);
                    if (parameter != null && parameter.key().length() > 0 && parameter.useKeyAsProperty()) {
                        key = parameter.key();
                    } else {
                        key = calculateAttributeFromGetter(name);
                    }
                    
                    
                    if (method.getReturnType() == Object.class) {
                        metaData.put(key, null);
                        continue;
                    }