springboot中RestTemplate 的getForObject 報錯ClassCastException錯誤

1、getForObject的定義如下：

    public <T> T getForObject(URI url, Class<T> responseType) throws RestClientException {
        RequestCallback requestCallback = this.acceptHeaderRequestCallback(responseType);
        HttpMessageConverterExtractor<T> responseExtractor = new HttpMessageConverterExtractor(responseType, this.getMessageConverters(), this.logger);
        return this.execute(url, HttpMethod.GET, requestCallback, responseExtractor);
    }

當responseType的泛型T中包含 List 的時候，結果無法轉換成 List，這時候便會包ClassCastException 錯誤

 

2、解決方案

使用 exchange() 方法代替 getForObject

示例：RegulateCommand 為帶有 List 的類

RegulateCommand regulateCommandResult = restTemplate.exchange(customConfig.getBaseUrl() + "/sws/regulate_pressure/executing",
                HttpMethod.GET,
                null,
                new ParameterizedTypeReference<RegulateCommand>() {}).getBody();