NO.94 RestTemplate.getForObject將PO中List的泛型變成LinkedHashMap問題的解決

我們有個PO，長這樣：

public class MyPO<T> implements java.io.Serializable{
	private List<T> data = new ArrayList<T>();
｝

結果用RestTemplate.getForObject 後，不管這個T是什麼，接收到都被轉化爲LinkedHashMap，造成ClassCastException。

上網查，在這篇找到關鍵信息（這是百度快照）：

http://cache.baiducontent.com/c?m=9d78d513d98316ee1efa950e4b4188244707c6342bd7a14028928449e3300601506793e6777a475595d27c165ff41505bda62173475973f6c197db08c9fcd27620d26172320b87320fce58e998177c9c64c71abdf144a2adf045c2f38dce9c13048b155e27dcb196500316c065fa112cb6f1c51f550441fbfa3013ba023173882336f705b9bb6e3b1081809d0b0d856c873e53c9fc73e7&p=8d6fc64ad4965bfa08e2977e0f5988&newp=c433c64ad48259eb08e2977e0f0e90231610db2151d3d201298ffe0cc4241a1a1a3aecbf26261a02d4c2766303ac4e56ecf43070350034f1f689df08d2ecce7e6e9063&user=baidu&fm=sc&query=resttemplate+getForObject++linkedhashmap&qid=da3603dd00003096&p1=1

You can refactor the code above to use exchange instead of postForObject, and use ParameterizedTypeReference to get a List<MyModelClass>.

For example:

ParameterizedTypeReference<List<MyModelClass>> typeRef = new ParameterizedTypeReference<List<MyModelClass>>() {
};
ResponseEntity<List<MyModelClass>> responseEntity = restTemplate.exchange(url, HttpMethod.POST, new HttpEntity<>(mvm), typeRef);
List<MyModelClass> myModelClasses = responseEntity.getBody();

結果使用RestTemplate.exchange 代替getForObject 後，問題確實解決了。