[英]Passing generic classes and objects to a Java method
我想用泛型替换以下内容:
for (Post post : postResponse.getResults()) {
,其中Post
可以是任何POJO。 List<Post> posts = postResponse.getResults();
其中List<Post>
可以是我传入的所有内容的列表。 我的方法调用和方法主体是什么样的?
方法调用的不同示例:
retrieveData(mCardAdapter, new Post(), Post.class);
retrieveData(mCardAdapter, new Contact(), Contact.class);
retrieveData(mCardAdapter, new Product(), Product.class);
retrieveData(mCardAdapter, new Booking(), Booking.class);
方法:
private void retrieveData(final CardAdapter mCardAdapter, final Object<T> postObject, Class<T> postClass) {
RetrofitService service = ServiceFactory.createRetrofitService(RetrofitService.class, RetrofitService.SERVICE_ENDPOINT);
service.getPosts()
.subscribeOn(Schedulers.newThread())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(new Subscriber<PostResponse>() {
@Override
public final void onCompleted() {
setRefreshingFalse();
Log.e("RetrofitService", "Retrofit Request Completed!");
}
@Override
public final void onError(Throwable e) {
setRefreshingFalse();
Log.e("RetrofitService", e.getMessage());
}
@Override
public final void onNext(PostResponse postResponse) {
if (postResponse != null) {
Log.e("RetrofitService", "Returned objects: " + postResponse.getResults());
for (postObject post : postResponse.getResults()) {
Log.e("RetrofitService", post.getObjectId() + ": " + post.getText());
}
setRefreshingFalse();
mCardAdapter.clear();
List<postClass> posts = postResponse.getResults();
mCardAdapter.addData(posts);
} else {
Log.e("RetrofitService", "Object returned is null.");
}
}
});
}
我正在获得Unknown class: 'tClass'
和Unknown class: 'postClass'
。 显然,这不是做到这一点的方法,因此也许将我上面显示的内容视为pseduo代码。 我要做什么有意义吗? 我真的想泛型化这个retrieveData
方法,以便我可以用于查询不同的类。
帮助理解。 我要避免的是:
retrievePosts(mCardAdapter);
retrieveUsers(mCardAdapter);
private void retrievePosts(final CardAdapter mCardAdapter) {
RetrofitService service = ServiceFactory.createRetrofitService(RetrofitService.class, RetrofitService.SERVICE_ENDPOINT);
service.getPosts()
.subscribeOn(Schedulers.newThread())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(new Subscriber<PostResponse>() {
@Override
public final void onCompleted() {
setRefreshingFalse();
Log.e("RetrofitService", "Retrofit Request Completed!");
}
@Override
public final void onError(Throwable e) {
setRefreshingFalse();
Log.e("RetrofitService", e.getMessage());
}
@Override
public final void onNext(PostResponse postResponse) {
if (postResponse != null) {
Log.e("RetrofitService", "Returned objects: " + postResponse.getResults());
for (Post post : postResponse.getResults()) {
Log.e("RetrofitService", post.getObjectId() + ": " + post.getText());
}
/*for (Post post : postResponse.getResults()) {
mCardAdapter.addData(post);
}*/
setRefreshingFalse();
mCardAdapter.clear();
List<Post> posts = postResponse.getResults();
mCardAdapter.addData(posts);
} else {
Log.e("RetrofitService", "Object returned is null.");
}
}
});
}
private void retrieveUsers(final CardAdapter mCardAdapter) {
RetrofitService service = ServiceFactory.createRetrofitService(RetrofitService.class, RetrofitService.SERVICE_ENDPOINT);
service.getUsers()
.subscribeOn(Schedulers.newThread())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(new Subscriber<PostResponse>() {
@Override
public final void onCompleted() {
setRefreshingFalse();
Log.e("RetrofitService", "Retrofit Request Completed!");
}
@Override
public final void onError(Throwable e) {
setRefreshingFalse();
Log.e("RetrofitService", e.getMessage());
}
@Override
public final void onNext(PostResponse postResponse) {
if (postResponse != null) {
Log.e("RetrofitService", "Returned objects: " + postResponse.getResults());
for (User user : userResponse.getResults()) {
Log.e("RetrofitService", user.getObjectId() + ": " + user.getText());
}
/*for (Post post : postResponse.getResults()) {
mCardAdapter.addData(post);
}*/
setRefreshingFalse();
mCardAdapter.clear();
List<User> users = userResponse.getResults();
mCardAdapter.addData(users);
} else {
Log.e("RetrofitService", "Object returned is null.");
}
}
});
}
如果我正确理解了您的问题,则希望对不同的类使用通用方法。 我没有看到您在列表中添加了某些内容,因此这可能对您有用。
private <clazz> void retrieveData(final Class<?> clazz) {
for (clazz post : postResponse.getResults()) {
// you can't do anything here since clazz can be anything
}
List<clazz> posts = postResponse.getResults();
}
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