import com.example.news.models.Posting;
import org.springframework.data.repository.CrudRepository;
import java.util.List;
public interface PostRepos extends CrudRepository<Posting, Long> {
List<Posting> findByTag(String tag);
}
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@PostMapping("find")
public String find(@RequestParam String find, Map<String, Object> model){
Iterable<Posting> posts;
if(find != null && find.isEmpty()) {
posts = postRepos.findByTag(find);
} else {
posts = postRepos.findAll();
}
model.put("posts",posts);
return "redirect:/newspage";
}
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<div th:fragment="head" xmlns:th="http://www.w3.org/1999/xhtml">
<div class="d-flex flex-column flex-md-row align-items-center p-3 px-md-4 mb-3 bg-white border-bottom shadow-sm">
<h5 class="my-0 mr-md-auto font-weight-normal">ASAP NEWS</h5>
<nav class="my-2 my-md-0 mr-md-3">
<a class="p-2 text-dark" href="/homepage">Main page</a>
<a class="p-2 text-dark" href="/newspage">News</a>
<a class="p-2 text-dark" href="/newspage/addpage">Add news</a>
<a class="p-2 text-dark" href="/aboutpage">About</a>
</nav>
<a>
<form method="post" action="find">
<label>
<input type="text" placeholder="Search" name="find">
</label>
<button type="submit">Find</button>
</form>
</a>
</div>
</div>