I'm trying to implement Spring caching in a Spring Boot RESTful service. This is the caching code for the getAllBlogs() and getBlogById() methods.
#Cacheable(value="allblogcache")
#Override
public List<Blog> getAllBlogs() {
System.out.println("******* "+ blogRepository.findAll().toString());
return (List<Blog>) blogRepository.findAll();
}
#Cacheable(value="blogcache", key = "#blogId")
#Override
public Blog getBlogById(int blogId) {
Blog retrievedBlog = null;
retrievedBlog = blogRepository.findById(blogId).get();
return retrievedBlog;
}
In the saveBlog method I want to evict the cache and have used the following code.
#Caching(evict = {
#CacheEvict(value="allblogcache"),
#CacheEvict(value="blogcache", key = "#blog.blogId")
})
#Override
public Blog saveBlog(Blog blog) {
return blogRepository.save(blog);
}
On running, I did the following using Postman:
Saved two blogs. Both blogs are getting saved to the database.
called get All blogs. Both the saved blogs are returned.
Saved a new blog. Here I assume the cache has been evicted.
I called get All blogs. However, only two blogs are getting returned. This
means the blogs are returned from the old cache. It didn't get evicted by the
call to the third save.
The github repo is at https://github.com/ximanta/spring-cache
You need to add allEntries = true attribute if you're evicting caches without specifying a key (see docs).
In your case, it would be #CacheEvict(value="allblogcache", allEntries = true)
P.S. tested it and managed to make it work. PR: https://github.com/ximanta/spring-cache/pull/1
It throw exception because you use wrong key expression:
#Caching(evict = {
#CacheEvict(value="allblogcache"),
#CacheEvict(value="blogcache", key = "#blogId")
~~~~~~~~~~ => Refer to parameter blogId but not found
})
public Blog saveBlog(Blog blog)
The correct expression is:
#Caching(evict = {
#CacheEvict(value="allblogcache"),
#CacheEvict(value="blogcache", key = "#blog.id") // Assume that the property for blog ID is "id"
})
public Blog saveBlog(Blog blog)
Related
I have a random issue with CaffeineCache in my Spring Boot application. The problem is with an integration test that makes next
find user
delete it
find it again
It seems that sometimes cache doesn't not refreshes on time before the second call of find that comes immediately after delete.
Here is a simplified signature of find method
#Cacheable(cacheNames = "name", key = "{#config.id, #userId}", unless = "#result == null")
public User find(SomeConfig config, String userId) {
// ...
}
And a simplified signature of delete
#Caching(put = {
#CachePut(cacheNames = "someOtherCache", key = "#userId.technicalId"),
#CachePut(cacheNames = "name", key = "{#config.id, #userId}")
})
public User delete(SomeConfig config, String userId) {
// ...
}
I suppose that after call delete cache is not updated immediately and that's why method find is not called the second time. It happens 1 times from 10.
Any ideas about fix?
Preface
I want to create a sub-resource of another resource in one call. These resources have a #ManyToMany relationship: Users and Groups.
I do not want to create first a user, then the group and after that the relation as it is shown in Working with Relationships in Spring Data REST - simply because I think a resource that cannot exist on its own, such as a group, should only be created if at least one user is also associated with that resource. For this I require a single endpoint like this one (which is not working for me, otherwise I wouldn't be here) that creates a group and also sets the associated "seeding" user in one transaction.
Currently, the only way to make this work for me is to "synchronize" the relation manually like this:
public void setUsers(Set<AppUser> users) {
users.forEach(u -> u.getGroups().add(this));
this.users = users;
}
this would allow me to
POST http://localhost:8080/groups
{
"name": "Group X",
"users": ["http://localhost:8080/users/1"]
}
but my problem with that is that this does not feel right to me - it does seem like a workaround and not the actual Spring-way to make this requirement work. So ..
I'm currently struggling with creating relational resources using Spring's #RepositoryRestResource. I want to create a new group and associate it with the calling user like this:
POST http://localhost:8080/users/1/groups
{
"name": "Group X"
}
but the only result is the response 204 No Content. I have no idea why. This may or may not be related to another question of mine (see here) where I try to achieve the same by setting the relating resource in the JSON payload - that doesn't work either.
Server side I am getting the following error:
tion$ResourceSupportHttpMessageConverter : Failed to evaluate Jackson deserialization for type [[simple type, class org.springframework.hateoas.Resources<java.lang.Object>]]: java.lang.NullPointerException
Please let me know in case you need any specific code.
Tried
I added exported = false to the #RepositoryRestResource of UserGroupRepository:
#RepositoryRestResource(collectionResourceRel = "groups", path = "groups", exported = false)
public interface UserGroupRepository extends JpaRepository<UserGroup, Long> {
List<UserGroup> findByName(#Param("name") String name);
}
and I am sending:
PATCH http://localhost:8080/users/1
{
"groups": [
{
"name": "Group X"
}
]
}
However, the result is still just 204 No Content and a ResourceNotFoundException on the server side.
Unit Test
Essentially, the following unit test is supposed to work but I can also live with an answer why this cannot work and which also shows how this is done correctly.
#Autowired
private TestRestTemplate template;
private static String USERS_ENDPOINT = "http://localhost:8080/users/";
private static String GROUPS_ENDPOINT = "http://localhost:8080/groups/";
// ..
#Test
#DirtiesContext(classMode = ClassMode.BEFORE_EACH_TEST_METHOD)
public void whenCreateUserGroup() {
// Creates a user
whenCreateAppUser();
ResponseEntity<AppUser> appUserResponse = template.getForEntity(USERS_ENDPOINT + "1/", AppUser.class);
AppUser appUser = appUserResponse.getBody();
UserGroup userGroup = new UserGroup();
userGroup.setName("Test Group");
userGroup.setUsers(Collections.singleton(appUser));
template.postForEntity(GROUPS_ENDPOINT, userGroup, UserGroup.class);
ResponseEntity<UserGroup> userGroupResponse = template.getForEntity(GROUPS_ENDPOINT + "2/", UserGroup.class);
Predicate<String> username = other -> appUser.getUsername().equals(other);
assertNotNull("Response must not be null.", userGroupResponse.getBody());
assertTrue("User was not associated with the group he created.",
userGroupResponse.getBody().getUsers().stream()
.map(AppUser::getUsername).anyMatch(username));
}
However, the line
userGroup.setUsers(Collections.singleton(appUser));
will break this test and return a 404 Bad Request.
According to SDR reference:
POST
Only supported for collection associations. Adds a new element to the collection. Supported media types:
text/uri-list - URIs pointing to the resource to add to the association.
So to add group to user try to do this:
POST http://localhost:8080/users/1/groups (with Content-Type:text/uri-list)
http://localhost:8080/groups/1
Additional info.
I'm running into an issue with Entity Framework code-first in MVC3. I'm hitting this exception:
An object with the same key already exists in the ObjectStateManager.
The ObjectStateManager cannot track multiple objects with the same
key.
This is addressed many times on SO, but I'm having trouble utilizing any of the suggested solutions in my situation.
Here is a code sample:
FestORM.SaleMethod method = new FestORM.SaleMethod
{
Id = 2,
Name = "Test Sale Method"
};
FestContext context = new FestContext();
//everything works without this line:
string thisQueryWillMessThingsUp =
context.SaleMethods.Where(m => m.Id == 2).Single().Name;
context.Entry(method).State = System.Data.EntityState.Modified;
context.SaveChanges();
EDITED to clarify: I am attempting to update an object that already exists in the database.
Everything works fine without the query noted in the code. In my application, my controller is instantiating the context, and that same context is passed to several repositories that are used by the controller--so I am not able to simply use a different context for the initial query operation. I've tried to remove the entity from being tracked in the ObjectStateManager, but I can't seem to get anywhere with that either. I'm trying to figure out a solution that will work for both conditions: sometimes I will be updating an object that is tracked by the ObjectStateManager, and sometimes it will happen to have not been tracked yet.
FWIW, my real repository functions look like this, just like the code above:
public void Update(T entity)
{
//works ONLY when entity is not tracked by ObjectStateManager
_context.Entry(entity).State = System.Data.EntityState.Modified;
}
public void SaveChanges()
{
_context.SaveChanges();
}
Any ideas? I've been fighting this for too long...
The problem is that this query
string thisQueryWillMessThingsUp =
context.SaleMethods.Where(m => m.Id == 2).Single().Name;
brings one instance of the SaleMethod entity into the context and then this code
context.Entry(method).State = System.Data.EntityState.Modified;
attaches a different instance to the context. Both instances have the same primary key, so EF thinks that you are trying to attach two different entities with the same key to the context. It doesn't know that they are both supposed to be the same entity.
If for some reason you just need to query for the name, but don't want to actually bring the full entity into the context, then you can do this:
string thisQueryWillMessThingsUp =
context.SaleMethods.Where(m => m.Id == 2).AsNoTracking().Single().Name;
If what you are tying to do is update an existing entity and you have values for all mapped properties of that entity, then the simplest thing to do is to not run the query and just use:
context.Entry(method).State = System.Data.EntityState.Modified;
If you don't want to update all properties, possibly because you don't have values for all properties, then querying for the entity and setting properties on it before calling SaveChanges is an acceptable approach. There are several ways to do this depending on your exact requirements. One way is to use the Property method, something like so:
var salesMethod = context.SaleMethods.Find(2); // Basically equivalent to your query
context.Entry(salesMethod).Property(e => e.Name).CurrentValue = newName;
context.Entry(salesMethod).Property(e => e.SomeOtherProp).CurrentValue = newOtherValue;
context.SaveChanges();
These blog posts contain some additional information that might be helpful:
http://blogs.msdn.com/b/adonet/archive/2011/01/29/using-dbcontext-in-ef-feature-ctp5-part-4-add-attach-and-entity-states.aspx
http://blogs.msdn.com/b/adonet/archive/2011/01/30/using-dbcontext-in-ef-feature-ctp5-part-5-working-with-property-values.aspx
The obvious answer would be that your not actually saving the method object to the database before you call:
//everything works without this line:
string thisQueryWillMessThingsUp = context.SaleMethods.Where(m => m.Id == 2).Single().Name;
However, I think perhaps this is just a bit a code you left out.
What if you make your entities inherit from an abstract class ie.
public abstract class BaseClass
{
public int Id { get; set; }
}
Then update your Repository to
public class Repository<T> where T : BaseClass
{
.....
public void Update(T entity)
{
_context.Entry(entity).State = entity.Id == 0 ? System.Data.EntityState.Added : System.Data.EntityState.Modified;
}
}
Also you might want to not set the ID of your SaleMethod and let it be generated by the database. Problem could also be because SaleMethod Object in the database has Id of 2 and then you try to add another SaleMethod object with Id 2.
The error you see stems from trying to add another SaleMethod object with ID of 2 to the ObjectStateManager.
Currently I'm developing an OAuth2 authorization server using DotNetOpenAuth CTP version. My authorization server is in asp.net MVC3, and it's based on the sample provided by the library. Everything works fine until the app reaches the point where the user authorizes the consumer client.
There's an action inside my OAuth controller which takes care of the authorization process, and is very similar to the equivalent action in the sample:
[Authorize, HttpPost, ValidateAntiForgeryToken]
public ActionResult AuthorizeResponse(bool isApproved)
{
var pendingRequest = this.authorizationServer.ReadAuthorizationRequest();
if (pendingRequest == null)
{
throw new HttpException((int)HttpStatusCode.BadRequest, "Missing authorization request.");
}
IDirectedProtocolMessage response;
if (isApproved)
{
var client = MvcApplication.DataContext.Clients.First(c => c.ClientIdentifier == pendingRequest.ClientIdentifier);
client.ClientAuthorizations.Add(
new ClientAuthorization
{
Scope = OAuthUtilities.JoinScopes(pendingRequest.Scope),
User = MvcApplication.LoggedInUser,
CreatedOn = DateTime.UtcNow,
});
MvcApplication.DataContext.SaveChanges();
response = this.authorizationServer.PrepareApproveAuthorizationRequest(pendingRequest, User.Identity.Name);
}
else
{
response = this.authorizationServer.PrepareRejectAuthorizationRequest(pendingRequest);
}
return this.authorizationServer.Channel.PrepareResponse(response).AsActionResult();
}
Everytime the program reaches this line:
this.authorizationServer.Channel.PrepareResponse(response).AsActionResult();
The system throws an exception which I have researched with no success. The exception is the following:
Only parameterless constructors and initializers are supported in LINQ to Entities.
The stack trace: http://pastebin.com/TibCax2t
The only thing I've done differently from the sample is that I used entity framework's code first approach, an I think the sample was done using a designer which autogenerated the entities.
Thank you in advance.
If you started from the example, the problem Andrew is talking about stays in DatabaseKeyNonceStore.cs. The exception is raised by one on these two methods:
public CryptoKey GetKey(string bucket, string handle) {
// It is critical that this lookup be case-sensitive, which can only be configured at the database.
var matches = from key in MvcApplication.DataContext.SymmetricCryptoKeys
where key.Bucket == bucket && key.Handle == handle
select new CryptoKey(key.Secret, key.ExpiresUtc.AsUtc());
return matches.FirstOrDefault();
}
public IEnumerable<KeyValuePair<string, CryptoKey>> GetKeys(string bucket) {
return from key in MvcApplication.DataContext.SymmetricCryptoKeys
where key.Bucket == bucket
orderby key.ExpiresUtc descending
select new KeyValuePair<string, CryptoKey>(key.Handle, new CryptoKey(key.Secret, key.ExpiresUtc.AsUtc()));
}
I've resolved moving initializations outside of the query:
public CryptoKey GetKey(string bucket, string handle) {
// It is critical that this lookup be case-sensitive, which can only be configured at the database.
var matches = from key in db.SymmetricCryptoKeys
where key.Bucket == bucket && key.Handle == handle
select key;
var match = matches.FirstOrDefault();
CryptoKey ck = new CryptoKey(match.Secret, match.ExpiresUtc.AsUtc());
return ck;
}
public IEnumerable<KeyValuePair<string, CryptoKey>> GetKeys(string bucket) {
var matches = from key in db.SymmetricCryptoKeys
where key.Bucket == bucket
orderby key.ExpiresUtc descending
select key;
List<KeyValuePair<string, CryptoKey>> en = new List<KeyValuePair<string, CryptoKey>>();
foreach (var key in matches)
en.Add(new KeyValuePair<string, CryptoKey>(key.Handle, new CryptoKey(key.Secret, key.ExpiresUtc.AsUtc())));
return en.AsEnumerable<KeyValuePair<string,CryptoKey>>();
}
I'm not sure that this is the best way, but it works!
It looks like your ICryptoKeyStore implementation may be attempting to store CryptoKey directly, but it's not a class that is compatible with the Entity framework (due to not have a public default constructor). Instead, define your own entity class for storing the data in CryptoKey and your ICryptoKeyStore is responsible to transition between the two data types for persistence and retrieval.
I have two tables in my database connected by foreign keys: Page (PageId, other data) and PageTag (PageId, Tag). I've used LINQ to generate classes for these tables, with the page as the parent and the Tag as the child collection (one to many relationship). Is there any way to mark PageTag records for deletion from the database from within the Page class?
Quick Clearification:
I want the child objects to be deleted when the parent DataContext calls SubmitChanges(), not before. I want TagString to behave exactly like any of the other properties of the Page object.
I would like to enable code like the following:
Page page = mDataContext.Pages.Where(page => page.pageId = 1);
page.TagString = "new set of tags";
//Changes have not been written to the database at this point.
mDataContext.SubmitChanges();
//All changes should now be saved to the database.
Here is my situation in detail:
In order to make working with the collection of tags easier, I've added a property to the Page object that treats the Tag collection as a string:
public string TagString {
get {
StringBuilder output = new StringBuilder();
foreach (PageTag tag in PageTags) {
output.Append(tag.Tag + " ");
}
if (output.Length > 0) {
output.Remove(output.Length - 1, 1);
}
return output.ToString();
}
set {
string[] tags = value.Split(' ');
PageTags.Clear();
foreach (string tag in tags) {
PageTag pageTag = new PageTag();
pageTag.Tag = tag;
PageTags.Add(pageTag);
}
}
}
Basically, the idea is that when a string of tags is sent to this property, the current tags of the object are deleted and a new set is generated in their place.
The problem I'm encountering is that this line:
PageTags.Clear();
Doesn't actually delete the old tags from the database when changes are submitted.
Looking around, the "proper" way to delete things seems to be to call the DeleteOnSubmit method of the data context class. But I don't appear to have access to the DataContext class from within the Page class.
Does anyone know of a way to mark the child elements for deletion from the database from within the Page class?
After some more research, I believe I've managed to find a solution. Marking an object for deletion when it's removed from a collection is controlled by the DeleteOnNull parameter of the Association attribute.
This parameter is set to true when the relationship between two tables is marked with OnDelete Cascade.
Unfortunately, there is no way to set this attribute from within the designer, and no way to set it from within the partial class in the *DataContext.cs file. The only way to set it without enabling cascading deletes is to manually edit the *DataContext.designer.cs file.
In my case, this meant finding the Page association, and adding the DeleteOnNull property:
[Association(Name="Page_PageTag", Storage="_Page", ThisKey="PageId", OtherKey="iPageId", IsForeignKey=true)]
public Page Page
{
...
}
And adding the DeleteOnNull attribute:
[Association(Name="Page_PageTag", Storage="_Page", ThisKey="PageId", OtherKey="iPageId", IsForeignKey=true, DeleteOnNull = true)]
public Page Page
{
...
}
Note that the attribute needed to be added to the Page property of the PageTag class, not the other way around.
See also:
Beth Massi -- LINQ to SQL and One-To-Many Relationships
Dave Brace -- LINQ to SQL: DeleteOnNull
Sorry, my bad. That won't work.
It really looks like you need to be doing this in your repository, rather than in your Page class. There, you have access to your original data context.
There is a way to "attach" the original data context, but by the time you do that, it has become quite the code smell.
Do you have a relationship, in your Linq to SQL entity diagram, linking the Page and PageTags tables? If you don't, that is why you can't see the PageTags class from the Page class.
If the foreign key in the PageTags database table is set to Allow Nulls, Linq to SQL will not create the link when you drag the tables into the designer, even if you created a relationship on the SQL Server.
This is one of those areas where OR mapping can get kind of hairy. Providing this TagString property makes things a bit more convenient, but in the long run it obfuscates what is really happening when someone utilizes the TagString property. By hiding the fact that your performing data modification, someone can very easily come along and set the TagString without using your Page entity within the scope of a DataContext, which could lead to some difficult to find bugs.
A better solution would be to add a Tags property on the Page class with the L2S model designer, and require that the PageTags be edited directly on the Tags property, within the scope of a DataContext. Make the TagString property read only, so it can be genreated (and still provide some convenience), but eliminate the confusion and difficulty around setting that property. This kind of change clarifies intent, and makes it obvious what is happening and what is required by consumers of the Page object to make it happen.
Since Tags is a property of your Page object, as long as it is attached to a DataContext, any changes to that collection will properly trigger deletions or insertions in the database in response to Remove or Add calls.
Aaron,
Apparently you have to loop thru your PageTag records, calling DeleteOnSubmit for each one. Linq to SQL should create an aggregate query to delete all of the records at once when you call SubmitChanges, so overhead should be minimal.
replace
PageTags.Clear();
with
foreach (PageTag tag in PageTags)
myDataContext.DeleteOnSubmit(tag);
Aaron:
Add a DataContext member to your PageTag partial class.
partial class PageTag
{
DataClassesDataContext myDataContext = new DataClassesDataContext();
public string TagString {
..etc.
Larger code sample posted at Robert Harvey's request:
DataContext.cs file:
namespace MyProject.Library.Model
{
using Tome.Library.Parsing;
using System.Text;
partial class Page
{
//Part of Robert Harvey's proposed solution.
MyDataContext mDataContext = new TomeDataContext();
public string TagString {
get {
StringBuilder output = new StringBuilder();
foreach (PageTag tag in PageTags) {
output.Append(tag.Tag + " ");
}
if (output.Length > 0) {
output.Remove(output.Length - 1, 1);
}
return output.ToString();
}
set {
string[] tags = value.Split(' ');
//Original code, fails to mark for deletion.
//PageTags.Clear();
//Robert Harvey's suggestion, thorws exception "Cannot remove an entity that has not been attached."
foreach (PageTag tag in PageTags) {
mDataContext.PageTags.DeleteOnSubmit(tag);
}
foreach (string tag in tags) {
PageTag PageTag = new PageTag();
PageTag.Tag = tag;
PageTags.Add(PageTag);
}
}
}
private bool mIsNew;
public bool IsNew {
get {
return mIsNew;
}
}
partial void OnCreated() {
mIsNew = true;
}
partial void OnLoaded() {
mIsNew = false;
}
}
}
Repository Methods:
public void Save() {
mDataContext.SubmitChanges();
}
public Page GetPage(string pageName) {
Page page =
(from p in mDataContext.Pages
where p.FileName == pageName
select p).SingleOrDefault();
return page;
}
Usage:
[AcceptVerbs(HttpVerbs.Post)]
public ActionResult Edit(string pageName, FormCollection formValues) {
Page updatedPage = mRepository.GetPage(pageName);
//TagString is a Form value, and is set via UpdateModel.
UpdateModel(updatedPage, formValues.ToValueProvider());
updatedPage.FileName = pageName;
//At this point NO changes should have been written to the database.
mRepository.Save();
//All changes should NOW be saved to the database.
return RedirectToAction("Index", "Pages", new { PageName = pageName });
}