pagination feature:

add pagination basic implementation

Author: PouyaPouryaie

src/main/java/ir/bigz/springbootreal/controller/SampleController.java

@@ -2,6 +2,7 @@
 
 import ir.bigz.springbootreal.service.UserService;
 import ir.bigz.springbootreal.viewmodel.UserModel;
+import org.springframework.data.domain.Page;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.MediaType;
 import org.springframework.http.ResponseEntity;
@@ -58,4 +59,12 @@ public ResponseEntity<?> getAllUser() {
         return ResponseEntity.ok(result);
     }
 
+    @GetMapping(path = "/user/search", produces = MediaType.APPLICATION_JSON_VALUE)
+    public ResponseEntity<?> getPage(@RequestParam(name = "pagenumber") Integer pageNumber,
+                                     @RequestParam(name = "pagesize") Integer pageSize,
+                                     @RequestParam(name = "sortorder") String sortOrder) {
+        Page<UserModel> userPageResult = userService.getUserSearchResult(pageNumber, pageSize, sortOrder);
+        return ResponseEntity.ok(userPageResult);
+    }
+
 }

src/main/java/ir/bigz/springbootreal/dal/DaoRepository.java

@@ -1,5 +1,7 @@
 package ir.bigz.springbootreal.dal;
 
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.Pageable;
 import org.springframework.stereotype.Repository;
 
 import java.io.Serializable;
@@ -26,4 +28,6 @@ public interface DaoRepository<T, K extends Serializable> {
     List<T> genericSearch(String query);
     void flush();
     void clear();
+
+    Page<T> genericSearch(String query, Pageable pageable);
 }

src/main/java/ir/bigz/springbootreal/dal/DaoRepositoryImpl.java

@@ -1,13 +1,18 @@
 package ir.bigz.springbootreal.dal;
 
+import ir.bigz.springbootreal.dao.User;
 import org.hibernate.Session;
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.PageImpl;
+import org.springframework.data.domain.Pageable;
 import org.springframework.stereotype.Component;
 import org.springframework.transaction.annotation.Propagation;
 import org.springframework.transaction.annotation.Transactional;
 
 import javax.management.openmbean.InvalidOpenTypeException;
 import javax.persistence.EntityManager;
 import javax.persistence.PersistenceContext;
+import javax.persistence.TypedQuery;
 import java.io.Serializable;
 import java.lang.reflect.ParameterizedType;
 import java.lang.reflect.Type;
@@ -131,4 +136,15 @@ public void flush() {
     public void clear() {
         entityManager.clear();
     }
+
+    @Override
+    public Page<T> genericSearch(String query, Pageable pageable){
+        TypedQuery<T> countQuery = entityManager.createQuery(query, daoType);
+        int totalCount = countQuery.getResultList().size();
+
+        TypedQuery<T> typedQuery = entityManager.createQuery(query, daoType);
+        List<T> resultList = typedQuery.setFirstResult((pageable.getPageNumber() - 1) * pageable.getPageSize())
+                .setMaxResults(pageable.getPageSize()).getResultList();
+        return new PageImpl(resultList, pageable, totalCount);
+    }
 }

src/main/java/ir/bigz/springbootreal/dal/UserRepository.java

@@ -6,5 +6,5 @@
 @Repository
 public interface UserRepository extends DaoRepository<User,Long> {
 
-    User getUserWithNationalId(String nationalId);
+    User getUserWithNationalCode(String nationalCode);
 }

src/main/java/ir/bigz/springbootreal/dal/UserRepositoryImpl.java

@@ -10,10 +10,10 @@
 public class UserRepositoryImpl extends DaoRepositoryImpl<User, Long> implements UserRepository {
 
     @Override
-    public User getUserWithNationalId(String nationalId) {
+    public User getUserWithNationalCode(String nationalCode) {
 
         List<User> resultList = new ArrayList<>();
-        String query = "select u from User u where u.nationalId like '" + nationalId + "'";
+        String query = "select u from User u where u.nationalCode like '" + nationalCode + "'";
 
         resultList = genericSearch(query);
 

src/main/java/ir/bigz/springbootreal/service/UserService.java

@@ -2,6 +2,7 @@
 
 import ir.bigz.springbootreal.dao.User;
 import ir.bigz.springbootreal.viewmodel.UserModel;
+import org.springframework.data.domain.Page;
 import org.springframework.stereotype.Service;
 
 import java.util.List;
@@ -18,4 +19,6 @@ public interface UserService {
     String deleteUser(long userId);
 
     List<UserModel> getAll();
+
+    Page<UserModel> getUserSearchResult(Integer pageNumber, Integer pageSize, String sortOrder);
 }

src/main/java/ir/bigz/springbootreal/service/UserServiceImpl.java

@@ -9,6 +9,7 @@
 import org.springframework.cache.annotation.CacheEvict;
 import org.springframework.cache.annotation.CachePut;
 import org.springframework.cache.annotation.Cacheable;
+import org.springframework.data.domain.*;
 import org.springframework.stereotype.Component;
 import org.springframework.transaction.annotation.Isolation;
 import org.springframework.transaction.annotation.Propagation;
@@ -51,7 +52,7 @@ public UserModel getUser(Long userId) {
     @Transactional(propagation = Propagation.REQUIRED, rollbackFor = Exception.class)
     public UserModel addUser(UserModel userModel) {
         try {
-            if(userRepository.getUserWithNationalId(userModel.getNationalCode()) == null){
+            if(userRepository.getUserWithNationalCode(userModel.getNationalCode()) == null){
                 User user = userMapper.userModelToUser(userModel);
                 return userMapper.userToUserModel(userRepository.insert(user));
             }
@@ -114,6 +115,24 @@ public List<UserModel> getAll() {
 
     }
 
+    @Override
+    @Transactional(propagation = Propagation.REQUIRED, isolation = Isolation.DEFAULT)
+    public Page<UserModel> getUserSearchResult(Integer pageNumber, Integer pageSize, String sortOrder) {
+        try {
+            Pageable pageable = PageRequest.of(pageNumber, pageSize);
+            String query = "select u from User u order by u.id " + sortOrder;
+            Page<User> users = userRepository.genericSearch(query, pageable);
+            List<UserModel> collect = users.get().map(userMapper::userToUserModel).collect(Collectors.toList());
+            return new PageImpl(collect, pageable, users.getTotalElements());
+        }catch (RuntimeException exception){
+            throw AppException.newInstance(
+                    HttpErrorCode.ERR_10701,
+                    String.format("getAll method has error: %s", exception.getCause())
+            );
+        }
+
+    }
+
     private void mapUserForUpdate(User sourceUser, User updateUser){
         if(!sourceUser.getFirstName().equals(updateUser.getFirstName())){
             sourceUser.setFirstName(updateUser.getFirstName());