Merge pull request #8125 from eugenp/revert-8119-BAEL-3275-2

Revert "BAEL-3275: Using blocking queue for pub-sub"

spring-data-rest/src/main/java/com/baeldung/books/SpringDataRestApplication.java

@@ -0,0 +1,13 @@
+package com.baeldung.books;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class SpringDataRestApplication {
+
+    public static void main(String[] args) {
+        SpringApplication.run(SpringDataRestApplication.class, args);
+    }
+
+}

spring-data-rest/src/main/java/com/baeldung/books/config/DbConfig.java

@@ -0,0 +1,87 @@
+package com.baeldung.books.config;
+
+import java.util.Properties;
+
+import javax.sql.DataSource;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Profile;
+import org.springframework.context.annotation.PropertySource;
+import org.springframework.core.env.Environment;
+import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
+import org.springframework.jdbc.datasource.DriverManagerDataSource;
+import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
+import org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter;
+
+@Configuration
+@EnableJpaRepositories(basePackages = "com.baeldung.books.repositories")
+// @PropertySource("persistence-h2.properties")
+// @PropertySource("persistence-hsqldb.properties")
+// @PropertySource("persistence-derby.properties")
+// @PropertySource("persistence-sqlite.properties")
+public class DbConfig {
+
+    @Autowired
+    private Environment env;
+
+    @Bean
+    public DataSource dataSource() {
+        final DriverManagerDataSource dataSource = new DriverManagerDataSource();
+        dataSource.setDriverClassName(env.getProperty("driverClassName"));
+        dataSource.setUrl(env.getProperty("url"));
+        dataSource.setUsername(env.getProperty("user"));
+        dataSource.setPassword(env.getProperty("password"));
+        return dataSource;
+    }
+
+    @Bean
+    public LocalContainerEntityManagerFactoryBean entityManagerFactory() {
+        final LocalContainerEntityManagerFactoryBean em = new LocalContainerEntityManagerFactoryBean();
+        em.setDataSource(dataSource());
+        em.setPackagesToScan(new String[] { "com.baeldung.books.models" });
+        em.setJpaVendorAdapter(new HibernateJpaVendorAdapter());
+        em.setJpaProperties(additionalProperties());
+        return em;
+    }
+
+    final Properties additionalProperties() {
+        final Properties hibernateProperties = new Properties();
+        if (env.getProperty("hibernate.hbm2ddl.auto") != null) {
+            hibernateProperties.setProperty("hibernate.hbm2ddl.auto", env.getProperty("hibernate.hbm2ddl.auto"));
+        }
+        if (env.getProperty("hibernate.dialect") != null) {
+            hibernateProperties.setProperty("hibernate.dialect", env.getProperty("hibernate.dialect"));
+        }
+        if (env.getProperty("hibernate.show_sql") != null) {
+            hibernateProperties.setProperty("hibernate.show_sql", env.getProperty("hibernate.show_sql"));
+        }
+        return hibernateProperties;
+    }
+
+}
+
+@Configuration
+@Profile("h2")
+@PropertySource("classpath:persistence-h2.properties")
+class H2Config {
+}
+
+@Configuration
+@Profile("hsqldb")
+@PropertySource("classpath:persistence-hsqldb.properties")
+class HsqldbConfig {
+}
+
+@Configuration
+@Profile("derby")
+@PropertySource("classpath:persistence-derby.properties")
+class DerbyConfig {
+}
+
+@Configuration
+@Profile("sqlite")
+@PropertySource("classpath:persistence-sqlite.properties")
+class SqliteConfig {
+}

spring-data-rest/src/main/java/com/baeldung/books/config/MvcConfig.java

@@ -0,0 +1,35 @@
+package com.baeldung.books.config;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.web.servlet.config.annotation.DefaultServletHandlerConfigurer;
+import org.springframework.web.servlet.config.annotation.EnableWebMvc;
+import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
+
+import com.baeldung.books.events.AuthorEventHandler;
+import com.baeldung.books.events.BookEventHandler;
+
+@Configuration
+@EnableWebMvc
+public class MvcConfig implements WebMvcConfigurer {
+
+    public MvcConfig() {
+        super();
+    }
+
+    @Override
+    public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
+        configurer.enable();
+    }
+
+    @Bean
+    AuthorEventHandler authorEventHandler() {
+        return new AuthorEventHandler();
+    }
+
+    @Bean
+    BookEventHandler bookEventHandler() {
+        return new BookEventHandler();
+    }
+
+}

spring-data-rest/src/main/java/com/baeldung/books/config/RestConfig.java

@@ -0,0 +1,21 @@
+package com.baeldung.books.config;
+
+import com.baeldung.books.models.WebsiteUser;
+import com.baeldung.books.projections.CustomBook;
+
+import org.springframework.context.annotation.Configuration;
+import org.springframework.data.rest.core.config.RepositoryRestConfiguration;
+import org.springframework.data.rest.core.mapping.ExposureConfiguration;
+import org.springframework.data.rest.webmvc.config.RepositoryRestConfigurer;
+import org.springframework.http.HttpMethod;
+
+@Configuration
+public class RestConfig implements RepositoryRestConfigurer {
+
+    @Override
+    public void configureRepositoryRestConfiguration(RepositoryRestConfiguration repositoryRestConfiguration) {
+        repositoryRestConfiguration.getProjectionConfiguration().addProjection(CustomBook.class);
+        ExposureConfiguration config = repositoryRestConfiguration.getExposureConfiguration();
+        config.forDomainType(WebsiteUser.class).withItemExposure((metadata, httpMethods) -> httpMethods.disable(HttpMethod.PATCH));
+    }
+}

spring-data-rest/src/main/java/com/baeldung/books/config/ValidatorEventRegister.java

@@ -0,0 +1,30 @@
+package com.baeldung.books.config;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.Map;
+
+import org.springframework.beans.factory.InitializingBean;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.data.rest.core.event.ValidatingRepositoryEventListener;
+import org.springframework.validation.Validator;
+
+@Configuration
+public class ValidatorEventRegister implements InitializingBean {
+
+    @Autowired
+    ValidatingRepositoryEventListener validatingRepositoryEventListener;
+
+    @Autowired
+    private Map<String, Validator> validators;
+
+    @Override
+    public void afterPropertiesSet() throws Exception {
+        List<String> events = Arrays.asList("beforeCreate", "afterCreate", "beforeSave", "afterSave", "beforeLinkSave", "afterLinkSave", "beforeDelete", "afterDelete");
+
+        for (Map.Entry<String, Validator> entry : validators.entrySet()) {
+            events.stream().filter(p -> entry.getKey().startsWith(p)).findFirst().ifPresent(p -> validatingRepositoryEventListener.addValidator(p, entry.getValue()));
+        }
+    }
+}

spring-data-rest/src/main/java/com/baeldung/books/dialect/SQLiteDialect.java

@@ -0,0 +1,78 @@
+package com.baeldung.books.dialect;
+
+import org.hibernate.dialect.Dialect;
+import org.hibernate.dialect.identity.IdentityColumnSupport;
+
+import java.sql.Types;
+
+public class SQLiteDialect extends Dialect {
+
+    public SQLiteDialect() {
+        registerColumnType(Types.BIT, "integer");
+        registerColumnType(Types.TINYINT, "tinyint");
+        registerColumnType(Types.SMALLINT, "smallint");
+        registerColumnType(Types.INTEGER, "integer");
+        registerColumnType(Types.BIGINT, "bigint");
+        registerColumnType(Types.FLOAT, "float");
+        registerColumnType(Types.REAL, "real");
+        registerColumnType(Types.DOUBLE, "double");
+        registerColumnType(Types.NUMERIC, "numeric");
+        registerColumnType(Types.DECIMAL, "decimal");
+        registerColumnType(Types.CHAR, "char");
+        registerColumnType(Types.VARCHAR, "varchar");
+        registerColumnType(Types.LONGVARCHAR, "longvarchar");
+        registerColumnType(Types.DATE, "date");
+        registerColumnType(Types.TIME, "time");
+        registerColumnType(Types.TIMESTAMP, "timestamp");
+        registerColumnType(Types.BINARY, "blob");
+        registerColumnType(Types.VARBINARY, "blob");
+        registerColumnType(Types.LONGVARBINARY, "blob");
+        registerColumnType(Types.BLOB, "blob");
+        registerColumnType(Types.CLOB, "clob");
+        registerColumnType(Types.BOOLEAN, "integer");
+    }
+
+    public IdentityColumnSupport getIdentityColumnSupport() {
+        return new SQLiteIdentityColumnSupport();
+    }
+
+    public boolean hasAlterTable() {
+        return false;
+    }
+
+    public boolean dropConstraints() {
+        return false;
+    }
+
+    public String getDropForeignKeyString() {
+        return "";
+    }
+
+    public String getAddForeignKeyConstraintString(String constraintName, String[] foreignKey, String referencedTable, String[] primaryKey, boolean referencesPrimaryKey) {
+        return "";
+    }
+
+    public String getAddPrimaryKeyConstraintString(String constraintName) {
+        return "";
+    }
+
+    public String getForUpdateString() {
+        return "";
+    }
+
+    public String getAddColumnString() {
+        return "add column";
+    }
+
+    public boolean supportsOuterJoinForUpdate() {
+        return false;
+    }
+
+    public boolean supportsIfExistsBeforeTableName() {
+        return true;
+    }
+
+    public boolean supportsCascadeDelete() {
+        return false;
+    }
+}

spring-data-rest/src/main/java/com/baeldung/books/dialect/SQLiteIdentityColumnSupport.java

@@ -0,0 +1,22 @@
+package com.baeldung.books.dialect;
+
+import org.hibernate.MappingException;
+import org.hibernate.dialect.identity.IdentityColumnSupportImpl;
+
+public class SQLiteIdentityColumnSupport extends IdentityColumnSupportImpl {
+
+    @Override
+    public boolean supportsIdentityColumns() {
+        return true;
+    }
+
+    @Override
+    public String getIdentitySelectString(String table, String column, int type) throws MappingException {
+        return "select last_insert_rowid()";
+    }
+
+    @Override
+    public String getIdentityColumnString(int type) throws MappingException {
+        return "integer";
+    }
+}

spring-data-rest/src/main/java/com/baeldung/books/events/AuthorEventHandler.java

@@ -0,0 +1,42 @@
+package com.baeldung.books.events;
+
+import org.springframework.data.rest.core.annotation.*;
+
+import com.baeldung.books.models.Author;
+import com.baeldung.books.models.Book;
+
+import java.util.logging.Logger;
+
+@RepositoryEventHandler
+public class AuthorEventHandler {
+    Logger logger = Logger.getLogger("Class AuthorEventHandler");
+
+    public AuthorEventHandler() {
+        super();
+    }
+
+    @HandleBeforeCreate
+    public void handleAuthorBeforeCreate(Author author) {
+        logger.info("Inside  Author Before Create....");
+        String name = author.getName();
+    }
+
+    @HandleAfterCreate
+    public void handleAuthorAfterCreate(Author author) {
+        logger.info("Inside  Author After Create ....");
+        String name = author.getName();
+    }
+
+    @HandleBeforeDelete
+    public void handleAuthorBeforeDelete(Author author) {
+        logger.info("Inside  Author Before Delete ....");
+        String name = author.getName();
+    }
+
+    @HandleAfterDelete
+    public void handleAuthorAfterDelete(Author author) {
+        logger.info("Inside  Author After Delete ....");
+        String name = author.getName();
+    }
+
+}

spring-data-rest/src/main/java/com/baeldung/books/events/BookEventHandler.java

@@ -0,0 +1,29 @@
+package com.baeldung.books.events;
+
+import java.util.logging.Logger;
+
+import org.apache.commons.logging.Log;
+import org.springframework.data.rest.core.annotation.HandleAfterDelete;
+import org.springframework.data.rest.core.annotation.HandleBeforeCreate;
+import org.springframework.data.rest.core.annotation.RepositoryEventHandler;
+
+import com.baeldung.books.models.Author;
+import com.baeldung.books.models.Book;
+
+@RepositoryEventHandler
+public class BookEventHandler {
+    Logger logger = Logger.getLogger("Class BookEventHandler");
+
+    @HandleBeforeCreate
+    public void handleBookBeforeCreate(Book book) {
+
+        logger.info("Inside Book Before Create ....");
+        book.getAuthors();
+    }
+
+    @HandleBeforeCreate
+    public void handleAuthorBeforeCreate(Author author) {
+        logger.info("Inside Author Before Create ....");
+        author.getBooks();
+    }
+}

spring-data-rest/src/main/java/com/baeldung/books/exception/handlers/RestResponseEntityExceptionHandler.java

@@ -0,0 +1,26 @@
+package com.baeldung.books.exception.handlers;
+
+import org.springframework.data.rest.core.RepositoryConstraintViolationException;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.validation.ObjectError;
+import org.springframework.web.bind.annotation.ControllerAdvice;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+import org.springframework.web.context.request.WebRequest;
+import org.springframework.web.servlet.mvc.method.annotation.ResponseEntityExceptionHandler;
+
+import java.util.stream.Collectors;
+
+@ControllerAdvice
+public class RestResponseEntityExceptionHandler extends ResponseEntityExceptionHandler {
+
+    @ExceptionHandler({ RepositoryConstraintViolationException.class })
+    public ResponseEntity<Object> handleAccessDeniedException(Exception ex, WebRequest request) {
+        RepositoryConstraintViolationException nevEx = (RepositoryConstraintViolationException) ex;
+
+        String errors = nevEx.getErrors().getAllErrors().stream().map(ObjectError::toString).collect(Collectors.joining("\n"));
+        return new ResponseEntity<>(errors, new HttpHeaders(), HttpStatus.NOT_ACCEPTABLE);
+    }
+
+}

spring-data-rest/src/main/java/com/baeldung/books/models/Address.java

@@ -0,0 +1,54 @@
+package com.baeldung.books.models;
+
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.OneToOne;
+
+@Entity
+public class Address {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private long id;
+
+    @Column(nullable = false)
+    private String location;
+
+    @OneToOne(mappedBy = "address")
+    private Library library;
+
+    public Address() {
+    }
+
+    public Address(String location) {
+        super();
+        this.location = location;
+    }
+
+    public long getId() {
+        return id;
+    }
+
+    public void setId(long id) {
+        this.id = id;
+    }
+
+    public String getLocation() {
+        return location;
+    }
+
+    public void setLocation(String location) {
+        this.location = location;
+    }
+
+    public Library getLibrary() {
+        return library;
+    }
+
+    public void setLibrary(Library library) {
+        this.library = library;
+    }
+}

spring-data-rest/src/main/java/com/baeldung/books/models/Author.java

@@ -0,0 +1,60 @@
+package com.baeldung.books.models;
+
+import java.util.List;
+
+import javax.persistence.CascadeType;
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.JoinColumn;
+import javax.persistence.JoinTable;
+import javax.persistence.ManyToMany;
+
+@Entity
+public class Author {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private long id;
+
+    @Column(nullable = false)
+    private String name;
+
+    @ManyToMany(cascade = CascadeType.ALL)
+    @JoinTable(name = "book_author", joinColumns = @JoinColumn(name = "book_id", referencedColumnName = "id"), inverseJoinColumns = @JoinColumn(name = "author_id", referencedColumnName = "id"))
+    private List<Book> books;
+
+    public Author() {
+    }
+
+    public Author(String name) {
+        super();
+        this.name = name;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public long getId() {
+        return id;
+    }
+
+    public void setId(long id) {
+        this.id = id;
+    }
+
+    public List<Book> getBooks() {
+        return books;
+    }
+
+    public void setBooks(List<Book> books) {
+        this.books = books;
+    }
+}

spring-data-rest/src/main/java/com/baeldung/books/models/Book.java

@@ -0,0 +1,82 @@
+package com.baeldung.books.models;
+
+import java.util.List;
+
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.FetchType;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.JoinColumn;
+import javax.persistence.ManyToMany;
+import javax.persistence.ManyToOne;
+
+@Entity
+public class Book {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private long id;
+
+    @Column(nullable = false)
+    private String title;
+
+    private String isbn;
+
+    @ManyToOne
+    @JoinColumn(name = "library_id")
+    private Library library;
+
+    @ManyToMany(mappedBy = "books", fetch = FetchType.EAGER)
+    private List<Author> authors;
+
+    public Book() {
+    }
+
+    public Book(String title) {
+        super();
+        this.title = title;
+    }
+
+    public String getTitle() {
+        return title;
+    }
+
+    public void setTitle(String title) {
+        this.title = title;
+    }
+
+    public long getId() {
+        return id;
+    }
+
+    public void setId(long id) {
+        this.id = id;
+    }
+
+    public String getIsbn() {
+        return isbn;
+    }
+
+    public void setIsbn(String isbn) {
+        this.isbn = isbn;
+    }
+
+    public Library getLibrary() {
+        return library;
+    }
+
+    public void setLibrary(Library library) {
+        this.library = library;
+    }
+
+    public List<Author> getAuthors() {
+        return authors;
+    }
+
+    public void setAuthors(List<Author> authors) {
+        this.authors = authors;
+    }
+
+}

spring-data-rest/src/main/java/com/baeldung/books/models/Library.java

@@ -0,0 +1,74 @@
+package com.baeldung.books.models;
+
+import java.util.List;
+
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.JoinColumn;
+import javax.persistence.OneToMany;
+import javax.persistence.OneToOne;
+
+import org.springframework.data.rest.core.annotation.RestResource;
+
+@Entity
+public class Library {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private long id;
+
+    @Column
+    private String name;
+
+    @OneToOne
+    @JoinColumn(name = "address_id")
+    @RestResource(path = "libraryAddress")
+    private Address address;
+
+    @OneToMany(mappedBy = "library")
+    private List<Book> books;
+
+    public Library() {
+    }
+
+    public Library(String name) {
+        super();
+        this.name = name;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public long getId() {
+        return id;
+    }
+
+    public void setId(long id) {
+        this.id = id;
+    }
+
+    public Address getAddress() {
+        return address;
+    }
+
+    public void setAddress(Address address) {
+        this.address = address;
+    }
+
+    public List<Book> getBooks() {
+        return books;
+    }
+
+    public void setBooks(List<Book> books) {
+        this.books = books;
+    }
+
+}

spring-data-rest/src/main/java/com/baeldung/books/models/Subject.java

@@ -0,0 +1,37 @@
+package com.baeldung.books.models;
+
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+
+@Entity
+public class Subject {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private long id;
+
+    @Column(nullable = false)
+    private String name;
+
+    public Subject() {
+    }
+
+    public long getId() {
+        return id;
+    }
+
+    public void setId(long id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+}

spring-data-rest/src/main/java/com/baeldung/books/models/WebsiteUser.java

@@ -0,0 +1,41 @@
+package com.baeldung.books.models;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+
+@Entity
+public class WebsiteUser {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.AUTO)
+    private long id;
+
+    private String name;
+    private String email;
+
+    public long getId() {
+        return id;
+    }
+
+    public void setId(long id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public String getEmail() {
+        return email;
+    }
+
+    public void setEmail(String email) {
+        this.email = email;
+    }
+}

spring-data-rest/src/main/java/com/baeldung/books/projections/CustomBook.java

@@ -0,0 +1,22 @@
+package com.baeldung.books.projections;
+
+import java.util.List;
+
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.data.rest.core.config.Projection;
+
+import com.baeldung.books.models.Author;
+import com.baeldung.books.models.Book;
+
+@Projection(name = "customBook", types = { Book.class })
+public interface CustomBook {
+    @Value("#{target.id}")
+    long getId();
+
+    String getTitle();
+
+    List<Author> getAuthors();
+
+    @Value("#{target.getAuthors().size()}")
+    int getAuthorCount();
+}

spring-data-rest/src/main/java/com/baeldung/books/repositories/AddressRepository.java

@@ -0,0 +1,9 @@
+package com.baeldung.books.repositories;
+
+import org.springframework.data.repository.CrudRepository;
+
+import com.baeldung.books.models.Address;
+
+public interface AddressRepository extends CrudRepository<Address, Long> {
+
+}

spring-data-rest/src/main/java/com/baeldung/books/repositories/AuthorRepository.java

@@ -0,0 +1,9 @@
+package com.baeldung.books.repositories;
+
+import org.springframework.data.repository.CrudRepository;
+
+import com.baeldung.books.models.Author;
+
+public interface AuthorRepository extends CrudRepository<Author, Long> {
+
+}

spring-data-rest/src/main/java/com/baeldung/books/repositories/BookRepository.java

@@ -0,0 +1,11 @@
+package com.baeldung.books.repositories;
+
+import org.springframework.data.repository.CrudRepository;
+import org.springframework.data.rest.core.annotation.RepositoryRestResource;
+
+import com.baeldung.books.models.Book;
+import com.baeldung.books.projections.CustomBook;
+
+@RepositoryRestResource(excerptProjection = CustomBook.class)
+public interface BookRepository extends CrudRepository<Book, Long> {
+}

spring-data-rest/src/main/java/com/baeldung/books/repositories/LibraryRepository.java

@@ -0,0 +1,9 @@
+package com.baeldung.books.repositories;
+
+import org.springframework.data.repository.CrudRepository;
+
+import com.baeldung.books.models.Library;
+
+public interface LibraryRepository extends CrudRepository<Library, Long> {
+
+}

spring-data-rest/src/main/java/com/baeldung/books/repositories/SubjectRepository.java

@@ -0,0 +1,16 @@
+package com.baeldung.books.repositories;
+
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.Pageable;
+import org.springframework.data.repository.PagingAndSortingRepository;
+import org.springframework.data.repository.query.Param;
+import org.springframework.data.rest.core.annotation.RestResource;
+
+import com.baeldung.books.models.Subject;
+
+public interface SubjectRepository extends PagingAndSortingRepository<Subject, Long> {
+
+    @RestResource(path = "nameContains")
+    public Page<Subject> findByNameContaining(@Param("name") String name, Pageable p);
+
+}

spring-data-rest/src/main/java/com/baeldung/books/repositories/UserRepository.java

@@ -0,0 +1,33 @@
+package com.baeldung.books.repositories;
+
+import org.springframework.data.repository.CrudRepository;
+import org.springframework.data.repository.query.Param;
+import org.springframework.data.rest.core.annotation.RepositoryRestResource;
+import org.springframework.data.rest.core.annotation.RestResource;
+import org.springframework.web.bind.annotation.CrossOrigin;
+
+import com.baeldung.books.models.WebsiteUser;
+
+@CrossOrigin
+@RepositoryRestResource(collectionResourceRel = "users", path = "users")
+public interface UserRepository extends CrudRepository<WebsiteUser, Long> {
+
+    @Override
+    @RestResource(exported = false)
+    void delete(WebsiteUser entity);
+
+    @Override
+    @RestResource(exported = false)
+    void deleteAll();
+
+    @Override
+    @RestResource(exported = false)
+    void deleteAll(Iterable<? extends WebsiteUser> entities);
+
+    @Override
+    @RestResource(exported = false)
+    void deleteById(Long aLong);
+
+    @RestResource(path = "byEmail", rel = "customFindMethod")
+    WebsiteUser findByEmail(@Param("email") String email);
+}

spring-data-rest/src/main/java/com/baeldung/books/validators/WebsiteUserValidator.java

@@ -0,0 +1,33 @@
+package com.baeldung.books.validators;
+
+import org.springframework.stereotype.Component;
+import org.springframework.validation.Errors;
+import org.springframework.validation.Validator;
+
+import com.baeldung.books.models.WebsiteUser;
+
+@Component("beforeCreateWebsiteUserValidator")
+public class WebsiteUserValidator implements Validator {
+
+    @Override
+    public boolean supports(Class<?> clazz) {
+        return WebsiteUser.class.equals(clazz);
+    }
+
+    @Override
+    public void validate(Object obj, Errors errors) {
+
+        WebsiteUser user = (WebsiteUser) obj;
+        if (checkInputString(user.getName())) {
+            errors.rejectValue("name", "name.empty");
+        }
+
+        if (checkInputString(user.getEmail())) {
+            errors.rejectValue("email", "email.empty");
+        }
+    }
+
+    private boolean checkInputString(String input) {
+        return (input == null || input.trim().length() == 0);
+    }
+}

spring-data-rest/src/main/java/com/baeldung/springdatawebsupport/application/Application.java

@@ -0,0 +1,28 @@
+package com.baeldung.springdatawebsupport.application;
+
+import com.baeldung.springdatawebsupport.application.entities.User;
+import com.baeldung.springdatawebsupport.application.repositories.UserRepository;
+import java.util.stream.Stream;
+import org.springframework.boot.CommandLineRunner;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.Bean;
+
+@SpringBootApplication
+public class Application {
+
+    public static void main(String[] args) {
+        SpringApplication.run(Application.class, args);
+    }
+
+    @Bean
+    CommandLineRunner initialize(UserRepository userRepository) {
+        return args -> {
+            Stream.of("John", "Robert", "Nataly", "Helen", "Mary").forEach(name -> {
+                User user = new User(name);
+                userRepository.save(user);
+            });
+            userRepository.findAll().forEach(System.out::println);
+        };
+    }
+}

spring-data-rest/src/main/java/com/baeldung/springdatawebsupport/application/controllers/UserController.java

@@ -0,0 +1,47 @@
+package com.baeldung.springdatawebsupport.application.controllers;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.PageRequest;
+import org.springframework.data.domain.Pageable;
+import org.springframework.data.domain.Sort;
+import org.springframework.data.querydsl.binding.QuerydslPredicate;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RestController;
+
+import com.baeldung.springdatawebsupport.application.entities.User;
+import com.baeldung.springdatawebsupport.application.repositories.UserRepository;
+import com.querydsl.core.types.Predicate;
+
+@RestController
+public class UserController {
+
+    private final UserRepository userRepository;
+
+    @Autowired
+    public UserController(UserRepository userRepository) {
+        this.userRepository = userRepository;
+    }
+
+    @GetMapping("/users/{id}")
+    public User findUserById(@PathVariable("id") User user) {
+        return user;
+    }
+
+    @GetMapping("/users")
+    public Page<User> findAllUsers(Pageable pageable) {
+        return userRepository.findAll(pageable);
+    }
+
+    @GetMapping("/sortedusers")
+    public Page<User> findAllUsersSortedByName() {
+        Pageable pageable = PageRequest.of(0, 5, Sort.by("name"));
+        return userRepository.findAll(pageable);
+    }
+
+    @GetMapping("/filteredusers")
+    public Iterable<User> getUsersByQuerydslPredicate(@QuerydslPredicate(root = User.class) Predicate predicate) {
+        return userRepository.findAll(predicate);
+    }
+}

spring-data-rest/src/main/java/com/baeldung/springdatawebsupport/application/entities/User.java

@@ -0,0 +1,38 @@
+package com.baeldung.springdatawebsupport.application.entities;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.Table;
+
+@Entity
+@Table(name = "users")
+public class User {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.AUTO)
+    private long id;
+    private final String name;
+
+    public User() {
+        this.name = "";
+    }
+
+    public User(String name) {
+        this.name = name;
+    }
+
+    public long getId() {
+        return id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    @Override
+    public String toString() {
+        return "User{" + "id=" + id + ", name=" + name + '}';
+    }
+}

spring-data-rest/src/main/java/com/baeldung/springdatawebsupport/application/repositories/UserRepository.java

@@ -0,0 +1,13 @@
+package com.baeldung.springdatawebsupport.application.repositories;
+
+import com.baeldung.springdatawebsupport.application.entities.User;
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.Pageable;
+import org.springframework.data.querydsl.QuerydslPredicateExecutor;
+import org.springframework.data.repository.PagingAndSortingRepository;
+import org.springframework.stereotype.Repository;
+
+@Repository
+public interface UserRepository extends PagingAndSortingRepository<User, Long>, QuerydslPredicateExecutor<User> {
+
+}