Allow more flexibility when adding book authors

Signed-off-by: Pekka Helenius <fincer89@hotmail.com>

bookstore/src/main/java/com/fjordtek/bookstore/model/Author.java

@@ -13,7 +13,6 @@ import javax.persistence.GenerationType;
 import javax.persistence.Id;
 import javax.persistence.OneToMany;
 import javax.persistence.SequenceGenerator;
-import javax.validation.constraints.NotBlank;
 import javax.validation.constraints.Pattern;
 import javax.validation.constraints.Size;
 
@@ -33,9 +32,9 @@ import com.fasterxml.jackson.annotation.JsonProperty;
 @Entity
 public class Author {
 
-	private static final int strMin         = 2;
 	private static final int strMax         = 100;
-	// We format length check in Size annotation, not here
+
+	// We format length check in Size annotations, not here
 	private static final String regexCommon = "^[a-zA-Z0-9\\-:\\s]*$";
 
 	////////////////////
@@ -56,16 +55,16 @@ public class Author {
 	//////////
 	@Column(
 			name = "firstname",
-			nullable = false,
+			nullable = true,
 			columnDefinition = "NVARCHAR(" + strMax + ")"
 			)
 	@Size(
-			min = strMin, max = strMax,
-			message = "First name length must be " + strMin + "-" + strMax + " characters"
+			max = strMax,
+			message = "First name length must be " + strMax + " characters at most"
 			)
-	@NotBlank(
+	/*@NotBlank(
 			message = "Fill the first name form"
-			)
+			)*/
 	@Pattern(
 			regexp  = regexCommon,
 			message = "Invalid characters"
@@ -78,16 +77,16 @@ public class Author {
 	//////////
 	@Column(
 			name = "lastname",
-			nullable = false,
+			nullable = true,
 			columnDefinition = "NVARCHAR(" + strMax + ")"
 			)
 	@Size(
-			min = strMin, max = strMax,
-			message = "Last name length must be " + strMin + "-" + strMax + " characters"
+			max = strMax,
+			message = "Last name length must be " + strMax + " characters at most"
 			)
-	@NotBlank(
+	/*@NotBlank(
 			message = "Fill the first name form"
-			)
+			)*/
 	@Pattern(
 			regexp  = regexCommon,
 			message = "Invalid characters"
@@ -118,13 +117,27 @@ public class Author {
 	}
 
 	public void setFirstName(String firstName) {
-		// Delete leading & trailing whitespaces (typos from user)
-		this.firstName = firstName.trim();
+
+		// Delete leading & trailing white spaces
+		firstName = firstName.trim();
+
+		if (firstName.isEmpty()) {
+			this.firstName = null;
+		} else {
+			this.firstName = firstName;
+		}
 	}
 
 	public void setLastName(String lastName) {
-		// Delete leading & trailing whitespaces (typos from user)
-		this.lastName = lastName.trim();
+
+		// Delete leading & trailing white spaces
+		lastName = lastName.trim();
+
+		if (lastName.isEmpty()) {
+			this.lastName = null;
+		} else {
+			this.lastName = lastName;
+		}
 	}
 
 	public void setBooks(List<Book> books) {

bookstore/src/main/java/com/fjordtek/bookstore/model/Book.java

@@ -20,6 +20,7 @@ import javax.persistence.ManyToOne;
 import javax.persistence.OneToOne;
 import javax.persistence.PrimaryKeyJoinColumn;
 import javax.persistence.SequenceGenerator;
+import javax.validation.Valid;
 import javax.validation.constraints.DecimalMax;
 import javax.validation.constraints.DecimalMin;
 import javax.validation.constraints.Digits;
@@ -144,6 +145,12 @@ public class Book {
     		name     = "author_id",
     		nullable = true
     		)
+	/*
+	 *  Trigger nested (web form) constraint validation when
+	 *  this entity object is referred from another entity
+	 *  object.
+	 */
+	@Valid
 	private Author author;
 
 	//////////

bookstore/src/main/java/com/fjordtek/bookstore/web/BookAuthorHelper.java

@@ -27,61 +27,79 @@ public class BookAuthorHelper {
 	@Autowired
 	private AuthorRepository authorRepository;
 
-	public void detectAndSaveUpdateAuthorForBook(Book book) {
+	public Author detectAndSaveUpdateAuthorByName(String firstName, String lastName) {
 
 		/*
-		 * Find an author from the current AUTHOR table by his/her first and last name,
-		 * included in the Book entity object. In CrudRepository, if a matching Id
-		 * value is not found, it is stored as a new Author entity object. Therefore,
-		 * it's crucial to identify whether author row values already exist in
-		 * AUTHOR table.
+		 * Find an author from the current AUTHOR table by his/her first and/or last
+		 * name. In CrudRepository, if a matching Id value is not found, it is stored
+		 * as a new Author entity object. Therefore, it's crucial to identify whether
+		 * author row values already exist in AUTHOR table.
 		 */
 
+		Author author = null;
+
 		try {
-			Author authorI = authorRepository.findByFirstNameIgnoreCaseContainingAndLastNameIgnoreCaseContaining(
-					book.getAuthor().getFirstName(),book.getAuthor().getLastName())
-					.get(0);
 
 			/*
-			 * When author is found, use it's Id attribute for book's author Id
-			 *
-			 * NOTE: This step is required by Hibernate, otherwise we get
-			 * TransientPropertyValueException
+			 * Find by first and last name; ignore case
 			 */
-			book.getAuthor().setId(authorI.getId());
+			if (firstName != null && lastName != null) {
+				author = authorRepository.findByFirstNameIgnoreCaseContainingAndLastNameIgnoreCaseContaining(
+					firstName,lastName).get(0);
+			}
 
 			/*
-			 * Otherwise, consider this a new author and store it appropriately.
-			 * Actually, when author is not found, we get IndexOutOfBoundsException.
+			 * Find by first name; ignore case
+			 * NOTE: There is a risk we get a wrong Author!
+			 * Should we auto-detect author or let the user absolutely
+			 * decide the naming scheme without 'intelligent' detection feature?
 			 */
+			if (firstName != null && lastName == null) {
+				author = authorRepository.findByFirstNameIgnoreCaseContaining(
+						firstName).get(0);
+			}
+
+			/*
+			 * Find by last name; ignore case
+			 * NOTE: There is a risk we get a wrong Author!
+			 * Should we auto-detect author or let the user absolutely
+			 * decide the naming scheme without 'intelligent' detection feature?
+			 */
+			if (firstName == null && lastName != null) {
+				author = authorRepository.findByLastNameIgnoreCaseContaining(
+						lastName).get(0);
+			}
+
+		/*
+		 * If author is still not found, we get IndexOutOfBoundsException
+		 * Consider this a new author and store it appropriately.
+		 */
 		} catch (IndexOutOfBoundsException e) {
-			authorRepository.save(book.getAuthor());
+			author = authorRepository.save(new Author(firstName, lastName));
 		}
 
+		return author;
 	}
 
-	public Author detectAndSaveAuthorByName(String firstName, String lastName) {
+	public void detectAndSaveUpdateAuthorForBook(Book book) {
+
+		Author author = this.detectAndSaveUpdateAuthorByName(
+				book.getAuthor().getFirstName(),
+				book.getAuthor().getLastName()
+				);
 
 		/*
-		 * Find an author from the current AUTHOR table by his/her first and last name.
-		 * In CrudRepository, if a matching Id value is not found, it is stored
-		 * as a new Author entity object. Therefore, it's crucial to identify
-		 * whether author row values already exist in AUTHOR table.
+		 * When author is found, use it's Id attribute for book's author Id
+		 *
+		 * NOTE: This step is required by Hibernate,
+		 * otherwise we get TransientPropertyValueException
 		 */
-
-		try {
-			return authorRepository.findByFirstNameIgnoreCaseContainingAndLastNameIgnoreCaseContaining(
-					firstName,lastName).get(0);
-			/*
-			 * Otherwise, consider this a new author and store it appropriately.
-			 * Actually, when author is not found, we get IndexOutOfBoundsException.
-			 */
-		} catch (IndexOutOfBoundsException e) {
-			return authorRepository.save(new Author(firstName,lastName));
+		if (author != null) {
+			book.getAuthor().setId(author.getId());
+		} else {
+			book.setAuthor(null);
 		}
 
 	}
 
-	// TODO implement methods to save author even if either his/her first or last name is missing
-
 }

bookstore/src/main/java/com/fjordtek/bookstore/web/BookBasePathAwareController.java

@@ -86,11 +86,10 @@ public class BookBasePathAwareController {
 		book.setAuthor(null);
 		book.setCategory(null);
 
-		if (authorFirstName != null && authorLastName != null) {
-			book.setAuthor(
-					bookAuthorHelper.detectAndSaveAuthorByName(authorFirstName, authorLastName)
-					);
-		}
+		book.setAuthor(
+				bookAuthorHelper.detectAndSaveUpdateAuthorByName(authorFirstName, authorLastName)
+				);
+
 		if (categoryName != null) {
 			book.setCategory(
 					categoryRepository.findByNameIgnoreCaseContaining(categoryName).get(0)

bookstore/src/main/java/com/fjordtek/bookstore/web/BookController.java

@@ -18,6 +18,7 @@ import org.springframework.transaction.annotation.Transactional;
 import org.springframework.ui.Model;
 import org.springframework.validation.BindingResult;
 import org.springframework.web.bind.WebDataBinder;
+import org.springframework.web.bind.annotation.ExceptionHandler;
 import org.springframework.web.bind.annotation.InitBinder;
 import org.springframework.web.bind.annotation.ModelAttribute;
 import org.springframework.web.bind.annotation.PathVariable;
@@ -176,8 +177,6 @@ public class BookController {
 
 		httpServerLogger.log(requestData, responseData);
 
-		bookAuthorHelper.detectAndSaveUpdateAuthorForBook(book);
-
 		/*
 		 * Generate hash id for the book. One-to-one unidirectional tables.
 		 * Associate generated book hash object information
@@ -189,10 +188,17 @@ public class BookController {
 		book.setBookHash(bookHash);
 		bookHash.setBook(book);
 
+		/*
+		 * More sophisticated methods are required to handle
+		 * user input with random letter cases etc. considered
+		 */
+		//authorRepository.save(book.getAuthor());
+		bookAuthorHelper.detectAndSaveUpdateAuthorForBook(book);
+
 		bookRepository.save(book);
 		bookHashRepository.save(bookHash);
 
-		return "redirect:" + bookListPageView;
+		return "redirect:/" + bookListPageView;
 	}
 
 	//////////////////////////////
@@ -269,6 +275,7 @@ public class BookController {
 			value    = bookEditPageView + "/{hash_id}",
 			method   = RequestMethod.POST
 			)
+	@ExceptionHandler
 	public String webFormUpdateBook(
 			@Valid @ModelAttribute("book") Book book,
 			BindingResult bindingResultBook,
@@ -326,7 +333,13 @@ public class BookController {
 			return bookEditPageView;
 		}
 
+		/*
+		 * More sophisticated methods are required to handle
+		 * user input with random letter cases etc. considered
+		 */
+		//authorRepository.save(book.getAuthor());
 		bookAuthorHelper.detectAndSaveUpdateAuthorForBook(book);
+
 		bookRepository.save(book);
 
 		httpServerLogger.log(requestData, responseData);