我正在为一个学校项目制作图书馆系统。
在处理大型 Java 应用程序时,一种简化编码的方法是使用 model / view / controller 模式。通过分离关注点,您可以一次专注于应用程序的一个部分。
好的,我将做一些假设。假设图书馆有书。
所以,让我们创建一个类来存放一本书。这个类是一个普通的 Java 类。它与 Swing 或任何类型的 GUI 无关。它是完全独立的。我们称之为模型类。
这个类是应用程序模型的一部分。还会有其他类来描述库的其他方面,
import java.util.ArrayList;
import java.util.List;
public class Book {
private final String title;
private final String isbn;
private List<String> author;
private List<String> genre;
public Book(String title, String isbn) {
this.title = title;
this.isbn = isbn;
this.author = new ArrayList<>();
this.genre = new ArrayList<>();
}
public String getTitle() {
return title;
}
public void addAuthor(String author) {
this.author.add(author);
}
public List<String> getAuthor() {
return author;
}
public String getIsbn() {
return isbn;
}
public void addGenre(String genre) {
this.genre.add(genre);
}
public List<String> getGenre() {
return genre;
}
}
在 Java 中,类名是 TitleCase。方法名和字段名都是驼峰式。
Book 类中的所有内容都与一本书有关。为了收集书籍,我们将在不同的模型类中创建一个List<Book>。
一本书有一个标题。它可以有字幕,但我选择不包括字幕字段。您可以根据需要添加字幕字段。
一本书有一个或多个作者。
一本书有一个 ISBN 码。
一本书可以分为一种或多种类型。
现在,我们仍然需要为顾客建模。从逻辑上讲,这将是一个Patron 类。
import java.util.ArrayList;
import java.util.List;
public class Patron {
private String name;
private String address;
private String phoneNumber;
private List<Book> checkedOut;
public Patron(String name, String address, String phoneNumber) {
this.name = name;
this.address = address;
this.phoneNumber = phoneNumber;
this.checkedOut = new ArrayList<>();
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
public String getPhoneNumber() {
return phoneNumber;
}
public void setPhoneNumber(String phoneNumber) {
this.phoneNumber = phoneNumber;
}
public List<Book> getCheckedOut() {
return checkedOut;
}
public void addCheckedOut(Book checkedOut) {
this.checkedOut.add(checkedOut);
}
public void removeCheckedOut(Book returned) {
this.checkedOut.remove(returned);
}
}
我想您已经了解了应用程序模型。
首先,创建完整的应用模型。
其次,从应用程序模型中,创建您的 SQL 表。创建一个包含所有 SQL 代码的 SQL 类。我没有看到足够多的代码来为您创建 SQL 类。
第三,创建 Swing GUI。您可以在此步骤中使用 Swing 默认模型。
这是我的一个 SQL 类,可让您了解应该如何编写 SQL 类。我正在使用 MySQL。您应该始终使用准备好的语句来防止SQL injection attacks。
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.sql.Timestamp;
import java.util.ArrayList;
import java.util.List;
import java.util.Optional;
import com.amazon.ask.model.User;
import com.ggl.bible.reader.model.Book;
import com.ggl.bible.reader.model.Verse;
import com.ggl.bible.reader.model.VerseKey;
public class SQL {
private Connection connection;
public boolean connect() {
try {
String[] params = createConnectionStrings();
connection = DriverManager.getConnection(params[0],
params[1], params[2]);
return true;
} catch (SQLException e) {
e.printStackTrace();
return false;
}
}
private String[] createConnectionStrings() {
String[] connection = new String[3];
String host = "bible-database.caaitaoyrsgp.us-east-1."
+ "rds.amazonaws.com";
String port = "3306";
String user = "ggleblanc";
String useSSL = "?useSSL=false";
String schema = "/bible";
String password = "******************";
String driver = "jdbc:mysql://" + host + ":" + port;
driver += schema + useSSL;
connection[0] = driver;
connection[1] = user;
connection[2] = password;
return connection;
}
public void close() {
try {
connection.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
public Optional<Timestamp> selectLastCreated() {
StringBuilder builder = new StringBuilder();
builder.append("SELECT `timestamp` ");
builder.append(" FROM `bible`.`lastCreated` ");
builder.append(" ORDER BY `timestamp` DESC ");
builder.append(" LIMIT 0, 1; ");
String sql = builder.toString();
try {
Statement statement = connection.createStatement();
ResultSet rs = statement.executeQuery(sql);
rs.next();
Optional<Timestamp> timestamp = Optional.of(
rs.getTimestamp(1));
rs.close();
return timestamp;
} catch (SQLException e) {
e.printStackTrace();
return Optional.empty();
}
}
public List<Book> selectBooks() {
List<Book> books = new ArrayList<>();
StringBuilder builder = new StringBuilder();
builder.append("SELECT `bookId`, `bookShortName`, ");
builder.append(" `bookName` ");
builder.append(" FROM `bible`.`book`; ");
String sql = builder.toString();
try {
Statement statement = connection.createStatement();
ResultSet rs = statement.executeQuery(sql);
while (rs.next()) {
int bookID = rs.getInt("bookID");
String bookShortName = rs.getString(
"bookShortName");
String bookName = rs.getString("bookName");
Book book = new Book(bookID, bookShortName,
bookName);
books.add(book);
}
rs.close();
return books;
} catch (SQLException e) {
e.printStackTrace();
return new ArrayList<Book>();
}
}
public int selectLastChapter(int bookID) {
StringBuilder builder = new StringBuilder();
builder.append("SELECT MAX(`chapter`) ");
builder.append(" FROM `bible`.`verse` ");
builder.append(" WHERE `bookID` = ? ");
String sql = builder.toString();
try {
PreparedStatement statement =
connection.prepareStatement(sql);
statement.setInt(1, bookID);
ResultSet rs = statement.executeQuery();
rs.next();
int result = rs.getInt(1);
rs.close();
return result;
} catch (SQLException e) {
e.printStackTrace();
return -1;
}
}
public int selectLastVerse(int bookID, int chapter) {
StringBuilder builder = new StringBuilder();
builder.append("SELECT MAX(`verse`) ");
builder.append(" FROM `bible`.`verse` ");
builder.append(" WHERE `bookID` = ? ");
builder.append(" AND `chapter` = ? ");
String sql = builder.toString();
try {
PreparedStatement statement =
connection.prepareStatement(sql);
statement.setInt(1, bookID);
statement.setInt(2, chapter);
ResultSet rs = statement.executeQuery();
rs.next();
int result = rs.getInt(1);
rs.close();
return result;
} catch (SQLException e) {
e.printStackTrace();
return -1;
}
}
public List<Verse> selectPassage(VerseKey startVerseKey,
VerseKey endVerseKey) {
List<Verse> verses = new ArrayList<>();
String[] sql = new String[2];
StringBuilder builder = new StringBuilder();
builder.append("SELECT `verseID` ");
builder.append(" FROM `bible`.`verse` ");
builder.append(" WHERE `bookID` = ? ");
builder.append(" AND `chapter` = ? ");
builder.append(" AND `verse` = ?; ");
sql[0] = builder.toString();
builder = new StringBuilder();
builder.append("SELECT `bookID`, `chapter`, `verse`, "
+ "`text` ");
builder.append(" FROM `bible`.`verse` ");
builder.append(" WHERE `verseID` BETWEEN ? AND ? ");
sql[1] = builder.toString();
try {
PreparedStatement statement =
connection.prepareStatement(sql[0]);
statement.setInt(1, startVerseKey.getBookID());
statement.setInt(2, startVerseKey.getChapter());
statement.setInt(3, startVerseKey.getVerse());
ResultSet rs = statement.executeQuery();
if (!rs.next()) {
rs.close();
return verses;
}
int startIndex = rs.getInt("verseID");
rs.close();
statement.setInt(1, endVerseKey.getBookID());
statement.setInt(2, endVerseKey.getChapter());
statement.setInt(3, endVerseKey.getVerse());
rs = statement.executeQuery();
if (!rs.next()) {
rs.close();
return verses;
}
int endIndex = rs.getInt("verseID");
rs.close();
statement = connection.prepareStatement(sql[1]);
statement.setInt(1, startIndex);
statement.setInt(2, endIndex);
rs = statement.executeQuery();
while (rs.next()) {
int bookID = rs.getInt("bookID");
int chapter = rs.getInt("chapter");
int verseNum = rs.getInt("verse");
String text = rs.getString("text");
Verse verse = new Verse(bookID, chapter,
verseNum, text);
verses.add(verse);
}
rs.close();
return verses;
} catch (SQLException e) {
e.printStackTrace();
return new ArrayList<Verse>();
}
}
public Optional<Verse> selectNextVerse(VerseKey verseKey) {
String[] sql = new String[2];
StringBuilder builder = new StringBuilder();
builder.append("SELECT `verseID` ");
builder.append(" FROM `bible`.`verse` ");
builder.append(" WHERE `bookID` = ? ");
builder.append(" AND `chapter` = ? ");
builder.append(" AND `verse` = ?; ");
sql[0] = builder.toString();
builder = new StringBuilder();
builder.append("SELECT `bookID`, `chapter`, "
+ "`verse`, `text` ");
builder.append(" FROM `bible`.`verse` ");
builder.append(" WHERE `verseID` = ? ");
sql[1] = builder.toString();
try {
PreparedStatement statement =
connection.prepareStatement(sql[0]);
statement.setInt(1, verseKey.getBookID());
statement.setInt(2, verseKey.getChapter());
statement.setInt(3, verseKey.getVerse());
ResultSet rs = statement.executeQuery();
if (!rs.next()) {
rs.close();
return Optional.empty();
}
int verseID = rs.getInt("verseID");
rs.close();
statement = connection.prepareStatement(sql[1]);
statement.setInt(1, verseID + 1);
rs = statement.executeQuery();
if (!rs.next()) {
rs.close();
return Optional.empty();
}
int bookID = rs.getInt("bookID");
int chapter = rs.getInt("chapter");
int verseNum = rs.getInt("verse");
String text = rs.getString("text");
Verse verse = new Verse(bookID, chapter,
verseNum, text);
rs.close();
return Optional.of(verse);
} catch (SQLException e) {
e.printStackTrace();
return Optional.empty();
}
}
public int selectVisitCount(User user) {
StringBuilder builder = new StringBuilder();
builder.append("SELECT `numberOfVisits` ");
builder.append(" FROM `bible`.`archive` ");
builder.append(" WHERE `userID` = ?; ");
String sql = builder.toString();
String userID = user.getUserId();
try {
PreparedStatement statement =
connection.prepareStatement(sql);
statement.setString(1, userID);
ResultSet rs = statement.executeQuery();
if (!rs.next()) {
rs.close();
return -1;
}
int result = rs.getInt(1);
rs.close();
return result;
} catch (SQLException e) {
e.printStackTrace();
return -1;
}
}
public int[] selectPassageChapter(User user) {
StringBuilder builder = new StringBuilder();
builder.append("SELECT `passageBookID`, "
+ "`passageChapter`, ");
builder.append(" `passageVerse` ");
builder.append(" FROM `bible`.`archive` ");
builder.append(" WHERE `userID` = ?; ");
String sql = builder.toString();
String userID = user.getUserId();
try {
int[] output = {-1, -1, -1};
PreparedStatement statement =
connection.prepareStatement(sql);
statement.setString(1, userID);
ResultSet rs = statement.executeQuery();
if (!rs.next()) {
rs.close();
return output;
}
output[0] = rs.getInt("passageBookID");
output[1] = rs.getInt("passageChapter");
output[2] = rs.getInt("passageVerse");
rs.close();
return output;
} catch (SQLException e) {
e.printStackTrace();
int[] output = {-1, -1, -1};
return output;
}
}
public int[] selectReadingChapter(User user) {
StringBuilder builder = new StringBuilder();
builder.append("SELECT `readingBookID`, "
+ "`readingChapter`, ");
builder.append(" `readingStartVerse`, "
+ "`readingEndVerse` ");
builder.append(" FROM `bible`.`archive` ");
builder.append(" WHERE `userID` = ?; ");
String sql = builder.toString();
String userID = user.getUserId();
try {
int[] output = {-1, -1, -1, -1};
PreparedStatement statement =
connection.prepareStatement(sql);
statement.setString(1, userID);
ResultSet rs = statement.executeQuery();
if (!rs.next()) {
rs.close();
return output;
}
output[0] = rs.getInt("readingBookID");
output[1] = rs.getInt("readingChapter");
output[2] = rs.getInt("readingStartVerse");
output[3] = rs.getInt("readingEndVerse");
rs.close();
return output;
} catch (SQLException e) {
e.printStackTrace();
int[] output = {-1, -1, -1, -1};
return output;
}
}
public void insertArchiveRow(User user) {
StringBuilder builder = new StringBuilder();
builder.append("INSERT INTO `bible`.`archive` ");
builder.append(" (`archiveID`, `numberOfVisits`, ");
builder.append(" `readingBookID`, `readingChapter`, ");
builder.append(" `readingStartVerse`, "
+ "`readingEndVerse`, ");
builder.append(" `passageBookID`, ");
builder.append(" `passageChapter`, `passageVerse`, ");
builder.append(" `lastVisitTimeStamp`, `userID`) ");
builder.append("VALUES (DEFAULT, ?, ?, ?, "
+ "?, ?, ?, ?, ?, ");
builder.append(" CURRENT_TIMESTAMP, ?); ");
String sql = builder.toString();
String userID = user.getUserId();
try {
connection.setAutoCommit(false);
PreparedStatement statement =
connection.prepareStatement(sql);
statement.setInt(1, 1);
statement.setInt(2, 0);
statement.setInt(3, 0);
statement.setInt(4, 0);
statement.setInt(5, 0);
statement.setInt(6, 0);
statement.setInt(7, 0);
statement.setInt(8, 0);
statement.setString(9, userID);
statement.executeUpdate();
connection.commit();
} catch (SQLException e) {
e.printStackTrace();
}
}
public void updateVisitCount(User user) {
StringBuilder builder = new StringBuilder();
builder.append("UPDATE `bible`.`archive` ");
builder.append("SET `numberOfVisits` = "
+ "`numberOfVisits` + 1, ");
builder.append(" `lastVisitTimestamp` = "
+ "CURRENT_TIMESTAMP ");
builder.append("WHERE `userID` = ? ");
String sql = builder.toString();
String userID = user.getUserId();
try {
connection.setAutoCommit(false);
PreparedStatement statement =
connection.prepareStatement(sql);
statement.setString(1, userID);
statement.executeUpdate();
connection.commit();
} catch (SQLException e) {
e.printStackTrace();
}
}
public void updatePassageChapter(User user,
VerseKey verseKey) {
StringBuilder builder = new StringBuilder();
builder.append("UPDATE `bible`.`archive` ");
builder.append("SET `passageBookID` = ?, ");
builder.append(" `passageChapter` = ?, ");
builder.append(" `passageVerse` = ? ");
builder.append("WHERE `userID` = ? ");
String sql = builder.toString();
String userID = user.getUserId();
try {
connection.setAutoCommit(false);
PreparedStatement statement =
connection.prepareStatement(sql);
statement.setInt(1, verseKey.getBookID());
statement.setInt(2, verseKey.getChapter());
statement.setInt(3, verseKey.getVerse());
statement.setString(4, userID);
statement.executeUpdate();
connection.commit();
} catch (SQLException e) {
e.printStackTrace();
}
}
public void updateReadingChapter(User user,
VerseKey verseKey, int endVerse) {
StringBuilder builder = new StringBuilder();
builder.append("UPDATE `bible`.`archive` ");
builder.append("SET `readingBookID` = ?, ");
builder.append(" `readingChapter` = ?, ");
builder.append(" `readingStartVerse` = ?, ");
builder.append(" `readingEndVerse` = ? ");
builder.append("WHERE `userID` = ? ");
String sql = builder.toString();
String userID = user.getUserId();
try {
connection.setAutoCommit(false);
PreparedStatement statement =
connection.prepareStatement(sql);
statement.setInt(1, verseKey.getBookID());
statement.setInt(2, verseKey.getChapter());
statement.setInt(3, verseKey.getVerse());
statement.setInt(4, endVerse);
statement.setString(5, userID);
statement.executeUpdate();
connection.commit();
} catch (SQLException e) {
e.printStackTrace();
}
}
}