Studium/Internet-Technologien
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+ get(Author/Publisher/Category/Book)

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This commit is contained in:
Johannes Theiner 2019-04-17 14:59:35 +02:00
parent 388459b6a2
commit 18efa59177
3 changed files with 150 additions and 4 deletions
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147
src/main/java/de/hsel/itech/db/Database.java
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@ -1,16 +1,26 @@
package de.hsel.itech.db;
import de.hsel.itech.config.Configuration;
import de.hsel.itech.db.pojo.Author;
import de.hsel.itech.db.pojo.Book;
import de.hsel.itech.db.pojo.Category;
import de.hsel.itech.db.pojo.Publisher;
import org.jetbrains.annotations.Nullable;
import org.mariadb.jdbc.MariaDbPoolDataSource;
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.net.URL;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.time.Year;
import java.util.AbstractMap;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
/**
*
@ -41,7 +51,9 @@ public class Database {
Connection connection = getConnection();
assert connection != null;
try(BufferedReader br = new BufferedReader(new FileReader(getClass().getClassLoader().getResource("database.sql").getFile()))) {
URL file = getClass().getClassLoader().getResource("database.sql");
assert file != null;
try(BufferedReader br = new BufferedReader(new FileReader(file.getFile()))) {
for (String line = br.readLine(); line != null; line = br.readLine()) {
PreparedStatement statement = connection.prepareStatement(line);
statement.executeUpdate();
@ -88,8 +100,141 @@ public class Database {
}
@Nullable
private Map.Entry<ResultSet, Connection> getResultSet(long id, String table) {
Connection connection = getConnection();
try{
assert connection != null;
PreparedStatement statement = connection.prepareStatement("SELECT * FROM ? WHERE ID = ?");
statement.setString(1, table);
statement.setLong(2, id);
ResultSet resultSet = statement.executeQuery();
if(resultSet.next()) {
return new AbstractMap.SimpleEntry<>(resultSet, connection);
}
return null;
}catch (SQLException ex) {
ex.printStackTrace();
}
return null;
}
@Nullable
private Map.Entry<List<ResultSet>, Connection> getResultSets(long id, String table, String column) {
Connection connection = getConnection();
try {
assert connection != null;
PreparedStatement statement = connection.prepareStatement("SELECT * FROM ? WHERE ? = ?");
statement.setString(1, table);
statement.setString(2, column);
statement.setLong(3, id);
ResultSet resultSet = statement.executeQuery();
Map.Entry<List<ResultSet>, Connection> entry = new AbstractMap.SimpleEntry<>(new ArrayList<>(), connection);
while(resultSet.next()) {
entry.getKey().add(resultSet);
}
return entry;
}catch (SQLException ex) {
ex.printStackTrace();
}
return null;
}
@Nullable
public Author getAuthor(long id) {
Map.Entry<ResultSet, Connection> entry = getResultSet(id, "author");
assert entry != null;
ResultSet rs = entry.getKey();
Author author = null;
try {
author = new Author(rs.getLong("id"), rs.getString("name"));
entry.getValue().close();
} catch (SQLException e) {
e.printStackTrace();
}
return author;
}
@Nullable
public Category getCategory(long id) {
Map.Entry<ResultSet, Connection> entry = getResultSet(id, "category");
assert entry != null;
ResultSet rs = entry.getKey();
Category category = null;
try {
category = new Category(rs.getLong("id"), rs.getString("name"), rs.getString("image"));
entry.getValue().close();
} catch (SQLException e) {
e.printStackTrace();
}
return category;
}
@Nullable
public Publisher getPublisher(long id) {
Map.Entry<ResultSet, Connection> entry = getResultSet(id, "category");
assert entry != null;
ResultSet rs = entry.getKey();
Publisher publisher = null;
try {
publisher = new Publisher(rs.getLong("id"), rs.getString("name"));
entry.getValue().close();
} catch (SQLException e) {
e.printStackTrace();
}
return publisher;
}
@Nullable
private List<Integer> getAuthors(long id) {
Map.Entry<List<ResultSet>, Connection> entry = getResultSets(id, "author_book", "book");
assert entry != null;
try {
List<Integer> list = new ArrayList<>();
for(ResultSet rs : entry.getKey()) {
list.add(rs.getInt("author"));
}
entry.getValue().close();
return list;
} catch (SQLException e) {
e.printStackTrace();
}
return null;
}
@Nullable
public Book getBook(long id) {
Map.Entry<ResultSet, Connection> entry = getResultSet(id, "book");
assert entry != null;
ResultSet rs = entry.getKey();
Book book = null;
try {
Category category = getCategory(rs.getLong("category"));
Publisher publisher = getPublisher(rs.getLong("publisher"));
List<Integer> authorIds = getAuthors(id);
assert authorIds != null;
List<Author> authors = new ArrayList<>();
for(int i : authorIds) {
Author author = getAuthor(i);
assert author != null;
authors.add(author);
}
book = new Book(rs.getLong("id"), authors, publisher, category, rs.getString("title"), Year.of(rs.getInt("year")), rs.getInt("price"), rs.getString("description"), rs.getString("image"));
entry.getValue().close();
} catch (SQLException e) {
e.printStackTrace();
}
return book;
}
}

5
src/main/java/de/hsel/itech/db/pojo/Book.java
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@ -4,6 +4,7 @@ import lombok.AllArgsConstructor;
import lombok.Data;
import java.time.Year;
import java.util.List;
/**
* @author Johannes Theiner
@ -15,8 +16,8 @@ import java.time.Year;
@AllArgsConstructor
public class Book {
private int isbn;
private Author author;
private long isbn;
private List<Author> authors;
private Publisher publisher;
private Category category;
private String title;

2
src/main/java/de/hsel/itech/db/pojo/Category.java
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@ -13,7 +13,7 @@ import lombok.Data;
@AllArgsConstructor
public class Category {
private int id;
private long id;
private String name;
private String image;
}