Dodatkowe przykłady JPA na serwerze

PC29-HibernateNaSerwerze/src/main/java/sklep/serwlety/Lista0.java

@@ -17,7 +17,7 @@ import javax.servlet.http.HttpServletResponse;
 import sklep.model.Product;
 
 // http://localhost:8080/PC29-HibernateNaSerwerze-1.0/Lista0
-@WebServlet("/Lista0")
+@WebServlet("/lista0")
 public class Lista0 extends HttpServlet {
 	private static final long serialVersionUID = 1L;
 

PC29-HibernateNaSerwerze/src/main/java/sklep/serwlety/Lista1.java

+package sklep.serwlety;
+
+import java.io.IOException;
+import java.io.PrintWriter;
+import java.util.List;
+
+import javax.persistence.EntityManager;
+import javax.persistence.EntityManagerFactory;
+import javax.persistence.Persistence;
+import javax.persistence.TypedQuery;
+import javax.servlet.ServletException;
+import javax.servlet.annotation.WebServlet;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+import sklep.model.Product;
+
+// Wersja z ręcznym uzyskaniem dostępu do `persistence` - poprzez fabrykę, a nie wstrzykiwanie zależności.
+// To jest napisane niemal tak, jak "zwykły program z mainem".
+// To serwer zapewnia implementację JPA - my nie dodajemy jej do pom.xml (dodajemy tylko javaee-web-api)
+// WildFly użyje Hibernate, a Glassfish użyje Eclipse Link.
+// Wersja zadziała także przy konfiguracji połączenia "RESOURCE_LOCAL" z parametrami połączenia podanymi w persistence.xml
+@WebServlet("/lista1")
+public class Lista1 extends HttpServlet {
+	private static final long serialVersionUID = 1L;
+
+	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
+		response.setContentType("text/plain");
+		response.setCharacterEncoding("UTF-8");
+		PrintWriter out = response.getWriter();
+		
+		EntityManagerFactory emf = null;
+		EntityManager em = null;
+		try {
+			emf = Persistence.createEntityManagerFactory("sklep");
+			em = emf.createEntityManager();
+			
+			TypedQuery<Product> query = em.createNamedQuery("Product.findAll", Product.class);
+			List<Product> products = query.getResultList();
+			out.println("Odczytano " + products.size() + " rekordów:");
+			for (Product product : products) {
+				out.println(product.getProductName() + " " + product.getPrice());
+			}
+		} catch(Exception e) {
+			out.println("Wyjątek: " + e);
+		} finally {
+			if(em != null) em.close();
+			if(emf != null) emf.close();
+		}
+	}
+
+}

PC29-HibernateNaSerwerze/src/main/java/sklep/serwlety/Lista2.java

+package sklep.serwlety;
+
+import java.io.IOException;
+import java.io.PrintWriter;
+import java.util.List;
+
+import javax.persistence.EntityManager;
+import javax.persistence.EntityManagerFactory;
+import javax.persistence.PersistenceUnit;
+import javax.persistence.TypedQuery;
+import javax.servlet.ServletException;
+import javax.servlet.annotation.WebServlet;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+import sklep.model.Product;
+
+// Wersja ze wstrzykiwaniem EntityManagerFactory za pomocą adnotacji @PersistenceUnit.
+// Jeśli w aplikacji jest tylko jeden persistence unit, to nazwy można nie podawać, ale ja wolę zawsze podać.
+// Ta wersja jest odpowiednia także dla konfiguracji opartej o RESOURCE_LOCAL
+
+@WebServlet("/lista2")
+public class Lista2 extends HttpServlet {
+	private static final long serialVersionUID = 1L;
+	
+	@PersistenceUnit(unitName="sklep")
+	private EntityManagerFactory emf;
+
+	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
+		response.setContentType("text/plain");
+		response.setCharacterEncoding("UTF-8");
+		PrintWriter out = response.getWriter();
+		
+		EntityManager em = null;
+		try {
+			em = emf.createEntityManager();
+			
+			TypedQuery<Product> query = em.createNamedQuery("Product.findAll", Product.class);
+			List<Product> products = query.getResultList();
+			out.println("Odczytano " + products.size() + " rekordów:");
+			for (Product product : products) {
+				out.println(product.getProductName() + " " + product.getPrice());
+			}
+		} catch(Exception e) {
+			out.println("Wyjątek: " + e + "\n");
+			e.printStackTrace(out);
+		} finally {
+			if(em != null) em.close();
+		}
+	}
+
+}

PC29-HibernateNaSerwerze/src/main/java/sklep/serwlety/Lista3.java

+package sklep.serwlety;
+
+import java.io.IOException;
+import java.io.PrintWriter;
+import java.util.List;
+
+import javax.persistence.EntityManager;
+import javax.persistence.PersistenceContext;
+import javax.persistence.TypedQuery;
+import javax.servlet.ServletException;
+import javax.servlet.annotation.WebServlet;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+import sklep.model.Product;
+
+// Wersja ze wstrzykiwaniem EntityManager (a nie fabryki) za pomocą adnotacji @PersistenceContext.
+// Jeśli w aplikacji jest tylko jeden persistence unit, to nazwy można nie podawać, ale ja wolę zawsze podać.
+// Ta wersja jest odpowiednia dla konfiguracji opartej o JTA
+
+//@WebServlet("/lista3")
+public class Lista3 extends HttpServlet {
+	private static final long serialVersionUID = 1L;
+	
+	@PersistenceContext(unitName="sklep")
+	private EntityManager em;
+
+	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
+		response.setContentType("text/plain");
+		response.setCharacterEncoding("UTF-8");
+		PrintWriter out = response.getWriter();
+		
+		try {
+			TypedQuery<Product> query = em.createNamedQuery("Product.findAll", Product.class);
+			List<Product> products = query.getResultList();
+			out.println("Odczytano " + products.size() + " rekordów:");
+			for (Product product : products) {
+				out.println(product.getProductName() + " " + product.getPrice());
+			}
+		} catch(Exception e) {
+			out.println("Wyjątek: " + e + "\n");
+			e.printStackTrace(out);
+		}
+	}
+
+}

PC29-HibernateNaSerwerze/src/main/java/sklep/serwlety/Sql1.java

+package sklep.serwlety;
+
+import java.io.IOException;
+import java.io.PrintWriter;
+import java.math.BigDecimal;
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+
+import javax.servlet.ServletException;
+import javax.servlet.annotation.WebServlet;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+@WebServlet("/sql1")
+public class Sql1 extends HttpServlet {
+	private static final long serialVersionUID = 1L;
+
+	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
+		response.setContentType("text/plain");
+		response.setCharacterEncoding("UTF-8");
+		PrintWriter out = response.getWriter();
+
+		try {
+			
+			final String sql = "SELECT * FROM products";
+			try (Connection c = DriverManager.getConnection("jdbc:postgresql://localhost/sklep", "kurs", "abc123")) {
+				out.println("Connection połączone: " + c);
+				try (PreparedStatement stmt = c.prepareStatement(sql)) {
+					try (ResultSet rs = stmt.executeQuery()) {
+						while (rs.next()) {
+							int id = rs.getInt("product_id");
+							String productName = rs.getString("product_name");
+							BigDecimal price = rs.getBigDecimal("price");
+							String description = rs.getString("description");
+							out.printf("\n * Produkt nr %d: %s w cenie %s (%s)\n", id, productName, price, description);
+						}
+					}
+				}
+			}
+		} catch (SQLException e) {
+			e.printStackTrace(out);
+		} catch (Exception e) {
+			e.printStackTrace(out);
+		}
+	}
+
+}

PC29-HibernateNaSerwerze/src/main/java/sklep/serwlety/Sql2.java

+package sklep.serwlety;
+
+import java.io.IOException;
+import java.io.PrintWriter;
+import java.math.BigDecimal;
+import java.sql.Connection;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+
+import javax.naming.InitialContext;
+import javax.naming.NamingException;
+import javax.servlet.ServletException;
+import javax.servlet.annotation.WebServlet;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import javax.sql.DataSource;
+
+@WebServlet("/sql2")
+public class Sql2 extends HttpServlet {
+	private static final long serialVersionUID = 1L;
+
+	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
+		response.setContentType("text/plain");
+		response.setCharacterEncoding("UTF-8");
+		PrintWriter out = response.getWriter();
+
+		try {
+			// Połączenie z bazą (jako DataSource) pobieramy z rejestru serwera (technologia JNDI - zasoby zarządzane przez serwer Java EE)
+			InitialContext ctx = new InitialContext();
+			DataSource ds = (DataSource) ctx.lookup("java:/SklepDS");
+			out.println("DataSource znaleziony: " + ds);
+			
+			final String sql = "SELECT * FROM products";
+			try (Connection c = ds.getConnection()) {
+				try (PreparedStatement stmt = c.prepareStatement(sql)) {
+					try (ResultSet rs = stmt.executeQuery()) {
+						while (rs.next()) {
+							int id = rs.getInt("product_id");
+							String productName = rs.getString("product_name");
+							BigDecimal price = rs.getBigDecimal("price");
+							String description = rs.getString("description");
+							out.printf("\n * Produkt nr %d: %s w cenie %s (%s)\n", id, productName, price, description);
+						}
+					}
+				}
+			}
+		} catch (SQLException e) {
+			e.printStackTrace(out);
+		} catch (NamingException e) {
+			e.printStackTrace(out);
+		} catch (Exception e) {
+			e.printStackTrace(out);
+		}
+	}
+
+}

PC29-HibernateNaSerwerze/src/main/java/sklep/serwlety/Sql3.java

+package sklep.serwlety;
+
+import java.io.IOException;
+import java.io.PrintWriter;
+import java.math.BigDecimal;
+import java.sql.Connection;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+
+import javax.annotation.Resource;
+import javax.servlet.ServletException;
+import javax.servlet.annotation.WebServlet;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import javax.sql.DataSource;
+
+@WebServlet("/sql3")
+public class Sql3 extends HttpServlet {
+	private static final long serialVersionUID = 1L;
+	
+	@Resource(lookup="java:/SklepDS")
+	private DataSource ds;
+
+	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
+		response.setContentType("text/plain");
+		response.setCharacterEncoding("UTF-8");
+		PrintWriter out = response.getWriter();
+
+		try {
+			out.println("DataSource wstrzyknięty: " + ds);
+			
+			final String sql = "SELECT * FROM products";
+			try (Connection c = ds.getConnection()) {
+				try (PreparedStatement stmt = c.prepareStatement(sql)) {
+					try (ResultSet rs = stmt.executeQuery()) {
+						while (rs.next()) {
+							int id = rs.getInt("product_id");
+							String productName = rs.getString("product_name");
+							BigDecimal price = rs.getBigDecimal("price");
+							String description = rs.getString("description");
+							out.printf("\n * Produkt nr %d: %s w cenie %s (%s)\n", id, productName, price, description);
+						}
+					}
+				}
+			}
+		} catch (SQLException e) {
+			e.printStackTrace(out);
+		} catch (Exception e) {
+			e.printStackTrace(out);
+		}
+	}
+
+}

PC29-HibernateNaSerwerze/src/main/java/sklep/serwlety/Zmiana2.java

+package sklep.serwlety;
+
+import java.io.IOException;
+import java.io.PrintWriter;
+import java.math.BigDecimal;
+
+import javax.persistence.EntityManager;
+import javax.persistence.EntityManagerFactory;
+import javax.persistence.EntityTransaction;
+import javax.persistence.PersistenceUnit;
+import javax.servlet.ServletException;
+import javax.servlet.annotation.WebServlet;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+import sklep.model.Product;
+
+@WebServlet("/zmiana2")
+public class Zmiana2 extends HttpServlet {
+	private static final long serialVersionUID = 1L;
+
+	@PersistenceUnit(unitName="sklep")
+	private EntityManagerFactory emf;
+
+	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
+		response.setContentType("text/plain");
+		response.setCharacterEncoding("utf-8");
+		PrintWriter out = response.getWriter();
+		
+		if(request.getParameter("id") == null) {
+			out.println("Trzeba podać id produktu");
+			return;
+		}
+		
+		Integer id = Integer.valueOf(request.getParameter("id"));
+		BigDecimal podwyzka = null;
+		if(request.getParameter("podwyzka") != null) {
+			podwyzka = new BigDecimal(request.getParameter("podwyzka"));
+		}
+		
+		EntityManager em = null;
+		try {
+			em = emf.createEntityManager();
+			EntityTransaction transaction = em.getTransaction();
+			transaction.begin();
+			
+			Product product = em.find(Product.class, id);
+			if(product == null) {
+				out.println("Nie znaleziono produktu o numerze " + id);
+				return;
+			}
+			
+			out.println(product.getProductName() + " " + product.getPrice());
+			
+			if(podwyzka != null) {
+				product.setPrice(product.getPrice().add(podwyzka));
+			}
+			
+			out.println("Po zmianie:");
+			out.println(product.getProductName() + " " + product.getPrice());
+			
+			transaction.commit();
+			
+		} catch (SecurityException | IllegalStateException e) {
+			throw new ServletException("wielka bieda", e);
+		} finally {
+			if(em != null) {
+				em.close();
+			}
+		}
+		
+	}
+
+}

PC29-HibernateNaSerwerze/src/main/java/sklep/serwlety/Zmiana3.java

+package sklep.serwlety;
+
+import java.io.IOException;
+import java.io.PrintWriter;
+import java.math.BigDecimal;
+
+import javax.annotation.Resource;
+import javax.persistence.EntityManager;
+import javax.persistence.PersistenceContext;
+import javax.servlet.ServletException;
+import javax.servlet.annotation.WebServlet;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import javax.transaction.UserTransaction;
+
+import sklep.model.Product;
+
+//@WebServlet("/zmiana3")
+public class Zmiana3 extends HttpServlet {
+	private static final long serialVersionUID = 1L;
+
+	@PersistenceContext(unitName="sklep")
+	private EntityManager em;
+	
+	@Resource
+	private UserTransaction transaction; // konwencja nazw: utx
+
+	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
+		response.setContentType("text/plain");
+		response.setCharacterEncoding("utf-8");
+		PrintWriter out = response.getWriter();
+		
+		if(request.getParameter("id") == null) {
+			out.println("Trzeba podać id produktu");
+			return;
+		}
+		
+		Integer id = Integer.valueOf(request.getParameter("id"));
+		BigDecimal podwyzka = null;
+		if(request.getParameter("podwyzka") != null) {
+			podwyzka = new BigDecimal(request.getParameter("podwyzka"));
+		}
+		
+		try {
+			transaction.begin();
+			
+			Product product = em.find(Product.class, id);
+			if(product == null) {
+				out.println("Nie znaleziono produktu o numerze " + id);
+				return;
+			}
+			
+			out.println(product.getProductName() + " " + product.getPrice());
+			
+			if(podwyzka != null) {
+				product.setPrice(product.getPrice().add(podwyzka));
+			}
+			
+			out.println("Po zmianie:");
+			out.println(product.getProductName() + " " + product.getPrice());
+			
+			transaction.commit();
+			
+		// } catch (SecurityException | IllegalStateException | RollbackException | HeuristicMixedException | HeuristicRollbackException | SystemException | NotSupportedException e) {
+		} catch (Exception e) {
+			throw new ServletException("wielka bieda", e);
+		}
+		
+	}
+
+}

PC29-HibernateNaSerwerze/src/main/webapp/index.html

@@ -6,8 +6,24 @@
 </head>
 <body>
 <h1>Hibernate na serwerze</h1>
+<h2>Zapytania SQL</h2>
 <ul>
-<li><a href="Lista0">lista0</a> - wersja bez konfiguracji serwera</li>
+<li><a href="sql1">sql1</a> - normalne <code>getConnection</code> - nie zadziała bez sterownika</li>
+<li><a href="sql2">sql2</a> - DataSource za pomocą <code>ctx.lookup</code></li>
+<li><a href="sql3">sql3</a> - wstrzykiwanie DataSource</li>
+</ul>
+<h2>Zapytania JPA/Hibernate</h2>
+<ul>
+<li><a href="lista0">lista0</a> - wersja bez konfiguracji serwera, później zmieniona na użycie data source typu resource/local</li>
+<li><a href="lista1">lista1</a> - stara wersja odstawowa</li>
+<li><a href="lista2">lista2</a> - wersja ze wstrzykiwaniem EntityManagerFactory, działająca dla datasource typu resource/local</li>
+<li><a href="lista3">lista3</a> - wersja ze wstrzykiwaniem EntityManager, działająca dla datasource typu JTA (wymaga zmiany konfiguracji)</li>
+</ul>
+<h2>Modyfikacja danych JPA/Hibernate</h2>
+<p>(podwyżka ceny pralki o 500)</p>
+<ul>
+<li><a href="zmiana2?id=1&amp;podwyzka=500">zmiana2</a> - wersja dla datasource typu resource/local</li>
+<li><a href="zmiana3?id=1&amp;podwyzka=500">zmiana3</a> - wersja dla datasource typu JTA (wymaga zmiany konfiguracji)</li>
 </ul>
 </body>
 </html>
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