3.2模型

3.3控制器

我不会在这里探索所有这些技术。 请随意查看本文结尾处的参考。

在本文中，我们将看到如何使用模型的JPA和控制器的NetBeans Lookup API来构建MVC GIS应用程序。 在以后的文章中，我们将看到替代技术，例如用Speedment替换JPA和用Dukescript用MVVM替换MVC。

4.1我们的观点

# These layers are turned on when the map is first started.  Order
# does not matter here...
openmap.startUpLayers=demo cities graticule shapePolitical# Layers listed here appear on the Map in the order of their names.
openmap.layers=demo cities graticule shapePolitical
...
###
# LocationLayer that holds cities.  The palette for this layer lets
# you turn on the names and declutter matrix, if you want.  The
# declutter matrix can get expensive at small scales.
cities.class=com.bbn.openmap.layer.location.LocationLayer
cities.prettyName=World Cities
cities.locationHandlers=csvcities
cities.useDeclutter=false
cities.declutterMatrix=com.bbn.openmap.layer.DeclutterMatrixcsvcities.class=com.bbn.openmap.layer.location.csv.CSVLocationHandler
csvcities.prettyName=World Cities
csvcities.locationFile=resources/map/cities.csv
csvcities.csvFileHasHeader=true
csvcities.locationColor=FF0000
csvcities.nameColor=008C54
csvcities.showNames=false
csvcities.showLocations=true
csvcities.nameIndex=0
csvcities.latIndex=5
csvcities.lonIndex=4
csvcities.csvFileHasHeader=true

CREATE TABLE supplier (
SID             INTEGER           PRIMARY KEY,
NAME               VARCHAR2 (30)     NOT NULL,
CITY               VARCHAR2 (30)     NOT NULL,
TYPE            VARCHAR2 (10)     NOT NULL
CONSTRAINT TYPE CHECK (TYPE IN ('GROSS','RETAIL')),
LATITUDE        NUMBER (12,10)    NOT NULL
CONSTRAINT LATITUDE CHECK (LATITUDE BETWEEN -90.0000000000 AND 90.0000000000),
LONGITUDE           NUMBER (13,10)    NOT NULL
CONSTRAINT LONGITUDE CHECK (LONGITUDE BETWEEN -180.0000000000 AND 180.0000000000),
CONSTRAINT UID UNIQUE (SID, NAME, LATITUDE, LONGITUDE)
)

INSERT INTO supplier (NAME, CITY, TYPE, LATITUDE, LONGITUDE)
VALUES ('HP', 'ATHENS', 'GROSS', 38.1216011, 23.65486336);
INSERT INTO supplier (NAME, CITY, TYPE, LATITUDE, LONGITUDE)
VALUES ('DELL', 'BRUSSELS', 'RETAIL', 50.83704758, 4.367612362);
INSERT INTO supplier (NAME, CITY, TYPE, LATITUDE, LONGITUDE)
VALUES ('APPLE', 'LONDON', 'RETAIL', 51.48791122, -0.177998126);
INSERT INTO supplier (NAME, CITY, TYPE, LATITUDE, LONGITUDE)
VALUES ('TOSHIBA', 'PARIS', 'GROSS', 48.88155365, 2.432832718);

<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.1" xmlns="http://xmlns.jcp.org/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd"><persistence-unit name="OpenMapPU" transaction-type="RESOURCE_LOCAL"><provider>org.eclipse.persistence.jpa.PersistenceProvider</provider><class>openmap.model.Supplier</class><properties><property name="javax.persistence.jdbc.url" value="jdbc:sqlite:C:\db\suppliers.sqlite3"/><property name="javax.persistence.jdbc.user" value=""/><property name="javax.persistence.jdbc.driver" value="org.sqlite.JDBC"/><property name="javax.persistence.jdbc.password" value=""/></properties></persistence-unit>
</persistence>

package openmap.model;import java.io.Serializable;
import javax.persistence.Basic;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.NamedQueries;
import javax.persistence.NamedQuery;
import javax.persistence.Table;
import javax.persistence.Transient;/**** @author ikost*/
@Entity
@Table(name = "supplier")
@NamedQueries({@NamedQuery(name = "Supplier.findAll", query = "SELECT s FROM Supplier s"),@NamedQuery(name = "Supplier.findBySid", query = "SELECT s FROM Supplier s WHERE s.sid = :sid"),@NamedQuery(name = "Supplier.findByName", query = "SELECT s FROM Supplier s WHERE s.name = :name"),@NamedQuery(name = "Supplier.findByCity", query = "SELECT s FROM Supplier s WHERE s.city = :city"),@NamedQuery(name = "Supplier.findByType", query = "SELECT s FROM Supplier s WHERE s.type = :type"),@NamedQuery(name = "Supplier.findByLatitude", query = "SELECT s FROM Supplier s WHERE s.latitude = :latitude"),@NamedQuery(name = "Supplier.findByLongitude", query = "SELECT s FROM Supplier s WHERE s.longitude = :longitude")})
public class Supplier implements Serializable {private static final long serialVersionUID = 1L;@Id@GeneratedValue(strategy = GenerationType.IDENTITY)@Basic(optional = false)@Column(name = "SID")private int sid;@Basic(optional = false)@Column(name = "NAME")private String name;@Basic(optional = false)@Column(name = "CITY")private String city;@Basic(optional = false)@Column(name = "TYPE")@Enumerated(EnumType.STRING)private String type;@Basic(optional = false)@Column(name = "LATITUDE")private double latitude;@Basic(optional = false)@Column(name = "LONGITUDE")private double longitude;public enum TYPE {GROSS, RETAIL};public Supplier() {}public Supplier(int id) {this.sid = id;}public Supplier(int id, String name, String city,TYPE type, double latitude, double longitude) {this.sid = id;this.name = name;this.city = city;this.type = type;this.latitude = latitude;this.longitude = longitude;}public int getSid() {return sid;}public void setSid(int sid) {this.sid = sid;}public String getName() {return name;}public void setName(String name) {this.name = name;}public String getCity() {return city;}public void setCity(String city) {this.city = city;}public TYPE getType() {return type;}public void setType(TYPE type) {this.type = type;}public double getLatitude() {return latitude;}public void setLatitude(double latitude) {this.latitude = latitude;}public double getLongitude() {return longitude;}public void setLongitude(double longitude) {this.longitude = longitude;}@Overridepublic int hashCode() {return sid;}@Overridepublic boolean equals(Object object) {if (!(object instanceof Supplier)) {return false;}Supplier other = (Supplier) object;if (this.sid != other.sid) {return false;}return true;}@Overridepublic String toString() {return "openmap.model.Supplier[ sid =" + sid + " ]";}}

package openmap.controller;import java.io.Serializable;
import java.util.List;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.Query;
import javax.persistence.EntityNotFoundException;
import javax.persistence.criteria.CriteriaQuery;
import javax.persistence.criteria.Root;
import openmap.controller.exceptions.NonexistentEntityException;
import openmap.model.Supplier;/**** @author ikost*/
public class SupplierJpaController implements Serializable {public SupplierJpaController(EntityManagerFactory emf) {this.emf = emf;}private EntityManagerFactory emf = null;public EntityManager getEntityManager() {return emf.createEntityManager();}public void create(Supplier supplier) {EntityManager em = null;try {em = getEntityManager();em.getTransaction().begin();em.persist(supplier);em.getTransaction().commit();} finally {if (em != null) {em.close();}}}public void edit(Supplier supplier) throws NonexistentEntityException, Exception {EntityManager em = null;try {em = getEntityManager();em.getTransaction().begin();supplier = em.merge(supplier);em.getTransaction().commit();} catch (Exception ex) {String msg = ex.getLocalizedMessage();if (msg == null || msg.length() == 0) {int id = supplier.getSid();if (findSupplier(id) == null) {throw new NonexistentEntityException("The supplier with id " + id + " no longer exists.");}}throw ex;} finally {if (em != null) {em.close();}}}public void destroy(int id) throws NonexistentEntityException {EntityManager em = null;try {em = getEntityManager();em.getTransaction().begin();Supplier supplier;try {supplier = em.getReference(Supplier.class, id);supplier.getSid();} catch (EntityNotFoundException enfe) {throw new NonexistentEntityException("The supplier with id " + id + " no longer exists.", enfe);}em.remove(supplier);em.getTransaction().commit();} finally {if (em != null) {em.close();}}}public List<Supplier> findSupplierEntities() {return findSupplierEntities(true, -1, -1);}public List<Supplier> findSupplierEntities(int maxResults, int firstResult) {return findSupplierEntities(false, maxResults, firstResult);}private List<Supplier> findSupplierEntities(boolean all, int maxResults, int firstResult) {EntityManager em = getEntityManager();try {CriteriaQuery cq = em.getCriteriaBuilder().createQuery();cq.select(cq.from(Supplier.class));Query q = em.createQuery(cq);if (!all) {q.setMaxResults(maxResults);q.setFirstResult(firstResult);}return q.getResultList();} finally {em.close();}}public Supplier findSupplier(int id) {EntityManager em = getEntityManager();try {return em.find(Supplier.class, id);} finally {em.close();}}public int getSupplierCount() {EntityManager em = getEntityManager();try {CriteriaQuery cq = em.getCriteriaBuilder().createQuery();Root<Supplier> rt = cq.from(Supplier.class);cq.select(em.getCriteriaBuilder().count(rt));Query q = em.createQuery(cq);return ((Long) q.getSingleResult()).intValue();} finally {em.close();}}
}

package openmap.controller;import java.util.List;
import openmap.model.Supplier;/*** A facade of our controllers.** @author ikost*/
public interface IDBManager {List getSuppliers();
}

package openmap.controller;import java.util.List;
import javax.persistence.EntityManagerFactory;
import javax.persistence.Persistence;
import openmap.model.Supplier;
import org.openide.util.lookup.ServiceProvider;@ServiceProvider(service = IDBManager.class)
public class DBManager implements IDBManager {private final EntityManagerFactory emf;private final SupplierJpaController suppliers;public DBManager() {emf = Persistence.createEntityManagerFactory("OpenMapPU");suppliers = new SupplierJpaController(emf);}@Overridepublic List getSuppliers() {return suppliers.findSupplierEntities();}
}

Provider provider = Lookup.getDefault().lookup(Provider.class);
provider.aMethod();

Collection providers = Lookup.getDefault().lookupAll(Provider.class);
for (Provider provider : providers) { ... }

最后，我们需要创建一个新图层，该图层将在地图上显示我们的供应商，并在openmap.properties中声明它，以便将其添加到地图中。 如果您遵循以前的教程，那么现在应该很容易做到。 让我们逐步构建SupplierLayer.java ：

清单9 – SupplierLayer.java

package openmap.controller;
public class SupplierLayer extends OMGraphicHandlerLayer {private static final String LOOKUP_OBJECT = "Lookup Object";public SupplierLayer() {// This is how to set the ProjectionChangePolicy, which// dictates how the layer behaves when a new projection is// received.setProjectionChangePolicy(new StandardPCPolicy(this, true));setRenderPolicy(new BufferedImageRenderPolicy());// Making the setting so this layer receives events from the// SelectMouseMode, which has a modeID of "Gestures". Other// IDs can be added as needed.setMouseModeIDsForEvents(new String[]{"Gestures"});}/*** Called from the prepare() method if the layer discovers that its* OMGraphicList is {@code null}.** @return new {@code OMGraphicList} with {@code OMGraphics{ that you always* want to display and reproject as necessary.*/public OMGraphicList init() {final IDBManager dbManager = Lookup.getDefault().lookup(IDBManager.class);final List suppliers = dbManager.getSuppliers();// This layer keeps a pointer to an OMGraphicList that it uses// for painting. It's initially set to null, which is used as// a flag in prepare() to signal that the OMGraphcs need to be// created. The list returned from prepare() gets set in the// layer.// This layer uses the StandardPCPolicy for new// projections, which keeps the list intact and simply calls// generate() on it with the new projection, and repaint()// which calls paint().OMGraphicList omList = new OMGraphicList();// Add suppliers as OMPoints.for (Supplier supplier : suppliers) {OMPoint omSupplier = new OMPoint(supplier.getLatitude(),supplier.getLongitude(), 3);  // radiusomSupplier.putAttribute(OMGraphicConstants.LABEL,new OMTextLabeler(supplier.getName(), OMText.JUSTIFY_LEFT));omSupplier.putAttribute(LOOKUP_OBJECT, supplier);omSupplier.setLinePaint(Color.BLUE);omSupplier.setSelectPaint(Color.ORANGE);omSupplier.setOval(true);omList.add(omSupplier);}return omList;}/*** This is an important Layer method to override. The prepare method gets* called when the layer is added to the map, or when the map projection* changes. We need to make sure the OMGraphicList returned from this method* is what we want painted on the map. The OMGraphics need to be generated* with the current projection. We test for a null OMGraphicList in the* layer to see if we need to create the OMGraphics. This layer doesn't* change it's OMGraphics for different projections, if your layer does, you* need to clear out the OMGraphicList and add the OMGraphics you want for* the current projection.** @return*/@Overridepublic synchronized OMGraphicList prepare() {OMGraphicList list = getList();// Here's a test to see if it's the first time that the layer has been// added to the map. This list object will be whatever was returned from// this method the last time prepare() was called. In this// example, we always return an OMGraphicList object, so if it's null,// prepare() must not have been called yet.if (list == null) {list = init();}/** This call to the list is critical! OMGraphics need to be told where* to paint themselves, and they figure that out when they are given the* current Projection in the generate(Projection) call. If an* OMGraphic's location is changed, it will need to be regenerated* before it is rendered, otherwise it won't draw itself. You generally* know you have a generate problem when OMGraphics show up with the* projection changes (zooms and pans), but not at any other time after* something about the OMGraphic changes.** If you want to be more efficient, you can replace this call to the* list as an else clause to the (list == null) check above, and call* generate(Projection) on all the OMGraphics in the init() method below* as you create them. This will prevent the* OMGraphicList.generate(Projection) call from making an additional* loop through all of the OMGraphics before they are returned.*/list.generate(getProjection());return list;}/*** Query that an OMGraphic can be highlighted when the mouse moves over it.* If the answer is true, then highlight with this OMGraphics will be* called.** @param omg* @return*/@Overridepublic boolean isHighlightable(OMGraphic omg) {return true;}/*** Query that an OMGraphic is selectable. Examples of handing selection are* in the EditingLayer. The default OMGraphicHandlerLayer behavior is to add* the OMGraphic to an OMGraphicList called selectedList. If you aren't* going to be doing anything in particular with the selection, then return* false here to reduce the workload of the layer.** @param omg* @return* @see com.bbn.openmap.layer.OMGraphicHandlerLayer#select* @see com.bbn.openmap.layer.OMGraphicHandlerLayer#deselect*/@Overridepublic boolean isSelectable(OMGraphic omg) {return true;}/*** Query for what tooltip to display for an OMGraphic* the mouse is over.** @param omg* @return*/@Overridepublic String getToolTipTextFor(OMGraphic omg) {String ttText = null;if (omg instanceof OMPoint) {OMPoint point = ((OMPoint) omg);Object attribute = point.getAttribute(OMGraphicConstants.LABEL);if (attribute != null && attribute instanceof OMTextLabeler) {OMTextLabeler labeler = (OMTextLabeler) attribute;ttText = labeler.getData();}}return ttText;}@Overridepublic Component getGUI() {JPanel panel = PaletteHelper.createPaletteJPanel("Suppliers Layer");JCheckBox chkShowLabels = new JCheckBox("Show/Hide Labels", true);chkShowLabels.addItemListener((ItemEvent e) -> {OMGraphicList omSuppliers = getList();for (OMGraphic omSupplier : omSuppliers) {if (chkShowLabels.isSelected()) {omSupplier.putAttribute(OMGraphicConstants.LABEL,new OMTextLabeler(((Supplier) omSupplier.getAttribute(LOOKUP_OBJECT)).getName(),OMText.JUSTIFY_LEFT));} else {omSupplier.removeAttribute(OMGraphicConstants.LABEL);}}repaint();});panel.add(chkShowLabels);return panel;}
}

将类型文本字段更改为组合框，因为type仅限制为enum值'GROSS'和'RETAIL' 。

1. 右键单击组合框，然后选择“ Customize Code…
2. 单击第二个默认代码组合框，然后将其更改为custom属性 。
3. 将代码更改为以下代码，然后单击“ 确定” ：

cmbType.setModel(new javax.swing.DefaultComboBoxModel<>(Supplier.TYPE.values()));

做得好！ 您已经构建了大多数功能，并且您的设计允许您进行修改而无需更改所有层。

这是您可以尝试的TODO列表：

• 将上述对话框中的纬度/经度文本字段设置为易于阅读的格式，即xxºyy'zzz"N|S ， xxxºyy'zzz"E|W
  • 提示 ：使用我们在上一篇文章中显示的DMSCoordInfoFormatter格式化纬度/经度双DMSCoordInfoFormatter值；
  • 您可以为纬度和经度的小时/分钟/秒使用单独的文本字段，以便用户可以轻松键入新值而不会弄乱特殊字符；
  • 保存更改后，确保OMPoint显示在其新位置； 你需要添加PropertyChangeListener在SupplierLayer监听在改变Supplier ：

  清单15 – SupplierLayer.java（续）
  

结论

参考资料