openjpa框架入门_项目框架搭建(二)

Openjpa2.2+Mysql+Maven+Servlet+JSP

首先说明几点,让大家更清楚整体结构:

官方source code 下载:http://openjpa.apache.org/downloads.html 我下载2.2.2的版本

下载后解压缩 openbooks的source code如图:

大家可以根据说明自己研究,也可以和我一起往下看,接下来是自己搭建maven管理的web project.

使用eclipse插件创建openbook web project.

1:create a maven project

2:select create a simple project(skip archetype select)

packing -----------------------war

.

这是web project,所以创建的project目录结构如下(如果不是或者有出入,那么请检查Maven的 user settings文件指向)

下面修改下,使我们的项目,能发布到server上运行. 项目上点击右键,选择属性convert to faceted from...(若符合的,有的可以跳过此步)

配置完成后,再来check下,Deployment Assembly (画红线的可以删除,也可不删),各个目录要路径指向正确

下面将官方的source code粘贴到我们项目指定的目录(删除client,tools)

根据红线,分别把文件copy到指定目录,下面再修改persistence.xml,web.xml和pom.xml 三个文件.

persistence.xml

<?xml version="1.0" encoding="UTF-8"?>

<persistence xmlns="http://java.sun.com/xml/ns/persistence"
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xsi:schemaLocation="http://java.sun.com/xml/ns/persistence
 http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd"
 version="2.0">
 <persistence-unit name="OpenBooks" transaction-type="RESOURCE_LOCAL">
 <provider>org.apache.openjpa.persistence.PersistenceProviderImpl</provider>

 <class>openbook.domain.Book</class>
 <class>openbook.domain.Inventory</class>
 <class>openbook.domain.PurchaseOrder</class>
 <class>openbook.domain.LineItem</class>
 <class>openbook.domain.Customer</class>
 <class>openbook.domain.Author</class>

 <validation-mode>NONE</validation-mode>
 <properties>
 
 <property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver"/>
 <property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost:3306/OpenBooks?characterEncoding=utf8"/>
 <property name="openjpa.jdbc.DBDictionary" value="mysql"/>
 <property name="javax.persistence.jdbc.user" value="root"/>
 <property name="javax.persistence.jdbc.password" value="root"/>

 
 <property name="openjpa.FetchBatchSize" value="0"/>
 <property name="openjpa.RemoteCommitProvider" value="sjvm" />
 <property name="openjpa.InitializeEagerly" value="true" />
 <property name="openjpa.jdbc.SynchronizeMappings" value="buildSchema(ForeignKeys=true)" />
 <property name="openjpa.jdbc.QuerySQLCache" value="true(EnableStatistics=true)" />

 <property name="openjpa.Log" value="DefaultLevel=INFO, Runtime=INFO, Tool=INFO, SQL=TRACE" />
 
 
 



 
 </properties>
 </persistence-unit>

</persistence>

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee"
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
 <display-name>openjpatest</display-name>
 <welcome-file-list>
 <welcome-file>intro.jsp</welcome-file>
 </welcome-file-list>
 <distributable />
</web-app>

POM.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 <modelVersion>4.0.0</modelVersion>
 <groupId>com.shen</groupId>
 <artifactId>openjpatest</artifactId>
 <version>0.0.1-SNAPSHOT</version>
 <packaging>war</packaging>
 <dependencies>
 <dependency>
 <groupId>org.apache.openjpa</groupId>
 <artifactId>openjpa</artifactId>
 <version>2.2.2</version>
 </dependency>
 <dependency>
 <groupId>org.antlr</groupId>
 <artifactId>antlr</artifactId>
 <version>3.2</version>
 </dependency>
 <dependency>
 <groupId>org.apache.ant</groupId>
 <artifactId>ant</artifactId>
 <version>1.8.1</version>
 </dependency>
 <dependency>
 <groupId>de.java2html</groupId>
 <artifactId>java2html</artifactId>
 <version>5.0</version>
 </dependency>

 <dependency>
 <groupId>org.apache.openjpa</groupId>
 <artifactId>openjpa-all</artifactId>
 <version>2.2.1</version>
 </dependency>
 <dependency>
 <groupId>org.apache.tomcat</groupId>
 <artifactId>servlet-api</artifactId>
 <version>6.0.35</version>
 <scope>provided</scope>
 </dependency>
 <dependency>
 <groupId>org.apache.tomcat</groupId>
 <artifactId>jsp-api</artifactId>
 <version>6.0.37</version>
 <scope>provided</scope>
 </dependency>

 <dependency>
 <groupId>mysql</groupId>
 <artifactId>mysql-connector-java</artifactId>
 <version>5.1.18</version>
 </dependency>
 <dependency>
 <groupId>junit</groupId>
 <artifactId>junit</artifactId>
 <version>4.11</version>
 </dependency>
 </dependencies>
 <build>
 <finalName>${project.artifactId}</finalName>
 <plugins>
 <plugin>
 <groupId>org.apache.maven.plugins</groupId>
 <artifactId>maven-compiler-plugin</artifactId>
 <version>2.3.2</version>
 <configuration>
 <source>1.6</source>
 <target>1.6</target>
 </configuration>
 </plugin>
 <plugin>
 <groupId>org.apache.felix</groupId>
 <artifactId>maven-bundle-plugin</artifactId>
 <version>2.3.6</version>
 <extensions>true</extensions>
 <configuration>
 <instructions>
 <Bundle-SymbolicName>${project.artifactId}</Bundle-SymbolicName>
 <Meta-Persistence>META-INF/persistence.xml</Meta-Persistence>
 </instructions>
 </configuration>
 </plugin>
 <plugin>
 <groupId>org.apache.openjpa</groupId>
 <artifactId>openjpa-maven-plugin</artifactId>
 <version>2.2.1</version>
 <configuration>
 <includes>**/representations/*.class</includes>
 <addDefaultConstructor>true</addDefaultConstructor>
 <enforcePropertyRestrictions>true</enforcePropertyRestrictions>
 </configuration>
 <executions>
 <execution>
 <id>enhancer</id>
 <phase>process-classes</phase>
 <goals>
 <goal>enhance</goal>
 </goals>
 </execution>
 </executions>
 <dependencies>
 <dependency>
 <groupId>org.apache.openjpa</groupId>
 <artifactId>openjpa</artifactId>
 <version>2.2.1</version>
 </dependency>
 </dependencies>
 </plugin>
 </plugins>
 <pluginManagement>
 <plugins>
 
 <plugin>
 <groupId>org.eclipse.m2e</groupId>
 <artifactId>lifecycle-mapping</artifactId>
 <version>1.0.0</version>
 <configuration>
 <lifecycleMappingMetadata>
 <pluginExecutions>
 <pluginExecution>
 <pluginExecutionFilter>
 <groupId>org.apache.openjpa</groupId>
 <artifactId>openjpa-maven-plugin</artifactId>
 <versionRange>[2.2.1,)</versionRange>
 <goals>
 <goal>enhance</goal>
 </goals>
 </pluginExecutionFilter>
 <action>
 <ignore></ignore>
 </action>
 </pluginExecution>
 </pluginExecutions>
 </lifecycleMappingMetadata>
 </configuration>
 </plugin>
 </plugins>
 </pluginManagement>
 </build>
</project>

最后再，修改下OpenBookServiceImpl.java类举例一个，下面类似（附完整的类）

/*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package openbook.server;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.Set;

import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.PersistenceContextType;
import javax.persistence.TypedQuery;
import javax.persistence.criteria.CriteriaBuilder;
import javax.persistence.criteria.CriteriaQuery;
import javax.persistence.criteria.Expression;
import javax.persistence.criteria.ParameterExpression;
import javax.persistence.criteria.Predicate;
import javax.persistence.criteria.Root;
import javax.persistence.metamodel.EntityType;

import openbook.domain.Author;
import openbook.domain.Book;
import openbook.domain.Customer;
import openbook.domain.Inventory;
import openbook.domain.LineItem;
import openbook.domain.PurchaseOrder;
import openbook.domain.Range;
import openbook.domain.ShoppingCart;
import openbook.util.PropertyHelper;
import openbook.util.Randomizer;

import org.apache.openjpa.persistence.criteria.OpenJPACriteriaBuilder;

/**
* A demonstrative example of a transaction service with persistent entity using Java Persistence API.
* 
* This example service operates on a persistent domain model to browse {@linkplain Book books},
* occasionally {@linkplain #placeOrder(ShoppingCart) placing} {@linkplain PurchaseOrder purchase orders},
* while {@linkplain Inventory inventory} gets updated either by {@linkplain #deliver() delivery} or
* by {@linkplain #supply() supply}.
* 
* The operational model as well as the persistent domain model is influenced by the fact that
* a JPA based application can benefit from
* <LI>Mostly Immutable Persistent Data Model
* <LI>Optimistic Transaction Model
* for better scalability and throughput.
* 
*
*/
@SuppressWarnings("serial")
class OpenBookServiceImpl extends PersistenceService implements OpenBookService {

 public static final int CUSTOMER_COUNT = 10;
 public static final int BOOK_COUNT = 100;
 public static final int AUTHOR_COUNT = 40;
 public static final int AUTHOR_PER_BOOK = 3;

 /**
 * Range of number of queries executed for a {@linkplain #shop() shopping} trip.
 */
 public static final Range<Double> PRICE_RANGE = new Range<Double>(4.99, 120.99);
 public static final Range<Integer> STOCK_RANGE = new Range<Integer>(5, 50);
 public static final int REORDER_LEVEL = 10;

 OpenBookServiceImpl(String unit, EntityManagerFactory emf, boolean managed,
 PersistenceContextType scope) {
 super(unit, emf, managed, scope);
 }

 /**
 * Initialize service by populating inventory of Books and Customers.
 * If the inventory exists, then returns immediately without creating any new inventory.
 *
 * @return true if new inventory is created. false otherwise.
 */
 public boolean initialize(Map<String,Object> config) {
 if (isInitialized()) {
 return false;
 }
 EntityManager em = begin();
 if (config == null) {
 config = Collections.EMPTY_MAP;
 }
 int nCustomer = PropertyHelper.getInteger(config, "openbook.Customer.Count", CUSTOMER_COUNT);
 int nBook = PropertyHelper.getInteger(config, "openbook.Book.Count", BOOK_COUNT);
 int nAuthor = PropertyHelper.getInteger(config, "openbook.Author.Count", AUTHOR_COUNT);
 int nAuthorPerBook = PropertyHelper.getInteger(config, "openbook.Book.Author.Count", AUTHOR_PER_BOOK);

 Double priceMax = PropertyHelper.getDouble(config, "openbook.Book.Price.Max", PRICE_RANGE.getMaximum());
 Double priceMin = PropertyHelper.getDouble(config, "openbook.Book.Price.Min", PRICE_RANGE.getMinimum());

 Integer stockMax = PropertyHelper.getInteger(config, "openbook.Inventory.Max", STOCK_RANGE.getMaximum());
 Integer stockMin = PropertyHelper.getInteger(config, "openbook.Inventory.Min", STOCK_RANGE.getMinimum());

 System.err.println("Creating " + nCustomer + " new Customer");
 for (int i = 1; i < nCustomer; i++) {
 Customer customer = new Customer();
 customer.setName("Customer-"+i);
 em.persist(customer);
 }

 List<Author> allAuthors = new ArrayList<Author>();
 System.err.println("Creating " + nAuthor + " new Authors");
 for (int i = 1; i <= nAuthor; i++) {
 Author author = new Author();
 author.setName("Author-"+i);
 allAuthors.add(author);
 em.persist(author);
 }
 System.err.println("Creating " + nBook + " new Books");
 System.err.println("Linking at most " + nAuthorPerBook + " Authors per Book");
 for (int i = 1; i <= nBook; i++) {
 Book book = new Book(Randomizer.randomString(4,2),
 "Book-" + i,
 Randomizer.random(priceMin, priceMax),
 Randomizer.random(stockMin, stockMax));
 List<Author> authors = Randomizer.selectRandom(allAuthors,
 Math.max(1, Randomizer.random(nAuthorPerBook)));
 for (Author author : authors) {
 author.addBook(book);
 book.addAuthor(author);
 }
 em.persist(book);
 }


 commit();
 return true;
 }

 /**
 * Affirms whether the database is loaded with some records.
 */
 public boolean isInitialized() {
 return count(Book.class) > 0;
 }

 /**
 * <A name="login">
 * Provide a name to login a Customer.
 * If such a customer exists, return it. Otherwise creates a new one.
 *
 * @param name name of an existing or a new Customer
 *
 * @return a Customer
 */
 public Customer login(String name) {
 EntityManager em = begin();
 CriteriaBuilder cb = em.getCriteriaBuilder();
 CriteriaQuery<Customer> q = cb.createQuery(Customer.class);
 Customer customer = null;
 Root<Customer> root = q.from(Customer.class);
 ParameterExpression<String> pName = cb.parameter(String.class);
 //TODO ��̬
 q.where(cb.equal(root.get("name"), pName));
 List<Customer> customers = em.createQuery(q).setParameter(pName, name).getResultList();
 if (customers.isEmpty()) {
 Customer newCustomer = new Customer();
 newCustomer.setName(name);
 em.persist(newCustomer);
 customer = newCustomer;
 } else {
 customer = customers.get(0);
 }
 commit();
 return customer;
 }

 /**
 * Find books that match title and price range.
 * @param title
 * @param minPrice
 * @param maxPrice
 * @param author
 * @return
 */

 public List<Book> select(String title, Double minPrice, Double maxPrice, String author,
 QueryDecorator...decorators) {
 CriteriaQuery<Book> q = buildQuery(title, minPrice, maxPrice, author);
 EntityManager em = begin();
 TypedQuery<Book> query =em.createQuery(q);
 List<Book> result=null;
 if(query!=null){
 result = query.getResultList();
 }
 commit();
 return result;
 }

 /**
 * <A name="getQuery">
 * Gets the string representation of a Criteria Query.
 * The string form of a Criteria Query is not specified in JPA specification.
 * But OpenJPA produces a readable form that is quite similar to
 * equivalent JPQL.
 */
 public String getQuery(String title, Double minPrice, Double maxPrice, String author) {
 CriteriaQuery<Book> q = buildQuery(title, minPrice, maxPrice, author);
 return q.toString();
 }

 /**
 * <A name="buildQuery">
 * Creates a Query based on the values of the user input form.
 * The user may or may not have filled a value for each form field
 * and accordingly the query will be different. 
 * This is typical of a form-based query. To account for all possible
 * combinations of field values to build a String-based JPQL can be
 * a daunting exercise. This method demonstrates how such dynamic,
 * conditional be alternatively developed using {@link CriteriaQuery}
 * introduced in JPA version 2.0.
 * 
 *
 * @return a typed query
 */

 private CriteriaQuery<Book> buildQuery(String title, Double minPrice, Double maxPrice, String author) {
 // builder generates the Criteria Query as well as all the expressions
 CriteriaBuilder cb = getUnit().getCriteriaBuilder();
 // The query declares what type of result it will produce
 CriteriaQuery<Book> q = cb.createQuery(Book.class);
 // Which type will be searched
 Root<Book> book = q.from(Book.class);
 // of course, the projection term must match the result type declared earlier
 q.select(book);

 // Builds the predicates conditionally for the filled-in input fields
 List<Predicate> predicates = new ArrayList<Predicate>();
 if (!isEmpty(title)) {
 Expression<String> title_e=book.get("title");
 Predicate matchTitle =cb.like(title_e, title);
 predicates.add(matchTitle);
 }
 if (!isEmpty(author)) {
 Expression<String> authors_e=book.join("authors").get("name");
 Predicate matchAuthor =cb.like(authors_e, "%"+author+"%");
 predicates.add(matchAuthor);
 }
 // for price fields, also the comparison operation changes based on whether
 // minimum or maximum price or both have been filled.
 if (minPrice != null && maxPrice != null) {
 Expression<Double> price_e=book.get("price");
 Predicate matchPrice =cb.between(price_e, minPrice, maxPrice);
 predicates.add(matchPrice);
 } else if (minPrice != null && maxPrice == null) {
 Expression<Double> price_e=book.get("price");
 Predicate matchPrice =cb.ge(price_e, minPrice);
 predicates.add(matchPrice);
 } else if (minPrice == null && maxPrice != null) {
 Expression<Double> price_e=book.get("price");
 Predicate matchPrice = cb.le(price_e, maxPrice);
 predicates.add(matchPrice);
 }
 // Sets the evaluation criteria
 if (!predicates.isEmpty())
 q.where(predicates.toArray(new Predicate[predicates.size()]));
 //SELECT b FROM Book b INNER JOIN b.authors ? WHERE (b.title LIKE 'Book-63' AND b.price BETWEEN 0.0 AND 100.0)
 return q;
 }

 boolean isEmpty(String s) {
 return s == null || s.trim().isEmpty();
 }


 /**
 * <A name="deliver"/>
 * Delivers the given order, if it is pending.
 * Delivery of an order amounts to decrementing inventory for each line item
 * and eventually nullify the line items to demonstrate orphan delete feature.
 * 
 * The transactions may fail because of either insufficient inventory or
 * concurrent modification of the same inventory by {@link #supply(Book, int) the supplier}.
 */
 public PurchaseOrder deliver(PurchaseOrder o) {
 if (o.isDelivered())
 return o;
 EntityManager em = begin();
 o = em.merge(o);
 for (LineItem item : o.getItems()) {
 item.getBook().getInventory().decrement(item.getQuantity());
 }
 o.setDelivered();
 commit();
 return o;
 }

 public List<PurchaseOrder> getOrders(PurchaseOrder.Status status, Customer customer) {
 EntityManager em = begin();
 CriteriaBuilder cb = em.getCriteriaBuilder();
 CriteriaQuery<PurchaseOrder> q = cb.createQuery(PurchaseOrder.class);
 Root<PurchaseOrder> order = q.from(PurchaseOrder.class);
 q.select(order);
 List<Predicate> predicates = new ArrayList<Predicate>();
 if (status != null) {
 //TODO PurchaseOrder_.status
 predicates.add(cb.equal(order.get("status"), status));
 }
 if (customer != null) {
 //TODO PurchaseOrder_.customer
 predicates.add(cb.equal(order.get("customer"), customer));
 }
 if (!predicates.isEmpty())
 q.where(predicates.toArray(new Predicate[predicates.size()]));
 //TODO PurchaseOrder_.placedOn
 q.orderBy(cb.desc(order.get("placedOn")));

 TypedQuery<PurchaseOrder> query = em.createQuery(q);
 List<PurchaseOrder> result = query.getResultList();
 commit();
 return result;
 }

 /**
 * <A name="placeOrder"/>
 * Creates a new {@linkplain PurchaseOrder} from the content of the given {@linkplain ShoppingCart}.
 * The content of the cart is cleared as a result.
 * 
 * The transaction is not expected to fail because the inventory is
 * not modified by placing an order.
 *
 * @param cart a non-null Shopping cart.
 */
 public PurchaseOrder placeOrder(ShoppingCart cart) {
 EntityManager em = begin();
 PurchaseOrder order = new PurchaseOrder(cart);
 em.persist(order);
 commit();
 cart.clear();
 return order;
 }

 /**
 * Supply books that have low inventory.
 * 
 * Queries for books with low inventory and supply each book in separate
 * transaction. Some of the transactions may fail due to concurrent modification on
 * the {@linkplain Inventory} by the {@linkplain #deliver() delivery} process.
 */
 public Book supply(Book b, int quantity) {
 EntityManager em = begin();
 b = em.merge(b);
 b.getInventory().increment(quantity);
 commit();
 return b;
 }

 public List<Inventory> getReorderableBooks(int limit) {
 EntityManager em = begin();
 CriteriaBuilder cb = em.getCriteriaBuilder();
 CriteriaQuery<Inventory> q = cb.createQuery(Inventory.class);
 Root<Inventory> inv = q.from(Inventory.class);
 q.select(inv);
 //TODO
 Expression<Integer> sup=inv.get("supplied");
 Expression<Integer> sold=inv.get("sold");
 Expression<Integer> inStock =cb.diff(sup,sold);
 q.orderBy(cb.asc(inStock));

 List<Inventory> result = em.createQuery(q)
 .setMaxResults(limit)
 .getResultList();
 commit();
 return result;
 }

 public long count(Class<?> cls) {
 EntityManager em = getEntityManager();
 CriteriaBuilder cb = em.getCriteriaBuilder();
 CriteriaQuery<Long> c = cb.createQuery(Long.class);
 Root<?> from = c.from(cls);
 c.select(cb.count(from));
 return em.createQuery(c).getSingleResult();
 }

 public List<Book> selectByExample(Book b, QueryDecorator...decorators) {
 return queryByTemplate(Book.class, b);
 }

 private <T> List<T> queryByTemplate(Class<T> type, T template) {
 EntityManager em = begin();
 CriteriaBuilder cb = em.getCriteriaBuilder();
 CriteriaQuery<T> c = cb.createQuery(type);
 c.where(((OpenJPACriteriaBuilder)cb).qbe(c.from(type), template));
 List<T> result = em.createQuery(c).getResultList();
 commit();
 return result;
 }

 public <T> List<T> getExtent(Class<T> entityClass) {
 EntityManager em = begin();
 CriteriaQuery<T> c = em.getCriteriaBuilder().createQuery(entityClass);
 c.from(entityClass);
 List<T> result = em.createQuery(c).getResultList();
 commit();
 return result;
 }

 public <T> List<T> query(String jpql, Class<T> resultClass, QueryDecorator... decorators) {
 EntityManager em = begin();
 TypedQuery<T> query = em.createQuery(jpql, resultClass);
 if (decorators != null) {
 for (QueryDecorator decorator : decorators) {
 decorator.decorate(query);
 }
 }
 List<T> result = query.getResultList();
 commit();
 return result;
 }

 public void clean() {
 EntityManager em = begin();
 Set<EntityType<?>> entities = em.getMetamodel().getEntities();
 for (EntityType<?> type : entities) {
 System.err.println("Deleting all instances of " + type.getName());
 em.createQuery("delete from " + type.getName() + " p").executeUpdate();
 }
 commit();
 }

}

****************************************************************************************************************

更新project configuration

后续再次更新Database.

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原文地址：https://www.cnblogs.com/james1207/p/3285828.html