用Java在各種框架下編譯Scala項(xiàng)目

作者：立方 2010-06-21 17:08:10

如何利用Java在各種框架下編譯Scala項(xiàng)目？本文轉(zhuǎn)載自一位外國開發(fā)人員的blog，是一篇利用Java語言在最流行的各種Java框架下調(diào)用Scala的項(xiàng)目的教程，從細(xì)微入手解決實(shí)際問題。

【51CTO編譯】51CTO曾經(jīng)在“與Scala的***次親密接觸 Java如影相隨”為大家講過Java于Scala。下面是一個(gè)教程文件是我在如今***或者說***的Java框架——Spring、Hibernate/JPA、Wicket、Maven和Intellij IDEA上充分利用Java語言調(diào)用Scala的項(xiàng)目，希望能幫助其他的Java程序員使用一個(gè)企業(yè)級的Scala項(xiàng)目。

在IDE上的設(shè)置

首先，下載的IntelliJ IDEA的9.0.x（社區(qū)版），因?yàn)槟壳八?**的Scala的IDE。然后選擇File |設(shè)置|插件，選擇可用的選項(xiàng)卡來安裝Scala插件。

創(chuàng)建Maven項(xiàng)目

在IntelliJ IDEA中，選擇文件|新建項(xiàng)目，然后選擇Maven的模塊創(chuàng)建一個(gè)Maven項(xiàng)目。然后修改如下所示的pom.xml。添加所有你需要的設(shè)置，建立Scala的匯編語言：

<project xmlnsxmlns="http://maven.apache.org/POM/4.0.0"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"           
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0http://maven.apache.org/maven-v4_0_0.xsd">           
    <modelVersion>4.0.0</modelVersion>           
    <groupId>com.foo</groupId>           
    <artifactId>myapp</artifactId>           
    <packaging>war</packaging>           
    <version>1.0-SNAPSHOT</version>           
    <name>myapp Java EE 6 Webapp</name>           
    <url>http://maven.apache.org</url>           
    <properties>           
        <spring.version>3.0.3.RELEASE</spring.version>           
     </properties>          
           
    <repositories>           
        <repository>           
            <id>java.net2</id>           
            <name>Repository hosting the jee6 artifacts</name>           
            <url>http://download.java.net/maven/2</url>           
         </repository>          
           
        <repository>           
            <id>scala-tools.org</id>           
             <name>Scala-tools Maven2 Repository</name>          
            <url>http://scala-tools.org/repo-releases</url>           
           
        </repository>           
        <repository>           
             <id>wpt-release</id>          
            <url>http://wicketpagetest.sourceforge.net/m2-repo/releases</url>           
           
        </repository>           
        <repository>           
             <id>wpt-snapshot</id>          
            <url>http://wicketpagetest.sourceforge.net/m2-repo/snapshots</url>           
           
        </repository>           
    </repositories>           
    <pluginRepositories>           
        <pluginRepository>           
            <id>scala-tools.org</id>           
            <name>Scala-tools Maven2 Repository</name>           
            <url>http://scala-tools.org/repo-releases</url>           
         </pluginRepository>          
           
    </pluginRepositories>           
    <dependencyManagement>           
        <dependencies>           
            <dependency>           
                 <groupId>org.springframework</groupId>          
                <artifactId>spring-context</artifactId>           
           
                <version>${spring.version}</version>           
             </dependency>          
           
             <dependency>          
                <groupId>org.springframework</groupId>           
           
                <artifactId>spring-core</artifactId>           
                <version>${spring.version}</version>           
            </dependency>           
            <dependency>           
                <groupId>org.springframework</groupId>           
                 <artifactId>spring-web</artifactId>          
           
                <version>${spring.version}</version>           
             </dependency>          
           
             <dependency>          
                <groupId>org.springframework</groupId>           
           
                 <artifactId>spring-orm</artifactId>          
                <version>${spring.version}</version>           
           
            </dependency>           
        </dependencies>           
    </dependencyManagement>           
    <dependencies>           
        <dependency>           
            <groupId>com.h2database</groupId>           
            <artifactId>h2</artifactId>           
            <version>1.2.120</version>           
        </dependency>           
        <dependency>           
             <groupId>org.hibernate</groupId>          
            <artifactId>hibernate-entitymanager</artifactId>           
           
            <version>3.4.0.GA</version>           
        </dependency>           
        <dependency>           
            <groupId>org.springframework</groupId>           
            <artifactId>spring-orm</artifactId>           
        </dependency>           
        <dependency>           
            <groupId>com.ttdev</groupId>           
            <artifactId>wpt-core</artifactId>           
            <version>1.5.2-SNAPSHOT</version>           
            <scope>test</scope>           
        </dependency>           
        <dependency>           
            <groupId>com.ttdev</groupId>           
            <artifactId>wpt-runtime-spring</artifactId>           
             <version>1.5.2-SNAPSHOT</version>          
           
        </dependency>           
        <dependency>           
             <groupId>javax</groupId>          
            <artifactId>javaee-web-api</artifactId>           
           
            <version>6.0</version>           
            <scope>provided</scope>           
        </dependency>           
        <dependency>           
            <groupId>junit</groupId>           
            <artifactId>junit</artifactId>           
            <version>3.8.2</version>           
            <scope>test</scope>           
        </dependency>           
        <dependency>           
            <groupId>org.scala-lang</groupId>           
            <artifactId>scala-library</artifactId>           
            <version>2.8.0.RC3</version>           
        </dependency>           
        <dependency>           
            <groupId>org.apache.wicket</groupId>           
            <artifactId>wicket</artifactId>           
            <version>1.4.9</version>           
        </dependency>           
        <dependency>           
            <groupId>org.slf4j</groupId>           
            <artifactId>slf4j-log4j12</artifactId>           
            <version>1.4.2</version>           
        </dependency>           
    </dependencies>           
    <build>           
        <pluginManagement>           
            <plugins>           
                 <plugin>          
                    <groupId>org.apache.maven.plugins</groupId>           
           
                    <artifactId>maven-compiler-plugin</artifactId>           
                     <version>2.0.2</version>          
           
                </plugin>           
                <plugin>           
                     <groupId>org.scala-tools</groupId>          
                    <artifactId>maven-scala-plugin</artifactId>           
           
                    <version>2.9.1</version>           
                </plugin>           
            </plugins>           
        </pluginManagement>           
        <plugins>           
            <plugin>           
                 <groupId>org.apache.maven.plugins</groupId>          
                <artifactId>maven-compiler-plugin</artifactId>           
           
                <executions>           
                    <execution>           
                        <phase>compile</phase>           
                        <goals>           
                            <goal>compile</goal>           
                        </goals>           
                    </execution>           
                </executions>           
                <configuration>           
                    <source>1.6</source>           
                    <target>1.6</target>           
                </configuration>           
            </plugin>           
            <plugin>           
                <groupId>org.apache.maven.plugins</groupId>           
                 <artifactId>maven-war-plugin</artifactId>          
           
                <version>2.1-beta-1</version>           
                <configuration>           
                    <failOnMissingWebXml>false</failOnMissingWebXml>           
                 </configuration>          
           
            </plugin>           
            <plugin>           
                 <groupId>org.scala-tools</groupId>          
                <artifactId>maven-scala-plugin</artifactId>           
           
                <executions>           
                    <execution>           
                         <id>scala-compile-first</id>          
                        <phase>process-resources</phase>           
           
                         <goals>          
                            <goal>add-source</goal>           
           
                            <goal>compile</goal>           
                        </goals>           
                    </execution>           
                    <execution>           
                         <id>scala-test-compile</id>          
                        <phase>process-test-resources</phase>           
           
                         <goals>          
                            <goal>testCompile</goal>           
           
                        </goals>           
                    </execution>           
                </executions>           
            </plugin>           
        </plugins>           
        <finalName>myapp</finalName>           
    </build>           
</project>

等待一段時(shí)間，IDEA將提示導(dǎo)入的項(xiàng)目是否需要更改。回答是肯定。

#p#

web.xml中設(shè)置

接下來，修改main/webapp/WEB-INF/web.xml。從而確立了Wicket的過濾器，打開Spring的JPA實(shí)體管理器和Spring監(jiān)聽器，進(jìn)行Spring的初始化。

 <?xml version="1.0" encoding="UTF-8"?>          
<web-app version="3.0"xmlns="http://java.sun.com/xml/ns/javaee"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"           
           
         xsi:schemaLocation="http://java.sun.com/xml/ns/javaeehttp://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">           
     <filter>          
           
         <filter-name>f2</filter-name>          
        <filter-class>org.springframework.orm.jpa.support.OpenEntityManagerInViewFilter</filter-class>           
           
    </filter>           
    <filter>           
         <filter-name>f1</filter-name>          
        <filter-class>org.apache.wicket.protocol.http.WicketFilter</filter-class>           
           
         <init-param>          
            <param-name>applicationClassName</param-name>           
           
            <param-value>com.foo.myapp.MyApp</param-value>           
         </init-param>          
           
    </filter>           
    <filter-mapping>           
        <filter-name>f1</filter-name>           
        <url-pattern>/app/*</url-pattern>           
    </filter-mapping>           
    <filter-mapping>           
        <filter-name>f2</filter-name>           
        <url-pattern>/*</url-pattern>           
    </filter-mapping>           
    <context-param>           
        <param-name>contextConfigLocation</param-name>           
        <param-value>classpath:/beans.xml</param-value>           
    </context-param>           
    <listener>           
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>           
     </listener>          
           
</web-app>

#p#

設(shè)置Spring bean訪問和調(diào)用的數(shù)據(jù)庫

要定義這些Spring bean，創(chuàng)建main/resources的beans.xml以及一下的內(nèi)容：

<?xml version="1.0" encoding="UTF-8" ?>         
<beansxmlnsbeansxmlns="http://www.springframework.org/schema/beans"          
          
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"         
       xmlns:context="http://www.springframework.org/schema/context"          
          
        xmlns:tx="http://www.springframework.org/schema/tx"         
       xsi:schemaLocation="http://www.springframework.org/schema/beans          
          
        http://www.springframework.org/schema/beans/spring-beans-3.0.xsd          
         http://www.springframework.org/schema/context         
          
        http://www.springframework.org/schema/context/spring-context-3.0.xsd          
         http://www.springframework.org/schema/tx         
          
        http://www.springframework.org/schema/tx/spring-tx-3.0.xsd">          
     <context:component-scan base-package="com.foo.myapp"/>         
          
    <bean id="emf"class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">          
        <property name="persistenceXmlLocation"value="classpath:/META-INF/my-persistence.xml"/>          
     </bean>         
    <bean id="transactionManager"class="org.springframework.orm.jpa.JpaTransactionManager">          
          
        <property name="entityManagerFactory" ref="emf"/>          
     </bean>         
          
    <tx:annotation-driven />          
</beans>

讀取數(shù)據(jù)庫配置中persistence.xml文件。在這里，您將獲得一個(gè)主目錄中名為MyApp的H2數(shù)據(jù)庫。因此，創(chuàng)建main/resources/META-INF文件的內(nèi)容如下。

<persistencexmlnspersistencexmlns="http://java.sun.com/xml/ns/persistence"          
            xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"           
          
            xsi:schemaLocation="http://java.sun.com/xml/ns/persistencehttp://java.sun.com/xml/ns/persistence/persistence_2_0.xsd"           
             version="2.0">          
          
   <persistence-unit name="myapp" transaction-type="RESOURCE_LOCAL">           
        <provider>org.hibernate.ejb.HibernatePersistence</provider>          
          
        <properties>          
           <propertynamepropertyname="hibernate.connection.driver_class"value="org.h2.Driver"/>           
          
           <property name="hibernate.connection.url"value="jdbc:h2:tcp://localhost/~/myapp"/>           
            <propertynamepropertyname="hibernate.connection.username" value="sa"/>          
          
            <propertynamepropertyname="hibernate.connection.password" value=""/>          
           <property name="hibernate.dialect"value="org.hibernate.dialect.H2Dialect"/>           
          
           <property name="hibernate.hbm2ddl.auto"value="create"/>           
        </properties>          
          
   </persistence-unit>           
/persistence>

#p#

創(chuàng)建Wicket的頁面

在這里，您將創(chuàng)建一個(gè)Wicket頁面顯示從數(shù)據(jù)庫加載一些內(nèi)容。因此，創(chuàng)建主/Scala文件夾，右鍵單擊它并選擇新建|Scala類。命名為我的頁面類和投入com.foo.myapp包中。如下所示：

package com.foo.myapp           
           
import org.apache.wicket.markup.html._           
import basic.Label           
 import list.{ListItem, ListView}          
importorg.apache.wicket.spring.injection.annot.SpringBean           
           
import org.apache.wicket.model.CompoundPropertyModel           
           
class MyPage extends WebPage {           
  @SpringBean           
   var ps: ProductService = _          
  val productListView = newListView[Product]("productListView", ps.getAll) {           
           
     def populateItem(item: ListItem[Product]) = {          
      item.setModel(newCompoundPropertyModel[Product](item.getDefaultModelObject))           
           
      item.add(new Label("name"))           
      item.add(new Label("price"))           
    }           
  }           
  add(productListView)           
}

請注意，在創(chuàng)建ProductService對象加載的文件之后使用。此外，請注意該字段被分配到一個(gè)下劃線（_），Scala編譯為不可初始化的，而是留在默認(rèn)狀態(tài)。在你將覆蓋作為編譯之前，執(zhí)行Spring bean的頁面構(gòu)造。現(xiàn)在，創(chuàng)建在src/main/resources/com/foo/myapp的的mypage.html文件：

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">           
<html>           
    <table border="1">           
        <tr wicket:id="productListView">           
            <td wicket:id="name"></td>           
            <td wicket:id="price"></td>           
        </tr>           
    </table>           
</html>

#p#

創(chuàng)建ProductService：

右鍵單擊在in the src/main/scala文件夾中的com.foo.myapp包并選擇New | Scala的類，然后選擇創(chuàng)建ProductService：

package com.foo.myapp           
           
import java.util.List           
           
trait ProductService {           
  def getAll: List[Product]           
}

這是接口。對創(chuàng)造一個(gè)DefaultProductService的Scala在同一個(gè)包內(nèi)進(jìn)行執(zhí)行操作：

package com.foo.myapp           
           
import javax.persistence.{PersistenceContext, EntityManager}           
import org.springframework.stereotype.{Service}           
importorg.springframework.transaction.annotation.Transactional           
 importorg.springframework.beans.factory.annotation.Autowired          
           
           
@Service           
@Transactional           
class DefaultProductService extends ProductService {           
  @Autowired           
  var products: Products = _           
           
  def getAll = products.getAll           
}

請注意，把它使用類型文件命名為DAO。

創(chuàng)建文件的DAO

要?jiǎng)?chuàng)建的DAO，創(chuàng)建一個(gè)名為在同一文件夾：

package com.foo.myapp           
           
import java.util.List           
           
trait Products {           
   def getAll: List[Product]           
}

然后創(chuàng)建在同一文件夾中的執(zhí)行Scala的DefaultProducts文件：

package com.foo.myapp           
           
import javax.persistence.{PersistenceContext, EntityManager}           
import org.springframework.stereotype.Repository           
import java.util.List           
           
@Repository           
class DefaultProducts extends Products {           
  @PersistenceContext           
  var em: EntityManager = _           
           
  def getAll = {           
    em.createQuery("select p from Product p").getResultList.asInstanceOf[List[Product]]           
  }           
}

#p#

創(chuàng)建entity程序

創(chuàng)建entity程序并將其映射到數(shù)據(jù)庫：

package com.foo.myapp           
           
import javax.persistence.{GeneratedValue, Id, Entity}           
           
@Entity           
class Product {           
  @Id           
  @GeneratedValue           
  var id: Long = _           
  var name: String = _           
  var price: Double = _           
}

創(chuàng)建Wicket的應(yīng)用程序

***，創(chuàng)建在同一個(gè)MyApp的Scala程序：

package com.foo.myapp           
           
 import org.apache.wicket.protocol.http.WebApplication          
importcom.ttdev.wicketpagetest.MockableSpringBeanInjector           
           
           
class MyApp extends WebApplication {           
  def getHomePage = classOf[MyPage]           
           
   override def init = {          
    MockableSpringBeanInjector.installInjector(this)           
           
  }           
}

在這里，您指定為首頁我的目錄，植入Spring Bean中。

運(yùn)行應(yīng)用程序

隨著IntelliJ IDEA的版本不斷改進(jìn)，您將嵌入到應(yīng)用服務(wù)器運(yùn)行您的應(yīng)用程序。這非常容易，在剛剛創(chuàng)建的測試com.foo.myapp的ManualTest在剛剛創(chuàng)建的測試com.foo.myapp包一類ManualTest/scala文件（不是main/scala文件），以下內(nèi)容是：

package com.foo.myapp           
           
importcom.ttdev.wicketpagetest.{WebAppJettyConfiguration, WicketAppJettyLauncher}           
           
           
object ManualTest {           
  def main(args: Array[String]) {           
    val l = new WicketAppJettyLauncher           
    l.startAppInJetty(new WebAppJettyConfiguration)           
  }           
}

要運(yùn)行的應(yīng)用程序，首先需要運(yùn)行數(shù)據(jù)庫服務(wù)器上的H2程序。所以，在http://www.h2database.com下載和解壓。然后變成h2/bin和運(yùn)行h2.bat（或在Linux上h2.sh）。ManualTest是在IDEA的編輯器上，在IDEA選擇運(yùn)行DEA。它將運(yùn)行ManualTest，Jetty的運(yùn)行您的應(yīng)用程序。

為了測試它，請嘗試通過在瀏覽器http://localhost:8888/app。

不知道各位感覺如何。感謝各位支持！謝謝！

原文地址：agileskills2.org/blog/2010/06/19/getting-started-with-scala-spring-hibernate-wicket/

原文名：Getting started with Scala, Spring, Hibernate & Wicket

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