java筆記：本身動手寫javaEE框架（二）--業務層Service

時間 2019-11-09

標籤 java 筆記本身手寫 javaee 框架業務 service 欄目 Java 简体版

原文原文鏈接

軟件151 黃旭 1531610120javascript

今天我將寫service層，而後寫service的測試類，而後我會加入一個攔截器：攔截service的請求，這個攔截器是針對方法的攔截，這個攔截器裏面咱們能夠知道調用到了那個service類，那個method，能夠截獲到傳入的參數，也能截獲到返回值。我在公司的項目裏的aop就會攔截到 service的方法，你們也許會很奇怪，爲何不作到action而是service，哎，這個無法子，咱們前臺用的是flex，而flex調用 java跟rpc很像，就是flex直接調用service的方法，所以控制層在前臺，和前臺的耦合度過高，只得作service方法級別的攔截了。
我是按下面順序開發的：
1.先看看我新的目錄結構

還要加入三個jar包，都是AspectJ相關的，以下圖：

2.在cn.com.sharpxiajun.service包下新建接口UsersService,代碼以下：前端

package cn.com.sharpxiajun.service;

import java.util.List;
import java.util.Map;

public interface UsersService {
    
    public List<Map<String, Object>> queryUsersList(Map<String, Object> map) throws Exception;

}

3.實現UsersService接口，在cn.com.sharpxiajun.service.impl包下面新建類UsersServiceImpl，代碼以下：java

package cn.com.sharpxiajun.service.impl;

import java.util.List;
import java.util.Map;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.context.annotation.Scope;
import org.springframework.stereotype.Service;

import cn.com.sharpxiajun.dao.UsersDao;
import cn.com.sharpxiajun.service.UsersService;

@SuppressWarnings("unchecked")
@Scope("prototype")
@Service("userService")
public class UsersServiceImpl implements UsersService {
    
    @Autowired
    @Qualifier("usersDao")
    private UsersDao usersDao = null;

    @Override
    public List<Map<String, Object>> queryUsersList(Map<String, Object> map)
            throws Exception {
        return usersDao.queryUserList(map);
    }

}

你們能夠看到service註解是@service，其餘和dao差很少（我感受要寫篇文章好好介紹下spring相關注解，只有這樣才能對框架有深入理解）spring

4.接下來編寫方法攔截器，這個類放在cn.com.sharpxiajun.common.aop包下，類名是：MethodServiceAdvisor，代碼以下：sql

package cn.com.sharpxiajun.common.aop;

import org.aopalliance.intercept.MethodInterceptor;
import org.aopalliance.intercept.MethodInvocation;

import cn.com.sharpxiajun.service.UsersService;

public class MethodServiceAdvisor implements MethodInterceptor {

    @Override
    public Object invoke(MethodInvocation invocation) throws Throwable {

        Object obj = null;
        
        System.out.println("進入到了方法攔截器。。。。");
        
        System.out.println("調用的service：");
        System.out.println(invocation.getThis());
        
        System.out.println("調用的方法:");
        System.out.println(invocation.getMethod());
        
        System.out.println("參數是：");
        
        for (int i = 0;i < invocation.getArguments().length;i++)
        {
            Object[] objs = invocation.getArguments();
            System.out.println(objs[i]);
        }
        
        obj = invocation.proceed();
        
        System.out.println("返回結果是:");
        System.out.println(obj);
        System.out.println("攔截器執行結束!!");
        
        return obj;
    }

}

攔截器的註解我今天不寫，太晚了，並且記得不清，下一篇裏我會補上這些內容。express

5.下面是修改後的applicationContext.xml配置文件，內容以下：apache

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xmlns:context="http://www.springframework.org/schema/context"
  xmlns:aop="http://www.springframework.org/schema/aop"
  xmlns:tx="http://www.springframework.org/schema/tx"
  xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.0.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.0.xsd">
        
        <!-- 掃描該路徑下的spring組件 -->
        <context:component-scan base-package="cn.com.sharpxiajun"/>
        
        <!-- 讀取資源文件 -->
        <bean id="propertyConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
            <property name="locations">
                <list>
                    <value>classpath:conf/constants.properties</value>
                </list>
            </property>
        </bean>
        
        <!-- 配置數據源 -->
         <!--  <bean id="myDataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
             <property name="driverClass" value="${db.driverClass}"/>
             <property name="jdbcUrl" value="${db.jdbcUrl}"/>
             <property name="user" value="${db.user}"/>
             <property name="password" value="${db.password}"/>
         </bean>-->
         
         <bean id="myDataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
             <property name="driverClassName" value="${db.driverClass}"/>
             <property name="url" value="${db.jdbcUrl}"/>
             <property name="username" value="${db.user}"/>
             <property name="password" value="${db.password}"/>
         </bean>
        
        <bean id="sqlMapClient" class="org.springframework.orm.ibatis.SqlMapClientFactoryBean">
            <property name="configLocation">
                <value>classpath:conf/SqlMapConfig.xml</value>
            </property>
            <property name="dataSource" ref="myDataSource"/>
        </bean>
        
        <bean id="sqlMapClientTemplate" class="org.springframework.orm.ibatis.SqlMapClientTemplate">
            <property name="sqlMapClient">
                <ref local="sqlMapClient"/>
            </property>
        </bean>
        
        <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
            <property name="dataSource">
                <ref local="myDataSource"/>
            </property>
        </bean>
        
        <!-- 將我本身定義的攔截器生成bean -->
        <bean id="methodServiceAdvisor" class="cn.com.sharpxiajun.common.aop.MethodServiceAdvisor"/>
        
        <aop:config>
            <!--配置規則，知足如下規則的將攔截，第一個*表示全部返回類型，第二個表示service包下的全部class，第三個表示全部方法-->
            <aop:pointcut id="baseServiceMethods" expression="execution(* cn.com.sharpxiajun.service.*.*(..))"/>
            <!-- 符合上面規則的攔截器都會調用到methodServiceAdvisor -->
            <aop:advisor advice-ref="methodServiceAdvisor" pointcut-ref="baseServiceMethods"/>
        </aop:config>

</beans>

這裏用到了aop:config這是spring爲了迎合AspectJ，對於AspectJ這個之後有機會我也想研究下，寫篇文章。app

6.最後編寫針對UsersService的測試類UsersServiceImplTest，所在包是：cn.com.sharpxiajun.junittest.service，代碼以下：框架

package cn.com.sharpxiajun.junittest.service;

import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.AbstractTransactionalJUnit4SpringContextTests;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import org.springframework.test.context.transaction.TransactionConfiguration;

import cn.com.sharpxiajun.service.UsersService;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations={"classpath:conf/applicationContext.xml"})
@TransactionConfiguration(defaultRollback = false)
public class UsersServiceImplTest extends
        AbstractTransactionalJUnit4SpringContextTests {
    
    @Autowired
    private UsersService usersService = null;
    
    public UsersServiceImplTest()
    {
        System.out.println("初始化測試類....");
    }
    
    @Before
    public void setUp() throws Exception
    {
        System.out.println("測試開始....");
    }
    
    @After
    public void tearDown() throws Exception
    {
        System.out.println("測試結束!!");
    }
    
    @Test
    public void testQueryUserList()
    {
        Map<String, Object> map = new HashMap<String, Object>();
        map.put("username", "sharpxiajun");
        try {
            List<Map<String, Object>> list = usersService.queryUsersList(map);
            System.out.println(list);
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

}

運行結果以下：ide

初始化測試類....
2011-10-11 23:44:45 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
信息: Loading XML bean definitions from class path resource [conf/applicationContext.xml]
2011-10-11 23:44:45 org.springframework.context.support.AbstractApplicationContext prepareRefresh
信息: Refreshing org.springframework.context.support.GenericApplicationContext@290fbc: startup date [Tue Oct 11 23:44:45 CST 2011]; root of context hierarchy
2011-10-11 23:44:46 org.springframework.core.io.support.PropertiesLoaderSupport loadProperties
信息: Loading properties file from class path resource [conf/constants.properties]
2011-10-11 23:44:46 org.springframework.beans.factory.support.DefaultListableBeanFactory preInstantiateSingletons
信息: Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@922804: defining beans [usersDao,userService,org.springframework.context.annotation.internalConfigurationAnnotationProcessor,org.springframework.context.annotation.internalAutowiredAnnotationProcessor,org.springframework.context.annotation.internalRequiredAnnotationProcessor,org.springframework.context.annotation.internalCommonAnnotationProcessor,propertyConfigurer,myDataSource,sqlMapClient,sqlMapClientTemplate,transactionManager,methodServiceAdvisor,org.springframework.aop.config.internalAutoProxyCreator,baseServiceMethods,org.springframework.aop.support.DefaultBeanFactoryPointcutAdvisor#0]; root of factory hierarchy
2011-10-11 23:44:46 org.springframework.test.context.transaction.TransactionalTestExecutionListener startNewTransaction
信息: Began transaction (1): transaction manager [org.springframework.jdbc.datasource.DataSourceTransactionManager@8de972]; rollback [false]
測試開始....
進入到了方法攔截器。。。。
調用的service：
cn.com.sharpxiajun.service.impl.UsersServiceImpl@15fc672
調用的方法:
public abstract java.util.List cn.com.sharpxiajun.service.UsersService.queryUsersList(java.util.Map) throws java.lang.Exception
參數是：
{username=sharpxiajun}
返回結果是:
[{enabled=false, username=admin, password=admin}, {enabled=false, username=test, password=test}]
攔截器執行結束!!
[{enabled=false, username=admin, password=admin}, {enabled=false, username=test, password=test}]
測試結束!!
2011-10-11 23:44:46 org.springframework.test.context.transaction.TransactionalTestExecutionListener endTransaction
信息: Committed transaction after test execution for test context [[TestContext@58e2a1 testClass = UsersServiceImplTest, locations = array<String>['classpath:conf/applicationContext.xml'], testInstance = cn.com.sharpxiajun.junittest.service.UsersServiceImplTest@186f3b3, testMethod = testQueryUserList@UsersServiceImplTest, testException = [null]]]

看來達到咱們預期的結果了！！！

總結下了：這樣寫程序蠻有成就感，並且一步步來感受很清晰。工做永遠是匆忙的，老是快的讓人沒法思考，我想這就是聰明的中國爲何沒有那麼多優秀開源框架的緣由把。今天我又獲得一個js開源框架，得到源碼，它能作出yfiles同樣的效果，很是強大，也是老外寫的，牛的不行啊，咱們平臺開發原本對前端要求很高的，要求圖形化實現，真正作圖形化才知道他的複雜度之高，之後我會介紹下這個圖形化的框架，他能實現畫圖，自定義工做流，還能爲關係複雜的圖形進行佈局合理的自動繪製，太牛了。

下個階段可能要回歸javascript了，java框架暫停一下。