Spring IoC 實例

方式一：配置文件實現Bean實例化和依賴注入

BaseDao.java

package com.demo.spring;

public interface BaseDao {

    public void insert();

    public void delete();

    public void update();

    public void select();

}

ObjectUserFactory.java

package com.demo.spring;

public class ObjectUserFactory {

    public UserDao getUserDao() {
        return new UserDao();
    }

}

StaticUserFactory.java

package com.demo.spring;

public class StaticUserFactory {

    public static UserDao getUserDao() {
        return new UserDao();
    }

}

UserDao.java

package com.demo.spring;

public class UserDao implements BaseDao {

    @Override
    public void insert() {
        System.out.println("insert()");
    }

    @Override
    public void delete() {
        System.out.println("delete()");
    }

    @Override
    public void update() {
        System.out.println("update()");
    }

    @Override
    public void select() {
        System.out.println("select()");
    }

}

UserService.java

package com.demo.spring;

public class UserService {

    private UserDao userDao;

    public UserService() {
        super();
    }

    public UserService(UserDao userDao) {
        super();
        this.userDao = userDao;
    }

    public UserDao getUserDao() {
        return userDao;
    }

    public void setUserDao(UserDao userDao) {
        this.userDao = userDao;
    }

}

applicationContext.xml

<?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"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context.xsd">

    <!-- 無參構造實例化配置 -->
    <bean id="userDao" class="com.demo.spring.UserDao"></bean>

    <!-- 靜態工廠實例化配置 -->
    <bean id="userDaoByStatic" class="com.demo.spring.StaticUserFactory"
        factory-method="getUserDao"></bean>

    <!-- 動態工廠實例化配置 -->
    <bean id="objectUserFactory" class="com.demo.spring.ObjectUserFactory"></bean>
    <bean id="userDaoByObject" factory-bean="objectUserFactory"
        factory-method="getUserDao"></bean>

    <!-- 構造器注入 -->
    <bean id="userServiceByContructor" class="com.demo.spring.UserService">
        <constructor-arg name="userDao" ref="userDao"></constructor-arg>
    </bean>

    <!-- Setter注入, 必須有無參構造 -->
    <bean id="userServiceBySetter" class="com.demo.spring.UserService">
        <property name="userDao" ref="userDao"></property>
    </bean>

</beans>

UserDaoTest.java

package com.demo.test;

import org.junit.Before;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.demo.spring.BaseDao;
import com.demo.spring.UserDao;

public class UserDaoTest {
    public ApplicationContext context;

    @Before
    public void init() {
        context = new ClassPathXmlApplicationContext("applicationContext.xml");
    }

    @Test
    public void test1() {
        System.out.println("--------------無參構造實例化-----------------");
        BaseDao userDao = context.getBean("userDao", BaseDao.class); // 無參構造實例化
        userDao.insert();

        BaseDao userDao1 = context.getBean("userDao", UserDao.class);
        userDao1.delete();

        UserDao userDao2 = context.getBean("userDao", UserDao.class);
        userDao2.update();
    }

    @Test
    public void test2() {
        System.out.println("--------------靜態工廠實例化-----------------");
        BaseDao userDao = context.getBean("userDaoByStatic", BaseDao.class);// 靜態工廠實例化
        userDao.insert();

        BaseDao userDao1 = context.getBean("userDaoByStatic", UserDao.class);// 靜態工廠實例化
        userDao1.delete();

        UserDao userDao2 = context.getBean("userDaoByStatic", UserDao.class);// 靜態工廠實例化
        userDao2.update();
    }

    @Test
    public void test3() {
        System.out.println("--------------動態工廠實例化-----------------");
        BaseDao userDao = context.getBean("userDaoByObject", BaseDao.class);// 動態工廠實例化
        userDao.insert();

        BaseDao userDao1 = context.getBean("userDaoByObject", UserDao.class);// 動態工廠實例化
        userDao1.delete();

        UserDao userDao2 = context.getBean("userDaoByObject", UserDao.class);// 動態工廠實例化
        userDao2.update();
    }

}

UserServiceTest.java

package com.demo.test;

import org.junit.Before;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.demo.spring.UserService;

public class UserServiceTest {
    public ApplicationContext context;

    @Before
    public void init() {
        context = new ClassPathXmlApplicationContext("applicationContext.xml");
    }

    @Test
    public void test() {// 構造器注入
        UserService userService = context.getBean("userServiceByContructor", UserService.class);
        userService.getUserDao().insert();

    }

    @Test
    public void test2() {// setter注入，必須有無參構造
        UserService userService = context.getBean("userServiceBySetter", UserService.class);
        userService.getUserDao().delete();
    }

}

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.demo</groupId>
    <artifactId>maven-spring</artifactId>
    <version>0.0.1-SNAPSHOT</version>

    <dependencies>
        <!-- junit單元測試 -->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>

        <!-- spring核心包 -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>4.3.0.RELEASE</version>
        </dependency>

    </dependencies>
    <build>
        <plugins>
            <plugin>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.5.1</version>
                <configuration>
                    <source>1.7</source>
                    <target>1.7</target>
                    <encoding>UTF-8</encoding>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-source-plugin</artifactId>
                <version>3.0.1</version>
                <executions>
                    <execution>
                        <id>attach-sources</id>
                        <goals>
                            <goal>jar</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

</project>

配置文件方式代碼源碼

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方式二：註解方式實現Bean實例化和依賴注入

BaseDao.java

package com.demo.spring;

public interface BaseDao {

    public void insert();

    public void delete();

    public void update();

    public void select();

}

UserDao.java

package com.demo.spring;

import org.springframework.stereotype.Repository;

@Repository
public class UserDao implements BaseDao {

    @Override
    public void insert() {
        System.out.println("insert()");
    }

    @Override
    public void delete() {
        System.out.println("delete()");
    }

    @Override
    public void update() {
        System.out.println("update()");
    }

    @Override
    public void select() {
        System.out.println("select()");
    }

}

UserService.java

package com.demo.spring;

import javax.annotation.Resource;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

@Service
public class UserService {

    // @Resource // 寫在字段前面，可以沒有setter方法，默認名稱優先
    @Autowired // 寫在字段前面，可以沒有setter方法，默認類型優先
    private UserDao userDao;

    public UserDao getUserDao() {
        return userDao;
    }

}

applicationContext.xml

<?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"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context.xsd">

    <context:component-scan base-package="com.demo.spring"></context:component-scan>

</beans>

UserDaoTest.java

package com.demo.test;

import org.junit.Before;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.demo.spring.BaseDao;
import com.demo.spring.UserDao;

public class UserDaoTest {
    public ApplicationContext context;

    @Before
    public void init() {
        context = new ClassPathXmlApplicationContext("applicationContext.xml");
    }

    @Test
    public void test1() {
        System.out.println("--------------無參構造實例化-----------------");
        BaseDao userDao = context.getBean("userDao", BaseDao.class); // 無參構造實例化
        userDao.insert();

        BaseDao userDao1 = context.getBean("userDao", UserDao.class);
        userDao1.delete();

        UserDao userDao2 = context.getBean("userDao", UserDao.class);
        userDao2.update();
    }

}

UserServiceTest.java

package com.demo.test;

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.SpringJUnit4ClassRunner;

import com.demo.spring.UserService;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = { "classpath*:applicationContext.xml" })
public class UserServiceTest {

    @Autowired
    private UserService userService;

    @Test
    public void test() {
        userService.getUserDao().insert();
    }

}

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.demo</groupId>
    <artifactId>maven-spring</artifactId>
    <version>0.0.1-SNAPSHOT</version>

    <dependencies>
        <!-- junit單元測試 -->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>4.2.0.RELEASE</version>
            <scope>test</scope>
        </dependency>

        <!-- spring核心包 -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>4.2.0.RELEASE</version>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.5.1</version>
                <configuration>
                    <source>1.7</source>
                    <target>1.7</target>
                    <encoding>UTF-8</encoding>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-source-plugin</artifactId>
                <version>3.0.1</version>
                <executions>
                    <execution>
                        <id>attach-sources</id>
                        <goals>
                            <goal>jar</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

</project>

註解方式代碼源碼