Spring4学习回顾之路07- 通过工厂方法配置Bean

一：通过静态工厂配置Bean

建立Student.java

package com.lql.srping04;

/**
 * @author: lql
 * @date: 2019.10.28
 * Description:
 */
public class Student {

    private String name;
    private Integer age;

    @Override
    public String toString() {
        return "Student{" +
                "name='" + name + '\'' +
                ", age=" + age +
                '}';
    }

    public Student() {
    }

    public Student(String name, Integer age) {
        this.name = name;
        this.age = age;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }
}

建立静态工厂StaticStudentFactory.java

package com.lql.srping04;
import    java.util.HashMap;

import java.util.Map;

/**
 * @author: lql
 * @date: 2019.10.28
 * Description:
 */
public class StaticStudentFactory {

    private static Map<String,Student> map = new HashMap<String, Student> ();

    static {
        map.put("张三",new Student("张三",18));
        map.put("李四",new Student("李四",17));
    }

    public static Student getStudent(String name) {
        return map.get(name);
    }
}

通过静态工厂方法配置Bean

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">

<bean id="studentfactory" class="com.lql.srping04.StaticStudentFactory" factory-method="getStudent">
    <constructor-arg value="李四"></constructor-arg>
</bean>
</beans>

注意的是：因为静态方法getStudent(String name)；有个参数，则在配置的时候需要<constructor-arg>来指定value;上图标签属性的说明:class:指向静态工厂方法的全类名，factory-method:指向静态工厂方法的名字

建立测试类：

package com.lql.srping04;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

/**
 * @author: lql
 * @date: 2019.10.28
 * Description:
 */
public class StudetnTest {
    public static void main(String[] args) {
        ApplicationContext app = new ClassPathXmlApplicationContext("spring04.xml");
        Student student = app.getBean("studentfactory", Student.class);
        System.out.println(student);
    }
}

测试结果：

"C:\Program Files\Java\jdk1.8.0_201\bin\java" "-javaagent:D:\Program\JetBrains\IntelliJ IDEA 2017.3.3\lib\idea_rt.jar=58238:D:\Program\JetBrains\IntelliJ IDEA 2017.3.3\bin" -Dfile.encoding=UTF-8 -classpath "C:\Program Files\Java\jdk1.8.0_201\jre\lib\charsets.jar;C:\Program Files\Java\jdk1.8.0_201\jre\lib\deploy.jar;C:\Program Files\Java\jdk1.8.0_201\jre\lib\ext\access-bridge-64.jar;C:\Program Files\Java\jdk1.8.0_201\jre\lib\ext\cldrdata.jar;C:\Program Files\Java\jdk1.8.0_201\jre\lib\ext\dnsns.jar;C:\Program Files\Java\jdk1.8.0_201\jre\lib\ext\jaccess.jar;C:\Program Files\Java\jdk1.8.0_201\jre\lib\ext\jfxrt.jar;C:\Program Files\Java\jdk1.8.0_201\jre\lib\ext\localedata.jar;C:\Program Files\Java\jdk1.8.0_201\jre\lib\ext\nashorn.jar;C:\Program Files\Java\jdk1.8.0_201\jre\lib\ext\sunec.jar;C:\Program Files\Java\jdk1.8.0_201\jre\lib\ext\sunjce_provider.jar;C:\Program Files\Java\jdk1.8.0_201\jre\lib\ext\sunmscapi.jar;C:\Program Files\Java\jdk1.8.0_201\jre\lib\ext\sunpkcs11.jar;C:\Program Files\Java\jdk1.8.0_201\jre\lib\ext\zipfs.jar;C:\Program Files\Java\jdk1.8.0_201\jre\lib\javaws.jar;C:\Program Files\Java\jdk1.8.0_201\jre\lib\jce.jar;C:\Program Files\Java\jdk1.8.0_201\jre\lib\jfr.jar;C:\Program Files\Java\jdk1.8.0_201\jre\lib\jfxswt.jar;C:\Program Files\Java\jdk1.8.0_201\jre\lib\jsse.jar;C:\Program Files\Java\jdk1.8.0_201\jre\lib\management-agent.jar;C:\Program Files\Java\jdk1.8.0_201\jre\lib\plugin.jar;C:\Program Files\Java\jdk1.8.0_201\jre\lib\resources.jar;C:\Program Files\Java\jdk1.8.0_201\jre\lib\rt.jar;F:\bdyc\SpringFramework\out\production\SpringFramework;F:\bdyc\SpringFramework\libs\c3p0-0.9.1.2.jar;F:\bdyc\SpringFramework\libs\commons-logging-1.1.1.jar;F:\bdyc\SpringFramework\libs\mysql-connector-java-5.1.7-bin.jar;F:\bdyc\SpringFramework\libs\spring-aop-4.0.0.RELEASE.jar;F:\bdyc\SpringFramework\libs\spring-beans-4.0.0.RELEASE.jar;F:\bdyc\SpringFramework\libs\spring-context-4.0.0.RELEASE.jar;F:\bdyc\SpringFramework\libs\spring-core-4.0.0.RELEASE.jar;F:\bdyc\SpringFramework\libs\spring-expression-4.0.0.RELEASE.jar" com.lql.srping04.StudetnTest
十月 28, 2019 1:49:35 下午 org.springframework.context.support.AbstractApplicationContext prepareRefresh
信息: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@37bba400: startup date [Mon Oct 28 13:49:35 GMT+08:00 2019]; root of context hierarchy
十月 28, 2019 1:49:35 下午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
信息: Loading XML bean definitions from class path resource [spring04.xml]
Student{name='李四', age=17}

二：通过实例工厂方法配置Bean

建立实例工厂InstanceFactory.java

package com.lql.srping04;

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

/**
 * @author: lql
 * @date: 2019.10.28
 * Description:实例工厂
 */
public class InstanceFactory {

    private Map<String,Student> map = null;

    public InstanceFactory(){
        map = new HashMap<>();
        map.put("张三",new Student("张三",18));
        map.put("李四",new Student("李四",17));
    }

    public Student getStudent(String name) {

        return map.get(name);
    }
}

配置：factory-bean：指定工厂实例bean.

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">

    <!-- 配置工厂实例 -->
    <bean id="instancefactory" class="com.lql.srping04.InstanceFactory"></bean>

    <!--通过实例工厂方法类来配置bean-->
    <bean id="student" factory-bean="instancefactory" factory-method="getStudent">
        <constructor-arg value="张三"></constructor-arg>
    </bean>
</beans>

测试：

package com.lql.srping04;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

/**
 * @author: lql
 * @date: 2019.10.28
 * Description:
 */
public class StudetnTest {
    public static void main(String[] args) {
        ApplicationContext app = new ClassPathXmlApplicationContext("spring04.xml");
//        Student student = app.getBean("studentfactory", Student.class);
        Student student = app.getBean("student", Student.class);
        System.out.println(student);
    }
}

结果：

十月 28, 2019 2:04:25 下午 org.springframework.context.support.AbstractApplicationContext prepareRefresh
信息: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@37bba400: startup date [Mon Oct 28 14:04:25 GMT+08:00 2019]; root of context hierarchy
十月 28, 2019 2:04:25 下午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
信息: Loading XML bean definitions from class path resource [spring04.xml]
Student{name='张三', age=18}