标签：
此文为基础回顾，估计是最后一次总结。
项目利用maven进行架构，其基本项目结构为：
其中pom.xml中的内容为：
<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.mc.base.learn</groupId> <artifactId>spring</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>jar</packaging> <name>spring</name> <url>http://maven.apache.org</url> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> </properties> <dependencies> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.12</version> <scope>test</scope> </dependency> <!-- Spring核心依赖 --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-core</artifactId> <version>4.2.6.RELEASE</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-beans</artifactId> <version>4.2.6.RELEASE</version> </dependency> <!-- 提供了Spring上下文对象 --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context</artifactId> <version>4.2.6.RELEASE</version> </dependency> </dependencies> </project>
项目基本结构完成
最基本的对象创建方式，只需要有一个无参构造函数（类中没有写任何的构造函数，默认就是有一个构造函数，如果写了任何一个构造函数，默认的无参构造函数就不会自动创建哦!!）和字段的setter方法。
Person类：
package com.mc.base.learn.spring.bean; public class Person { private String name; private Integer id; public String getName() { return name; } public void setName(String name) { this.name = name; } public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } @Override public String toString() { return "Person [name=" + name + ", id=" + id + "]"; } }
XML配置：
<?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 class="com.mc.base.learn.spring.bean.Person" id="person"> <property name="name" value="LiuChunfu"></property> <property name="id" value="125"></property> </bean> </beans>
其本质为：
SpringContext利用无参的构造函数创建一个对象，然后利用setter方法赋值。所以如果无参构造函数不存在，Spring上下文创建对象的时候便会报错。
Exception in thread "main" org.springframework.beans.factory.BeanCreationException: Error creating bean with name ‘person‘ defined in class path resource [applicationContext.xml]: Instantiation of bean failed;
nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.mc.base.learn.spring.bean.Person]: No default constructor found;
nested exception is java.lang.NoSuchMethodException: com.mc.base.learn.spring.bean.Person.<init>() at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1105) 。。。。。
Person类：
package com.mc.base.learn.spring.bean; public class Person { private String name; private Integer id; public Person(String name, Integer id) { super(); this.name = name; this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } @Override public String toString() { return "Person [name=" + name + ", id=" + id + "]"; } }
XML配置：
<?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 class="com.mc.base.learn.spring.bean.Person" id="person"> <constructor-arg name="id" value="123"></constructor-arg> <constructor-arg name="name" value="LiuChunfu"></constructor-arg> </bean> </beans>
package com.mc.base.learn.spring.factory; import com.mc.base.learn.spring.bean.Person; public class PersonStaticFactory { public static Person createPerson(){ return new Person(); } /** * 工厂方法带有参数如何处理？ * @Title: createPerson * @Description: TODO(这里用一句话描述这个方法的作用) * @param @param id * @param @param name * @param @return * @return Person 返回类型 * @throws */ public static Person createPerson(Integer id,String name){ return new Person(name,id); } }
<!--静态的工厂方法核心是class+factory-method --> <bean id="person" class="com.mc.base.learn.spring.factory.PersonStaticFactory" factory-method="createPerson"></bean>
package com.mc.base.learn.spring.factory; import com.mc.base.learn.spring.bean.Person; public class PersonFactory { public Person createInstance() { return new Person(); } }
<!-- 实例工程方法需要先创建工厂实例，然后在创建所需对象的时候，将其赋值为factory-bean --> <bean id="personFactory" class="com.mc.base.learn.spring.factory.PersonFactory"></bean> <bean id="person2" factory-bean="personFactory" factory-method="createInstance"></bean>
setter方法设置属性
标签：
原文地址：http://www.cnblogs.com/LiuChunfu/p/5574383.html
