例子:

bean.xml

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-4.1.xsd">

测试代码

importorg.springframework.beans.factory.support.DefaultListableBeanFactory;importorg.springframework.beans.factory.xml.XmlBeanDefinitionReader;importorg.springframework.core.io.ClassPathResource;public classBeanFactoryExample {public static voidmain(String[] args) {//根据配置文件创建ClassPathResource对象

ClassPathResource resource = new ClassPathResource("com/qst/chapter08/bean.xml");//创建BeanFactory对象

DefaultListableBeanFactory factory = new DefaultListableBeanFactory();

XmlBeanDefinitionReader reader = new XmlBeanDefinitionReader(factory);

reader.loadBeanDefinitions(resource);//从BeanFactory对象中，根据id获取具体对象

Book book = (Book) factory.getBean("book");

System.out.println(book.getName());

System.out.println(book.getAuthor());

System.out.println(book.getPublishHouse());

System.out.println(book.getPrice());

}

}

ApplicationContext的例子

public classApplicationContextExample {public static voidmain(String[] args) {

ClassPathXmlApplicationContext context= new ClassPathXmlApplicationContext("com/qst/chapter08/bean.xml");

Book book = (Book) context.getBean("book");

System.out.println(book.getName());

System.out.println(book.getAuthor());

System.out.println(book.getPublishHouse());

System.out.println(book.getPrice());

context.close();

}

}

例如

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-4.1.xsd">

测试类不变,需要改变bean和配置文件,测试类里的调用方法不变:

bean中加一个构造方法,配置文件中加入这个构造方法的相关配置

public classOrder {private intid;private String orderNo; //订单编号

private double amount; //订单金额

privateObject[] myArray;private List>myList;private Set>mySet;private Map, ?>myMap;privateProperties myProp;public Order(int id, String orderNo) {

this.id = id;

this.orderNo =orderNo;

}

//其他省略

}

ABCDEF

5678.123

示例如下:

public class Order {

private int id;

private String orderNo; // 订单编号

private double amount; // 订单金额

private Object[] myArray;

private List> myList;

private Set>mySet;

private Map, ?>myMap;

private Properties myProp;

public Order(int id, String orderNo) {

this.id = id;

this.orderNo = orderNo;

}

public int getId() {

return id;

}

public String getOrderNo() {

return orderNo;

}

public void setOrderNo(String orderNo) {

this.orderNo = orderNo;

}

public double getAmount() {

return amount;

}

public void setAmount(double amount) {

this.amount = amount;

}

public Object[] getMyArray() {

return myArray;

}

public void setMyArray(Object[] myArray) {

this.myArray = myArray;

}

public List> getMyList() {

return myList;

}

public void setMyList(List>myList) {

this.myList = myList;

}

public Set> getMySet() {

return mySet;

}

public void setMySet(Set>mySet) {

this.mySet = mySet;

}

public Map,?>getMyMap() {

return myMap;

}

public void setMyMap(Map,?>myMap) {

this.myMap = myMap;

}

public Properties getMyProp() {

return myProp;

}

public void setMyProp(Properties myProp) {

this.myProp = myProp;

}

}

http://www.springframework.org/schema/beans

http://www.springframework.org/schema/beans/spring-beans-4.1.xsd">

ABCDEF

5678.123

1234

1234

1234

AAA

BBBBB

这里的继承指的是配置信息的重用,跟面向对象里的继承毫无关系.

前置依赖是指,有时要求Bean A的初始化必须在Bean B的初始化之后,而B并不是A的属性.这种情况下,无法通过ref来保证B先初始化,所以Spring提供了depends-on.

这里重点说一下by Type,by Type方式只根据类型与否匹配来决定是否注入依赖关系,加入A实例有setB(B b)方法,而Spring配置文件中恰好有一个类型B的Bean实例,则Spring会注入此实例,如果容器总没有一个类型为B的实例或多于一个的B实例,则都会抛出异常.