详解Spring框架

详解Spring框架

IOC装配Bean

（1）Spring框架Bean实例化的方式提供了三种方式实例化Bean

构造方法实例化(默认无参数，用的最多)

静态工厂实例化

实例工厂实例化

下面先写这三种方法的applicationContext.xml配置文件：

xmlns:xsi="http://w3.org/2001/XMLSchema-instance"

xmlns:p="http://springframework.org/schema/p"

xmlns:context="http://springframework.org/schema/context" xsi:schemaLocation="

http://springframework.org/schema/beans http://springframework.org/schema/beans/spring-beans.xsd

http://springframework.org/schema/context http://springframework.org/schema/context/spring-context.xsd">

Bean1类

public class Bean1 {

//必须提供无参的构造函数 系统有默认无参的构造函数

}

Bean2类

public class Bean2 {

private static Bean2 Bean2 = new Bean2();

private Bean2() {

}

public static Bean2 createInstance() {

return Bean2;

}

}

Bean3类

public class Bean3 {

}

Bean3Factory类

public class Bean3Factory {

private Bean3Factory(){

}

public Bean3 getInstance(){

return new Bean3();

}

}

测试类InstanceDemo

import org.junit.Test;

import org.springframework.context.ApplicationContext;

import org.springframework.context.support.ClassPathXmlApplicationContext;

public class InstanceDemo {

//实例化工厂方法

@Test

public void demo3(){

//加载配置文件 创建工厂

ApplicationContext applicationContext=new ClassPathXmlApplicationContext("applicationContext.xml");

Bean3 bean3 =(Bean3) applicationContext.getBean("bean3");

System.out.println(bean3);

}

//静态工厂方法

@Test

public void demo2(){

//加载配置文件 创建工厂

ApplicationContext applicationContext=new ClassPathXmlApplicationContext("applicationContext.xml");

Bean2 bean2 =(Bean2) applicationContext.getBean("bean2");

System.out.println(bean2);

}

//构造方法得到bean对象

@Test

public void demo1(){

//加载配置文件 创建工厂

ApplicationContext applicationContext=new ClassPathXmlApplicationContext("applicationContext.xml");

Bean1 bean1 =(Bean1) applicationContext.getBean("bean1");

System.out.println(bean1);

}

}

/*

* 这三个都得到类似于com.study.spring.b_instance.Bean1@7229c204 的内存地址

*/

(2).Bean的其他配置:

一般情况下，装配一个Bean时，通过指定一个id属性作为Bean的名称

id 属性在IoC容器中必须是唯一的

id 的命名要满足XML对ID属性命名规范 必须以字母开始，可以使用字母、数字、连字符、下划线、句话、冒号

如果Bean的名称中含有特殊字符，就需要使用name属性 例如：

因为name属性可以相同，所以后出现Bean会覆盖之前出现的同名的Bean

id和name的区别:

id遵守XML约束的id的约束.id约束保证这个属性的值是唯一的,而且必须以字母开始，可以使用字母、数字、连字符、下划线、句话、冒号

name没有这些要求

如果bean标签上没有配置id,那么name可以作为id.

Bean的scope属性

* singleton :单例的.(默认的值.)

* prototype :多例的.

* request :web开发中.创建了一个对象,将这个对象存入request范围,request.setAttribute();

* session :web开发中.创建了一个对象,将这个对象存入session范围,session.setAttribute();

* globalSession :一般用于Porlet应用环境.指的是分布式开发.不是porlet环境,globalSession等同于session;

3.Bean属性的依赖注入

前面已经知道如何获得对象，那我们接下来要知道如果给对象对象的属性赋值。

下面通过举例说明:

Car 类

public class Car {

private String name;

private double price;

public Car(String name, double price) {

super();

this.name = name;

this.price = price;

}

@Override

public String toString() {

return "Car [name=" + name + ", price=" + price + "]";

}

}

Car2类

public class Car2 {

private String name;

private double price;

public void setName(String name) {

this.name = name;

}

public void setPrice(double price) {

this.price = price;

}

@Override

public String toString() {

return "Car2 [name=" + name + ", price=" + price + "]";

}

}

CarInfo类

public class CarInfo {

public String getName(){

return "哈弗H6";

}

public double caculatePrice(){

return 110000;

}

}

CollectionBean类

import java.util.List;

import java.util.Map;

import java.util.Properties;

import java.util.Set;

public class CollectionBean {

private String name;

private Integer age;

private List hobbies;

private Set numbers;

private Map map;

private Properties properties;

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;

}

public List getHobbies() {

return hobbies;

}

public void setHobbies(List hobbies) {

this.hobbies = hobbies;

}

public Set getNumbers() {

return numbers;

}

public void setNumbers(Set numbers) {

this.numbers = numbers;

}

public Map getMap() {

return map;

}

public void setMap(Map map) {

this.map = map;

}

public Properties getProperties() {

return properties;

}

public void setProperties(Properties properties) {

this.properties = properties;

}

@Override

public String toString() {

return "CollectionBean [name=" + name + ", age=" + age + ", hobbies=" + hobbies + ", numbers=" + numbers

+ ", map=" + map + ", properties=" + properties + "]";

}

}

Employee类

public class Employee {

private String name;

private Car2 car2;

public void setName(String name) {

this.name = name;

}

public void setCar2(Car2 car2) {

this.car2 = car2;

}

@Override

public String toString() {

return "Employee [name=" + name + ", car2=" + car2 + "]";

}

}

TestDi测试类

import org.junit.Test;

import org.springframework.context.ApplicationContext;

import org.springframework.context.support.ClassPathXmlApplicationContext;

public class TestDi {

@Test

public void demo6() {

ApplicationContext applicationContext = new ClassPathOasoVnSBxVXmlApplicationContext("applicationContext.xml");

CollectionBean collectionBean = (CollectionBean) applicationContext.getBean("collectionBean");

System.out.println(collectionBean);

}

@Test

public void demo5() {

ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");

Car2 car2 = (Car2) applicationContext.getBean("car2_2");

System.out.println(car2);

}

@Test

public void demo4() {

ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");

Employee e = (Employee) applicationContext.getBean("employee2");

System.out.println(e);

}

@Test

public void demo3() {

ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");

Employee e = (Employee) applicationContext.getBean("employee");

System.out.println(e);

}

@Test

public void demo2() {

ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");

Car2 car2 = (Car2) applicationContext.getBean("car2");

System.out.println(car2);

}

@Test

public void demo1() {

ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");

Car car = (Car) applicationContext.getBean("car");

System.out.println(car);

}

}

上面这几个类都不是最主要的，我们主要是来看配置文件怎么写，这才是最关键的：

applicationContext.xml

xmlns:xsi="http://w3.org/2001/XMLSchema-instance"

xmlns:p="http://springframework.org/schema/p"

xmlns:context="http://springframework.org/schema/context" xsi:schemaLocation="

http://springframework.org/schema/beans http://springframework.org/schema/beans/spring-beans.xsd

http://springframework.org/schema/context http://springframework.org/schema/context/spring-context.xsd">

吃饭

睡觉

敲代码

10

20

30

40

50

杭州归谷

200

有关applicationContext.xml这个配置文件里的内容一定要看懂，我写的还是比较基础和全面的。

有关命名空间p的使用我这里在解释下：

p:<属性名>="xxx" 引入常量值

p:<属性名>-ref="xxx" 引用其它Bean对象

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支http://持我们。

xmlns:xsi="http://w3.org/2001/XMLSchema-instance"

xmlns:p="http://springframework.org/schema/p"

xmlns:context="http://springframework.org/schema/context" xsi:schemaLocation="

http://springframework.org/schema/beans http://springframework.org/schema/beans/spring-beans.xsd

http://springframework.org/schema/context http://springframework.org/schema/context/spring-context.xsd">

Bean1类

public class Bean1 {

//必须提供无参的构造函数 系统有默认无参的构造函数

}

Bean2类

public class Bean2 {

private static Bean2 Bean2 = new Bean2();

private Bean2() {

}

public static Bean2 createInstance() {

return Bean2;

}

}

Bean3类

public class Bean3 {

}

Bean3Factory类

public class Bean3Factory {

private Bean3Factory(){

}

public Bean3 getInstance(){

return new Bean3();

}

}

测试类InstanceDemo

import org.junit.Test;

import org.springframework.context.ApplicationContext;

import org.springframework.context.support.ClassPathXmlApplicationContext;

public class InstanceDemo {

//实例化工厂方法

@Test

public void demo3(){

//加载配置文件 创建工厂

ApplicationContext applicationContext=new ClassPathXmlApplicationContext("applicationContext.xml");

Bean3 bean3 =(Bean3) applicationContext.getBean("bean3");

System.out.println(bean3);

}

//静态工厂方法

@Test

public void demo2(){

//加载配置文件 创建工厂

ApplicationContext applicationContext=new ClassPathXmlApplicationContext("applicationContext.xml");

Bean2 bean2 =(Bean2) applicationContext.getBean("bean2");

System.out.println(bean2);

}

//构造方法得到bean对象

@Test

public void demo1(){

//加载配置文件 创建工厂

ApplicationContext applicationContext=new ClassPathXmlApplicationContext("applicationContext.xml");

Bean1 bean1 =(Bean1) applicationContext.getBean("bean1");

System.out.println(bean1);

}

}

/*

* 这三个都得到类似于com.study.spring.b_instance.Bean1@7229c204 的内存地址

*/

(2).Bean的其他配置:

一般情况下，装配一个Bean时，通过指定一个id属性作为Bean的名称

id 属性在IoC容器中必须是唯一的

id 的命名要满足XML对ID属性命名规范 必须以字母开始，可以使用字母、数字、连字符、下划线、句话、冒号

如果Bean的名称中含有特殊字符，就需要使用name属性 例如：

因为name属性可以相同，所以后出现Bean会覆盖之前出现的同名的Bean

id和name的区别:

id遵守XML约束的id的约束.id约束保证这个属性的值是唯一的,而且必须以字母开始，可以使用字母、数字、连字符、下划线、句话、冒号

name没有这些要求

如果bean标签上没有配置id,那么name可以作为id.

Bean的scope属性

* singleton :单例的.(默认的值.)

* prototype :多例的.

* request :web开发中.创建了一个对象,将这个对象存入request范围,request.setAttribute();

* session :web开发中.创建了一个对象,将这个对象存入session范围,session.setAttribute();

* globalSession :一般用于Porlet应用环境.指的是分布式开发.不是porlet环境,globalSession等同于session;

3.Bean属性的依赖注入

前面已经知道如何获得对象，那我们接下来要知道如果给对象对象的属性赋值。

下面通过举例说明:

Car 类

public class Car {

private String name;

private double price;

public Car(String name, double price) {

super();

this.name = name;

this.price = price;

}

@Override

public String toString() {

return "Car [name=" + name + ", price=" + price + "]";

}

}

Car2类

public class Car2 {

private String name;

private double price;

public void setName(String name) {

this.name = name;

}

public void setPrice(double price) {

this.price = price;

}

@Override

public String toString() {

return "Car2 [name=" + name + ", price=" + price + "]";

}

}

CarInfo类

public class CarInfo {

public String getName(){

return "哈弗H6";

}

public double caculatePrice(){

return 110000;

}

}

CollectionBean类

import java.util.List;

import java.util.Map;

import java.util.Properties;

import java.util.Set;

public class CollectionBean {

private String name;

private Integer age;

private List hobbies;

private Set numbers;

private Map map;

private Properties properties;

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;

}

public List getHobbies() {

return hobbies;

}

public void setHobbies(List hobbies) {

this.hobbies = hobbies;

}

public Set getNumbers() {

return numbers;

}

public void setNumbers(Set numbers) {

this.numbers = numbers;

}

public Map getMap() {

return map;

}

public void setMap(Map map) {

this.map = map;

}

public Properties getProperties() {

return properties;

}

public void setProperties(Properties properties) {

this.properties = properties;

}

@Override

public String toString() {

return "CollectionBean [name=" + name + ", age=" + age + ", hobbies=" + hobbies + ", numbers=" + numbers

+ ", map=" + map + ", properties=" + properties + "]";

}

}

Employee类

public class Employee {

private String name;

private Car2 car2;

public void setName(String name) {

this.name = name;

}

public void setCar2(Car2 car2) {

this.car2 = car2;

}

@Override

public String toString() {

return "Employee [name=" + name + ", car2=" + car2 + "]";

}

}

TestDi测试类

import org.junit.Test;

import org.springframework.context.ApplicationContext;

import org.springframework.context.support.ClassPathXmlApplicationContext;

public class TestDi {

@Test

public void demo6() {

ApplicationContext applicationContext = new ClassPathOasoVnSBxVXmlApplicationContext("applicationContext.xml");

CollectionBean collectionBean = (CollectionBean) applicationContext.getBean("collectionBean");

System.out.println(collectionBean);

}

@Test

public void demo5() {

ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");

Car2 car2 = (Car2) applicationContext.getBean("car2_2");

System.out.println(car2);

}

@Test

public void demo4() {

ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");

Employee e = (Employee) applicationContext.getBean("employee2");

System.out.println(e);

}

@Test

public void demo3() {

ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");

Employee e = (Employee) applicationContext.getBean("employee");

System.out.println(e);

}

@Test

public void demo2() {

ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");

Car2 car2 = (Car2) applicationContext.getBean("car2");

System.out.println(car2);

}

@Test

public void demo1() {

ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");

Car car = (Car) applicationContext.getBean("car");

System.out.println(car);

}

}

上面这几个类都不是最主要的，我们主要是来看配置文件怎么写，这才是最关键的：

applicationContext.xml

xmlns:xsi="http://w3.org/2001/XMLSchema-instance"

xmlns:p="http://springframework.org/schema/p"

xmlns:context="http://springframework.org/schema/context" xsi:schemaLocation="

http://springframework.org/schema/beans http://springframework.org/schema/beans/spring-beans.xsd

http://springframework.org/schema/context http://springframework.org/schema/context/spring-context.xsd">

吃饭

睡觉

敲代码

10

20

30

40

50

杭州归谷

200

xmlns:xsi="http://w3.org/2001/XMLSchema-instance"

xmlns:p="http://springframework.org/schema/p"

xmlns:context="http://springframework.org/schema/context" xsi:schemaLocation="

http://springframework.org/schema/beans http://springframework.org/schema/beans/spring-beans.xsd

http://springframework.org/schema/context http://springframework.org/schema/context/spring-context.xsd">

吃饭

睡觉

敲代码

10

20

30

40

50

杭州归谷

200

有关applicationContext.xml这个配置文件里的内容一定要看懂，我写的还是比较基础和全面的。

有关命名空间p的使用我这里在解释下：

p:<属性名>="xxx" 引入常量值

p:<属性名>-ref="xxx" 引用其它Bean对象

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支http://持我们。

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