spring中属性注入的四种方式

1、set⽅法注⼊

配置：

//测试demo

public class Demo {

@Test

public void test(){ //1、创建容器对象

ApplicationContext ac =new ClassPathXmlApplicationContext(\"cn/itcast/injection/applicationContext.xml\"); //2、像容器要User对象

User user = (User)ac.getBean(\"user\"); //3、打印user对象

System.out.println(user.toString()); } }

结果：

2、构造⽅法注⼊

配置：

实体：

package cn.itcast.bean;

public class User { private String name; private Integer age;

private Car car;

public User(String name, Car car) {

System.out.println(\"User(String name, Car car)\"); this.name = name; this.car = car; }

public User(Integer name, Car car) {

System.out.println(\"User(Integer name, Car car)\"); this.name = name+\"\"; this.car = car; }

public User(){

System.out.println(\"user对象空参构造\"); }

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 Car getCar() { return car; }

public void setCar(Car car) { this.car = car; }

@Override

public String toString() {

return \"User [name=\" + name + \ } }

demopublic class Demo {

@Test

public void test(){ //1、创建容器对象

ApplicationContext ac =new ClassPathXmlApplicationContext(\"cn/itcast/injection/applicationContext.xml\"); //2、像容器要User对象

User user = (User)ac.getBean(\"user1\"); //3、打印user对象

System.out.println(user.toString()); } }

结果

由 name+index + type 可以任意指定⼀个构造参数

3、p名称空间注⼊

配置

demopublic class Demo {

@Test

public void test(){ //1、创建容器对象

ApplicationContext ac =new ClassPathXmlApplicationContext(\"cn/itcast/injection/applicationContext.xml\"); //2、像容器要User对象

User user = (User)ac.getBean(\"user3\"); //3、打印user对象

System.out.println(user.toString()); }

}

结果：

4、spel注⼊

配置:

xsi:schemaLocation=\"http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.2.xsd \">

demo

public class Demo {

@Test

public void test(){ //1、创建容器对象

ApplicationContext ac =new ClassPathXmlApplicationContext(\"cn/itcast/injection/applicationContext.xml\"); //2、像容器要User对象

User user = (User)ac.getBean(\"user4\"); //3、打印user对象

System.out.println(user.toString()); } }

结果