Spring的依赖注入
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spring依赖注入
1.构造器注入
2.Set方式注入
依赖注入:Set注入
? 依赖: bean对象的创建依赖于容器
? 注入: bean对象中的所有属性,由容器来注入
package com.liqiliang.pojo;
import java.util.*;
public class Student {
private String name;
private Address address;
private String[] books;
private List<String> hobbys;
private Map<String,String> card;
private Set<String> games;
private String wife;
private Properties info;
@Override
public String toString() {
return "Student{" +
"name=‘" + name + ‘‘‘ +
", address=" + address.toString() +
", books=" + Arrays.toString(books) +
", hobbys=" + hobbys +
", card=" + card +
", games=" + games +
", wife=‘" + wife + ‘‘‘ +
", info=" + info +
‘}‘;
}
public Set<String> getGames() {
return games;
}
public void setGames(Set<String> games) {
this.games = games;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Address getAddress() {
return address;
}
public void setAddress(Address address) {
this.address = address;
}
public String[] getBooks() {
return books;
}
public void setBooks(String[] books) {
this.books = books;
}
public List<String> getHobbys() {
return hobbys;
}
public void setHobbys(List<String> hobbys) {
this.hobbys = hobbys;
}
public Map<String, String> getCard() {
return card;
}
public void setCard(Map<String, String> card) {
this.card = card;
}
public String getWife() {
return wife;
}
public void setWife(String wife) {
this.wife = wife;
}
public Properties getInfo() {
return info;
}
public void setInfo(Properties info) {
this.info = info;
}
}
package com.liqiliang.pojo;
public class Address {
private String address;
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
@Override
public String toString() {
return "Address{" +
"address=‘" + address + ‘‘‘ +
‘}‘;
}
}
<?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="address" class="com.liqiliang.pojo.Address">
<property name="address" value="上海"/>
</bean>
<bean id="student" class="com.liqiliang.pojo.Student">
<!--普通值注入,value-->
<property name="name" value="李启亮"/>
<!--bean注入,ref-->
<property name="address" ref="address"/>
<!--数组注入-->
<property name="books">
<array>
<value>红楼梦</value>
<value>西游记</value>
<value>三国演义</value>
</array>
</property>
<!--List-->
<property name="hobbys">
<list>
<value>听课</value>
<value>敲代码</value>
<value>看电影</value>
</list>
</property>
<!--Map-->
<property name="card">
<map>
<entry key="学号" value="1"/>
<entry key="性别" value="男"/>
<entry key="年龄" value="18"/>
</map>
</property>
<!--Set-->
<property name="games">
<set>
<value>LOL</value>
<value>CF</value>
<value>QQcar</value>
</set>
</property>
<!--null-->
<property name="wife">
<null/>
</property>
<!--Properties-->
<property name="info">
<props>
<prop key="学号">20200513</prop>
<prop key="姓名">小李</prop>
<prop key="driver">1</prop>
<prop key="url">2</prop>
<prop key="username">3</prop>
<prop key="password">4</prop>
</props>
</property>
</bean>
</beans>
import com.liqiliang.pojo.Student;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class MyTest {
public static void main(String[] args) {
ApplicationContext applicationContext =
new ClassPathXmlApplicationContext("bean.xml");
Student student = (Student) applicationContext.getBean("student");
System.out.println(student.toString());
/*
Student{
name=‘李启亮‘,
address=Address{address=‘上海‘},
books=[红楼梦, 西游记, 三国演义],
hobbys=[听课, 敲代码, 看电影],
card={学号=1, 性别=男, 年龄=18},
games=[LOL, CF, QQcar],
wife=‘null‘,
info={学号=20200513, password=4, url=2, driver=1, 姓名=小李, username=3}}
*/
}
}
3.拓展方式注入(p命名空间和c命名空间)
实体类
package com.liqiliang.pojo;
public class User {
private int id;
private String name;
public User(int id, String name) {
this.id = id;
this.name = name;
}
public User() {
}
@Override
public String toString() {
return "User{" +
"id=" + id +
", name=‘" + name + ‘‘‘ +
‘}‘;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
xml文件
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:p="http://www.springframework.org/schema/p"
xmlns:c="http://www.springframework.org/schema/c"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd">
<!--p命名和c命名必须要有上面的声名
xmlns:p="http://www.springframework.org/schema/p"
xmlns:c="http://www.springframework.org/schema/c"
并且实体类中要有构造器 -->
<!--p命名空间注入 , 可以直接注入属性的值:property-->
<bean id="user" class="com.liqiliang.pojo.User" p:name="李启亮" p:id="1"/>
<!--c命名空间注入,通过构造器注入:construct-args-->
<bean id="user2" class="com.liqiliang.pojo.User" c:id="2" c:name="小李"/>
</beans>
测试类
import com.liqiliang.pojo.Student;
import com.liqiliang.pojo.User;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class MyTest {
@Test
public void test2(){
ApplicationContext applicationContext =
new ClassPathXmlApplicationContext("UserBean.xml");
User user = (User) applicationContext.getBean("user");
System.out.println(user);
}
@Test
public void test3(){
ApplicationContext applicationContext =
new ClassPathXmlApplicationContext("UserBean.xml");
User user = (User) applicationContext.getBean("user2");
System.out.println(user);
}
}
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