1.設值注入：底層呼叫屬性setter方法進行賦值，一定要有setter方法。使用property.
2.構造注入：一定要有帶引數的構造方法。使用constructor-arg.

通過設值注入原始碼為：
1.School類：

public class School {
private String sname;

public void setSname(String sname) {
	this.sname = sname;
}

@Override
public String toString() {
	return "School [sname=" + sname + "]";
}
 

}

2.Student類及setter方法

public class Student {
private String name; //成員變數
private int age;
private School school; //自定義類物件

public void setXxx(String name) {
	this.name = name;
}
public void setAge(int age) {
	this.age = age;
}
public void setSchool(School school) {
	this.school = school;
}
@Override
public String toString() {
	return "Student [name=" + name + ", age=" + age + ", school=" + school + "]";
}
 

}

3.XML配置檔案

<bean id="mySchool" class="com.abc.di01.School">
	<property name="sname" value="清華大學"/>
</bean>
<bean id="student" class="com.abc.di01.Student">
	<property name="xxx" value="張三"/>
	<property name="age" value="21"/>
	<property name="school" ref="mySchool"/>
</bean>
 

4.測試類MyTest

import org.junit.Test;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.xml.XmlBeanFactory;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.context.support.FileSystemXmlApplicationContext;
import org.springframework.core.io.ClassPathResource;

//設值注入
public class MyTest {

@Test
public void tests01(){
	//建立Spring容器物件，載入Spring的配置檔案（在類路徑下）
	String config = "com/abc/di01/applicationContext.xml";
	ApplicationContext ac = new ClassPathXmlApplicationContext(config);
	Student student = (Student) ac.getBean("student");
	System.out.println(student);
}

}

測試結果為：

Student [name=張三, age=21, school=School [sname=清華大學]]

通過構造注入原始碼為：

1.School類：

public class School {
private String sname;

public void setSname(String sname) {
	this.sname = sname;
}

@Override
public String toString() {
	return "School [sname=" + sname + "]";
}

}
2.Student類及有參構造方法

public class Student {
private String name; //成員變數
private int age;
private School school; //自定義類物件

public Student(String name, int age, School school) {
	super();
	this.name = name;
	this.age = age;
	this.school = school;
}

@Override
public String toString() {
	return "Student [name=" + name + ", age=" + age + ", school=" + school + "]";
}

}

3.XML配置檔案

<bean id="mySchool" class="com.abc.di02.School">
	<property name="sname" value="清華大學"/>
</bean>
<bean id="student" class="com.abc.di02.Student">
	<constructor-arg name="name" value="李四"/>
	<constructor-arg name="age" value="22"/>
	<constructor-arg name="school" ref="mySchool"/>
</bean>

4.測試類MyTest

Student [name=李四, age=22, school=School [sname=清華大學]]