spring裝配bean及引數注入
阿新 • • 發佈：2019-01-27
個人使用建議：不要使用3.2.4版本 因為在進行xml檔案載入的時候會出錯。
首先搭建環境
Student.java
package com.demo.entity; public class Student { private String name; private char gender; private int age; private School school; public Student() { super(); // TODO Auto-generated constructor stub } public Student(String name, char gender, int age, School school) { super(); this.name = name; this.gender = gender; this.age = age; this.school = school; } public School getSchool() { return school; } public void setSchool(School school) { this.school = school; } public String getName() { return name; } public void setName(String name) { this.name = name; } public char getGender() { return gender; } public void setGender(char gender) { this.gender = gender; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } @Override public String toString() { return "Student [name=" + name + ", gender=" + gender + ", age=" + age + ", "+this.school.toString() + "]"; } }
School.java
package com.demo.entity; public class School { private String name; private String address; public String getName() { return name; } public void setName(String name) { this.name = name; } public String getAddress() { return address; } public void setAddress(String address) { this.address = address; } @Override public String toString() { return "School [name=" + name + ", address=" + address + "]"; } }
Junit測試
（注意：FileSystemXmlApplicationContext("applicationContext.xml")找配置檔案是從專案根目錄下找的，也可以是絕對路徑）
package com.demo.entity; import static org.junit.Assert.*; import org.springframework.beans.factory.BeanFactory; import org.springframework.beans.factory.xml.XmlBeanFactory; import org.springframework.context.ApplicationContext; import org.junit.After; import org.junit.Before; import org.junit.Test; import org.springframework.context.support.ClassPathXmlApplicationContext; import org.springframework.context.support.FileSystemXmlApplicationContext; import org.springframework.core.io.ClassPathResource; public class MyTest { @Before public void setUp() throws Exception { } @After public void tearDown() throws Exception { } @Test public void test_ClassPath() { ApplicationContext ac = new ClassPathXmlApplicationContext("applicationContext.xml"); Student student = (Student)ac.getBean("student"); System.out.println(student.toString()); } @Test public void test_FileSystem() { ApplicationContext ac = new FileSystemXmlApplicationContext("applicationContext.xml"); Student student = (Student)ac.getBean("student"); System.out.println(student.toString()); } @Test public void test_BeanFactory() { BeanFactory bf = new XmlBeanFactory(new ClassPathResource("applicationContext.xml")); Student student = (Student)bf.getBean("student"); System.out.println(student.toString()); } }
結果
注入分 設值注入、構造注入、p名稱空間注入、c名稱空間注入
（1）設值注入
注意：資料型別為School的注入是開闢了myschool容器的，而注入的時候是引用（ref）不是（value）
<?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 definitions here -->
<!-- 相當於 new Student() -->
<bean id="student" class="com.demo.entity.Student" >
<!-- 相當於setName("enrico") -->
<property name="name" value="enrico"></property>
<property name="gender" value="男"></property>
<property name="age" value="20"></property>
<property name="school" ref="myschool"></property>
</bean>
<bean id="myschool" class="com.demo.entity.School">
<property name="name" value="武漢大學"></property>
<property name="address" value="湖北"></property>
</bean>
</beans>
（2）構造注入
注意：構造注入需要有參構造方法的支援，使用構造注入又包含（型別，索引，型別+索引）
【型別注入】
<!-- 型別 -->
<bean id="student" class="com.demo.entity.Student">
<constructor-arg type="String" value="enrico"></constructor-arg>
<constructor-arg type="char" value='男'></constructor-arg>
<constructor-arg type="int" value="20"></constructor-arg>
<constructor-arg type="School" index="3" ref="myschool"></constructor-arg>
</bean> 【索引注入】
<!-- 索引 -->
<bean id="student" class="com.demo.entity.Student">
<constructor-arg index="0" value="enrico"></constructor-arg>
<constructor-arg index="1" value='男'></constructor-arg>
<constructor-arg index="2" value="20"></constructor-arg>
<constructor-arg type="School" index="3" ref="myschool"></constructor-arg>
</bean> 【型別+索引注入】
<!-- 型別+索引 -->
<bean id="student" class="com.demo.entity.Student">
<constructor-arg type="String" index="0" value="enrico"></constructor-arg>
<constructor-arg type="char" index="1" value='男'></constructor-arg>
<constructor-arg type="int" index="2" value="20"></constructor-arg>
<constructor-arg type="School" index="3" ref="myschool"></constructor-arg>
</bean>（3）p名稱空間注入
注意：p名稱空間注入是通過set方法注入資料，又叫p名稱空間設值注入。
配置檔案中引入：xmlns:p="http://www.springframework.org/schema/p"
<?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"
xsi:schemaLocation="
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd">
<!-- bean definitions here -->
<bean id="student" class="com.demo.entity.Student"
p:name="enrico" p:gender="男" p:age="20" p:school-ref="myschool">
</bean>
</beans>
（4）c名稱空間注入
注意：c名稱空間注入是通過有參構造方法注入，又叫c名稱空間構造注入。
配置檔案中引入：xmlns:c="http://www.springframework.org/schema/c"
<?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:c="http://www.springframework.org/schema/c"
xsi:schemaLocation="
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd">
<!-- bean definitions here -->
<bean id="student" class="com.demo.entity.Student"
c:name="enrico" c:gender="男" c:age="20" c:school-ref="myschool">
</bean>
</beans>