Spring注入方式及注解配置
一:基于xml的DI(Dependency Injection)
注入类型:
定义学生Student实体类和小汽车Car实体类:进行封装和生成ToString(),并自定义属性Car
Student
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public class Student {
private String name;
private String age;
private Car car;
//无参构造 public Student() {
//System.out.println("Student.Student()");
} //带参构造 public Student(String name, String age, Car car) {
this .name = name;
this .age = age;
this .car = car;
} @Override public String toString() {
return "Student [name=" + name + ", age=" + age + ", car=" + car + "]" ;
} public Car getCar() {
return car;
} public void setCar(Car car) {
this .car = car;
} public String getAge() {
return age;
} public void setAge(String age) {
this .age = age;
} public String getName() {
return name;
} public void setName(String name) {
this .name = name;
} } |
Car:
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public class Car {
private String color;
private String brand;
//无参构造 public Car() {
} //带参构造 public Car(String color, String brand) {
super ();
this .color = color;
this .brand = brand;
} @Override public String toString() {
return "Car [color=" + color + ", brand=" + brand + "]" ;
} public String getColor() {
return color;
} public void setColor(String color) {
this .color = color;
} public String getBrand() {
return brand;
} public void setBrand(String brand) {
this .brand = brand;
} } |
1.设值注入(set方法注入):本质上是调用了Bean的setXXX()进行值的注入。分为普通属性和域属性
实现效果:
2.构造注入
实现效果:
3.命名空间p注入
使用前要先要在Spring配置文件中引入p命名空间
实现效果:
二、集合属性注入[List、Set、Map]
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public class MyCollection {
private List<String> list;
private Set<String> set;
private Map<String,String> map;
public Map<String, String> getMap() {
return map;
} public void setMap(Map<String, String> map) {
this .map = map;
} public Set<String> getSet() {
return set;
} public void setSet(Set<String> set) {
this .set = set;
} public List<String> getList() {
return list;
} public void setList(List<String> list) {
this .list = list;
} |
配置文件:
List与Set同理:
Map双列集合:
三:基于注解的DI
@Component[不分层的情况下]
@Repository() [Dao层]
@Service() [Biz层]
@Controller() [Action类]
注:在项目中添加Spring AOP相关的JAR文件以及xsd约束文件。
由于是基于注解的DI,所以无需再Spring配置文件中进行节点配置,只需配置包扫描器即可!
配置包扫描器用途:
该包下以及子包中的类才可以被Spring扫描,去寻找被注解的类和属性,让Spring容器管理赋值
Student类:
指定@Component中的value即可在测试类中的getBean()中植入即可。
@Value为该属性赋值
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@Component (value= "stu" )
public class Student {
@Value ( "呵呵" )
private String name;
@Value ( "13" )
private String age;
/* * JDK注解 @Resource(name="car2")
*/
/* * Spring注解
*/
@Autowired @Qualifier (value= "car2" )
private Car car;
@Override public String toString() {
return "Student [name=" + name + ", age=" + age + ", car=" + car + "]" ;
} |
Car类:
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@Component (value= "car2" )
public class Car {
@Value ( "黑色" )
private String color;
@Value ( "奥迪" )
private String brand;
@Override public String toString() {
return "Car [color=" + color + ", brand=" + brand + "]" ;
} |