java框架之spring（三）
阿新 • • 發佈：2018-12-29
註解方式 IOC/DI
在本知識點中，講演示如何使用註解的方式完成注入物件中的效果
1、修改applicationContext.xml檔案
新增<context:annotation-config/>表示告訴Spring要用註解的方式進行配置，注入物件註釋掉，這個行為在後面將使用註解來完成
2、 在Product.java的category屬性前加上@Autowired註解<?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:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd"> <context:annotation-config/> <bean name="hjsy" class="com.hjsy.pojo.Category"> <property name="name" value="花季歲月" /> </bean> <bean name="hjsy1" class="com.hjsy.pojo.Product"> <property name="name" value="花季歲月1" /> <!-- <property name="category" ref="hjsy" /> --> </bean> </beans>
package com.hjsy.pojo; import org.springframework.beans.factory.annotation.Autowired; public class Product { private int id; private String name; @Autowired private Category category; 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; } public Category getCategory() { return category; } public void setCategory(Category category) { this.category = category; } }
3、測試
4、執行輸出結果package spring; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; import com.hjsy.pojo.Product; public class TestSpring { public static void main(String[] args) { ApplicationContext context = new ClassPathXmlApplicationContext(new String[] { "applicationContext.xml" }); Product product = (Product) context.getBean("hjsy1"); System.out.println(product.getName()); System.out.println(product.getCategory().getName()); } }
5、除了前面在屬性前加上@Autowired的這種方式外，也可以在setCategory方法前加上@Autowired，這樣來達到相同的效果
package com.hjsy.pojo;
import org.springframework.beans.factory.annotation.Autowired;
public class Product {
private int id;
private String name;
private Category category;
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;
}
public Category getCategory() {
return category;
}
@Autowired
public void setCategory(Category category) {
this.category = category;
}
}
package com.hjsy.pojo;
import javax.annotation.Resource;
import org.springframework.beans.factory.annotation.Autowired;
public class Product {
private int id;
private String name;
//@Autowired
@Resource(name="hjsy")
private Category category;
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;
}
public Category getCategory() {
return category;
}
public void setCategory(Category category) {
this.category = category;
}
}上述例子是對注入物件行為的註解，那麼bean物件本身，比如Category,Product可不可以移出applicationContext.xml配置檔案，也通過註解進行呢？
接下來就講解如何對Bean進行註解配置
8、修改applicationContext.xml，什麼都去掉，只新增
<context:component-scan base-package="com.hjsy.pojo"/>
<?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:aop="http://www.springframework.org/schema/aop"
xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop-3.0.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.0.xsd">
<context:component-scan base-package="com.hjsy.pojo"/>
</beans>package com.hjsy.pojo;
import javax.annotation.Resource;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
@Component("hjsy1")
public class Product {
private int id;
private String name="花季歲月1";
@Autowired
//@Resource(name="hjsy")
private Category category;
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;
}
public Category getCategory() {
return category;
}
public void setCategory(Category category) {
this.category = category;
}
}
package com.hjsy.pojo;
import org.springframework.stereotype.Component;
@Component("hjsy")
public class Category {
private int id;
private String name="花季歲月";
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;
}
}
如上：private String name="花季歲月1";和private String name="花季歲月";
12、測試
package spring;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import com.hjsy.pojo.Product;
public class TestSpring {
public static void main(String[] args) {
ApplicationContext context = new ClassPathXmlApplicationContext(new String[] { "applicationContext.xml" });
Product product = (Product) context.getBean("hjsy1");
System.out.println(product.getName());
System.out.println(product.getCategory().getName());
}
}
原始碼：連結：https://pan.baidu.com/s/1mkrapKW 密碼：euto