package com.xgj.spel;
/**
 * 
 * 
 * @ClassName: Address
 * 
 * @Description: 地址信息
 * 
 * @author: Mr.Yang
 * 
 * @date: 2018年4月7日 下午8:29:12
 */
public class Address {
    private String city;
    private String street;
    public String getCity() {
        return city;
    }
    public void setCity(String city) {
        this.city = city;
    }
    public String getStreet() {
        return street;
    }
    public void setStreet(String street) {
        this.street = street;
    }
    @Override
    public String toString() {
        return "Address [city=" + city + ", street=" + street + ", getClass()=" + getClass() + ", hashCode()=" + hashCode() + ", toString()=" + super.toString() + "]";
    }
}

package com.xgj.spel;
/**
 * 
 * 
 * @ClassName: Car
 * 
 * @Description: 車(chē)輛
 * 
 * @author: Mr.Yang
 * 
 * @date: 2018年4月7日 下午8:30:01
 */
public class Car {
    private String brand;
    private double price;
    // 調(diào)用靜態(tài)方法或靜態(tài)屬性：通過(guò) T() 調(diào)用一個(gè)類(lèi)的靜態(tài)方法，它將返回一個(gè) Class Object，然后再調(diào)用相應(yīng)的方法或?qū)傩?
    private long weight;
    public long getWeight() {
        return weight;
    }
    public void setWeight(long weight) {
        this.weight = weight;
    }
    public String getBrand() {
        return brand;
    }
    public void setBrand(String brand) {
        this.brand = brand;
    }
    public double getPrice() {
        return price;
    }
    public void setPrice(double price) {
        this.price = price;
    }
    @Override
    public String toString() {
        return "Car [brand=" + brand + ", price=" + price + ", weight=" + weight + "]";
    }
}

package com.xgj.spel;
public class Boss {
    private String name;
    private Car car;
    // 通過(guò) Spring El 引用 Address的city
    private String city;
    // 通過(guò) Car的price屬性，確定info ,如果car.price>=500000 ,info 為CEO,否則為 Staff
    private String info;
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public Car getCar() {
        return car;
    }
    public void setCar(Car car) {
        this.car = car;
    }
    public String getCity() {
        return city;
    }
    public void setCity(String city) {
        this.city = city;
    }
    public String getInfo() {
        return info;
    }
    public void setInfo(String info) {
        this.info = info;
    }
    @Override
    public String toString() {
        return "Boss [name=" + name + ", car=" + car + ", city=" + city + ", info=" + info + "]";
    }
}

<?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 id="car" class="com.xgj.spel.Car" 
        p:brand="Bench" 
        p:price="700000"
        p:weight="#{T(java.lang.Math).PI * 4567}" />
    <!-- 通過(guò)Spring El表達(dá)式為屬性賦值一個(gè)字面值 ,
           當(dāng)然了，如果是字面值就沒(méi)有必要使用Spring El表達(dá)式了，這里僅僅是演示該用法 -->
    <bean id="address" class="com.xgj.spel.Address" 
        p:city="#{'NanJing'}"
        p:street="RuanJianDaDao" />
    <bean id="boss" class="com.xgj.spel.Boss" 
        p:name="Artisan" 
        p:city="#{address.city}"
        p:car-ref="car"
        p:info="#{car.price > 500000 ? 'CEO' : 'staff'}" />
</beans>

package com.xgj.spel;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class SpelTest {
    public static void main(String[] args) {
        String configLocation = "com/xgj/spel/beans_spel.xml";
        ApplicationContext ctx = new ClassPathXmlApplicationContext(configLocation);
        Car car = (Car) ctx.getBean("car");
        System.out.println(car);
        Boss boss = (Boss) ctx.getBean("boss");
        System.out.println(boss);
    }
}

@Value("#{properties['jdbc.driverClassName']}")

package com.xgj.spel.annotation;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;
/**
 * 
 * 
 * @ClassName: MyDataSource
 * 
 * @Description: 數(shù)據(jù)源 @Component標(biāo)注
 * 
 * @author: Mr.Yang
 * 
 * @date: 2018年4月7日 下午9:26:32
 */
@Component
public class MyDataSource {
    private String driverClass;
    private String url;
    private String username;
    private String password;
    public String getDriverClass() {
        return driverClass;
    }
    /**
     * 
     * 
     * @Title: setDriverClass
     * 
     * @Description: @Value注解自動(dòng)注入屬性配置文件中對(duì)應(yīng)屬性的值
     * 
     * @param driverClass
     * 
     * @return: void
     */
    @Value("${jdbc.driverClassName}")
    public void setDriverClass(String driverClass) {
        this.driverClass = driverClass;
    }
    public String getUrl() {
        return url;
    }
    @Value("${jdbc.url}")
    public void setUrl(String url) {
        this.url = url;
    }
    public String getUsername() {
        return username;
    }
    // @Value("$(jdbc.username)")
    @Value("${jdbc.username}")
    public void setUsername(String username) {
        this.username = username;
    }
    public String getPassword() {
        return password;
    }
    @Value("${jdbc.password}")
    public void setPassword(String password) {
        this.password = password;
    }
    @Override
    public String toString() {
        return "MyDataSource [driverClass=" + driverClass + ", url=" + url + ", username=" + username + ", password=" + password + "]";
    }
}

<?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:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd">
    <!-- 掃描的基包 -->
    <context:component-scan base-package="com.xgj.spel.annotation"/>
    <!-- 加載外部properties文件 -->
    <context:property-placeholder location="classpath:mysql/db_mysql.properties"/>  
</beans>

jdbc.driverClassName=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/artisan
jdbc.username=artisan
jdbc.password=artisan

package com.xgj.spel.annotation;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class TestCase {
    @Test
    public void test() {
        String configurationLocation = "com/xgj/spel/annotation/beans_anno.xml";
        ApplicationContext ctx = new ClassPathXmlApplicationContext(configurationLocation);
        MyDataSource myDataSource = (MyDataSource) ctx.getBean("myDataSource");
        System.out.println(myDataSource);
        System.out.println("driverClassName:" + myDataSource.getDriverClass());
        System.out.println("url:" + myDataSource.getUrl());
        System.out.println("username:" + myDataSource.getUsername());
        System.out.println("password:" + myDataSource.getPassword());
    }
}