Spring使用XML解析引入外部的属性配置文件-----Spring框架

<?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: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.xsd">
    <context:property-placeholder location="jdbc.properties"/>
    <bean id="myDataSource" class="com.powernode.spring6.jdbc.MyDataSource">
<!--        引入context标签,利用placeholder的location来指定属性配置文件的路径,默认从类的根路径下开始加载-->
<!--        老方法,全写死的方法,非常不灵活-->
        <property name="driver" value="${jdbc.Driver}"></property>
        <property name="url" value="${jdbc.url}"></property>
<!--        ${}方法加载的释放会优先加载windows的username,导致错误出现-->
        <property name="username" value="${jdbc.username}"></property>
        <property name="password" value="${jdbc.password}"></property>
    </bean>
</beans>

<?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: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.xsd">
<context:property-placeholder location="jdbc.properties"/>
<bean id="myDataSource" class="com.powernode.spring6.jdbc.MyDataSource">
<!-- 引入context标签,利用placeholder的location来指定属性配置文件的路径,默认从类的根路径下开始加载-->
<!-- 老方法,全写死的方法,非常不灵活-->
<property name="driver" value="${jdbc.Driver}"></property>
<property name="url" value="${jdbc.url}"></property>
<!-- ${}方法加载的释放会优先加载windows的username,导致错误出现-->
<property name="username" value="${jdbc.username}"></property>
<property name="password" value="${jdbc.password}"></property>
</bean>
</beans>

jdbc.Driver=com.mysql.cj.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:13306/spring6
jdbc.username=root
jdbc.password=abc123

jdbc.Driver=com.mysql.cj.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:13306/spring6
jdbc.username=root
jdbc.password=abc123

package com.powernode.spring6.jdbc;

import javax.sql.DataSource;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.SQLException;
import java.sql.SQLFeatureNotSupportedException;
import java.util.logging.Logger;

public class MyDataSource implements DataSource
{
    private String Driver;
    private String url;
    private String username;
    private String password;

    @Override
    public String toString() {
        return "MyDataSource{" +
                "Driver='" + Driver + '\'' +
                ", url='" + url + '\'' +
                ", username='" + username + '\'' +
                ", password='" + password + '\'' +
                '}';
    }

    public void setDriver(String driver) {
        Driver = driver;
    }

    public void setUrl(String url) {
        this.url = url;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    @Override
    public Connection getConnection() throws SQLException {
        return null;
    }

    @Override
    public Connection getConnection(String username, String password) throws SQLException {
        return null;
    }

    @Override
    public PrintWriter getLogWriter() throws SQLException {
        return null;
    }

    @Override
    public void setLogWriter(PrintWriter out) throws SQLException {

    }

    @Override
    public void setLoginTimeout(int seconds) throws SQLException {

    }

    @Override
    public int getLoginTimeout() throws SQLException {
        return 0;
    }

    @Override
    public Logger getParentLogger() throws SQLFeatureNotSupportedException {
        return null;
    }

    @Override
    public <T> T unwrap(Class<T> iface) throws SQLException {
        return null;
    }

    @Override
    public boolean isWrapperFor(Class<?> iface) throws SQLException {
        return false;
    }
}

package com.powernode.spring6.jdbc;

import javax.sql.DataSource;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.SQLException;
import java.sql.SQLFeatureNotSupportedException;
import java.util.logging.Logger;

public class MyDataSource implements DataSource
{
private String Driver;
private String url;
private String username;
private String password;

@Override
public String toString() {
return "MyDataSource{" +
"Driver='" + Driver + '\'' +
", url='" + url + '\'' +
", username='" + username + '\'' +
", password='" + password + '\'' +
'}';
}

public void setDriver(String driver) {
Driver = driver;
}

public void setUrl(String url) {
this.url = url;
}

public void setUsername(String username) {
this.username = username;
}

public void setPassword(String password) {
this.password = password;
}

@Override
public Connection getConnection() throws SQLException {
return null;
}

@Override
public Connection getConnection(String username, String password) throws SQLException {
return null;
}

@Override
public PrintWriter getLogWriter() throws SQLException {
return null;
}

@Override
public void setLogWriter(PrintWriter out) throws SQLException {

}

@Override
public void setLoginTimeout(int seconds) throws SQLException {

}

@Override
public int getLoginTimeout() throws SQLException {
return 0;
}

@Override
public Logger getParentLogger() throws SQLFeatureNotSupportedException {
return null;
}

@Override
public <T> T unwrap(Class<T> iface) throws SQLException {
return null;
}

@Override
public boolean isWrapperFor(Class<?> iface) throws SQLException {
return false;
}
}

    @Test
    public void TestProperties()
    {
        ApplicationContext applicationContext = new ClassPathXmlApplicationContext("Spring-properties.xml");
        MyDataSource MyDataSource = applicationContext.getBean("myDataSource", MyDataSource.class);
        System.out.println(MyDataSource);
    }

@Test
public void TestProperties()
{
ApplicationContext applicationContext = new ClassPathXmlApplicationContext("Spring-properties.xml");
MyDataSource MyDataSource = applicationContext.getBean("myDataSource", MyDataSource.class);
System.out.println(MyDataSource);
}