独立出properties的mybatis连接池

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/java505?useSSL=true&characterEncoding=utf8&useSSL=true
jdbc.username=root
jdbc.password=root

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
  PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
  "http://mybatis.org/dtd/mybatis-3-config.dtd">
  <configuration>
      <properties resource="db.properties"/>
      <!-- 用于指定使用哪个开发
                                用于指定使用的环境id
       -->
      <environments default="dev">
          <!-- 用于配置开发环境
               id：环境的唯一识别码
           -->
          <environment id="dev">
              <!-- 事务管理器
                   type：用于设定mybatis采用什么方式管理事务
                   JDBC表示和JDBC一样事务的管理方式
               -->
              <transactionManager type="JDBC"/>
              <!-- 数据源/连接池
                                                         用于配置链接池和数据库链接的参数
                   type：用于设置mybatis是否采用链接池技术
                                                        连接池：用来存数据库链接的，减少数据库的频繁开关
                   POOLED表示mybatis采用连接池技术                                     
               -->
              <dataSource type="POOLED">
                  <property name="driver" value="${jdbc.driver}"/>
                  <property name="url" value="${jdbc.url}"/>
                  <property name="username" value="${jdbc.username}"/>
                  <property name="password" value="${jdbc.password}"/>
              </dataSource>
          </environment>
      </environments>
      <!-- 扫描mapper文件 -->
      <!-- 文件的全限制路径要用/ -->
      <mappers>
          <mapper resource="com/bjsxt/mapper/UserMapper.xml"/>
      </mappers>
  </configuration>

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
  PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
  "http://mybatis.org/dtd/mybatis-|3-mapper.dtd">
  <!-- namespa：命名空间，可以随意定义，一般情况下要写全限定路径（包名加类）
       MyBatis管理SQL语句是通过namespace+id来定位的
   -->
<mapper namespace="com.bjsxt.mapper.UserMapper">
    <!-- select标签用于编写查询语句
         id:sql语句的唯一的标识，类比为方法名
         resultType：用于设定返回结果的类型(全限定路径)
         如果返回结果是集合，要写集合泛型的类型
     -->
    <select id="sellAll" resultType="com.bjsxt.pojo.User">
        select * from t_user
    </select>
    <select id="selOne" resultType="com.bjsxt.pojo.User">
        select * from t_user where id=1
    </select>
</mapper>

package com.bjsxt.pojo;

import java.io.Serializable;

public class User implements Serializable {
private int id;
private String username;
private String password;
public String toString() {
    return "User [id=" + id + ", username=" + username + ", password="
            + password + "]";
}
public int hashCode() {
    final int prime = 31;
    int result = 1;
    result = prime * result + id;
    result = prime * result + ((password == null) ? 0 : password.hashCode());
    result = prime * result + ((username == null) ? 0 : username.hashCode());
    return result;
}
public boolean equals(Object obj) {
    if (this == obj)
        return true;
    if (obj == null)
        return false;
    if (getClass() != obj.getClass())
        return false;
    User other = (User) obj;
    if (id != other.id)
        return false;
    if (password == null) {
        if (other.password != null)
            return false;
    } else if (!password.equals(other.password))
        return false;
    if (username == null) {
        if (other.username != null)
            return false;
    } else if (!username.equals(other.username))
        return false;
    return true;
}
public int getId() {
    return id;
}
public void setId(int id) {
    this.id = id;
}
public String getUsername() {
    return username;
}
public void setUsername(String username) {
    this.username = username;
}
public String getPassword() {
    return password;
}
public void setPassword(String password) {
    this.password = password;
}
public User(int id, String username, String password) {
    super();
    this.id = id;
    this.username = username;
    this.password = password;
}
public User() {
    super();
}

}

# Set root category priority to INFO and its only appender to CONSOLE.
log4j.rootCategory=DEBUG, CONSOLE
#log4j.rootCategory=INFO, CONSOLE, LOGFILE

# 单独设置sql语句的输出级别为debug
#方法级别
#log4j.logger.com.bjsxt.mapper.UserMapper.selAll=DEBUG
#类级别
#log4j.logger.com.bjsxt.mapper.UserMapper=DEBUG
#包级别
log4j.logger.com.bjsxt.mapper=DEBUG

# LOGFILE is set to be a File appender using a PatternLayout.
log4j.appender.LOGFILE=org.apache.log4j.FileAppender
#存的位置
log4j.appender.LOGFILE.File=axis.log
log4j.appender.LOGFILE.Append=true
log4j.appender.LOGFILE.layout=org.apache.log4j.PatternLayout
log4j.appender.LOGFILE.layout.ConversionPattern=%-4r [%t] %-5p %c %x - %m%n