设计模式课程 设计模式精讲 15-3 桥接模式源码解析

//
// Source code recreated from a .class file by IntelliJ IDEA
// (powered by Fernflower decompiler)
//

package com.mysql.jdbc;

import java.sql.DriverManager;
import java.sql.SQLException;

public class Driver extends NonRegisteringDriver implements java.sql.Driver {
    public Driver() throws SQLException {
    }
//class.forName 直接调用该静态块
    static {
        try {
            DriverManager.registerDriver(new Driver());
        } catch (SQLException var1) {
            throw new RuntimeException("Can‘t register driver!");
        }
    }
}

public class Driver extends NonRegisteringDriver implements java.sql.Driver {
    public Driver() throws SQLException {
    }
}

public class DriverManager {
    // List of registered JDBC drivers
    private final static CopyOnWriteArrayList<DriverInfo> registeredDrivers = new CopyOnWriteArrayList<DriverInfo>();
    private static volatile int loginTimeout = 0;
    private static volatile java.io.PrintWriter logWriter = null;
    private static volatile java.io.PrintStream logStream = null;
    // Used in println() to synchronize logWriter
    private final static  Object logSync = new Object();

    /* Prevent the DriverManager class from being instantiated. */
    private DriverManager(){}

 /**
    *内部类，对driver进行封装
    */
class DriverInfo {

    final Driver driver;
    DriverInfo(Driver driver) {
        this.driver = driver;
    }

    public boolean equals(Object other) {
        return (other instanceof DriverInfo)
                && this.driver == ((DriverInfo) other).driver;
    }

    public int hashCode() {
        return driver.hashCode();
    }

    public String toString() {
        return ("driver[className="  + driver + "]");
    }
}

//注册驱动的方法

public static synchronized void registerDriver(java.sql.Driver driver)
    throws SQLException {

    /* Register the driver if it has not already been added to our list */
    if(driver != null) {
        registeredDrivers.addIfAbsent(new DriverInfo(driver));
    } else {
        // This is for compatibility with the original DriverManager
        throw new NullPointerException();
    }

    println("registerDriver: " + driver);
}

//获取数据库连接

@CallerSensitive
public static Connection getConnection(String url,
    String user, String password) throws SQLException {
    java.util.Properties info = new java.util.Properties();

    if (user != null) {
        info.put("user", user);
    }
    if (password != null) {
        info.put("password", password);
    }

    return (getConnection(url, info, Reflection.getCallerClass()));
}
}