SPI机制破坏双亲委派模型

初始化DriverManager.javastatic {   loadInitialDrivers();   println(\"JDBC DriverManager initialized\");}

loadedDrivers.iterator();

lookupIterator.next();

java.util.ServiceLoader.LazyIterator#next

java.sql.DriverManager

ServiceLoader.load(Driver.class);

程序启动（设置上下文类加载器）public Launcher(){   ...   this.loader = Launcher.AppClassLoader.getAppClassLoader(var1);   Thread.currentThread().setContextClassLoader(this.loader);   ... }

Connection conn = DriverManager.getConnection(\"jdbc:mysql://localhost:3306/mydb?xxxx\

sun.misc.Launcher#Launcher

java.util.ServiceLoader

SPI机制破坏双亲委派模型 >

hasNextService()：作用：判断是否有下一个Service，且将META-INF/services/*目录下的文件读取出来。

java.util.ServiceLoader.LazyIterator#nextService

driversIterator.next();

ServiceLoader<Driver> loadedDrivers = ServiceLoader.load(Driver.class);Iterator<Driver> driversIterator = loadedDrivers.iterator();try{    while(driversIterator.hasNext()) {        driversIterator.next();    } } catch(Throwable t) {    // Do nothing}

加载并初始化驱动loadInitialDrivers();