博学谷狂野大数据（四期）
// 模板方法public class BookWriter {
public void writeBook() {
writeTitle();
writeContent();
writeEnding();
}
public void writeTitle() {
System.out.println("标题");
}
public void writeContent() {
System.out.println("内容");
}
public void writeEnding() {
System.out.println("谢谢大家");
}}// 实现 => 多态public class MyBookWriter exten
