//員工基類
public abstract class Employee {
    public String name;
    public int kpi;//員工KPI
    public Employee(String name) {
        this.name = name;
        kpi = new Random().nextInt(10);
    }
    //核心方法，接受訪問者的訪問
    public abstract void accept(IVisitor visitor);
}

//工程師
public class Engineer extends Employee {
    public Engineer(String name) {
        super(name);
    }
    @Override
    public void accept(IVisitor visitor) {
        visitor.visit(this);
    }
    //工程師一年的代碼量
    public int getCodeLines() {
        return new Random().nextInt(10 * 10000);
    }
}

//經(jīng)理
public class Manager extends Employee {
    public Manager(String name) {
        super(name);
    }
    @Override
    public void accept(IVisitor visitor) {
        visitor.visit(this);
    }
    //一年做的新產(chǎn)品數(shù)量
    public int getProducts() {
        return new Random().nextInt(10);
    }
}

//員工業(yè)務(wù)報(bào)表類
public class BusinessReport {
    private List<Employee> employees = new LinkedList<Employee>();
    public BusinessReport() {
        employees.add(new Manager("經(jīng)理-A"));
        employees.add(new Engineer("工程師-A"));
        employees.add(new Engineer("工程師-B"));
        employees.add(new Engineer("工程師-C"));
        employees.add(new Manager("經(jīng)理-B"));
        employees.add(new Engineer("工程師-D"));
    }
    /**
     * 為訪問者展示報(bào)表
     * @param visitor 公司高層，如CEO、CTO
     */
    public void showReport(IVisitor visitor) {
        for (Employee employee : employees) {
            employee.accept(visitor);
        }
    }
}

public interface IVisitor {
    //訪問工程師類型
    void visit(Engineer engineer);
    //訪問經(jīng)理類型
    void visit(Manager manager);
}

//CEO訪問者
public class CEOVisitor implements IVisitor {
    public void visit(Engineer engineer) {
        System.out.println("工程師: " + engineer.name + ", KPI: " + engineer.kpi);
    }
    public void visit(Manager manager) {
        System.out.println("經(jīng)理: " + manager.name + ", KPI: " + manager.kpi +
                ", 新產(chǎn)品數(shù)量: " + manager.getProducts());
    }
}

public class ReportUtil {
    public void visit(Employee employee) {
        if (employee instanceof Manager) {
            Manager manager = (Manager) employee;
            System.out.println("經(jīng)理: " + manager.name + ", KPI: " + manager.kpi +
                    ", 新產(chǎn)品數(shù)量: " + manager.getProducts());
        } else if (employee instanceof Engineer) {
            Engineer engineer = (Engineer) employee;
            System.out.println("工程師: " + engineer.name + ", KPI: " + engineer.kpi);
        }
    }
}

public class CTOVisitor implements IVisitor {
    public void visit(Engineer engineer) {
        System.out.println("工程師: " + engineer.name + ", 代碼行數(shù): " + engineer.getCodeLines());
    }
    public void visit(Manager manager) {
        System.out.println("經(jīng)理: " + manager.name + ", 產(chǎn)品數(shù)量: " + manager.getProducts());
    }
}

public static void main(String[] args) {
        //構(gòu)建報(bào)表
        BusinessReport report = new BusinessReport();
        System.out.println("=========== CEO看報(bào)表 ===========");
        report.showReport(new CEOVisitor());
        System.out.println("=========== CTO看報(bào)表 ===========");
        report.showReport(new CTOVisitor());
}

List list = null;
list = new ArrayList();

public class Main {
    public void test(String string){
        System.out.println("string");
    }
    public void test(Integer integer){
        System.out.println("integer");
    }
    public static void main(String[] args) {
        String string = "1";
        Integer integer = 1;
        Main main = new Main();
        main.test(integer);
        main.test(string);
    }
}

interface Person{
    void test();
}
class Man implements Person{
    public void test(){
        System.out.println("男人");
    }
}
class Woman implements Person{
    public void test(){
        System.out.println("女人");
    }
}
public class Main {
    public static void main(String[] args) {
        Person man = new Man();
        Person woman = new Woman();
        man.test();
        woman.test();
    }
}

public void showReport(IVisitor visitor) {
        for (Employee employee : employees) {
            employee.accept(visitor);
        }
}

    public void accept(IVisitor visitor) {
        visitor.visit(this);
    }
		

public interface FileVisitor<T> {
    FileVisitResult preVisitDirectory(T dir, BasicFileAttributes attrs)
        throws IOException;
    FileVisitResult visitFile(T file, BasicFileAttributes attrs)
        throws IOException;
    FileVisitResult visitFileFailed(T file, IOException exc)
        throws IOException;
    FileVisitResult postVisitDirectory(T dir, IOException exc)
        throws IOException;
}

public class SimpleFileVisitor<T> implements FileVisitor<T> {
    protected SimpleFileVisitor() {
    }
    @Override
    public FileVisitResult preVisitDirectory(T dir, BasicFileAttributes attrs)
        throws IOException
    {
        Objects.requireNonNull(dir);
        Objects.requireNonNull(attrs);
        return FileVisitResult.CONTINUE;
    }
    @Override
    public FileVisitResult visitFile(T file, BasicFileAttributes attrs)
        throws IOException
    {
        Objects.requireNonNull(file);
        Objects.requireNonNull(attrs);
        return FileVisitResult.CONTINUE;
    }
    @Override
    public FileVisitResult visitFileFailed(T file, IOException exc)
        throws IOException
    {
        Objects.requireNonNull(file);
        throw exc;
    }
    @Override
    public FileVisitResult postVisitDirectory(T dir, IOException exc)
        throws IOException
    {
        Objects.requireNonNull(dir);
        if (exc != null)
            throw exc;
        return FileVisitResult.CONTINUE;
    }
}

public class BeanDefinitionVisitor {
	@Nullable
	private StringValueResolver valueResolver;

	public BeanDefinitionVisitor(StringValueResolver valueResolver) {
		Assert.notNull(valueResolver, "StringValueResolver must not be null");
		this.valueResolver = valueResolver;
	}
	protected BeanDefinitionVisitor() {
	}
	public void visitBeanDefinition(BeanDefinition beanDefinition) {
		visitParentName(beanDefinition);
		visitBeanClassName(beanDefinition);
		visitFactoryBeanName(beanDefinition);
		visitFactoryMethodName(beanDefinition);
		visitScope(beanDefinition);
		if (beanDefinition.hasPropertyValues()) {
			visitPropertyValues(beanDefinition.getPropertyValues());
		}
		if (beanDefinition.hasConstructorArgumentValues()) {
			ConstructorArgumentValues cas = beanDefinition.getConstructorArgumentValues();
			visitIndexedArgumentValues(cas.getIndexedArgumentValues());
			visitGenericArgumentValues(cas.getGenericArgumentValues());
		}
	}
	...
}