循循渐进08篇 HttpServlet Session代码

Set Session:

public class SessionDome01 extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

        //解决乱码问题
        req.setCharacterEncoding("utf-8");
        resp.setCharacterEncoding("utf-8");
        resp.setContentType("text/html;charset=utf-8");

        //得到Session
        HttpSession session = req.getSession();


        //给Session中存东西
        session.setAttribute("name",new Person("张三",50));

        //获取Session中的id
        String sessionid = session.getId();

        //判断Session是不是新创建
        if (session.isNew()) {
            resp.getWriter().write("session创建成功，ID：" + sessionid);
        } else {
            resp.getWriter().write("session已经在服务中存在了,ID:"+sessionid);
        }
           //Session创建的时候做了什么事情
//        Cookie cookie = new Cookie("JSESSIONID",sessionid);
//        resp.addCookie(cookie);




    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doGet(req, resp);
    }
}
Get Session:

public class SessionDome02 extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

        //解决乱码问题
        req.setCharacterEncoding("utf-8");
        resp.setCharacterEncoding("utf-8");
        resp.setContentType("text/html;charset=utf-8");

        //得到Session
        HttpSession session = req.getSession();
        Person person = (Person) session.getAttribute("name");
        PrintWriter writer = resp.getWriter();
        writer.write(person.toString());


    }


    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doGet(req, resp);
    }
}

手动注销Session:

public class SessionDome03 extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

        //解决乱码问题
        req.setCharacterEncoding("utf-8");
        resp.setCharacterEncoding("utf-8");
        resp.setContentType("text/html;charset=utf-8");

        //手动注销Session
        HttpSession session = req.getSession();
        session.removeAttribute("name");//删除session
        session.invalidate();//注销方法


    }


    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doGet(req, resp);
    }
}

封装类：

public class Person {

    public Person() {
    }

    private String name;
    private int age;

    public Person(String name, int age) {
        this.name = name;
        this.age = age;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    @Override
    public String toString() {
        return "Person{" +
                "name=‘" + name + ‘\‘‘ +
                ", age=" + age +
                ‘}‘;
    }
}

webxml 方式设置session有效时间：

<!--设置session默认失效时间-->
    <session-config>
<!--1分钟后session自动消失，以分钟为单位-->
        <session-timeout>1</session-timeout>
    </session-config>

循循渐进08篇 HttpServlet Session代码

原文：https://www.cnblogs.com/huhao2000/p/11980781.html