package club.guoshizhan.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

@Controller
public class HelloController {

    @RequestMapping("/hello")
    public String Hello() {
        System.out.println("Hello, SpringMVC!!！");
        return "success";    // 跳转到 success 页面
    }

}

/**
 * @RequestMapping 注解源码
 */
@Target({ElementType.METHOD, ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Mapping
public @interface RequestMapping {
    ……
}

/**
 * @RequestParam 注解源码
 */
@Target(ElementType.PARAMETER)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface RequestParam {
    ……
}

/**
 * @RequestBody 注解源码
 */
@Target(ElementType.PARAMETER)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface RequestBody {
    ……
}

/**
 * @PathVariable 注解源码
 */
@Target(ElementType.PARAMETER)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface PathVariable {
    ……
}

/**
 * @RequestHeader 注解源码
 */
@Target(ElementType.PARAMETER)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface RequestHeader {
    ……
}

/**
 * @CookieValue 注解源码
 */
@Target(ElementType.PARAMETER)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface CookieValue {
    ……
}

/**
 * @ModelAttribute 注解源码
 */
@Target({ElementType.PARAMETER, ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface ModelAttribute {
    ……
}

/**
 * @SessionAttributes 注解源码
 */
@Target({ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Inherited
@Documented
public @interface SessionAttributes {
    ……
}

package club.guoshizhan.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

/**
 * 请求参数绑定
 */
@Controller
@RequestMapping("/param")
public class ParamController {

    @RequestMapping("/testParam")
    public String testParam(String username, String password) {
        System.out.println("请求参数入门……");
        System.out.println(username);
        System.out.println(password);
        return "param";
    }
    
}

package club.guoshizhan.domain;

import java.io.Serializable;

public class Account implements Serializable {

    private String username;
    private String password;
    private Double money;

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public Double getMoney() {
        return money;
    }

    public void setMoney(Double money) {
        this.money = money;
    }

    @Override
    public String toString() {
        return "Account{" +
                "username='" + username + '\'' +
                ", password='" + password + '\'' +
                ", money=" + money +
                '}';
    }

}

package club.guoshizhan.controller;

import club.guoshizhan.domain.Account;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

/**
 * 请求参数绑定
 */
@Controller
@RequestMapping("/param")
public class ParamController {

    // 请求参数绑定入门
    @RequestMapping("/testParam")
    public String testParam(String username, String password) {
        System.out.println("请求参数入门……");
        System.out.println(username);
        System.out.println(password);
        return "param";
    }

    // 把数据封装到 JavaBean 中，即我们的实体类中
    @RequestMapping("/saveAccount")
    public String testSaveAccount(Account account) {
        System.out.println("请求参数入门……");
        System.out.println(account);
        return "success";
    }

    @RequestMapping("/toParam")
    public String toParam() {
        return "param";
    }

}

package club.guoshizhan.domain;

import java.io.Serializable;

public class User implements Serializable {

    private String uname;
    private Integer age;

    public String getUname() {
        return uname;
    }

    public void setUname(String uname) {
        this.uname = uname;
    }

    public Integer getAge() {
        return age;
    }

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

    @Override
    public String toString() {
        return "User{" +
                "uname='" + uname + '\'' +
                ", age=" + age +
                '}';
    }

}

package club.guoshizhan.domain;

import java.io.Serializable;

public class Account implements Serializable {

    private String username;
    private String password;
    private Double money;

    private User user;

    public User getUser() {
        return user;
    }

    public void setUser(User user) {
        this.user = user;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public Double getMoney() {
        return money;
    }

    public void setMoney(Double money) {
        this.money = money;
    }

    @Override
    public String toString() {
        return "Account{" +
                "username='" + username + '\'' +
                ", password='" + password + '\'' +
                ", money=" + money +
                ", user=" + user +
                '}';
    }

}

package club.guoshizhan.domain;

import java.io.Serializable;
import java.util.List;
import java.util.Map;

public class Account implements Serializable {

    private String username;
    private String password;
    private Double money;

    private List<User> list;
    private Map<String, User> map;

    public List<User> getList() {
        return list;
    }

    public void setList(List<User> list) {
        this.list = list;
    }

    public Map<String, User> getMap() {
        return map;
    }

    public void setMap(Map<String, User> map) {
        this.map = map;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public Double getMoney() {
        return money;
    }

    public void setMoney(Double money) {
        this.money = money;
    }

    @Override
    public String toString() {
        return "Account{" +
                "username='" + username + '\'' +
                ", password='" + password + '\'' +
                ", money=" + money +
                ", list=" + list +
                ", map=" + map +
                '}';
    }

}

package club.guoshizhan.domain;

import java.io.Serializable;
import java.util.Date;

public class User implements Serializable {

    private String uname;
    private Integer age;

    public Date getBirthday() {
        return birthday;
    }

    public void setBirthday(Date birthday) {
        this.birthday = birthday;
    }

    private Date birthday;

    public String getUname() {
        return uname;
    }

    public void setUname(String uname) {
        this.uname = uname;
    }

    public Integer getAge() {
        return age;
    }

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

    @Override
    public String toString() {
        return "User{" +
                "uname='" + uname + '\'' +
                ", age=" + age +
                ", birthday=" + birthday +
                '}';
    }

}

// 自定义的类型转换器
@RequestMapping("/saveUser")
public String saveUser(User user) {
    System.out.println("自定义的类型转换器……");
    System.out.println(user);
    return "success";
}

自定义的类型转换器……
User{uname='Java', age=23, birthday=Thu Sep 17 00:00:00 CST 2020}

package club.guoshizhan.utils;

import org.springframework.core.convert.converter.Converter;

import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;

/**
 * 自定义类型转换器，把字符串以指定的格式转换成日期类型，需要实现 Converter 接口
 */
public class StringToDateConverter implements Converter<String, Date> {

    @Override
    public Date convert(String source) {
        if (source == null) {
            throw new RuntimeException("您未输入数据！！！");
        }

        DateFormat df = new SimpleDateFormat("yyyy-MM-dd");

        try {
            return df.parse(source);
        } catch (Exception e) {
            throw new RuntimeException("数据转换出现错误！！！");
        }
    }

}

// 获取 Servlet 原生的 API
@RequestMapping("/testServlet")
public String testServlet(HttpServletRequest request, HttpServletResponse response) {
    System.out.println("获取 Servlet 原生的 API……");
    System.out.println("request：" + request);

    HttpSession session = request.getSession();
    System.out.println("session：" + session);

    ServletContext servletContext = session.getServletContext();
    System.out.println("servletContext：" + servletContext);

    System.out.println("response：" + response);
    return "success";
}

获取 Servlet 原生的 API……
request：org.apache.catalina.connector.RequestFacade@1b4aceb
session：org.apache.catalina.session.StandardSessionFacade@1e5b14
servletContext：org.apache.catalina.core.ApplicationContextFacade@15bbed9
response：org.apache.catalina.connector.ResponseFacade@1afcf1f

package club.guoshizhan.domain;

import java.io.Serializable;

public class User implements Serializable {

    private String username;
    private Integer age;

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public Integer getAge() {
        return age;
    }

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

    @Override
    public String toString() {
        return "User{" +
                "username='" + username + '\'' +
                ", age=" + age +
                '}';
    }

}

package club.guoshizhan.controller;

import club.guoshizhan.domain.User;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;

@Controller
@RequestMapping("/user")
public class UserController {

    @RequestMapping("/testString")
    public String testString(Model model) {
        System.out.println("test String is running……");
        // 模拟从数据库查出 User 对象
        User user = new User();
        user.setUsername("Jack");
        user.setAge(23);
        // 把 user 对象放到 request 域中，方便页面取数据
        model.addAttribute("user", user);
        return "success";
    }

}

package club.guoshizhan.controller;

import club.guoshizhan.domain.User;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@Controller
@RequestMapping("/user")
public class UserController {

    /**
     * 返回值是 String 类型
     */
    @RequestMapping("/testString")
    public String testString(Model model) {
        System.out.println("test String is running……");
        // 模拟从数据库查出 User 对象
        User user = new User();
        user.setUsername("Jack");
        user.setAge(23);
        // 把 user 对象放到 request 域中，方便页面取数据
        model.addAttribute("user", user);
        return "success";
    }

    /**
     * 返回值是 void 类型，如果没有重定向或转发，默认会去查找 testVoid.jsp 页面
     * 请求转发：只会发一次请求，不用编写项目名称
     * 重定向：需要发两次请求，需要写项目名称
     */
    @RequestMapping("/testVoid")
    public void testVoid(HttpServletRequest request, HttpServletResponse response) throws Exception {

        System.out.println("test Void is running……");

        // 请求转发的方式，它不会去执行视图解析器，所以需要自己加上路径
//        request.getRequestDispatcher("/WEB-INF/pages/success.jsp").forward(request, response);

        // 重定向方式，需要加上项目的名称，使用 request.getContextPath() 获得项目的路径
//        response.sendRedirect(request.getContextPath() + "/redirect.jsp");

        // 设置中文乱码
        response.setCharacterEncoding("UTF-8");
        response.setContentType("text/html;charset=utf-8");
        // 直接向页面写数据
        response.getWriter().println("Hello, SpringMVC！！！");
        response.getWriter().println("<br>");
        response.getWriter().println("你好呀, SpringMVC！！！");
    }

}

/**
 * 返回值是 ModelAndView 类型
 */
@RequestMapping("/testModelAndView")
public ModelAndView testModelAndView(Model model) {
    ModelAndView mv = new ModelAndView();
    System.out.println("test ModelAndView is running……");
    // 模拟从数据库查出 User 对象
    User user = new User();
    user.setUsername("Jack");
    user.setAge(23);
    // 把 user 对象放到 mv 对象中，同时也会存到 request 对象中
    mv.addObject("user", user);
    // 跳转到哪个页面
    mv.setViewName("success");
    return mv;
}