@Controller
@RequestMapping(value = "/vote")
public class VoteHandler {
     /**
     *  @RequestParam(value="name", required=false)
     * 1. 獲取到超鏈接傳遞的數(shù)據(jù) 請(qǐng)求 http://localhost:8080/springmvc/vote/vote01?name=xx
     * 2. @RequestParam 表示會(huì)接收提交的參數(shù)
     * 3. value="name" 表示提交的參數(shù)名是name
     * 4. required=false 表示該參數(shù)可以沒有, 默認(rèn)是true,表示必須有這個(gè)參數(shù)
     * 5. 當(dāng)我們使用了@RequestParam(value="name", required=false)后就請(qǐng)求的參數(shù)名和方法的形參名可以不一致
     */
    @RequestMapping(value = "/vote01")
    public String test01(@RequestParam(value = "name")String userName){
        System.out.println("userName = "+userName);
        return "success";
    }
}

<h2>獲取到超鏈接參數(shù)值</h2>
<hr/>
<a href="vote/vote01?name=hsp">獲取超鏈接的參數(shù)</a>

@RequestMapping(value = "/vote02")
public String test02(@RequestHeader("Accept-Encoding") String ae,
                     @RequestHeader("Host") String host) {
    System.out.println("Accept-Encoding= " + ae);
    System.out.println("Host= " + host);
    //返回到一個(gè)結(jié)果
    return "success";
}

<h1>獲取到消息頭</h1>
<hr>
<a href="vote/vote02">獲取http消息頭信息</a>

public class Pet {
    private Integer id;
    private String name;
    public Integer getId() {
        return id;
    }
    public void setId(Integer id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    @Override
    public String toString() {
        return "Pet{" +
                "id=" + id +
                ", name='" + name + '\'' +
                '}';
    }
}

public class Master {
    private Integer id;
    private String name;
    //對(duì)象的屬性是另外一個(gè)對(duì)象[涉及級(jí)聯(lián)]
    private Pet pet;
    public Integer getId() {
        return id;
    }
    public void setId(Integer id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public Pet getPet() {
        return pet;
    }
    public void setPet(Pet pet) {
        this.pet = pet;
    }
    @Override
    public String toString() {
        return "Master{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", pet=" + pet +
                '}';
    }
}

/**
 * 演示如果獲取到提交數(shù)據(jù)->封裝成java對(duì)象
 * @return 
 * 1. 方法的形參用對(duì)應(yīng)的類型來指定即可, SpringMVC會(huì)自動(dòng)的進(jìn)行封裝
 * 2. 如果自動(dòng)的完成封裝, 要求提交的數(shù)據(jù)，參數(shù)名和對(duì)象的字段名保持一致
 * 3. 如果屬性是對(duì)象，這里就是仍然是通過 字段名.字段名 比如Master [pet]
 * , 即提交的數(shù)據(jù) 參數(shù)名 是 pet.id pet.name， 這就是級(jí)聯(lián)操作
 * 4. 如果提交的數(shù)據(jù) 的參數(shù)名和對(duì)象的字段名不匹配，則對(duì)象的屬性值就是null
 */
@RequestMapping(value = "/vote03")
public String test03(Master master) {
    System.out.println("master=" + master);
    //返回結(jié)果
    return "success";
}

<!--
1. 這是一個(gè)表單，表單的數(shù)據(jù)對(duì)應(yīng)Master對(duì)象
2. 提交的數(shù)據(jù)參數(shù)名和對(duì)象的字段名一致即可
-->
<form action="vote/vote03" method="post">
    主人號(hào):<input type="text" name="id"><br>
    主人名:<input type="text" name="name"><br>
    寵物號(hào):<input type="text" name="pet.id"><br>
    寵物名:<input type="text" name="pet.name"><br>
    <input type="submit" value="添加主人和寵物">
</form>

<!--在使用springmvc過程中接收客戶端的請(qǐng)求參數(shù)時(shí)有時(shí)會(huì)出現(xiàn)中文亂碼,這是因?yàn)閟pringmvc并沒有對(duì)象請(qǐng)求參數(shù)進(jìn)行編碼控制,如果需要控制需要自行指定-->
<filter>
    <filter-name>charset</filter-name>
    <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
    <init-param>
    <param-name>encoding</param-name>
    <param-value>utf-8</param-value>
</init-param>
</filter>

/**
 * 使用servlet api, 來獲取提交的數(shù)據(jù)
 *
 * @return
 */
@RequestMapping(value = "/vote04")
public String test04(HttpServletRequest request,
                     HttpServletResponse response,
                     HttpSession hs) {
    //獲取到session
    //servlet原生的方式
    HttpSession session = request.getSession();
    System.out.println("session=" + session);
    //注意:通過參數(shù)傳入的 hs 和 通request.getSession() 得到的對(duì)象是
    //同一個(gè)
    System.out.println("hs= " + hs);
    String username = request.getParameter("username");
    String pwd = request.getParameter("pwd");
    System.out.println("username= " + username);
    System.out.println("pwd= " + pwd);
    //返回結(jié)果
    return "success";
}

<hr>
<h1>演示 servlet api的使用 </h1>
<form action="vote/vote04" method="post">
    用戶名:<input type="text" name="username"><br>
    密　碼:<input type="password" name="pwd"><br>
    <input type="submit" value="添加用戶">
</form>