SpringMVC请求参数绑定

绑定机制

SpringMVC绑定请求参数的过程是通过把表单提交请求参数，作为控制器中方法参数进行绑定的。

基本类型或者String

如果是基本类型或者String类型：要求我们的参数名称必须和控制器中方法的形参名称保持一致。(严格区分大小写)

补充：如果在servlet中传123，接收到是字符串，还需要自己做类型转换；但是springmvc不需要，它有内置转换器

POJO类型

如果是 POJO 类型，或者它的关联对象：要求表单中参数名称和 POJO 类的属性名称保持一致。并且控制器方法的参数类型是 POJO 类型。

使用示例

基本类型和String类型作为参数

jsp 代码：

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
    <h2>
        <a href="/account/queryAccount?accountId=123456&accountName=jack">查询账户</a>
    </h2>
</body>
</html>

控制器代码：

package com.qzcsbj.controller;

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

@Controller
@RequestMapping("/account")
public class AccountController {
    @RequestMapping("/queryAccount")
    public String findAccount(Integer accountId, String accountName ) {
        System.out.println("查询账户id为："+accountId + ", name为：" + accountName);
        return "success";
    }
}

启动tomcat

点击“查询账户”，可以看到url对参数做了拼接

日志

POJO 类型作为参数

表单数据多，可以用对象来封装

Account类

package com.qzcsbj.pojo;

import java.io.Serializable;


public class Account implements Serializable {
    private static final long serialVersionUID = 418607476187912306L;

    private Integer id;
    private String name;
    private Float money;
    private Address address;  // 对象属性

    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 Float getMoney() {
        return money;
    }

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

    public Address getAddress() {
        return address;
    }

    public void setAddress(Address address) {
        this.address = address;
    }


    @Override
    public String toString() {
        return "Account{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", money=" + money +
                ", address=" + address +
                '}';
    }
}

Address类

package com.qzcsbj.pojo;

import java.io.Serializable;


public class Address implements Serializable {

    private static final long serialVersionUID = -8420350157709769474L;

    private String province;
    private String city;

    public String getProvince() {
        return province;
    }

    public void setProvince(String province) {
        this.province = province;
    }

    public String getCity() {
        return city;
    }

    public void setCity(String city) {
        this.city = city;
    }

    @Override
    public String toString() {
        return "Address{" +
                "province='" + province + '\'' +
                ", city='" + city + '\'' +
                '}';
    }
}

jsp 代码：

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
    <div class="form">
        <form action="/account/saveAccount" method="post">
            账户名称:<input type="text" name="name"/><br/>
            账户金额:<input type="text" name="money"/><br/>
            所在省份:<input type="text" name="address.province"/><br/>
            所在城市:<input type="text" name="address.city"/><br/>
            <input type="submit" value="提交"/>
        </form>
    </div>
</body>
</html>

控制器代码：

package com.qzcsbj.controller;

import com.qzcsbj.pojo.Account;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

@Controller
@RequestMapping("/account")
public class AccountController {
    @RequestMapping("/queryAccount")
    public String findAccount(Integer accountId, String accountName ) {
        System.out.println("查询账户id为："+accountId + ", name为：" + accountName);
        return "success";
    }

    @RequestMapping("/saveAccount")
    public String saveAccount(Account account) {
        System.out.println("账户是："+account);
        return "success";
    }
}

重启tomcat

结果