springmvc的自动类型转换(自动将客户端提交的数据转换为对应的数据)

创建类和方法：

package cn.cdulm.entity;

import org.springframework.stereotype.Component;

import java.util.Date;
import java.util.Objects;

@Component // 注入Bean
public class User {
    private Integer id;
    private String username;
    private Date birthday;
    private Double balance;

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

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        User user = (User) o;
        return Objects.equals(id, user.id) && Objects.equals(username, user.username) && Objects.equals(birthday, user.birthday) && Objects.equals(balance, user.balance);
    }

    @Override
    public int hashCode() {
        return Objects.hash(id, username, birthday, balance);
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getUsername() {
        return username;
    }

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

    public Date getBirthday() {
        return birthday;
    }

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

    public Double getBalance() {
        return balance;
    }

    public void setBalance(Double balance) {
        this.balance = balance;
    }
}

请求处理方法：

    @RequestMapping("/con01")
    public String con01(User user){
        System.out.println(user);
        return "show";
    }

(在xml配置中做过了前后缀的处理)

访问并输入参数：

查看输出：

可以发现 Integer、String、Date类型的参数都可以进行自动转换。

重新添加balance参数发现，Double类型也能自动转化，那么可以认为，springmvc可以将请求传入的参数进行自动类型转换，不需要我们手动进行操作。