index.jsp前台页面加上这些，把值输入之后，通过post提交到后台。

<form action="springmvc/testPOJO" method="post">
        username: <input type="text" name="username"/>
        <br/>
        password: <input type="password" name="password"/>
        <br/>
        email: <input type="text" name="email"/>
        <br/>
        age: <input type="text" name="age"/>
        <br/>
        city: <input type="text" name="address.city"/>
        <br/>
        province: <input type="text" name="address.province"/>
        <br/>
        <input type="submit" value="Submit"/>
    </form>

user.java

package com.hust.springmvc.entities;

public class User {
    private String username;
    private String password;

    private String email;
    private int age;

    private Address address;

    public Address getAddress() {
        return address;
    }

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

    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 String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public int getAge() {
        return age;
    }

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

    @Override
    public String toString() {
        return "User [username=" + username + ",password=" + password + ",email=" + email + ",age=" + age + ",adress"
                + address + "]";
    }
}

address.java

package com.hust.springmvc.entities;

public class Address {
    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 + "]";
    }

}

SpringMVCTest.java

package com.hust.springmvc1;

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

import com.hust.springmvc.entities.User;

@Controller
@RequestMapping("/springmvc")
public class SpringMVCTest { 

    private static final String SUCCESS = "success";

    /**
     * SpringMVC 会按请求参数名和 POJO 属性名进行自动匹配， 自动为该对象填充属性值。
     * 支持级联属性。如 address.city、address.province 等
     */
    @RequestMapping("/testPOJO")
    public String testPOJO(User user) {
        System.out.println("testPOJO User: " + user);
        return SUCCESS;
    }

}

这个时候控制台就会收到前台传过来的所有的值，包括adress里面的city和province。