spring mvc各种常见类型参数绑定方式以及json字符串绑定对象

提示：扫一扫查出行
【扫一扫了解最新限行尾号】
复制提示

在使用spring mvc作为框架的时候，为了规范，我们通常希望客户端的请求参数符合规范直接通过DTO的方式从客户端提交到服务端，以便保持规范的一致性，除了很简单的情况使用RequestParam映射外，我们通常使用比较的有以下几种情形：

1、pojo嵌套pojo。

public class ContactInfo {
private String tel;
private String address; public String getTel() {
return tel;
} public void setTel(String tel) {
this.tel = tel;
} public String getAddress() {
return address;
} public void setAddress(String address) {
this.address = address;
}}public class User {
private String firstName;
private String lastName;
private ContactInfo contactInfo; public String getFirstName() {
return firstName;
} public void setFirstName(String firstName) {
this.firstName = firstName;
} public String getLastName() {
return lastName;
} public void setLastName(String lastName) {
this.lastName = lastName;
} public ContactInfo getContactInfo() {
return contactInfo;
} public void setContactInfo(ContactInfo contactInfo) {
this.contactInfo = contactInfo;
}}

@RequestMapping("test.html")
public void test(User user) {
System.out.println(user.getFirstName());
System.out.println(user.getLastName());
System.out.println(user.getContactInfo().getTel());
System.out.println(user.getContactInfo().getAddress());
}

2、pojo嵌套map。

public class User {
private String firstName;
private String lastName; public String getFirstName() {
return firstName;
} public void setFirstName(String firstName) {
this.firstName = firstName;
} public String getLastName() {
return lastName;
} public void setLastName(String lastName) {
this.lastName = lastName;
}}public class UserMapForm {
private Map<String, User> users; public Map<String, User> getUsers() {
return users;
} public void setUsers(Map<String, User> users) {
this.users = users;
}}

@RequestMapping("saysth.do")
public void test(UserMapForm userForm) {
for (Map.Entry<String, User> entry : userForm.getUsers().entrySet()) {
System.out.println(entry.getKey() + ": " + entry.getValue().getFirstName() + " - " +
entry.getValue().getLastName());
}
}

<form action="saysth.do" method="post">
<table>
<thead>
<tr>
<th>First Name</th>
<th>Last Name</th>
</tr>
</thead>
<tfoot>
<tr>
<td colspan="2"><input type="submit" value="Save" /></td>
</tr>
</tfoot>
<tbody>
<tr>
<td><input name="users['x'].firstName" value="aaa" /></td>
<td><input name="users['x'].lastName" value="bbb" /></td>
</tr>
<tr>
<td><input name="users['y'].firstName" value="ccc" /></td>
<td><input name="users['y'].lastName" value="ddd" /></td>
</tr>
<tr>
<td><input name="users['z'].firstName" value="eee" /></td>
<td><input name="users['z'].lastName" value="fff" /></td>
</tr>
</tbody>
</table>
</form>

3、pojo嵌套list。

<form action="saysth.do" method="post">
<table>
<thead>
<tr>
<th>First Name</th>
<th>Last Name</th>
</tr>
</thead>
<tfoot>
<tr>
<td colspan="2"><input type="submit" value="Save" /></td>
</tr>
</tfoot>
<tbody>
<tr>
<td><input name="users[0].firstName" value="aaa" /></td>
<td><input name="users[0].lastName" value="bbb" /></td>
</tr>
<tr>
<td><input name="users[1].firstName" value="ccc" /></td>
<td><input name="users[1].lastName" value="ddd" /></td>
</tr>
<tr>
<td><input name="users[20].firstName" value="eee" /></td>
<td><input name="users[20].lastName" value="fff" /></td>
</tr>
</tbody>
</table>
</form>
2-19的记录的属性会使用默认值。其实上述的方式应该算是很早版本spring的用法了，现在一般都使用RequestBody，直接将json字符串绑定到对象上，如下所示：

@RequestMapping(value = "saveUser", method = {RequestMethod.POST }})
@ResponseBody
public void saveUser(@RequestBody List<User> users) {
userService.batchSave(users);
}

注意：