《SpringMVC数据绑定入门》笔记
基本类型
最好使用封装类型
简单多数据&多层级对象
简单多数据
单个对象，直接使用属性名=值即可
多层级对象
属性.属性=值即可
同属性多对象
WebDataBinder只在当前类中生效，不是全局的
//TODO http://localhost:8080/object.do?user.name=Tom&admin.name=Lucy&age=10
@RequestMapping(value = "object.do")
@ResponseBody
public String object(User user,Admin admin){
return user.toString()+" "+admin.toString();
}
@InitBinder("user")
public void initUser(WebDataBinder binder){
binder.setFieldDefaultPrefix("user.");
}
@InitBinder("admin")
public void initAdmin(WebDataBinder binder){
binder.setFieldDefaultPrefix("admin.");
}
List、Set、Map类型的数据绑定
list
下标，最好是连续的，不然中间都是null
//TODO http://localhost:8080/list.do?users[0].name=Tom&users[1].name=Lucy&users[20].name=Jim
@RequestMapping(value = "list.do")
@ResponseBody
public String list(UserListForm userListForm){
return "listSize:"+userListForm.getUsers().size() + " " + userListForm.toString();
}
public class UserListForm {
private List<User> users;
public List<User> getUsers() {
return users;
}
public void setUsers(List<User> users) {
this.users = users;
}
@Override
public String toString() {
return "UserListForm{" + "users=" + users + '}';
}
}
Set
主要是用来去除重复，初始化时，需要设置大小。
//TODO http://localhost:8080/set.do?users[0].name=Tom&users[20].name=Lucy
@RequestMapping(value = "set.do")
@ResponseBody
public String set(UserSetForm userSetForm){
return userSetForm.toString();
}
public class UserSetForm {
private Set<User> users;
private UserSetForm(){
users = new LinkedHashSet<User>();
users.add(new User());
users.add(new User());
}
public Set<User> getUsers() {
return users;
}
public void setUsers(Set<User> users) {
this.users = users;
}
@Override
public String toString() {
return "UserSetForm{" + "users=" + users + '}';
}
}
Map
//TODO http://localhost:8080/map.do?users['X'].name=Tom&users['X'].age=10&users['Y'].name=Lucy
@RequestMapping(value = "map.do")
@ResponseBody
public String map(UserMapForm userMapForm){
return userMapForm.toString();
}
public class UserMapForm {
private Map<String,User> users;
@Override
public String toString() {
return "UserMapForm{" + "users=" + users + '}';
}
public Map<String, User> getUsers() {
return users;
}
public void setUsers(Map<String, User> users) {
this.users = users;
}
}
Json、Xml数据类型的绑定
JSON
User类有name与age属性，并包含一个contactInfo
// {
// "name": "Jim",
// "age": 16,
// "contactInfo": {
// "address": "beijing",
// "phone": "10010"
// }
// }
//content-Type：application/json
@RequestMapping(value = "json.do")
@ResponseBody
public String json(@RequestBody User user){
return user.toString();
}
XML
// <?xml version="1.0" encoding="UTF-8" ?>
// <admin>
// <name>Jim</name>
// <age>16</age>
// </admin>
//content-Type：application/xml
@RequestMapping(value = "xml.do")
@ResponseBody
public String xml(@RequestBody Admin admin){
return admin.toString();
}
@XmlRootElement(name="admin")
public class Admin {
private String name;
private Integer age;
@XmlElement(name="name")
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
@XmlElement(name="age")
public Integer getAge() {
return age;
}
public void setAge(Integer age) {
this.age = age;
}
@Override
public String toString() {
return "Admin{" + "name='" + name + '\'' + ", age=" + age + '}';
}
}
格式化工具和类型转换器
应用：前台传入一字符串，后台接收一个java.util.Date类型
PropertyEditor的应用
内置的可扩展性；局部使用webdatabinder
binder.registerCustomEditor
// http://localhost:8080/date1.do?date1=2016-07-18
@RequestMapping(value = "date1.do")
@ResponseBody
public String date1(Date date1){
return date1.toString();
}
@InitBinder("date1")
public void initDate1(WebDataBinder binder){
binder.registerCustomEditor(Date.class,new CustomDateEditor(new SimpleDateFormat("yyyy-MM-dd"),true));
}
PropertyEditorSupport有很多子类，可以根据使用场景来选择
Formatter的应用
内置的可扩展性；全局/局部；Source=String
- 添加自定义的formatter
public class MyDateFormatter implements Formatter<Date> {
public Date parse(String text, Locale locale) throws ParseException {
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
return sdf.parse(text);
}
public String print(Date object, Locale locale) {
return null;
}
}
- 配置，全局生效
<!-- 如果不加conversion-service是不会生效的 -->
<mvc:annotation-driven conversion-service="myDateFormatter"/>
<bean id ="myDateFormatter" class="org.springframework.format.support.FormattingConversionServiceFactoryBean">
<property name="formatters">
<set>
<bean class="com.imooc.common.MyDateFormatter"></bean>
</set>
</property>
</bean>
- 使用，由于当前MyDateFormatter是全局生效，所有直接使用Date即可，不需要WebDataBinder了
@RequestMapping(value = "date2.do")
@ResponseBody
public String date2(Date date2){
return date2.toString();
}
Converter的应用
内置的不可扩展性；全局/局部；Source=自定义的
与Formatter类似，Converter高级一些，可设置Source
- 实现converter
public class MyDateConverter implements Converter<String,Date> {
public Date convert(String source) {
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
try {
return sdf.parse(source);
} catch (ParseException e) {
e.printStackTrace();
}
return null;
}
}
- 配置，全局生效
<!-- 如果不加conversion-service是不会生效的 -->
<mvc:annotation-driven conversion-service="myDateConverter"/>
<bean id ="myDateConverter" class="org.springframework.format.support.FormattingConversionServiceFactoryBean">
<property name="converters">
<set>
<bean class="com.imooc.common.MyDateConverter"></bean>
</set>
</property>
</bean>
- 使用，由于当前MyDateConverter是全局生效，所有直接使用Date即可，不需要WebDataBinder了
@RequestMapping(value = "date2.do")
@ResponseBody
public String date2(Date date2){
return date2.toString();
}
RESTful
Resource Representational State Transfer
资源表现层状态转换
表现层：如果图片可以表现为jpg、png等
表现形式：content-Type
幂等性：每次HTTP请求相同的参数，相同的URI，产生的结果是相同的
- GET：获取资源
示例：http://www.book.com/book/001 - POST：创建资源-不具有幂等性
面向的不是资源本身，而是资源的接收者
示例：http://www.book.com/book/ - PUT：创建（更新）资源
示例：http://www.book.com/book/001 - DELETE：删除资源
示例：http://www.book.com/book/001
@RequestMapping(value = "/book",method = RequestMethod.GET)
@ResponseBody
public String book(HttpServletRequest request){
String contentType = request.getContentType();
if(contentType == null){
return "book.default";
}else if(contentType.equals("txt")){
return "book.txt";
}else if(contentType.equals("html")){
return "book.html";
}
return "book.default";
}
@RequestMapping(value = "/subject/{subjectId}",method = RequestMethod.GET)
@ResponseBody
public String subjectGet(@PathVariable("subjectId") String subjectId){
return "this is a get method,subjectId:"+subjectId;
}
@RequestMapping(value = "/subject/{subjectId}",method = RequestMethod.POST)
@ResponseBody
public String subjectPost(@PathVariable("subjectId") String subjectId){
return "this is a post method,subjectId:"+subjectId;
}
@RequestMapping(value = "/subject/{subjectId}",method = RequestMethod.DELETE)
@ResponseBody
public String subjectDelete(@PathVariable("subjectId") String subjectId){
return "this is a delete method,subjectId:"+subjectId;
}
@RequestMapping(value = "/subject/{subjectId}",method = RequestMethod.PUT)
@ResponseBody
public String subjectPut(@PathVariable("subjectId") String subjectId){
return "this is a put method,subjectId:"+subjectId;
}
- RESTful设计
moive/douban.com/show/subject/11620560 # 不正确，不应有动词show
moive/douban.com/subject/11620560 # 正确
POST /accounts/1/transfer/500/to/2 # 不正确，不应有动词trfansfer
POST /transaction # 正确
from=1&to=2&amount=500.00
www.example.com/app/1.0 # 不正确
www.example.com/app # 正确
HEADER
version=1.0
