上一篇,我们讲解了如何使用
jaguar_serializer
,今天,我们来学习一下如何通过该package
,并结合之前的东西,封装起RestfulApi
,该封装同样也适合Flutter
,dart web
阅读该文章之前,我会默认的认为你已经看过我之前的文章,并知道如何使用数据库,开启服务器等!
1.定义规范
- 资源
使用JSON
的形式表现 - 资源格式
code
表示状态,0
表示处理成功,-1
表示处理失败
msg
表示消息,对客户端需要说明的一些信息,如:成功
,请求方法不允许
等
data
表示数据,返回客户端的数据 - 接口
get
获取资源,查询资源
post
新建资源,更新资源,查询资源
put
更新资源
delete
删除资源 - URI
请求的地址可以附带id等,例如: Get http://localhost:8080/user/123 查询id为123的用户,Get http://localhost/user 查询所有用户, Post http://localhost:8080/user/123 修改id为123的的用户等
2. 定义Restful
我们新建一个Restful文件,输入下面代码
class Restful {
int code;
String msg;
Object data;
}
然后导入jaguar_serializer
包,添加下面代码
@GenSerializer()
class RestfulSerializer extends Serializer<Restful> with _$RestfulSerializer {}
运行命令pub run build_runner build
,完后继续添加
part 'Restful.jser.dart';
ok,我们已经准备好Restful,那怎么把数据放到data里面呢
我们先来创建一个user.dart
文件,创建一个用户模型,
class User {
String id;
String username;
String password;
int role;
String phoneNumber;
int sex;
}
与数据库进行关联
import 'package:jaguar_orm/jaguar_orm.dart';
import 'dart:async';
part 'user.jorm.dart';
class User {
@PrimaryKey()
String id;
String username;
String password;
int role;
@Column(length: 11)
String phoneNumber;
int sex;
static const String tableName='_user';
@override
String toString()=> 'User(id:$id,username:$username,password:$password,role:$role,phoneNumber:$phoneNumber,sex:$sex)';
}
@GenBean()
class UserBean extends Bean<User> with _UserBean {
UserBean(Adapter adapter) : super(adapter);
@override
String get tableName => User.tableName;
}
创建一个serializer.dart
文件,用于存放所有json_serializer
工具文件,添加下面代码
import 'package:jaguar_serializer/jaguar_serializer.dart';
import 'user.dart';
part 'serializer.jser.dart';
@GenSerializer()
class UserSerializer extends Serializer<User> with _$UserSerializer {
}
运行pub run build_runner build
命令
下面是打印一个通过数据库查询id
为2的restful api
返回数据
import 'package:jaguar_query_postgres/jaguar_query_postgres.dart';
import 'package:TestDB/user.dart';
import 'package:TestDB/Restful.dart';
import 'package:TestDB/serializer.dart';
import 'dart:convert';
final PgAdapter pgAdapter =
new PgAdapter('postgres', username: 'postgres', password: '123456');
main() async {
await pgAdapter.connect();
Restful restful = new Restful()
..code = 0
..msg = 'success'
..data = new UserSerializer().toMap((await new UserBean(pgAdapter).find("2")));
print(json.encode(new RestfulSerializer().toMap(restful)));
}
我们可以简单的知道,一个模型转换为json数据需要经过两步操作
-
模型
转换为Map
-
map
经过json.encode
编码为字符串
相反的,json数据转换为模型也是两步
-
字符串
经过json.decode
译码为map
-
map
转换为模型
所以,我们可以结合jaguar_serializer
封装一下Restful,封装如下
import 'dart:convert';
import 'package:jaguar_serializer/jaguar_serializer.dart';
part 'Restful.jser.dart';
RestfulSerializer serializer = new RestfulSerializer();
class Restful {
int code;
String msg;
Object data;
Restful();
Map toMap([Serializer dataSerializer]) {
if(dataSerializer==null){
return serializer.toMap(this);
}
if (data is List) {
List list =data;
if(list.length!=0&& list[0] is Map){
}else if(list.length!=0){
data = dataSerializer.toList(data);
}
} else if (data is Map) {
} else {
data = dataSerializer.toMap(data);
}
return serializer.toMap(this);
}
String toJson([Serializer dataSerializer]) {
return json.encode(toMap(dataSerializer));
}
factory Restful.fromMap(Map<String,dynamic> map, [Serializer dataSerializer]) {
Restful api = serializer.fromMap(map);
if(dataSerializer==null){
return api;
}
if (api.data is List) {
List<Map<dynamic,dynamic>> data=(api.data as List<dynamic>).map((d)=>d as Map<dynamic,dynamic>).toList();
api.data = dataSerializer.fromList(data);
} else if (api.data == null) {
} else {
api.data = dataSerializer.fromMap(api.data);
}
return api;
}
factory Restful.fromJson(String Json, [Serializer dataSerializer]) {
return new Restful.fromMap(json.decode(Json),dataSerializer);
}
T fromJsonToData<T>(String Json,Serializer dataSerializer) {
Restful api = serializer.fromMap(json.decode(Json));
if (api.data is List) {
// throw ArgumentError('data is List');
return null;
} else if (api.data == null) {
return null;
} else {
return dataSerializer.fromMap(api.data);
}
}
List<T> fromJsonToListData<T>(String Json, [Serializer dataSerializer]) {
Restful restful = new Restful.fromJson(Json, dataSerializer);
if (restful.data is List) {
if(dataSerializer==null){
return restful.data;
}
return restful.data;
} else if (restful.data == null) {
return null;
} else {
return null;
}
}
}
@GenSerializer()
class RestfulSerializer extends Serializer<Restful> with _$RestfulSerializer {}
上面主要有6个方法
-
toMap([Serializer dataSerializer])
将Restful
转换为map
,传入的是data对应的类型序列化工具[]
表示非必填,如果data
是基本类型,可不填 -
toJson([Serializer dataSerializer])
将Restful
转换为字符串
-
Restful.fromMap(Map<String,dynamic> map, [Serializer dataSerializer])
将map
转换为Restful
-
Restful.fromJson(String Json, [Serializer dataSerializer])
将字符串
转换为Restful
-
fromJsonToData<T>(String Json,Serializer dataSerializer)
将字符串
直接转换为data
(T
为泛型) -
fromJsonToListData<T>(String Json, [Serializer dataSerializer])
将字符串
直接转换为List<T>
3.定制接口
工具已经有了,数据也有了,那么我们现在就开始着手写接口了
main.dart
import 'package:jaguar_query_postgres/jaguar_query_postgres.dart';
import 'package:jaguar/jaguar.dart';
import 'package:jaguar_reflect/jaguar_reflect.dart';
import 'package:TestDB/UserController.dart';
final PgAdapter pgAdapter =
new PgAdapter('postgres', username: 'postgres', password: '123456');
main() async {
await pgAdapter.connect();
new Jaguar( port: 1000)
..add(reflect(new UserController(pgAdapter)))
..serve();
}
UserController.dart
import 'package:jaguar/jaguar.dart';
import 'package:jaguar_orm/jaguar_orm.dart';
import 'serializer.dart';
import 'Restful.dart';
import 'user.dart';
@Controller(path: '/user')
class UserController {
final UserBean userBean;
UserController(Adapter adapter):userBean=new UserBean(adapter);
@Get( path: '/:id')
user(Context ctx) async{
String id=ctx.pathParams['id'];
Restful restful=new Restful()
..code=0
..msg='success'
..data=await userBean.find(id);
return Response.json( restful.toMap(new UserSerializer()));
}
}
我们来请求一下数据看看http://localhost:1000/user/1
可以看到,我们成功的在数据库中查找到一条记录,然后以json的形式传递给客户端
下面就是写其他的增删查改接口了
import 'package:jaguar/jaguar.dart';
import 'package:jaguar_orm/jaguar_orm.dart';
import 'serializer.dart';
import 'Restful.dart';
import 'user.dart';
@Controller(path: '/user')
class UserController {
final UserBean userBean;
UserController(Adapter adapter):userBean=new UserBean(adapter);
@Get( path: '/:id')
user(Context ctx) async{
String id=ctx.pathParams['id'];
Restful restful=new Restful()
..code=0
..msg='success'
..data=await userBean.find(id);
return Response.json( restful.toMap(new UserSerializer()));
}
@Post(path: '/:id')
userEdit(Context ctx) async{
String id=ctx.pathParams['id'];
User user=await ctx.bodyAsJson(convert: new UserSerializer().fromMap);
user.id=id;
await userBean.update(user);
return Response.json((new Restful()
..code=0
..msg='ok').toMap());
}
@Put(path: '/')
userAdd(Context ctx) async{
User user=await ctx.bodyAsJson(convert: new UserSerializer().fromMap);
await userBean.insert(user);
return Response.json((new Restful()
..code=0
..msg='ok').toMap());
}
@Delete(path: '/:id')
userDelete(Context ctx) async{
String id=ctx.pathParams['id'];
await userBean.remove(id);
return Response.json((new Restful()
..code=0
..msg='ok').toMap());
}
}
ok,上面就是今天的全部内容,我们明天见!
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