Spring/springmvc/mybatis (persistence layer, business layer, control layer thinking summary)

preparatory work:# # 7 Importing provincial and municipal data into the database

1. Download the SQL script file from FTP

2. Move the script file to a location that is easy to describe the absolute path

3. Go to MySQL Console

4. Using the ' Tedu_store ' database

5. Run ' source E:\t_dict.sql ' to execute the script file (the command under Linux is source/home/soft01/Desktop/t_dict.sql;)-------------------------------- -----------------------------------------------------------

# # get provincial and municipal data

# # Target

Get a list of all provinces

Get the province's information according to the province's code name

Get a list of all municipalities in a province

According to the city code, get the city information

Get a list of all areas of a city

According to the code of the district, get the information of the District------------------------------------------------------------------------------------------

### Create entity classes (analyze front-end pages and write corresponding entity classes according to the fields of the tables in the database)

Create 3 entity classes in the ' Cn.tedu.store.entity ' package:

   Public classProvince {PrivateInteger ID; PrivateString Code; PrivateString name; //construction method, set/get,tostring, implement serializable    }     Public classCity {PrivateInteger ID; PrivateString Provincecode; PrivateString Code; PrivateString name; //construction method, set/get,tostring, implement serializable    }     Public classArea {PrivateInteger ID; PrivateString Citycode; PrivateString Code; PrivateString name; //construction method, set/get,tostring, implement serializable}

--------------------------------------------------------------------------------------------------------------- -------

### Persistence Layer

Create the ' Cn.tedu.store.mapper.ProvinceMapper ' interface and add an abstract method:

/**      * Get a list of all     provinces */Lists <Province> getprovincelist (    );      /**      * According to the province code, obtain the province     's information *    /province Getprovincebycode (String provincecode);

Then, create (copy and paste and modify) the ' provincemapper.xml ' mapping file under ' resources\mappers\ ':

<Mappernamespace= "Cn.tedu.store.mapper.ProvinceMapper">                <!--get a list of all provinces -        <!--list<province> getprovincelist () -        <SelectID= "Getprovincelist"Resulttype= "Cn.tedu.store.entity.Province">SELECT ID, province_code as code, province_name as name From T_dict_provinces</Select>        <!--get the province's information according to the province's code name -        <!--province Getprovincebycode (String provincecode) -        <SelectID= "Getprovincebycode"Resulttype= "Cn.tedu.store.entity.Province">SELECT ID, province_code as code, province_name as name From T_dict_provinces WHERE Province_code=#{provincecode}</Select>    </Mapper>    

### Business LayerTake the information for the province as an example, first create the corresponding business interface ' Cn.tedu.store.service.IProvinceService ' and add the same abstract method as the persistence layer interface:

/**      * Get a list of all     provinces */Lists <Province> getprovincelist (    );      /**      * According to the province code, obtain the province     's information *    /province Getprovincebycode (String provincecode);

Create ' Cn.tedu.store.service.ProvinceServiceImpl ' to implement the above interface and use ' @Service (' provinceservice ') ' annotations, then declare ' @Autowired in the class Provincemapper provincemapper; ' property, and then implement the abstract method in the interface:    

 Public List<province> getprovincelist () {        return  provincemapper.getprovincelist ();    }      Public province Getprovincebycode (String provincecode) {        return  Provincemapper.getprovincebycode (Provincecode);    }

### Controller Layer

Get a list of provinces

Request path: '/province/list.do ' request parameter: ' None ' request type: ' GET ' response: ' responseresult<list<province>> '

Get the province's information according to the province's code name

Request path: '/province/info.do ' request parameter: ' code=110000 ' request type: ' GET ' response: ' responseresult<province> '

Get a list of municipalities in a province

Request path: '/city/list.do ' request parameter: ' province_code=xx ' request type: ' GET ' response: ' responseresult<list<city>> '

...... ......

(In fact, the general idea is the idea of MVC, but there are a lot of details to pay attention to, to practice more.) ）

-------------------------------------------------------------------------------------------

###the difference between a POST request and a GET request（ Face TestGet is often used for address bar requests
Post request form submission, JSON application ( look at the previous code), generally Add method body

The amount of data submitted for a GET request is small
Post request data is generally unlimited

Get exposes a lot of information, such as ID, so it's less secure than a POST request.

Get requests are easy to bookmark because it is specific to a page, and post is not ( find a code to see）。

Spring/springmvc/mybatis (persistence layer, business layer, control layer thinking summary)