"Java Learning" Spring MVC Common DAO Implementation, definition of basic additions and deletions

Interface class:

　　

 PackageCom.blog.db.dao;Importcom.blog.util.Pagination;Importjava.util.List; Public InterfacePublicdao<t> {     Public voidSetmapper (Class t);  Public voidSettablename (String tn);  PublicList<t>querylist (pagination pagination);  Public voidDeletebyid (intID);  Public voidAdd (T t,object[] values,int[] types);  PublicT Querybyid (intID);  PublicT Querybyfield (String fieldname,string value);  Public voidUpdatebyid (T T,intId,object[] values,int[] types);}

Implementation class:

 PackageCom.blog.db.dao.impl;ImportCom.blog.db.dao.PublicDao;Importcom.blog.util.Pagination;ImportOrg.springframework.beans.factory.annotation.Value;Importorg.springframework.dao.EmptyResultDataAccessException;ImportOrg.springframework.jdbc.core.BeanPropertyRowMapper;Importorg.springframework.jdbc.core.JdbcTemplate;ImportOrg.springframework.jdbc.core.RowMapper;Importorg.springframework.stereotype.Repository;ImportJavax.annotation.Resource;Importjava.sql.Types;Importjava.util.List;/*** Public DAO Implementation *@deprecatedprovide common lists, insert, query single, update data Services *@authorZTF **/@Repository ("Publicdao") Public classPublicdaoimpl<t>ImplementsPublicdao<t>{@ResourcePrivateJdbcTemplate JdbcTemplate; PrivateString table_name = "";//Table name    Privatelist<string> fields;//table Field@Value ("${db_schema}")    PrivateString schema;//Table Mode    PrivateRowmapper<t>mapper; /*** Set Mapper mappings*/     Public voidSetmapper (Class t) { This. Mapper =NewBeanpropertyrowmapper<t>(t); }     PublicRowmapper<t>Getmapper () {returnmapper; }     Public voidSettablename (String tn) { This. table_name =TN; }     PublicString Gettable_name () {returnSchema+ "." +table_name; }     PublicList<string>GetFields () {return  This. Fields; }     Publicstring getfieldstostring () {string _fields; List<String> fields =GetFields (); _fields= String.Join (",", fields); return_fields; }    /*** Query list *@parampagination The paging object defined in the incoming public util *@returnlist<t> **/     PublicList<t>querylist (pagination pagination) {List lists=NULL; String SQL= "SELECT * from??"; Lists=jdbctemplate.queryforlist (SQL, Gettable_name (), Pagination.getsql (),        Getmapper ()); returnlists; }    /*** Delete a line by ID *@paramID incoming Line ID **/     Public voidDeletebyid (intID) {String SQL= "Delete from" +Gettable_name ()+ "where id=?"; Jdbctemplate.update (SQL,Newobject[] {ID},New int[] {types.integer}); }    /*** Insert Data *@paramT data object for incoming operation *@paramobject[] Object * for values@paramtypes The type of the value object **/     Public voidAdd (T t,object[] values,int[] types) {String SQL= "INSERT INTO" +gettable_name () + "(" +getfieldstostring () + ") VALUES (?)";    Jdbctemplate.update (SQL, values, types); }    /*** Query the specified line based on ID *@paramID Incoming ID **/     PublicT Querybyid (intid) {T t=NULL; String SQL= "SELECT * from" +gettable_name () + "where id=?"; Try{T=jdbctemplate.queryforobject (SQL,Newobject[] {ID},New int[] {Types.integer}, Getmapper ()); }Catch(emptyresultdataaccessexception e) {T=NULL; }        returnT; }    /*** Single-line data with specified values based on the specified fieldname query *@paramfieldname Incoming ID **/     PublicT Querybyfield (String fieldname,string value) {T T=NULL; String SQL= "SELECT * from" +gettable_name () + "where" +fieldname+ "=?"; Try{T=jdbctemplate.queryforobject (SQL,Newobject[] {value},New int[] {Types.varchar}, Getmapper ()); }Catch(emptyresultdataaccessexception e) {T=NULL; }        returnT; }    /*** Update a single row of data for the specified value according to the specified ID *@paramT incoming update object *@paramID passed in the specified ID *@paramobject[] Object * for values@paramtype of types value object int[] **/     Public voidUpdatebyid (T T,intId,object[] values,int[] types) {String SQL= "Update" +gettable_name () + "set username=?,password=?,pic=?,describe=?,check_time=?" where id= "+ID;    Jdbctemplate.update (SQL, values, types); }}

The core of the place in: How To pass Mapper

Here, I'm using a

Private rowmapper<t> mapper;     /**      * Set Mapper map      */public     void  setmapper (Class t) {         Thisnew beanpropertyrowmapper<t>(T);    }      Public Rowmapper<t> Getmapper () {        return  mapper;    }

The. Class object that passed in the T class when calling DAO

Call for example (partial code):

@Qualifier ("Publicdao")    private publicdao<user> ud;      Public throws unsupportedencodingexception {        = md5encryption.getencryption (password);        Ud.settablename ("users"); Specifies the query table name        ud.setmapper (User. class // specifying the Mapping class object        

Can realize the basic table additions and deletions, improve the development efficiency,

If you have a special DAO, you can customize a specific DAO and add special methods.

"Java Learning" Spring MVC Common DAO Implementation, definition of basic additions and deletions