Based on the mybatis annotation extension, the implementation can be used without configuration __mybatis

First, use the article

If the project itself is built on springmvc+mybatis, you do not need to add any configuration mapper class simply inherits Basemapper, that is, it has additions, deletions, and modifications, without any configuration files.

1.

Package com.springmvc.mapper;

Import org.springframework.stereotype.Repository;

Import Com.nmtx.mybatis.ext.mapper.BaseMapper;
Import Com.springmvc.model.User;
@Repository public
Interface Usermapper extends basemapper<user>{

}

2.

Package Com.springmvc.service.impl;

Import Javax.annotation.Resource;

Import Org.springframework.stereotype.Service;

Import Com.springmvc.mapper.UserMapper;
Import Com.springmvc.model.User;
Import Com.springmvc.service.UserService;


@Service public
class Userserviceimpl implements userservice{
    
    @Resource
    private usermapper usermapper;
    
    public int insertuser (user user) {return
        usermapper.insert (user);
    }

    @Override public
    int updateuser (user user) {return
        usermapper.update (user);
    }

    @Override public
    int deleteuser (user user) {return
        usermapper.delete (user);
    }

    @Override public
    User finduser (user user) {return
        Usermapper.findfirst (user)}
}

3.

<?xml version= "1.0" encoding= "UTF-8"?> <!
DOCTYPE Mapper Public
 "-//mybatis.org//dtd mapper 3.0//en"
"HTTP://MYBATIS.ORG/DTD/MYBATIS-3-MAPPER.DTD" >
<mapper namespace= "Com.springmvc.mapper.UserMapper" >
         
</mapper>

The extension principle is based on the @InsertProvider in MyBatis, @DeleteProvider, @UpdateProvider, @SelectProvider annotation, the implementation code is as follows

1.

Package com.nmtx.mybatis.ext.mapper;

Import Org.apache.ibatis.annotations.DeleteProvider;
Import Org.apache.ibatis.annotations.InsertProvider;
Import org.apache.ibatis.annotations.Options;
Import Org.apache.ibatis.annotations.SelectProvider;
Import Org.apache.ibatis.annotations.UpdateProvider;

Import Com.nmtx.mybatis.ext.common.SqlProvider;

Public interface Basemapper<t> {

    @InsertProvider (type = Sqlprovider.class, method = "Insert")
    @Options ( usegeneratedkeys=true) public
    int Insert (T bean);

    @DeleteProvider (type = sqlprovider.class, method = ' delete ') public
    int Delete (T bean);

    @UpdateProvider (type = sqlprovider.class, method = ' update ') public
    int update (T bean);

    @SelectProvider (type = sqlprovider.class, method = ' FindFirst ') public
    t FindFirst (t Bean);

2.

Package Com.nmtx.mybatis.ext.common;
Import Java.lang.reflect.Field;
Import java.util.ArrayList;

Import java.util.List;
Import Org.apache.commons.lang3.ArrayUtils;

Import Org.springframework.util.StringUtils;
Import Com.nmtx.mybatis.ext.common.table.TableFormat;
Import Com.nmtx.mybatis.ext.common.table.annotation.Column;
Import com.nmtx.mybatis.ext.common.table.annotation.Table;

Import Com.nmtx.mybatis.ext.common.table.impl.HumpToUnderLineFormat;

    public class SQLProvider {private Tableformat Tableformat = new Humptounderlineformat ();
        Public String Insert (Object bean) {class<?> beanclass = Bean.getclass ();
        String tablename = Gettablename (Beanclass);
        field[] fields = GetFields (Beanclass);
        StringBuilder insertsql = new StringBuilder ();
        list<string> Insertparas = new arraylist<string> ();
        list<string> insertparanames = new arraylist<string> (); Insertsql.append ("INSERT into"). AppenD (tablename). Append ("(");
                try {for (int i = 0; i < fields.length; i++) {Field field = Fields[i];
                Column column = Field.getannotation (column.class);
                String columnName = "";
                    if (column!= null) {if (!column.required ()) continue;
                ColumnName = Column.value (); } if (Stringutils.isempty (ColumnName)) {columnName = tableformat.getcolumnname (field.
                GetName ());
                } field.setaccessible (True);
                Object object = Field.get (bean);
                    if (object!= null) {Insertparanames.add (columnName);
                Insertparas.add ("#{" + field.getname () + "}");
        (Exception e) {new RuntimeException ("Get Insert SQL is exceptoin:" + e); for (int i = 0; I &lT Insertparanames.size ();
            i++) {insertsql.append (Insertparanames.get (i));
        if (I!= insertparanames.size ()-1) insertsql.append (",");
        } insertsql.append (")"). Append ("VALUES (");
            for (int i = 0; i < insertparas.size (); i++) {Insertsql.append (Insertparas.get (i));
        if (I!= insertparas.size ()-1) insertsql.append (",");
        } insertsql.append (")");
    return insertsql.tostring ();
        Public String Update (Object bean) {class<?> beanclass = Bean.getclass ();
        String tablename = Gettablename (Beanclass);
        field[] fields = GetFields (Beanclass);
        StringBuilder updatesql = new StringBuilder ();
        Updatesql.append ("Update"). Append (tablename). Append ("set");
                try {for (int i = 0; i < fields.length; i++) {Field field = Fields[i]; Column column = Field.getannotation (columN.class);
                String columnName = "";
                    if (column!= null) {if (!column.required ()) continue;
                ColumnName = Column.value (); } if (Stringutils.isempty (ColumnName)) {columnName = tableformat.getcolumnname (field.
                GetName ());
                } field.setaccessible (True);
                Object beanvalue = Field.get (bean); if (beanvalue!= null) {updatesql.append (columnName). Append ("=#{"). Append (Field.getname ()). Append ("}"
                    );
                    if (i!= fields.length-1) {updatesql.append (","); catch (Exception e) {new RuntimeException ("Get Update SQL is EXCE
        Ptoin: "+ e);
        } updatesql.append ("where"). Append (Tableformat.getid () + "=#{id}");
    return updatesql.tostring ();
}
    Public String Delete (Object bean) {class<?> beanclass = Bean.getclass ();
        String tablename = Gettablename (Beanclass);
        field[] fields = GetFields (Beanclass);
        StringBuilder deletesql = new StringBuilder ();
        Deletesql.append ("Delete from"). Append (tablename). Append ("where");
                try {for (int i = 0; i < fields.length; i++) {Field field = Fields[i];
                Column column = Field.getannotation (column.class);
                String columnName = "";
                    if (column!= null) {if (!column.required ()) continue;
                ColumnName = Column.value (); } if (Stringutils.isempty (ColumnName)) {columnName = tableformat.getcolumnname (field.
                GetName ());
                } field.setaccessible (True);
                Object beanvalue = Field.get (bean); if (BeanvaLue!= null) {deletesql.append (columnName). Append ("=#{"). Append (Field.getname ()). Append ("}");
                    if (i!= fields.length-1) {deletesql.append ("and"); catch (Exception e) {new runtimeexception (' Get delete sql. exce
        Ptoin: "+ e);
    return deletesql.tostring ();
        Public String FindFirst (Object Bean) {class<?> beanclass = Bean.getclass ();
        String tablename = Gettablename (Beanclass);
        field[] fields = GetFields (Beanclass);
        StringBuilder selectsql = new StringBuilder ();
        list<string> selectparanames = new arraylist<string> ();
        list<string> Selectparas = new arraylist<string> ();
        Selectsql.append ("select");
                try {for (int i = 0; i < fields.length; i++) {Field field = Fields[i]; Column Column = field.getannotation (column.class);
                String columnName = "";
                    if (column!= null) {if (!column.required ()) continue;
                ColumnName = Column.value (); } if (Stringutils.isempty (ColumnName)) {columnName = tableformat.getcolumnname (field.
                GetName ());
                } field.setaccessible (True);
                Object object = Field.get (bean);
                Selectsql.append (Field.getname ());
                    if (object!= null) {Selectparanames.add (columnName);
                Selectparas.add ("#{" + field.getname () + "}");
            } if (i!= fields.length-1) selectsql.append (",");
        } catch (Exception e) {new RuntimeException ("Get Select SQL is exceptoin:" + e); } selectsql.append ("from"). Append (tablename). AppEnd ("where"); for (int i = 0; i < selectparanames.size (); i++) {Selectsql.append (Selectparanames.get (i)). Append ("="). App
            End (Selectparas.get (i));
        if (I!= selectparanames.size ()-1) selectsql.append ("and");
    return selectsql.tostring ();
        private String Gettablename (class<?> beanclass) {string tablename = "";
        Table table = Beanclass.getannotation (Table.class);
        if (table!= null) {tablename = Table.value ();
        else {tablename = Tableformat.gettablename (Beanclass.getsimplename ());
    return tablename;
        Private field[] GetFields (class<?> beanclass) {field[] Beanfields = Beanclass.getdeclaredfields ();
        class<?> Beansuperclass = Beanclass.getsuperclass ();
        field[] Beansuperfields = Beansuperclass.getdeclaredfields ();
    Return Arrayutils.addall (Beanfields, beansuperfields); }
}