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花了几天的时间研究了一下mybatis的源代码，觉得这个框架还是很不错的。但是有一些缺陷的地方。
先来说说它和别的框架比起来我认为的好处：
（1）sql外置，把sql文件写在配置文件中加上强大的动态sql支持。
（2）利用cjk动态代理，实现配置文件映射接口。
这样我们在使用这套orm框架的时候就可以不再写那个拼接sql语句的dao实现类（dao-impl class），把dao实现类的工作都移交给那些*mapper.xml文件，如果数据库查询业务需要修改sql的话，那么只需要修改xml文件中的sql语句。
需要扩展的地方：
（1）没有内置物理分页的实现。
我们一般的习惯都是返回我们自己的分页实现类，网上大多的mybatis分页实现都是先返回分页列表，再查下返回总页数，然后处理成我们自己的分页类。我自己也写了一个分页，把这部分工作交给mybatis来处理，以后会把代码贴出来。
（2）公用范型接口dao
公用范型接口dao类几乎成为我们开发中最长使用的，把一些长操作的方法封装一下，供我们的业务dao调用，但是在mybatis中，我现在不想再写dao的实现类，只有接口类，取缔他的是mapper-xml文件，这样如何才能封装我们的公用方法呢。
幸好mybatis提供了插件拦截器，我们可以在不修改mybatis源码的基础上来扩展它的功能。
好忙啊，花了些时间写了一个范型接口dao，还没有经过验证，先贴上代码。
使用方法很简单，只要你使用MappInterceptor这个拦截器，在你的Mapper接口中继承这个IGenericDao这样 公用的方法就可以使用了，这样的好处是在一般业务的类中不用再写Dao的实现，直接使用 IGenericDao中提供的方法就ok
公用dao，你的接口只要继承这个dao就可以使用里面的方法。
package org.cf.guott.mybatis;
import java.util.List;
import org.apache.ibatis.annotations.Delete;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.annotations.Update;
import org.cf.guott.mybatis.pagination.PageMyBatis;
public interface IGenericDao<T,PK> {
@Select("MapperGD.find.entityById")
public T findEntityById(PK id);
@Select("MapperGD.find.entitys")
public List<T> findEntity(Object... obj);
@Select("MapperGD.find.ListByLike")
public List<T> findLikeEntity(Object... obj);
@Insert("MapperGD.insert.entity")
public void insertEntity(T t);
@Update("MapperGD.update.entity")
public void updateEntityById(T entity);
@Delete("MapperGD.delete.id")
public void deleteById(PK id);
@Delete("MapperGD.delete.condition")
public void deleteByCondition(Object param);
@Select("MapperGD.find.entity.queryByVo")
public PageMyBatis<T> queryByVo(int i,int c,Object... obj);
@Select("MapperGD.find.entity.queryByVoLike")
public PageMyBatis<T> LikequeryByVo(int i,int c,Object... obj);
}
这个一个拦截器，来处理你的公用dao中的方法
package org.cf.guott.mybatis.dbmapper.interceptor;
import java.util.Map;
import java.util.Properties;
import org.apache.commons.lang3.reflect.FieldUtils;
import org.apache.ibatis.executor.Executor;
import org.apache.ibatis.mapping.BoundSql;
import org.apache.ibatis.mapping.MappedStatement;
import org.apache.ibatis.plugin.Interceptor;
import org.apache.ibatis.plugin.Intercepts;
import org.apache.ibatis.plugin.Invocation;
import org.apache.ibatis.plugin.Plugin;
import org.apache.ibatis.plugin.Signature;
import org.apache.ibatis.session.ResultHandler;
import org.apache.ibatis.session.RowBounds;
import org.cf.guott.mybatis.helpers.MapperSqlHelper;
import org.cf.guott.mybatis.pagination.MappedStatmentHelper;
@Intercepts({
@Signature(
type = Executor.class,
method = "query",
args = {MappedStatement.class, Object.class, RowBounds.class, ResultHandler.class})
,@Signature(
type = Executor.class,
method = "update",
args = {MappedStatement.class, Object.class})
})
public class MappInterceptor implements Interceptor{
private final static String _sql_regex = ".*MapperGD.*";
@SuppressWarnings("unchecked")
private void processIntercept(final Object[] queryArgs) {
final MappedStatement ms = (MappedStatement) queryArgs[0];
final Object parameter = queryArgs[1];
String mapperSQL = ms.getBoundSql(parameter).getSql();
BoundSql boundSQL = ms.getBoundSql(parameter);
Class<?> entityclazz = MappedStatmentHelper.getEntityClazz(ms.getResource());
queryArgs[0] = MappedStatmentHelper.setMSReturnSetMap(ms, entityclazz);
boolean interceptor = mapperSQL.matches(_sql_regex);
if(!interceptor){
return;
}
if(entityclazz == null){
throw new RuntimeException("使用公共dao必須給mapper接口的@MyBatisRepository(User.class) 注解設置值.");
}
String new_sql = MapperSqlHelper.getExecuSQL(entityclazz,mapperSQL,parameter);
BoundSql newBoundSql = MappedStatmentHelper.copyFromBoundSql(ms,
boundSQL, new_sql);
MappedStatement newMs = MappedStatmentHelper
.copyFromMappedStatement(ms, newBoundSql);
queryArgs[0] = newMs;
}
public Object intercept(Invocation invocation) throws Throwable {
processIntercept(invocation.getArgs());
return invocation.proceed();
}
public Object plugin(Object o) {
return Plugin.wrap(o, this);
}
public void setProperties(Properties arg0) {
}
}
这个类来处理你的sql语句
package org.cf.guott.mybatis.helpers;
import java.lang.annotation.Annotation;
import java.lang.reflect.Field;
import java.util.Arrays;
import java.util.Collection;
import java.util.Map;
import org.apache.commons.lang3.reflect.FieldUtils;
import org.cf.guott.mybatis.annotation.MyBatisColumn;
import org.cf.guott.mybatis.annotation.MyBatisRepository;
import org.cf.guott.mybatis.annotation.MybatisID;
import org.cf.guott.mybatis.annotation.MybatisTable;
import org.cf.guott.mybatis.entity.User;
public class MapperSqlHelper{
public static final Class<? extends Annotation> MYBATISREPOSITORY = MyBatisRepository.class;
public static final Class<? extends Annotation> MYBATISTABLE = MybatisTable.class;
public static final Class<? extends Annotation> MYBATISCOLUMN = MyBatisColumn.class;
public static final Class<? extends Annotation> MYBATISID = MybatisID.class;
public String getUpdateSQL(){
return null;
}
/**
* 传入mapper接口class
* @param mapperclazz
* @return
*/
private String insertEntity(Class<?> clazz){
StringBuilder sql = new StringBuilder();
StringBuilder intosql = new StringBuilder();
StringBuilder valuessql = new StringBuilder();
if(!clazz.isAnnotationPresent(MYBATISTABLE)){
sql.append("INSERT INTO "+clazz.getName());
}else{
MybatisTable antable = (MybatisTable)clazz.getAnnotation(MYBATISTABLE);
if(antable.value() == ""){
sql.append("INSERT INTO "+clazz.getName());
}else{
sql.append("INSERT INTO "+antable.value());
}
}
Field[] files = clazz.getDeclaredFields();
intosql.append("(");
for(Field file : files){
file.setAccessible(true);
if(file.isAnnotationPresent(MYBATISCOLUMN)){
MyBatisColumn anColumn = (MyBatisColumn)file.getAnnotation(MYBATISCOLUMN);
if(!anColumn.isAutoKey()){
if(anColumn.value().equals("")){
intosql.append(file.getName()+",");
}else{
intosql.append(anColumn.value()+",");
}
}
}else{
intosql.append(file.getName()+",");
}
}
valuessql.append(" values (");
for(Field file : files){
file.setAccessible(true);
if(file.isAnnotationPresent(MYBATISCOLUMN)){
MyBatisColumn anColumn = (MyBatisColumn)file.getAnnotation(MYBATISCOLUMN);
if(!anColumn.isAutoKey()){
if(anColumn.value().equals("")){
valuessql.append("#{"+file.getName()+"},");
}else{
valuessql.append("#{"+file.getName()+"},");
}
}
}else{
valuessql.append("#{"+file.getName()+"},");
}
}
return sql.append(intosql.substring(0, intosql.length()-1)).append(") ").append(valuessql.substring(0, valuessql.length()-1)).append(")").toString();
}
/**
* 传入mapper接口class
* @param mapperclazz
* @return
*/
private String updateEntityById(Class<?> clazz){
StringBuilder sql = new StringBuilder();
StringBuilder set = new StringBuilder();
StringBuilder wheresql = new StringBuilder();
if(!clazz.isAnnotationPresent(MYBATISTABLE)){
sql.append("UPDATE "+clazz.getName());
}else{
MybatisTable antable = (MybatisTable)clazz.getAnnotation(MYBATISTABLE);
if(antable.value() == ""){
sql.append("UPDATE "+clazz.getName());
}else{
sql.append("UPDATE "+antable.value());
}
}
Field[] files = clazz.getDeclaredFields();
set.append(" set ");
wheresql.append(" where 1=1 ");
for(Field file : files){
file.setAccessible(true);
if(file.isAnnotationPresent(MYBATISCOLUMN)){
MyBatisColumn anColumn = (MyBatisColumn)file.getAnnotation(MYBATISCOLUMN);
if(!anColumn.isID()){//判断字段不为主键
if(anColumn.value().equals("")){
set.append(file.getName()+" = #{"+file.getName()+"} ,");
}else{
set.append(anColumn.value()+" = #{"+file.getName()+"} ,");
}
}else{
if(anColumn.value().equals("")){
wheresql.append(" and "+file.getName()+" = #{"+file.getName()+"},");
}else{
wheresql.append(" and "+anColumn.value()+" = #{"+anColumn.value()+"},");
}
}
}else{
set.append(file.getName()+" = #{"+file.getName()+"} ,");
}
}
if(wheresql.equals(" where 1=1 ")){
throw new RuntimeException("实体变量没有设置ID字段值");
}
sql.append(set.substring(0, set.length()-1)).append(wheresql.substring(0, wheresql.length()-1));
return sql.toString();
}
private String findEntityAll(Class<?> clazz,Object args,boolean islike){
StringBuilder sql = new StringBuilder();
StringBuilder whereSQL = new StringBuilder(" where 1=1 ");
StringBuffer orderby = new StringBuffer();
if(!clazz.isAnnotationPresent(MYBATISTABLE)){
sql.append("select * from "+clazz.getName());
}else{
MybatisTable antable = (MybatisTable)clazz.getAnnotation(MYBATISTABLE);
if(antable.value() == ""){
sql.append("select * from "+clazz.getSimpleName());
}else{
sql.append("select * from "+antable.value());
}
}
Object[] paramObjs = (Object[]) ((Map)args).get("array");
if(paramObjs != null && paramObjs.length>0){
Object param = paramObjs[0];
if(param != null ){
if(param instanceof Map){
Map<String,Object> map = (Map)param;
if(map.containsKey("orderby")){
orderby.append(" order by "+map.get("orderby"));
}
if(map.containsKey("sortby")){
orderby.append(" "+map.get("sortby")+" ");
}
for(String key : map.keySet())
{
if(islike)
whereSQL.append(" and "+key + " like '%" + map.get(key)+"%',");
else whereSQL.append(" and "+key + " = '" + map.get(key)+"',");
}
sql.append(whereSQL.subSequence(0,whereSQL.length()-1)).append(orderby);
}else if(param instanceof Conditions){
Conditions<String,Object> map = (Conditions)param;
if(map.containsKey("orderby")){
orderby.append(" order by "+map.get("orderby"));
}
if(map.containsKey("sortby")){
orderby.append(" "+map.get("sortby")+" ");
}
for(String key : map.keySet())
{
if(key.equals("orderby") || key.equals("sortby")){
continue;
}
if(islike)
whereSQL.append(" and "+key + " like '%" + map.get(key)+"%',");
else whereSQL.append(" and "+key + " = '" + map.get(key)+"',");
}
sql.append(whereSQL.subSequence(0,whereSQL.length()-1)).append(orderby);
}
}
}
return sql.toString();
}
private String findEntityById(Class<?> clazz){
StringBuilder sql = new StringBuilder();
if(!clazz.isAnnotationPresent(MYBATISTABLE)){
sql.append("select * from "+clazz.getName());
}else{
MybatisTable antable = (MybatisTable)clazz.getAnnotation(MYBATISTABLE);
if(antable.value() == ""){
sql.append("select * from "+clazz.getSimpleName());
}else{
sql.append("select * from "+antable.value());
}
}
sql.append(" where 1=1 ");
Field[] files = clazz.getDeclaredFields();
boolean falg = false;
for(Field file : files){
file.setAccessible(true);
if(file.isAnnotationPresent(MyBatisColumn.class)){
MyBatisColumn anColumn = (MyBatisColumn)file.getAnnotation(MYBATISCOLUMN);
if(anColumn.isID()){//判断字段不为主键
falg = true;
if(anColumn.value().equals("")){
sql.append(" and "+file.getName()+" = #{"+file.getName()+"},");
}else{
sql.append(" and "+file.getName()+" = #{"+file.getName()+"},");
}
}
}
}
if(!falg){
throw new RuntimeException("不能通過id查詢實體,實體中沒有定義@mybatisID");
}
return sql.subSequence(0, sql.length()-1).toString();
}
public String deleteById(Class<?> clazz){
StringBuilder sql = new StringBuilder();
StringBuilder wheresql = new StringBuilder(" where 1=1 ");
if(!clazz.isAnnotationPresent(MYBATISTABLE)){
sql.append("delete "+clazz.getName());
}else{
MybatisTable antable = (MybatisTable)clazz.getAnnotation(MYBATISTABLE);
if(antable.value() == ""){
sql.append("delete "+clazz.getName());
}else{
sql.append("delete "+antable.value());
}
}
Field[] files = clazz.getDeclaredFields();
for(Field file : files){
file.setAccessible(true);
if(file.isAnnotationPresent(MYBATISCOLUMN)){
MyBatisColumn anColumn = (MyBatisColumn)file.getAnnotation(MYBATISCOLUMN);
if(anColumn.isID()){//判断字段不为主键
if(anColumn.value().equals("")){
wheresql.append(" and "+file.getName()+" = #{"+file.getName()+"},");
}else{
wheresql.append(" and "+anColumn.value()+" = #{"+anColumn.value()+"},");
}
}
}
}
if(wheresql.equals(" where 1=1 ")){
throw new RuntimeException("实体变量没有设置ID字段值");
}
sql.append(wheresql.substring(0,wheresql.length()-1));
return sql.toString();
}
public String queryByVo(Class<?> clazz,Object args,boolean islike){
StringBuilder sql = new StringBuilder();
StringBuilder whereSQL = new StringBuilder(" where 1=1 ");
StringBuilder orderbySQL = new StringBuilder("");
if(!clazz.isAnnotationPresent(MYBATISTABLE)){
sql.append("select * from "+clazz.getName());
}else{
MybatisTable antable = (MybatisTable)clazz.getAnnotation(MYBATISTABLE);
if(antable.value() == ""){
sql.append("select * from "+clazz.getName());
}else{
sql.append("select * from "+antable.value());
}
}
if(args instanceof Map){
Map map = (Map)args;
Object[] arr = (Object[])map.get("param3");
if(arr.length>0){
Map<String,Object> params = (Map)arr[0];
if(params.containsKey("orderby")){
orderbySQL.append(" order by "+params.get("orderby"));
}
if(params.containsKey("sortby")){
orderbySQL.append(" "+params.get("sortby")+" ");
}
for(String key:params.keySet()){
if(key.equals("orderby") || key.equals("sortby")){
continue;
}
if(islike)
whereSQL.append(" and "+key + " like '%" + params.get(key)+"%',");
else whereSQL.append(" and "+key + " = '" + params.get(key)+"',");
}
}
}
return sql.append(whereSQL.substring(0, whereSQL.length()-1)).append(orderbySQL).toString();
}
public String count(Class<?> clazz,Object args){
StringBuilder sql = new StringBuilder();
StringBuilder whereSQL = new StringBuilder(" where 1=1 ");
if(!clazz.isAnnotationPresent(MYBATISTABLE)){
sql.append("select count(*) from "+clazz.getName());
}else{
MybatisTable antable = (MybatisTable)clazz.getAnnotation(MYBATISTABLE);
if(antable.value() == ""){
sql.append("select count(*) from "+clazz.getName());
}else{
sql.append("select count(*) from "+antable.value());
}
}
Object[] paramObjs = (Object[]) ((Map)args).get("array");
if(paramObjs != null && paramObjs.length>0){
Object param = paramObjs[0];
if(param != null ){
if(param instanceof Map){
Map<String,Object> map = (Map)param;
for(String key : map.keySet())
{
whereSQL.append(" and "+key + " = '" + map.get(key)+"',");
}
sql.append(whereSQL.subSequence(0,whereSQL.length()-1));
}else if(param instanceof Conditions){
Conditions<String,Object> map = (Conditions)param;
for(String key : map.keySet())
{
whereSQL.append(" and "+key + " = '" + map.get(key)+"',");
}
sql.append(whereSQL.subSequence(0,whereSQL.length()-1));
}
}
}
return sql.toString();
}
public String deleteByCondition(Class<?> clazz,Object param){
StringBuilder sql = new StringBuilder();
StringBuilder whereSQL = new StringBuilder(" where 1=1 ");
if(!clazz.isAnnotationPresent(MYBATISTABLE)){
sql.append("delete "+clazz.getName());
}else{
MybatisTable antable = (MybatisTable)clazz.getAnnotation(MYBATISTABLE);
if(antable.value() == ""){
sql.append("delete "+clazz.getName());
}else{
sql.append("delete "+antable.value());
}
}
if(param != null ){
if(param instanceof Map){
Map<String,Object> map = (Map)param;
for(String key : map.keySet())
{
whereSQL.append(" and "+key + " = '" + map.get(key)+"',");
}
sql.append(whereSQL.subSequence(0,whereSQL.length()-1));
}else if(param instanceof Conditions){
Conditions<String,Object> map = (Conditions)param;
for(String key : map.keySet())
{
whereSQL.append(" and "+key + " = '" + map.get(key)+"',");
}
sql.append(whereSQL.subSequence(0,whereSQL.length()-1));
}
}
if(whereSQL.equals(" where 1=1 ")){
throw new RuntimeException("实体变量没有设置ID字段值");
}
return sql.toString();
}
private static MapperSqlHelper App(){
return new MapperSqlHelper();
}
public static String getExecuSQL(Class<?> clazz, String mapperDBsql,Object param) {
if(mapperDBsql.equals("MapperGD.find.entitys")){
return MapperSqlHelper.App().findEntityAll(clazz,param,false);//条件查询实体列表
}else if(mapperDBsql.equals("MapperGD.find.entityById")){
return MapperSqlHelper.App().findEntityById(clazz);//id查询实体
}else if(mapperDBsql.equals("MapperGD.find.ListByLike")){
return MapperSqlHelper.App().findEntityAll(clazz,param,true);//条件查询实体列表
}else if(mapperDBsql.equals("MapperGD.insert.entity")){
return MapperSqlHelper.App().insertEntity(clazz);//保存单一实体
}else if(mapperDBsql.equals("MapperGD.update.entity")){
return MapperSqlHelper.App().updateEntityById(clazz);//保存单一实体
}else if(mapperDBsql.equals("MapperGD.update.entity.condistion")){
return mapperDBsql;
}else if(mapperDBsql.equals("MapperGD.delete.id")){
return MapperSqlHelper.App().deleteById(clazz);
}else if(mapperDBsql.equals("MapperGD.delete.condition")){
return MapperSqlHelper.App().deleteByCondition(clazz,param);
}else if(mapperDBsql.equals("MapperGD.count.condition")){
return MapperSqlHelper.App().count(clazz,param);
}else if(mapperDBsql.equals("MapperGD.find.entity.queryByVo")){
return MapperSqlHelper.App().queryByVo(clazz,param,false);
}else if(mapperDBsql.equals("MapperGD.find.entity.queryByVoLike")){
return MapperSqlHelper.App().queryByVo(clazz,param,true);
}
return null;
}
//预留接口
private String updateEntityByConditions(Class<?> clazz,Object param){
return null;
}
public void getParam(Object param){
StringBuffer bf = new StringBuffer();
if (isPrimitiveType(param.getClass())) {
bf.append(param);
} else if (param instanceof Map) {
Map<String,Object> map = (Map)param;
}
}
public static boolean isPrimitiveType(Class clazz) {
return clazz != null && (clazz.isPrimitive() || clazz.equals(Long.class) || clazz.equals(Integer.class)
|| clazz.equals(Short.class) || clazz.equals(Byte.class) || clazz.equals(Double.class)
|| clazz.equals(Float.class) || clazz.equals(Boolean.class) || clazz.equals(Character.class) || clazz.equals(String.class));
}
public static void main(String[] args) {
// Object object = null;
// if (isPrimitiveType(object.getClass())) {
// } else if (object instanceof Map) {
// }
Field[] files = User.class.getDeclaredFields();
User u = new User();
try {
System.out.println(FieldUtils.readDeclaredField(u, "id",true));
} catch (IllegalAccessException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
测试用例：
业务dao,这个接口继承自 IGenericDao
package org.cf.guott.mybatis.mapper;
import java.util.List;
import java.util.Map;
import org.apache.ibatis.annotations.Select;
import org.cf.guott.mybatis.ITestGDAO;
import org.cf.guott.mybatis.annotation.MyBatisRepository;
import org.cf.guott.mybatis.entity.User;
import org.cf.guott.mybatis.pagination.PageMyBatis;
@MyBatisRepository(User.class)
public interface UserMapper extends IGenericDao<User,Integer>{
}
main运行方法
package org.cf.guott.mybatis.main;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.apache.ibatis.session.RowBounds;
import org.cf.guott.mybatis.entity.User;
import org.cf.guott.mybatis.helpers.Conditions;
import org.cf.guott.mybatis.mapper.UserMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.stereotype.Component;
@Component
public class Main {
@Autowired
UserMapper userMapper;
public static void main(String[] args) {
ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext-mybatis.xml");
Main main = context.getBean(Main.class);
Map map = new HashMap();
map.put("name", "ccc");
List<User> users = main.userMapper.LikequeryByVo(0,2,new Conditions<String, Object>().add("name", "guotiantdddian").addOrderBy("id").setSortByDesc());
System.out.println(users.size());
}
}
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