activerecordhelper.java

一个Java持久层类库

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package ActiveObject.core;

import ActiveObject.common.Flag;
import ActiveObject.exception.ObjectAnalysisException;
import ActiveObject.po.Role;
import ActiveObject.vo.*;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.sql.*;
import java.util.*;

/**
 * @author tanjiazhang
 */
public class ActiveRecordHelper {

    //表名到对象信息的映射
    static Map<String, ObjectInfo> activeLibrary = new HashMap();
    
     /**
     * 公共的更新方法，方便以后统一修改
     * @param sql
     * @param params
     * @throws java.sql.SQLException
     */
    static int excuteUpdate (String sql, Object... params) throws java.sql.SQLException {
        Connection connection = ActiveRecord.getConnection();
        PreparedStatement stmt = connection.prepareStatement(sql);
        int index = 1;//System.err.println(sql+" "+params.length);
        for(Object item : params)
        {
            stmt.setObject(index++, item);
        }
        index = stmt.executeUpdate();
        stmt.close();
        connection.close();
        return index;
    }

    static ResultReader excuteQuery(String sql, Object... params) throws java.sql.SQLException
    {
        return new ResultReader(sql, params);
    }

//    static Map<Field, Accesstor> analizeObjectFields_deleted(ActiveRecord object)
//    {
//        ObjectInfo objs = ActiveRecord.objectInformationBase.get(object.getClass().getName());
//        Map<Field, Accesstor> objects = null;
//        if(objs != null)
//            objects = objs.getFieldAccesstorMapping();
//        if(objects != null)
//            return objects;
//
//        //如果该持久化类的信息未被缓存，则开始分析
//        objects = new HashMap<Field, Accesstor>();
//        Class currentClass = object.getClass();
//
//        /**开始读取所有符合规范的字段
//         * 命名符合JavaBean的命名规范,存取器声明为公开
//         */
//        while(currentClass != null)
//        {
//            for(Field field : currentClass.getDeclaredFields())
//            {
//                if(field.getName().equals("id"))
//                    continue;
//                try
//                {
//                    Method getter = currentClass.getMethod(ActiveRecordHelper.getGetterNameByField(field.getName()));
//                    Method setter = currentClass.getMethod(ActiveRecordHelper.getSetterNameByField(field.getName()), field.getType());
//                    if(getter.getModifiers() == Modifier.PUBLIC && setter.getModifiers() == Modifier.PUBLIC)
//                        objects.put(field, new Accesstor(getter, setter));
//                }
//                catch(Exception err)
//                {
//                    //It means that it's not a valid field
//                }
//            }
//            if(currentClass == ActiveRecord.class)
//                break;
//            else
//                currentClass = currentClass.getSuperclass();
//        }
//
//        if(objs != null)
//            objs.setFieldAccesstorMapping(objects);
//        else
//        {
//            objs = new ObjectInfo();
//            objs.setFieldAccesstorMapping(objects);
//            ActiveRecord.objectInformationBase.put(object.getClass().getName(), objs);
//        }
//        return objects;
//    }

    static ObjectInfo analizeObjectInfo(Class recordType) throws ObjectAnalysisException
    {
        Class currentClass = recordType;
        String recordTypeName = currentClass.getName();
        String tableName = null;
        ObjectInfo objectInfo = ActiveRecordHelper.activeLibrary.get(recordTypeName);
        if(objectInfo != null)
            return objectInfo;
        //recordTypeName = currentClass.getSimpleName();
        objectInfo = new ObjectInfo();
        //读取类所关联的表--------------------------------------
        table tableAnno = (table)currentClass.getAnnotation(table.class);
        if(tableAnno == null)
            tableName = currentClass.getSimpleName();
        else
            tableName = tableAnno.value();
        objectInfo.setTableName(tableName);

        //建立连接对象的映射表----------------------------------
        List<LinkMap> linkMap = new ArrayList<LinkMap>();
        has_one one = (has_one)currentClass.getAnnotation(has_one.class);
        if(one != null)
        for(Class item : one.value())
        {
            linkMap.add(new LinkMap(item, LinkMap.HasOne));
        }
        has_many many = (has_many)currentClass.getAnnotation(has_many.class);
        if(many != null)
        for(Class item : many.value())
        {
            linkMap.add(new LinkMap(item, LinkMap.HasMany));
        }
        //--------------------------------------------------

        List<Accesstor> accesstorList = new ArrayList<Accesstor>();//缓存对象属性
        List<Accesstor> idList = new ArrayList<Accesstor>();//缓存对象ID

        //开始读取所有符合规范的字段命名符合JavaBean的命名规范,存取器声明为公开
        while(currentClass!=null)
        {
            if(currentClass.equals(ActiveRecord.class))
                break;
            for(Field field : currentClass.getDeclaredFields())
            {
                if(!currentClass.equals(recordType))
                    if(field.getModifiers()!=Modifier.PROTECTED && field.getModifiers()!=Modifier.PUBLIC)
                        continue;//跳过不可继承的Field
                //先检查annotation
                column col = field.getAnnotation(column.class);//System.err.println(col);
                if(col!=null)
                {
                    if(column.NonColumn.equals(col.value()))
                        continue;
                }
                link link = field.getAnnotation(link.class);
                if(link!=null)//如果link符号存在，则取出该ActiveRecord类的has_xxx映射并存入字段关联
                {
                    FieldColumnNode fieldNode = new FieldColumnNode();
                    fieldNode.setFieldName(field.getName());
                    fieldNode.setColumnName(link.refer());//System.err.println(currentClass.getName()+" : "+linkMap.get(0).recordType.getName());
                    LinkMap tempLinkMap = findFromList(linkMap, link.value());
                    if(tempLinkMap == null)//如果ActiveRecord类并没有声明has_该类，则抛出异常
                    {
                        throw new ObjectAnalysisException("LinkTypeNotFound: " + link.value().getName());
                    }
                    if(tempLinkMap.getLinkedField() == null)
                         tempLinkMap.setLinkedField(new FieldColumnNode[]{fieldNode});
                    else
                    {
                        int len = tempLinkMap.getLinkedField().length;
                        FieldColumnNode[] fms = new FieldColumnNode[len+1];
                        int i=0;
                        for(;i<len;i++)
                            fms[i] = tempLinkMap.getLinkedField()[i];
                        fms[i] = fieldNode;
                        tempLinkMap.setLinkedField(fms);
                    }
                }
                try
                {
                    String name = field.getName();
                    Method getter = currentClass.getMethod(ActiveRecordHelper.getGetterNameByField(name));
                    Method setter = currentClass.getMethod(ActiveRecordHelper.getSetterNameByField(name), field.getType());
                    Accesstor attri = new Accesstor(name, getter, setter);
                    if(col!=null)
                        attri.setColumnName(col.value());
                    else
                        attri.setColumnName(name);
                    id ID = field.getAnnotation(id.class);//判断是否ID
                    if(ID!=null)
                    {
                        idList.add(attri);
                    }
                    else
                        accesstorList.add(attri);
                }
                catch(Exception err)
                {//It means that it's not a valid field
                }
            }
            currentClass = currentClass.getSuperclass();
        }
        int size = idList.size();
        Accesstor[] ids = null;
        if(size > 0)
        {
            ids = new Accesstor[size];
            idList.toArray(ids);
        }
        else//如果没有自定义id，则添加默认id到id列表，并添加id字段到accesstor列表
        {
            try
            {
                ids = new Accesstor[]{new Accesstor(Flag.Record.IdName, Flag.Record.IdName, recordType.getMethod(ActiveRecordHelper.getGetterNameByField(Flag.Record.IdName)), recordType.getMethod(ActiveRecordHelper.getSetterNameByField(Flag.Record.IdName), Object.class))};
            }
            catch(Exception err)
            {//It won't happen.
                System.err.println(err);
            }
        }
        objectInfo.setIdentify(ids);
        objectInfo.setLinkMap(linkMap.toArray(new LinkMap[linkMap.size()]));
        Accesstor[] accesstors = new Accesstor[accesstorList.size()];
        objectInfo.setAccesstor(accesstorList.toArray(accesstors));

        objectInfo.setBasicSqlStatement(SQLCreator.createBasicSQL(tableName, accesstors, ids));
//        //构造SQL语句-------------------------------------------------------------------
//        BasicSqlStatement stmts = new BasicSqlStatement();
//        StringBuffer bufInsert = new StringBuffer(200);
//        StringBuffer bufUpdate = new StringBuffer(200);
//        StringBuffer bufSelect = new StringBuffer(200);
//        StringBuffer bufDelete = new StringBuffer(100);
//        //insert语句
//        bufInsert.append("insert into ");
//        bufInsert.append(tableName);
//        bufInsert.append("(");
//        //update语句
//        bufUpdate.append("update ");
//        bufUpdate.append(tableName);
//        bufUpdate.append(" set ");
//        //select语句
//        bufSelect.append("select ");
//        //delete语句
//        bufDelete.append("delete from ");
//        bufDelete.append(tableName);
//        int index = 0;
//        int idLength = ids.length-1;
//        for(index = 0;index<=idLength;index++)
//        {
//            String columnName = ids[index].getColumnName();
//            bufInsert.append(columnName);
//            bufSelect.append(columnName);
//            bufInsert.append(',');
//            bufSelect.append(',');
//        }
//        int accLength = accesstors.length-1;
//        for(index = 0;index<=accLength;index++)
//        {
//            String columnName = accesstors[index].getColumnName();
//            bufInsert.append(columnName);
//            bufSelect.append(columnName);
//            bufUpdate.append(columnName);
//            if(index==accLength)
//            {
//                bufUpdate.append("=?");
//            }
//            else
//            {
//                bufInsert.append(',');
//                bufSelect.append(',');
//                bufUpdate.append("=?,");
//            }
//        }
//        bufInsert.append(")values(");
//        index = idLength+accLength+2;
//        for(;index>0;index--)//添加insert语句的占位符
//        {
//            bufInsert.append('?');
//            if(index==1)
//                bufInsert.append(')');
//            else
//                bufInsert.append(',');
//        }
//        bufSelect.append(" from ");
//        bufSelect.append(tableName);
//        //where子句
//        StringBuffer whereClause = new StringBuffer(50);
//        whereClause.append(" where ");
//        for(index = 0;index<=idLength;index++)
//        {
//            whereClause.append(ids[index].getColumnName());
//            if(index==idLength)
//                whereClause.append("=?");
//            else
//                whereClause.append("=?,");
//        }
//        bufUpdate.append(whereClause);
//        bufSelect.append(whereClause);
//        bufDelete.append(whereClause);
//        //-----------------------------------------------------------------------------
//        stmts.setInsertStatement(bufInsert.toString());
//        stmts.setUpdateStatement(bufUpdate.toString());
//        stmts.setSelectStatement(bufSelect.toString());