filter.java

一个Java持久层类库

package ActiveObject.core;

import ActiveObject.vo.Command;
import ActiveObject.vo.CompareReference;
import ActiveObject.vo.CompareValue;
import ActiveObject.vo.TableType;
import ActiveObject.exception.*;
import java.util.*;

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

    private int limitStart = -1;
    private int limitLength = -1;
    
    //表名-别称 映射
    private List<TableType> tables = new ArrayList<TableType>();

    /**
     * 用于字段与值的比较
     */
    private Map<String, CompareValue> valueFilters = new HashMap<String, CompareValue>();
    /**
     * 用于字段与字段的比较
     */
    private Map<String, CompareReference> referenceFilters = new HashMap<String, CompareReference>();

    private Map<String, Order> orders = new HashMap<String, Order>();

    public Filter (Class objectType) {
        this.tables.add(new TableType(objectType));
    }
    
    public Filter (Class objectType, String nickName) {
        this.tables.add(new TableType(objectType, nickName));
    }

    public Filter (ActiveRecord record) {
    }

    public Filter join(Class objectType, String nickName) throws TableAliasDuplicateException{
        for(TableType item : this.tables)
        {
            if(item.getNickName().equals(nickName))
                throw new TableAliasDuplicateException();
        }
        this.tables.add(new TableType(objectType, nickName));
        return this;
    }
    
    public Filter join(Class objectType) throws TableAliasDuplicateException{
        return join(objectType, objectType.getSimpleName());
    }
    
//    Class getMainObject()
//    {
//        return this.tables.get(0).getObjectType();
//    }
    
    /**
     *  添加过滤条件
     *       @param field
     *       @param value
     *       @return
     */
//    public Filter addEqualValue (String field, Object value) {
//        valueFilters.put(field, new CompareValue("=", value));
//        return this;
//    }
//    public Filter addEqualReference (String field, String reference) throws ReferenceFormatNotValid{
//是否有必要对参数进行检查？待定
//        if(!referenceFilters.keySet().contains(field.substring(0, field.indexOf("."))))
//            throw new ReferenceFormatNotValid();
//        referenceFilters.put(field, new CompareReference("=", reference));
//        return this;
//    }

//    public Filter addLargerValue (String field, Object value) {
//        valueFilters.put(field, new CompareValue(">", value));
//        return this;
//    }
//    public Filter addLargerReference (String field, String reference) {
//        referenceFilters.put(field, new CompareReference(">", reference));
//        return this;
//    }
//
//    public Filter addSmallerValue (String field, Object value) {
//        valueFilters.put(field, new CompareValue("<", value));
//        return this;
//    }
//    public Filter addSmallerReference (String field, String reference) {
//        referenceFilters.put(field, new CompareReference("<", reference));
//        return this;
//    }
//
//    public Filter addLikeValue (String field, Object value) {
//        valueFilters.put(field, new CompareValue(" like ", value));
//        return this;
//    }
//    public Filter addLikeReference (String field, String reference) {
//        referenceFilters.put(field, new CompareReference(" like ", reference));
//        return this;
//    }

    /**
     *  添加排序条件
     *       @param field
     *       @param sortOrder
     *       @return
     */
    public Filter addOrder (String field, Order sortOrder) {
        this.orders.put(field, sortOrder);
        return this;
    }

    public Command createQueryCommand () {
        StringBuffer buf = new StringBuffer(200);
        buf.append("select * from ");
        int tableCount = this.tables.size();
        for(int i=0;i<tableCount;i++)
        {
            TableType table = this.tables.get(i);
            buf.append(table.getObjectType().getSimpleName());
            if(table.getNickName() != null)
            {
                buf.append(" as ");
                buf.append(table.getNickName());
            }
            if(i == tableCount-1)
                buf.append(" ");
            else
                buf.append(",");
        }
        int totalFilterCount = this.valueFilters.size() + this.referenceFilters.size();
        List params = new ArrayList();
        
        //添加过滤条件
        if(totalFilterCount > 0)
        {
            buf.append(" where ");
            for(String key : this.valueFilters.keySet())
            {
                CompareValue value = this.valueFilters.get(key);
                buf.append(key);
                buf.append(value.getCompare());
                buf.append("?,");
                params.add(value.getValue());
            }
            buf.replace(buf.length()-1, buf.length(), "");
        }
        
        //添加排序控制
        if(this.orders.size() > 0)
        {
            buf.append(" order by ");
            int size = this.orders.size();
            int index = 1;
            for(String key : this.orders.keySet())
            {
                buf.append(key);
                if(this.orders.get(key) == Order.DESC)
                    buf.append(" DESC ");
                else
                    buf.append(" ASC ");
                if(index < size)
                    buf.append(",");
                index++;
            }
        }
        
        //添加记录个数限制
        if(this.limitLength > -1)
        {
            buf.append(" limit ");
            if(this.limitStart > -1)
            {
                buf.append(this.limitStart);
                buf.append(",");
            }
            buf.append(this.limitLength);
        }
        
        return new Command(buf.toString(), params.toArray());
    }

//    protected Command createUpdateCommand (Value fields, Class objectType) {
//        StringBuffer buf = new StringBuffer(200);
//        buf.append("update ");
//        buf.append(objectType.getSimpleName());
//        buf.append(" set ");
//        int totalFilterCount = this.valueFilters.size() + this.referenceFilters.size();
//        List params = new ArrayList();
//        
//        //添加set语句的内容
//        for(String item : fields.getColumns())
//        {
//            buf.append(item);
//            buf.append("=?,");
//            params.add(fields.getColumnValue(item));
//        }
//        buf.replace(buf.length()-1, buf.length(), "");
//        
//        //添加过滤条件
//        if(totalFilterCount == 0)
//        {
//            buf.append(" where ");
//            for(String key : this.valueFilters.keySet())
//            {
//                CompareValue value = this.valueFilters.get(key);
//                buf.append(key);
//                buf.append(value.getCompare());
//                buf.append("?,");
//                params.add(value.getValue());
//            }
//            buf.replace(buf.length()-1, buf.length(), "");
//        }
//        
//        //添加排序控制
//        if(this.orders.size() > 0)
//        {
//            buf.append(" order by ");
//            int size = this.orders.size();
//            int index = 1;
//            for(String key : this.orders.keySet())
//            {
//                buf.append(key);
//                if(this.orders.get(key) == Order.DESC)
//                    buf.append(" DESC ");
//                else
//                    buf.append(" ASC ");
//                if(index < size)
//                    buf.append(",");
//                index++;
//            }
//        }
//        
//        //添加记录个数限制
//        if(this.limitLength > -1)
//        {
//            buf.append(" limit ");
//            if(this.limitStart > -1)
//            {
//                buf.append(this.limitStart);
//                buf.append(",");
//            }
//            buf.append(this.limitLength);
//        }
//        return new Command(buf.toString(), params.toArray());
//    }
    
    public Command createDeleteCommand () {
        StringBuffer buf = new StringBuffer(200);
        buf.append("delete ");
        int tableCount = this.tables.size();
        if(tableCount > 1)
        {
            for(int i=0;i<tableCount;i++)
            {
                buf.append(tables.get(i).getNickName());
                if(i == tableCount-1)
                    buf.append(" ");
                else
                    buf.append(",");
            }
        }
        buf.append("from ");
        for(int i=0;i<tableCount;i++)
        {
            TableType table = this.tables.get(i);
            buf.append(table.getObjectType().getSimpleName());
            if(table.getNickName() != null)
            {
                buf.append(" as ");
                buf.append(table.getNickName());
            }
            if(i == tableCount-1)
                buf.append(" ");
            else
                buf.append(",");
        }
        int totalFilterCount = this.valueFilters.size() + this.referenceFilters.size();
        List params = new ArrayList();
        
        //添加过滤条件
        if(totalFilterCount > 0)
        {
            buf.append(" where ");
            for(String key : this.valueFilters.keySet())
            {
                CompareValue value = this.valueFilters.get(key);
                buf.append(key);
                buf.append(value.getCompare());
                buf.append("?,");
                params.add(value.getValue());
            }
            buf.replace(buf.length()-1, buf.length(), "");
        }
        
        if(tableCount == 1)
        {
            //添加排序控制
            if(this.orders.size() > 0)
            {
                buf.append(" order by ");
                int size = this.orders.size();
                int index = 1;
                for(String key : this.orders.keySet())
                {
                    buf.append(key);
                    if(this.orders.get(key) == Order.DESC)
                        buf.append(" DESC ");
                    else
                        buf.append(" ASC ");
                    if(index < size)
                        buf.append(",");
                    index++;
                }
            }
            //添加记录个数限制
            if(this.limitLength > -1)
            {
                buf.append(" limit ");
                if(this.limitStart > -1)
                {
                    buf.append(this.limitStart);
                    buf.append(",");
                }
                buf.append(this.limitLength);
            }
        }
        
        return new Command(buf.toString(), params.toArray());
    }

    /**
     *  设置记录个数
     *  @param length
     */
    public Filter setLength (int length) {
        this.limitLength = length;
        return this;
    }
    
    /**
     * 设置记录范围
     * @param start 开始位置
     * @param length 记录个数
     * @return
     */
    public Filter setRange (int start, int length) {
        this.limitStart = start;
        this.limitLength = length;
        return this;
    }

    /**
     *  添加过滤和排序条件
     *       @param field
     *       @param value
     *       @param sortOrder
     *       @return
     */
    private Filter add (String field, Object value, Order sortOrder) {
        return null;
    }

    public List<TableType> getTables() {
        return tables;
    }
}