stringmanager.java

一个简单的数据库

                {
                    attribNames.add(name);
                    attribTypes.add(assist[0]);
                    if(assist[1].equals("unique"))
                        features.add(1);
                    else
                        features.add(0);
                }       
            }
        } 
    }
    public static boolean verifyQuotation(String instr) throws Exception
    {
        instr=instr.trim();
        if(instr.startsWith("'")&&instr.endsWith("'"))
            return true;
        if(instr.startsWith("\"")&&instr.endsWith("\""))
            return true;
        return false;
    }
    public static String extractValue(String val,String type) throws Exception
    {
        val=val.trim();
        if(type.equals("int"))
        {
            try
            {
                return String.valueOf(Integer.parseInt(val));
            }catch(Exception ex)
            {
                throw new OperationInfo("Insert value type error!:["+val+"]"+"is not a valid int!");
            }
        }else if(type.equals("float"))
        {
            try
            {
                return String.valueOf(Float.parseFloat(val));
            }catch(Exception ex)
            {
                throw new OperationInfo("Insert value type error!:["+val+"]"+"is not a valid float!");
            }
        }else
        {
            try
            {
                if(verifyQuotation(val))
                {
                    String value=val.substring(1,val.length()-1);
                    if(value.length()>Integer.parseInt(type.substring(4)))
                        throw new OperationInfo("Insert value type error!:["+val+"]"+"char variable out of bound!");
                    return value;
                }
                else 
                     throw new OperationInfo("Insert value type error!:["+val+"]"+"Quotation not balanced!");
            }catch(Exception ex)
            {
               throw ex;
            }   
        }     
    }
    public static String[] getValues(String[] vals,TableData table) throws Exception
    {
        //最后一个不是value而是这个tuple所在的table名字
        int len=vals.length;
        String[] types=table.getAttribTypes();
        String[] values=new String[len+1];
        for(int i=0;i<len;i++)
        {
            values[i]=extractValue(vals[i].trim(),types[i]);
        }
        values[len]=table.getName();
        return values;
    }
    public static String[] operCreateIndex(String instr) throws Exception
    {
        //这个instr是从这个要新建的index的name开始的
        //params依次存放index name，table name,attribute name
        String[] params=new String[3];
        String tbName,indName,attribName;
        if(!verifyBracket(instr))
            throw new OperationInfo("Creating index error!:[create index "+instr+"]");
        if(instr.indexOf("on")==-1)
            throw new OperationInfo("Creating index error!:+[create index "+instr+"]");
        indName=instr.substring(0,instr.indexOf("on")).trim();
        if(!verifyName(indName))
            throw new OperationInfo("Creating index error!The index name:["+indName+"] is not valid!");
        instr=instr.substring(instr.indexOf("on")+2).trim();
        if(instr.indexOf("(")==-1||instr.indexOf(")")==-1||instr.indexOf("(")>=instr.indexOf(")"))
            throw new OperationInfo("Creating index error!The form of the braket:"+instr+" is not valid!");
        tbName=instr.substring(0,instr.indexOf("(")).trim();
        if(!verifyName(tbName))
            throw new OperationInfo("Creating index error!The table name:["+tbName+"] is not valid!");
        if(CatalogManager.getTableByName(tbName)==null)
            throw new OperationInfo("Creating index error!The table :["+tbName+"] doesn't exist!");
        attribName=instr.substring(instr.indexOf("(")+1,instr.indexOf(")"));
        if(!verifyName(attribName))
            throw new OperationInfo("Creating index error!The attibute name:["+attribName+"] is not valid!");
        if(!verifyAttribName(CatalogManager.getTableByName(tbName),attribName))
            throw new OperationInfo("Creating index error!The attribte name:["+attribName+"]doesn't exist!");
        TableData tb=CatalogManager.getTableByName(tbName);
        ArrayList<IndexTag> indices=tb.getIndices();
        for(int i=0;i<indices.size();i++)
        {
            IndexTag tag=indices.get(i);
            if(tag.getAttribName().equals(attribName))
            {
                if(tag.getIndexName().equals(tag.getAttribName()+"_auto_index"))
                {
                    Index index=FileManager.readInIndex(tag.getFullName());
                    String fullN=index.getFullName();
                    index.setIndexName(indName);
                    tag.setIndexName(tb, indName);
                    FileManager.writeOutIndex(index);
                    //FileManager.deleteFile(fullN);
                    APIManager.deleteOnCasecade(fullN);
                    if(!tag.isInFile())
                    {
                        ArrayList<Index> is=IndexManager.getIndices();
                        int len=is.size();
                        for(int j=0;j<len;j++)
                        {
                            Index ind=is.get(j);
                            if(ind.getTBName().equals(tbName)&&
                                    ind.getAttribName().equals(tag.getAttribName()))
                                    ind.setIndexName(indName);
                        }
                    }
                }
                else
                    throw new OperationInfo("Define another index on the same attribute!:["+attribName+"]");
            }
        }
        params[0]=indName;
        params[1]=tbName;
        params[2]=attribName;
        return params;
    }
    public static String[] operInsertTuple(String instr) throws Exception
    {
        if(!verifySemicolon(instr))
            throw new OperationInfo("Insert syntax error!Semicolon not valid!:["+"insert"+instr+"]\n");
        if(!verifyBracket(instr))
            throw new OperationInfo("Insert syntax error!Bracket not balanced!:["+"insert"+instr+"]\n");
        instr=instr.substring(6).trim();
        if(instr.indexOf("into")==-1)
            throw new OperationInfo("Insert syntax error!:["+"insert "+instr+"]\n");
        instr=instr.substring(4).trim();
        if(instr.indexOf("values")==-1)
            throw new OperationInfo("Insert syntax error!:["+"insert "+instr+"]\n");
        String tbName=instr.substring(0,instr.indexOf("values")).trim();
        if(!verifyName(tbName))
            throw new OperationInfo("Insert syntax error!Table name error!:["+tbName+"]\n");
        if(!verifyTableName(tbName))
            throw new OperationInfo("Insert syntax error!:Table :["+tbName+"]doesn't exist!\n");
            
        try
        {
            instr=instr.substring(instr.indexOf("(")+1,instr.indexOf(")")).trim();
        }catch(Exception ex)
        {
            throw new OperationInfo("Insert syntax error!Bracket not valid!:["+"insert"+instr+"]\n");
        }
        TableData table=CatalogManager.getTableByName(tbName);
        String[] tempValues=instr.split(",");
        if(tempValues.length!=table.getAttributes().size())
            throw new OperationInfo("Insert syntax error!The size of the attributes doesn't match!");
        String[] values=null;
        values=getValues(tempValues,table);
        return values;
    }
/*    public static String opearaDropIndex(String instr) throws Exception
    {
        if(!verifySemicolon(instr))
            throw new OperationInfo("Drop index syntax error!Semicolon not valid!:["+instr+"]");
        if(!verifyBracket(instr))
            throw new OperationInfo("Drop index syntax error!Bracket not balanced!:["+instr+"]");
        String indName=instr.substring(instr.indexOf("index")+5).trim();
        if(!verifyName(indName))
            throw new OperationInfo("Drop index name is not valid!:["+indName+"]");
        //ArrayLis<IndexTag> indTags=Catalog
    }
 */ 
    public static void operaDropIndex(String instr) throws Exception
    {
        if(!verifySemicolon(instr))
            throw new OperationInfo("Drop index syntax error!:The instruction doesn't ends with ;");
        if(!verifyBracket(instr))
            throw new OperationInfo("Drop index syntax error!The instruction's brackets are not balanced!");
        String temp=instr.substring(instr.indexOf("drop")+4,instr.indexOf("index"));
        if(temp.trim().length()!=0)
            throw new OperationInfo("Drop index syntax error!There can't be anything but white space between 'drop' and 'index'!");
        String indName;
        if(instr.indexOf("from")==-1)
            throw new OperationInfo("Drop index syntax error!There is no 'from'!in["+instr+"]");
        int fromIndex=instr.indexOf("from");
        indName=instr.substring(instr.indexOf("index")+5,fromIndex).trim();
        String tbName;
        if(instr.substring(instr.indexOf(";")+1).trim().length()!=0)
            throw new OperationInfo("Drop index syntax error!There can't be anything but white space after ';'!");
        tbName=instr.substring(fromIndex+4,instr.indexOf(";")).trim();
        if(!verifyName(tbName))
            throw new OperationInfo("Drop index syntax error!The table name:["+tbName+"]specified is not valid!");
        if(!verifyTableName(tbName))
            throw new OperationInfo("Drop index error!The table :["+tbName+"]doesn't exit!");
        TableData tb=CatalogManager.getTableByName(tbName);
       
        APIManager.dropIndex(indName, tb);
    }
    public static String operaDropTable(String instr) throws Exception
    {
        //这个instr是从最开头开始的
        String tbName;
        
        if(!verifySemicolon(instr))
            throw new OperationInfo("Drop table syntax error!The brackets are not balanced!:["+instr+"]");
        String temp=instr.substring(instr.indexOf("drop")+4,instr.indexOf("table")).trim();
        if(temp.length()!=0)
            throw new OperationInfo("Draop tabe syntax error!There can't be anything but white space between 'drop' and 'table'!");
        tbName=instr.substring(instr.indexOf("table")+5,instr.indexOf(";")).trim();
        if(!verifyName(tbName))
            throw new OperationInfo("Drop table syntax error!The table name:["+tbName+"] is not valid");
        if(!verifyTableName(tbName))
            throw new OperationInfo("Drop table error!The table :["+tbName+"] doesn't exist!");
        return tbName;
    }
    public static ArrayList<String> getSelectAttribs(String att) throws Exception
    {
        try
        {
            ArrayList<String> attribs=new ArrayList<String>();
            if(att.equals("*"))
                attribs.add("*");
            else
            {
                String[] temp=att.split(",");
                for(int i=0;i<temp.length;i++)
                    temp[i]=temp[i].trim();
                for(int i=0;i<temp.length;i++)
                {
                    if(!verifyName(temp[i]))
                        throw new Exception();
                    attribs.add(temp[i]);
                }
            }
            return attribs;