关于PreparedStatement 的一个问题


这是一段递归代码
public string obtainPartNumberInfo ( string leftobid ) {
        
        省略……
        
        stmt1 = con.createStatement();
        Sql1 = "select /*+RULE*/ CLASS2,RIGHTID from PDMM31A.ASSMSTRC where LEFTID='"+leftobid+"'" ;
        rs1 = stmt1.executeQuery( Sql1 ) ;
        
        stmt2 = con.createStatement();
        Sql2 =  "select PARTNUMBER from PDMM31A."+ rs1.getString( "CLASS2" ) + " where OBID='"+rs1.getString("RIGHTID")+"'" ;        
        rs2 = stmt2.executeQuery( Sql2 );        if( rs.getString( "CLASS2" ).equals( "W2ProMtr" ) ) String tableName = "W2PRODCT";
        if( rs.getString( "CLASS2" ).equals( "W2AsmMtr" ) ) String tableName = "W2ASSM";
        if( rs.getString( "CLASS2" ).equals( "W2CmpMtr" ) ) String tableName = "W2COMPT";
        if( rs.getString( "CLASS2" ).equals( "W2FStMtr" ) ) String tableName = "W2FACSTD";
        if( rs.getString( "CLASS2" ).equals( "W2BStMtr" ) ) String tableName = "W2BUYSTD";
        
        stmt3 = con.createStatement();
        Sql3 = "select OBID from PDMM31A."+ tableName  +" where PARTNUMBER='"+rs2.getString( "PARTNUMBER" )+"'" ;
        rs3 = stmt3.executeQuery( Sql3 );
        
        obid = rs3.getString( "OBID" )        省略……
        
        obtainPartNumberInfo( obid )
        
}请问这段代码用 PreparedStatement 是否可以提高些速度？用prepareStatement应该如何实现，请朋友们帮我改一下