产品目录-论坛 树形结构的实现.htm

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      <DIV align=center><B><FONT size=3>产品目录/论坛 树形结构的实现 <BR><FONT 
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      color=#333300>产品目录/论坛&nbsp;树形结构的实现&nbsp;<BR><BR>发布日期：2001/09/20&nbsp;　发&nbsp;布&nbsp;者：51jsp.net&nbsp;　&nbsp;<BR>&nbsp;<BR>&nbsp;&nbsp;&nbsp;&nbsp;原理请参见www.chinaasp.com/sqlbbs中的ASP论坛版精华区&nbsp;<BR>本例采用Access做为实例，所有还有很多要改进的地方。&nbsp;<BR>请读者自已改进&nbsp;<BR><BR>package&nbsp;product;&nbsp;<BR>import&nbsp;java.sql.*;&nbsp;<BR>public&nbsp;class&nbsp;ConnectDB{&nbsp;<BR>String&nbsp;strDBDriver="sun.jdbc.odbc.JdbcOdbcDriver";&nbsp;<BR>String&nbsp;strConnstr="jdbc:odbc:product";&nbsp;<BR>Connection&nbsp;conn=null;&nbsp;<BR>ResultSet&nbsp;rs=null;&nbsp;<BR>Statement&nbsp;stmt=null;&nbsp;<BR>//&nbsp;Statement&nbsp;stmt=null;&nbsp;<BR>//构造函数&nbsp;<BR>public&nbsp;ConnectDB(){&nbsp;<BR>try{&nbsp;<BR>Class.forName(strDBDriver);&nbsp;conn=DriverManager.getConnection(strConnstr);&nbsp;<BR>stmt=conn.createStatement();&nbsp;<BR>}&nbsp;<BR>catch(Exception&nbsp;e){&nbsp;<BR>System.out.println(e);&nbsp;<BR>}&nbsp;<BR>}&nbsp;<BR><BR>public&nbsp;ResultSet&nbsp;execute(String&nbsp;sql){&nbsp;<BR>rs=null;&nbsp;<BR>try{&nbsp;<BR><BR>rs=stmt.executeQuery(sql);&nbsp;<BR>}&nbsp;<BR>catch(SQLException&nbsp;e){&nbsp;<BR>System.out.println(e.getMessage());&nbsp;<BR>}&nbsp;<BR>return&nbsp;rs;&nbsp;<BR>}&nbsp;<BR><BR>public&nbsp;Connection&nbsp;getConnection(){&nbsp;<BR>return&nbsp;conn;&nbsp;<BR>}&nbsp;<BR><BR>public&nbsp;boolean&nbsp;close(){&nbsp;<BR>try{&nbsp;<BR>if(this.rs!=null){&nbsp;<BR>this.rs.close();&nbsp;<BR>}&nbsp;<BR>if(stmt!=null){&nbsp;<BR>this.stmt.close();&nbsp;<BR>}&nbsp;<BR>if(conn!=null){&nbsp;<BR>this.conn.close();&nbsp;<BR>}&nbsp;<BR>return&nbsp;true;&nbsp;<BR>}catch(Exception&nbsp;err){&nbsp;<BR>return&nbsp;false;&nbsp;<BR>}&nbsp;<BR>}&nbsp;<BR><BR>}&nbsp;<BR>//=======================================&nbsp;<BR>package&nbsp;product;&nbsp;<BR>import&nbsp;java.sql.*;&nbsp;<BR>public&nbsp;class&nbsp;catalog&nbsp;<BR>{&nbsp;<BR>ConnectDB&nbsp;conn=new&nbsp;ConnectDB();&nbsp;<BR>String&nbsp;str=null;&nbsp;<BR>String&nbsp;sql=null;&nbsp;<BR>ResultSet&nbsp;rs=null;&nbsp;<BR>String&nbsp;AncestorID,LinkStr;&nbsp;<BR><BR>public&nbsp;String&nbsp;getCatalog(){&nbsp;<BR><BR>str="&lt;select&nbsp;name=\"FatherID\"&nbsp;class=\"p9\"&gt;\n"+&nbsp;<BR>"&lt;option&nbsp;value=\"-1\"&nbsp;selected&gt;请选择父类&lt;/option&gt;\n";&nbsp;<BR>String&nbsp;sql=null;&nbsp;<BR>sql="select&nbsp;*&nbsp;from&nbsp;catalog&nbsp;order&nbsp;by&nbsp;AncestorID,Linkstr";&nbsp;<BR>ResultSet&nbsp;rs=conn.execute(sql);&nbsp;<BR>try{&nbsp;<BR>while&nbsp;(rs.next())&nbsp;{&nbsp;<BR>str=str+"&lt;option&nbsp;value="+rs.getString("Productid")+"&gt;";&nbsp;<BR>int&nbsp;nbspCount=rs.getString("LinkStr").length()-1;&nbsp;<BR>for(int&nbsp;i=0;i&lt;nbspCount;i++){&nbsp;<BR>str=str+"&nbsp;";&nbsp;<BR>}&nbsp;<BR>if(nbspCount&gt;0)&nbsp;<BR>str=str+"┠"+rs.getString("title")+"&lt;/option&gt;\n";&nbsp;<BR>else&nbsp;<BR>str=str+rs.getString("title")+"&lt;/option&gt;\n";&nbsp;<BR><BR>}&nbsp;<BR>str=str+"&lt;/select&gt;";&nbsp;<BR>rs.close();&nbsp;<BR>}&nbsp;<BR>catch(SQLException&nbsp;e){&nbsp;<BR>System.out.println(e.getMessage());&nbsp;<BR>}&nbsp;<BR>return&nbsp;str;&nbsp;<BR>}&nbsp;<BR>public&nbsp;void&nbsp;setCatalog(String&nbsp;CatalogName,String&nbsp;FatherID){&nbsp;<BR>int&nbsp;ChildNum=0;&nbsp;<BR>if(FatherID.compareTo("-1")!=0){&nbsp;<BR>sql="select&nbsp;AncestorID,ChildNum,linkstr&nbsp;from&nbsp;catalog&nbsp;where&nbsp;productid="+FatherID;&nbsp;<BR>//out.println(sql);&nbsp;<BR>try{&nbsp;<BR>rs=conn.execute(sql);&nbsp;<BR>if(rs.next()){&nbsp;<BR>AncestorID=rs.getString("AncestorID");&nbsp;<BR>ChildNum=rs.getInt("ChildNum");&nbsp;<BR>LinkStr=rs.getString("linkstr");&nbsp;<BR>}&nbsp;<BR>else{&nbsp;<BR>AncestorID="";&nbsp;<BR>LinkStr="1";&nbsp;<BR>ChildNum=0;&nbsp;<BR>}&nbsp;<BR>LinkStr=LinkStr+(ChildNum+1);&nbsp;<BR>//out.println(AncestorID+":"+LinkStr+":"+ChildNum);&nbsp;<BR>sql="insert&nbsp;into&nbsp;catalog(title,fatherID,AncestorID,LinkStr)&nbsp;values(''"+CatalogName+"'',''"+FatherID+"'',''"+AncestorID+"'',''"+LinkStr+"'')";&nbsp;<BR>//out.println(sql);&nbsp;<BR>conn.execute(sql);&nbsp;<BR>sql="update&nbsp;catalog&nbsp;set&nbsp;childNum="+(ChildNum+1)+"&nbsp;where&nbsp;productID="+FatherID;&nbsp;<BR>//out.println("&lt;br&gt;"+sql);&nbsp;<BR>conn.execute(sql);&nbsp;<BR>}catch(Exception&nbsp;e){&nbsp;<BR>System.out.println(e);&nbsp;<BR>}&nbsp;<BR><BR>}else{&nbsp;<BR>sql="insert&nbsp;into&nbsp;catalog(title,fatherID,LinkStr)&nbsp;values(''"+CatalogName+"'',''"+FatherID+"'',''1'')";&nbsp;<BR>//out.println(sql);&nbsp;<BR>try{&nbsp;<BR>conn.execute(sql);&nbsp;<BR>sql="select&nbsp;top&nbsp;1&nbsp;productID&nbsp;from&nbsp;catalog&nbsp;order&nbsp;by&nbsp;productID&nbsp;desc&nbsp;";&nbsp;<BR>rs=conn.execute(sql);&nbsp;<BR>if(rs.next()){&nbsp;<BR>AncestorID=rs.getString("productID");&nbsp;<BR>}&nbsp;<BR>else{&nbsp;<BR>AncestorID="";&nbsp;<BR>}&nbsp;<BR>rs.close();&nbsp;<BR>sql="update&nbsp;catalog&nbsp;set&nbsp;AncestorID=''"+AncestorID+"''&nbsp;where&nbsp;productID="+AncestorID;&nbsp;<BR>//out.println(sql);&nbsp;<BR>conn.execute(sql);&nbsp;<BR>}catch(Exception&nbsp;e){&nbsp;<BR>System.out.println(e);&nbsp;<BR><BR>}&nbsp;<BR><BR>}//end&nbsp;if&nbsp;<BR><BR>if(rs!=null){&nbsp;<BR>try{&nbsp;<BR>rs.close();&nbsp;<BR>}catch(Exception&nbsp;e){&nbsp;<BR>System.out.println(e);&nbsp;<BR>}&nbsp;<BR>}&nbsp;<BR><BR>}&nbsp;<BR><BR>public&nbsp;void&nbsp;deleteCatalog(String&nbsp;FatherID){&nbsp;<BR>int&nbsp;tempData=0;&nbsp;<BR>sql="select&nbsp;fatherID,linkstr,AncestorID&nbsp;from&nbsp;catalog&nbsp;where&nbsp;productID="+FatherID;&nbsp;<BR>rs=conn.execute(sql);&nbsp;<BR>try{&nbsp;<BR>if(rs.next()){&nbsp;<BR>tempData=rs.getInt("fatherID");&nbsp;<BR>LinkStr=rs.getString("linkstr");&nbsp;<BR>AncestorID=rs.getString("AncestorID");&nbsp;<BR>}&nbsp;<BR><BR>try{rs.close();}&nbsp;<BR>catch(Exception&nbsp;e){&nbsp;<BR>System.out.println(e);&nbsp;<BR>}&nbsp;<BR>sql="delete&nbsp;from&nbsp;catalog&nbsp;where&nbsp;ProductID="+FatherID;&nbsp;<BR>//&nbsp;out.println(sql);&nbsp;<BR>try{&nbsp;<BR>conn.execute(sql);&nbsp;<BR>}catch(Exception&nbsp;e){&nbsp;<BR>System.out.println(e);&nbsp;<BR>}&nbsp;<BR>sql="delete&nbsp;from&nbsp;catalog&nbsp;where&nbsp;linkstr&nbsp;like&nbsp;''"+LinkStr+"%''&nbsp;and&nbsp;AncestorID="+AncestorID;&nbsp;<BR>//out.println(sql);&nbsp;<BR>try{&nbsp;<BR>conn.execute(sql);&nbsp;<BR>}catch(Exception&nbsp;e){&nbsp;<BR>System.out.println(e);&nbsp;<BR>}&nbsp;<BR>sql="update&nbsp;catalog&nbsp;set&nbsp;ChildNum=ChildNum-1&nbsp;where&nbsp;productID="+tempData;&nbsp;<BR>//out.println(sql);&nbsp;<BR>try{&nbsp;<BR>conn.execute(sql);&nbsp;<BR>}catch(Exception&nbsp;e){&nbsp;<BR>System.out.println(e);&nbsp;<BR>}&nbsp;<BR>}catch(Exception&nbsp;e){&nbsp;<BR>System.out.println(e);&nbsp;<BR>}&nbsp;<BR>}&nbsp;//end&nbsp;public&nbsp;<BR><BR>public&nbsp;void&nbsp;updateCatalog(int&nbsp;id){&nbsp;<BR><BR>}&nbsp;<BR><BR>public&nbsp;String&nbsp;getCatalog(int&nbsp;id){&nbsp;<BR><BR>str="&lt;select&nbsp;name=\"FatherID\"&nbsp;class=\"p9\"&gt;\n"+&nbsp;<BR>"&lt;option&nbsp;value=\"-1\"&nbsp;&gt;请选择父类&lt;/option&gt;\n";&nbsp;<BR>String&nbsp;sql=null;&nbsp;<BR>sql="select&nbsp;*&nbsp;from&nbsp;catalog&nbsp;order&nbsp;by&nbsp;AncestorID,Linkstr";&nbsp;<BR>ResultSet&nbsp;rs=conn.execute(sql);&nbsp;<BR>try{&nbsp;<BR>while&nbsp;(rs.next())&nbsp;{&nbsp;<BR>int&nbsp;ProductID=rs.getInt("productID");&nbsp;<BR>if&nbsp;(ProductID==id)&nbsp;{&nbsp;<BR>str=str+"&lt;option&nbsp;value="+ProductID+"&nbsp;selected&gt;";&nbsp;<BR>}&nbsp;<BR>else{&nbsp;<BR>str=str+"&lt;option&nbsp;value="+ProductID+"&gt;";&nbsp;<BR>}&nbsp;<BR>int&nbsp;nbspCount=rs.getString("LinkStr").length()-1;&nbsp;<BR>for(int&nbsp;i=0;i&lt;nbspCount;i++){&nbsp;<BR>str=str+"&nbsp;";&nbsp;<BR>}&nbsp;<BR>if(nbspCount&gt;0)&nbsp;<BR>str=str+"┠"+rs.getString("title")+"&lt;/option&gt;\n";&nbsp;<BR>else&nbsp;<BR>str=str+rs.getString("title")+"&lt;/option&gt;\n";&nbsp;<BR><BR>}&nbsp;<BR>str=str+"&lt;/select&gt;";&nbsp;<BR>rs.close();&nbsp;<BR>}&nbsp;<BR>catch(SQLException&nbsp;e){&nbsp;<BR>System.out.println(e.getMessage());&nbsp;<BR>}&nbsp;<BR>return&nbsp;str;&nbsp;<BR>}&nbsp;<BR><BR>public&nbsp;String&nbsp;getCatalogList(){&nbsp;<BR><BR>str="&lt;select&nbsp;name=\"FatherID\"&nbsp;class=\"p9\"&nbsp;size=\"20\"&nbsp;onClick=\"MM_jumpMenu(''parent.mainFrame'',this,0)\"&gt;\n"+&nbsp;<BR>"&lt;option&nbsp;value=\"-1\"&nbsp;selected&gt;请选择父类&lt;/option&gt;\n";&nbsp;<BR>String&nbsp;sql=null;&nbsp;<BR>sql="select&nbsp;*&nbsp;from&nbsp;catalog&nbsp;order&nbsp;by&nbsp;AncestorID,Linkstr";&nbsp;<BR>ResultSet&nbsp;rs=conn.execute(sql);&nbsp;<BR>try{&nbsp;<BR>while&nbsp;(rs.next())&nbsp;{&nbsp;<BR>str=str+"&lt;option&nbsp;value="+rs.getString("Productid")+"&gt;";&nbsp;<BR>int&nbsp;nbspCount=rs.getString("LinkStr").length()-1;&nbsp;<BR>for(int&nbsp;i=0;i&lt;nbspCount;i++){&nbsp;<BR>str=str+"&nbsp;";&nbsp;<BR>}&nbsp;<BR>if(nbspCount&gt;0)&nbsp;<BR>str=str+"┠"+rs.getString("title").trim()+"&lt;/option&gt;\n";&nbsp;<BR>else&nbsp;<BR>str=str+rs.getString("title")+"&lt;/option&gt;\n";&nbsp;<BR><BR>}&nbsp;<BR>str=str+"&lt;/select&gt;";&nbsp;<BR>rs.close();&nbsp;<BR>}&nbsp;<BR>catch(SQLException&nbsp;e){&nbsp;<BR>System.out.println(e.getMessage());&nbsp;<BR>}&nbsp;<BR>return&nbsp;str;&nbsp;<BR>}&nbsp;<BR>}&nbsp;<BR>&nbsp;<BR></FONT></TD></TR>
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产品目录-论坛 树形结构的实现.htm - 源码说明

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