奇怪的iText输出与＆amp;边界崩溃：崩溃

Question

我有以下基本表：

 .tabella-test{
	border-collapse: collapse;
    }
 
    .tabella-test td, .tabella-test th{
	
	border: 1px solid black;
    }

    <TABLE class="tabella-test">     
		<thead>
			<tr>
				<th colspan="1" rowspan="2">Tree</th>
				<th colspan="1" rowspan="2">Short Description</th>
				<th colspan="2">Alberto - Group 12/2009</th>
				<th colspan="2">Andrea - Group 12/2010</th>
			</tr>
			<tr>
				<th colspan="1" rowspan="1">Value (x1)</th>
				<th colspan="1" rowspan="1">%</th>
				<th colspan="1" rowspan="1">Value (x1)</th>
				<th colspan="1" rowspan="1">%</th>
			</tr>
		</thead>
		<tbody>		
		<tr>
        <td>ciao</td>
		<td>test</td>
		<td>-165.889.226</td>
		<td>-29,6</td>
		<td>310.819.176</td>
		<td>150,6</td>
		</tr>		
		</tbody>
    </TABLE>


   

我想在每个td和th细胞周围放置黑色重叠边框。我试过上面的CSS， 但是在iText生成的pdf中，输出混乱了，只有一些边框重叠。任何提示？