//编辑:我改变了我的ArrayList转换,但我无法加载第二个微调器
我究竟做错了什么.我想根据第一个微调器中选择的行填充第二个带有w数组的微调器,但是在尝试从数组列表转换时会收到此警告.
***我在代码中标记了Null指针异常11-06 19:03:34.050:WARN/System.err(5342):在RetrievingAmazonXMLDataActivity.onCreate(RetrievingAmazonXMLDataActivity.java:88)
//编辑过的代码
for (int i = 0; i < tokens.length; i++) {
String a = dumpTitles("ProductName", i);
element = a.split("!");
allProducts.add(element);
}
w = (String[][])allProducts.toArray(new String[allProducts.size()][]);
Spinner spinnerProducts = (Spinner) findViewById(R.id.spinner2);
spinnerProducts.setOnItemSelectedListener(this);
// **下面的错误行
ArrayAdapter<String> productsArrayAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, productArrayToShow);
productsArrayAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinnerProducts.setAdapter(productsArrayAdapter);
public void onItemSelected(AdapterView<?> parent, View v, int position, long id)
{
try {
selected = parent.getItemAtPosition(position).toString();
productArrayToShow = w[position];
} catch (Exception e) {}
}
//原始代码
ArrayList<String[]>allProducts = new ArrayList<String[]>();
for (int i …我是 java 新手，正在尝试通过 html servlet 从文件路径添加图像“space.gif”。
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException
{
response.setContentType("text/html");
PrintWriter out = response.getWriter();
out.print("<HTML>");
out.print("<HEAD><TITLE>Upload Image</TITLE></HEAD>");
out.print("<BODY>");
out.print("<img src='space.gif' alt='image' />");
out.print("</BODY>");
out.print("</HTML>");
out.close();
}