Question

您好我正在尝试通过Web服务从数据库加载我的listview。我尝试过两次这样做，我对每个阶段都不太自信。

从我的tomcat返回一个列表/数组，这里是代码

String mylist[] = {"", "", "", "", "", ""};

try {
    Class.forName(driver).newInstance();
    con = DriverManager.getConnection(url + db, user, pass);

    String query1 = "select username from Users where online = 'yes'";
    PreparedStatement preparedStmt1 = con.prepareStatement(query1);
    ResultSet result1 = preparedStmt1.executeQuery();

    int i = 0;
    while (result1.next()) {
        mylist[i] = result1.getString(1);               
    }
} catch (Exception e1) {
    e1.printStackTrace();
}

out.println(mylist);
out.close();

我的问题是这是从网络服务返回列表的正确方法吗？

第二阶段是将列表放到我的列表视图中，这是我的代码

try {
    HttpClient client = new DefaultHttpClient();
    HttpGet request = new HttpGet();
    URI webservice = new URI("http://192.168.0.3:8080/Users/users");
    request.setURI(webservice);
    HttpResponse response = client.execute(request);

    BufferedReader rd = new BufferedReader(
            new InputStreamReader(response.getEntity()
                    .getContent()));

    while ((rd.readLine()) != null) {

        ArrayList<String> list = rd.readLine();
    }
} catch (Exception e1) {
    e1.printStackTrace();
}

这似乎仅在webservice返回单行文本时才起作用。如何从Http请求中检索类似数组的内容？

谢谢！

Answer 1

WebService只能返回xml或字符串类型，因此您可以将列表放入一个字符串，格式如下：

"this is a string 1; this is a string 2; this is a string 3"

服务器端如下所示：

  StringBuilder myList = new StringBuilder();

 try {
     Class.forName(driver).newInstance();
     con = DriverManager.getConnection(url + db, user, pass);

     String query1 = "select username from Users where online = 'yes'";
     PreparedStatement preparedStmt1 = con.prepareStatement(query1);
     ResultSet result1 = preparedStmt1.executeQuery();

     int i = 0;
      while (result1.next()) {
          myList.append( result1.getString(1) + ";");               
  }
} catch (Exception e1) {
  e1.printStackTrace();
 }

out.println(mylist.toString());
out.close();

然后从 Android客户端，您可以通过String.split（“;”）获取它;
这是一个例子：

private String inputStreamToString(InputStream is)
{
String line = "";
StringBuilder total = new StringBuilder();
// Wrap a BufferedReader around the InputStream
BufferedReader rd = new BufferedReader(new InputStreamReader(is), 1024 * 4);
// Read response until the end
try
{

    while ((line = rd.readLine()) != null)
    {
        total.append(line);
    }
} catch (IOException e)
{
    Log.e(TAG, "error build string" + e.getMessage());
}
// Return full string
return total.toString();
 }

InputStream is = response.getEntity().getContent();
String strResponse = inputStreamToString(is);
String mylist[] = strResponse .split(";");

或者您可以使用JSON解析列表对象并从WebService转移到Android客户端

从WebService加载ListView

1 个答案: