一个联网小程序，模拟器上可以，在Nokia真机上也可以，但是MOTO真机上却失败，请各位老大帮忙看看，谢谢啦

自己写的一个MIDLET，访问一个servlet获取一段文字显示在屏幕上，在模拟器上运行没有问题，在Nokia真机上也可以，但是换到Moto真机上却失败，现象是这样的：运行后，提示连接网络，确认后等了一会，屏幕顶端出现一个电话的小图标，闪了一下后，程序就退出了。我也试图catch里面抛出来的Exception，但是错误信息也是null。另外Moto的上网连接我也改成cmnet方式了，听说Moto默认的方式是cmwap，是不是改成cmnet也没有用，还有，我在moto的浏览器里访问这个servlet是可以显示信息的，但是在java程序里访问就出现上面的情况。请各位老大帮忙看看，程序如下：

import javax.microedition.midlet.*;

import javax.microedition.lcdui.*;

import javax.microedition.io.*;

import java.io.*;

public class HttpMidlet extends MIDlet implements Runnable,CommandListener {

// 使用默认的URL。用户可以从图形用户接口改变这个值

private static String defaultURL = "http://127.0.0.1:8000/test";
// 主MIDP 显示

private Display myDisplay = null;
// 输入URL的图形用户接口组件

private Form requestScreen;

private TextField requestField;
// 用于提交请求的图形用户接口组件

private List list;

private String[] menuItems;
// 用于显示服务器响应的图形用户接口组件

private Form resultScreen;

private StringItem resultField;
// 用于requestScreen的"send"按钮

Command sendCommand;

// 用于requestScreen的"exit"按钮

Command exitCommand;

// 用于requestScreen的"back"按钮

Command backCommand;

public HttpMidlet() {

// 初始化图形用户接口组件

myDisplay = Display.getDisplay(this);

sendCommand = new Command("SEND", Command.OK, 1);

exitCommand = new Command("EXIT", Command.OK, 1);

backCommand = new Command("BACK", Command.OK, 1);
// 显示请求的URL

requestScreen = new Form("Type in a URL:");

requestField = new TextField(null, defaultURL, 100, TextField.URL);

requestScreen.append(requestField);

requestScreen.addCommand(sendCommand);

requestScreen.addCommand(exitCommand);

requestScreen.setCommandListener(this);
// 选择想要的HTTP请求方法

menuItems = new String[] { "GET Request", "POST Request" };

list = new List("Select an HTTP method:", List.IMPLICIT, menuItems,
null);

list.setCommandListener(this);
// 先是从服务器上收到的信息

resultScreen = new Form("Server Response:");

resultScreen.addCommand(backCommand);

resultScreen.setCommandListener(this);
}// 结束HttpMidlet()

public void startApp() {
myDisplay.setCurrent(requestScreen);



}// 结束 startApp()

public void commandAction(Command com, Displayable disp) {

// 当用户点击"send"按钮

if (com == sendCommand) {

myDisplay.setCurrent(list);

} else if (com == backCommand) {

requestField.setString(defaultURL);

myDisplay.setCurrent(requestScreen);

} else if (com == exitCommand) {

destroyApp(true);

notifyDestroyed();

}// 结束 if ( com == sendCommand )


if (disp == list && com == List.SELECT_COMMAND) {
Thread funcTh = new Thread(this);
funcTh.start();


}
// 结束if ( dis == list && com == List.SELECT_COMMAND )

}// 结束 commandAction( Command, Displayable )

private String sendHttpGet(String url)

{

HttpConnection hcon = null;

DataInputStream dis = null;

StringBuffer responseMessage = new StringBuffer();
try {

// 使用READ权限的标准的 HttpConnection

hcon = (HttpConnection) Connector.open(url);
// 从HttpConnection取得一个 DataInputStream

dis = new DataInputStream(hcon.openInputStream());
// 从服务器上取回响应

int ch;

while ((ch = dis.read()) != -1) {

responseMessage.append((char) ch);

}// 结束while ( ( ch = dis.read() ) != -1 )

}

catch (Exception e)

{

e.printStackTrace();

responseMessage.append("ERROR：" +e.getMessage());

} finally {

try {

if (hcon != null)
hcon.close();

if (dis != null)
dis.close();

} catch (IOException ioe) {

ioe.printStackTrace();

}// 结束try/catch

}// 结束try/catch/finally

return responseMessage.toString();

}// 结束sendHttpGet( String )

private String sendHttpPost(String url)

{

HttpConnection hcon = null;

DataInputStream dis = null;

DataOutputStream dos = null;

StringBuffer responseMessage = new StringBuffer();

// 请求体

String requeststring = "This is a POST.";
try {

// 使用读写权限的 HttpConnection

hcon = (HttpConnection) Connector.open(url, Connector.READ_WRITE);
// 设置请求方法为POST

hcon.setRequestMethod(HttpConnection.POST);
// 取得发送请求字符串的DataOutputStream

dos = hcon.openDataOutputStream();

byte[] request_body = requeststring.getBytes();
// 发送请求字符串到服务器

for (int i = 0; i < request_body.length; i++) {

dos.writeByte(request_body[i]);

}// 结束 for( int i = 0; i < request_body.length; i++ )
// 取得做为接收服务器响应的DataInputStream

dis = new DataInputStream(hcon.openInputStream());
// 从服务器上取回响应

int ch;

while ((ch = dis.read()) != -1) {

responseMessage.append((char) ch);

}// 结束while( ( ch = dis.read() ) != -1 ) {

}

catch (Exception e)

{

e.printStackTrace();

responseMessage.append("ERROR");

}

finally {

// 释放输入输出流和HTTP连接

try {

if (hcon != null)
hcon.close();

if (dis != null)
dis.close();

if (dos != null)
dos.close();

} catch (IOException ioe) {

ioe.printStackTrace();

}// 结束try/catch

}// 结束try/catch/finally

return responseMessage.toString();

}// 结束sendHttpPost( String )

public void pauseApp() {

}// 结束pauseApp()

public void destroyApp(boolean unconditional) {

myDisplay = null;

requestScreen = null;

requestField = null;

resultScreen = null;

resultField = null;

}// 结束 destroyApp( boolean )
public void run()
{
String result;
if (list.getSelectedIndex() == 0) // 发送一个 GET 请求到服务器

result = sendHttpGet(requestField.getString());

else
// 发送一个 POST 请求到服务器

result = sendHttpPost(requestField.getString());
resultField = new StringItem(null, result);

resultScreen.append(resultField);

myDisplay.setCurrent(resultScreen);
}
}// 结束HttpMidlet