我有这个 JSP，它只检查usernameandpassword和"out.write" 1or0基于trueorfalse.
<%@ page import="java.io.*" %>
<%
if(request.getParameter("username").equals("anas") && request.getParameter("password").equals("azeem"))
{
out.write("1");
}
else
out.write("0");
%> </br>
现在我的android代码是这样的
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_agent_login);
edit_username = (EditText) findViewById(R.id.edit_username);
edit_password = (EditText) findViewById(R.id.edit_password);
btn_login = (Button) findViewById(R.id.btnLogin);
if (android.os.Build.VERSION.SDK_INT > 9) { // must add this code in
// order not to get the
// Exception while executing
// program
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder()
.permitAll().build();
StrictMode.setThreadPolicy(policy);
}
btn_login.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
username = edit_username.getText().toString();
password = edit_password.getText().toString();
Log.d(TAG, "Username:" + username);
Log.d(TAG, "Password:" + password);
try {
new Thread() {
public void run() {
try {
HttpClient client = new DefaultHttpClient();
HttpPost post = new HttpPost("http://10.0.2.2:8080/MyApp/login.jsp");
List<NameValuePair> pairs = new ArrayList<NameValuePair>(2);
pairs.add(new BasicNameValuePair("username",edit_username.getText().toString()));
pairs.add(new BasicNameValuePair("password",edit_password.getText().toString()));
post.setEntity(new UrlEncodedFormEntity(pairs));
HttpResponse response = client.execute(post);
HttpEntity httpEntity = response.getEntity();
xml = EntityUtils.toString(httpEntity);
Log.d("xml", ""+xml.length()); //To confirm anything is there in the "xml"
} catch (Exception e) {
e.printStackTrace();
}
}
}.start();
} catch (Exception e) {
Log.d("xml", xml.toString());
Log.d("Server", e.toString());
}
try {
if (Integer.parseInt(String.valueOf(xml.charAt(10))) == 1) { //****HERE*******
Toast.makeText(getApplicationContext(), "LoginSuccessful",Toast.LENGTH_SHORT).show();
Intent intent = new Intent(Agent_Login.this,AgentHome.class);
startActivity(intent);
} else {
Toast.makeText(getApplicationContext(),"Invalid Username or Password", Toast.LENGTH_SHORT).show();
edit_password.setText("");
}
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
});
}
现在在这里（在评论中）给出了一个NullPointerException，我认为这是因为它xml是空的。
所以，我的问题是如何从 Android 中的 JSP 获得回复。我在 PC 上使用 HTML 表单对其进行了测试，它工作得非常好。
任何帮助将不胜感激。