我想通过 Web 服务访问 Android 应用程序。 在 Web 服务中执行新注册。 在 Android 应用程序中，创建新注册的 xml 文件。 数据已成功保存在 SQL Server 数据库中，并且通过 Web 服务正确保存并以 jason 字符串返回数据。
但是当字符串转换为 JSONObject 时，它会给我这样的错误:
org.json.JSONException: Value <br of type java.lang.String cannot be converted to JSONObject
登录 Activity
package com.example.shy.wel.activity;
import android.app.Activity;
import android.app.ProgressDialog;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
import com.android.volley.Request.Method;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.StringRequest;
import com.example.shy.wel.LoadingActivity;
import com.example.shy.wel.MainActivity;
import com.example.shy.wel.R;
import com.example.shy.wel.app.AppConfig;
import com.example.shy.wel.app.AppController;
import com.example.shy.wel.helper.SQLiteHandler;
import com.example.shy.wel.helper.SessionManager;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.HashMap;
import java.util.Map;
public class LoginActivity extends Activity {
private static final String TAG = RegisterActivity.class.getSimpleName();
private Button btnLogin;
private Button btnLinkToRegister;
private EditText inputEmail;
private EditText inputPassword;
private ProgressDialog pDialog;
private SessionManager session;
private SQLiteHandler db;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
Intent loading = new Intent(this, LoadingActivity.class);
startActivity(loading);
inputEmail = (EditText) findViewById(R.id.email);
inputPassword = (EditText) findViewById(R.id.password);
btnLogin = (Button) findViewById(R.id.btnLogin);
btnLinkToRegister = (Button) findViewById(R.id.btnLinkToRegisterScreen);
// Progress dialog
pDialog = new ProgressDialog(this);
pDialog.setCancelable(false);
// SQLite database handler
db = new SQLiteHandler(getApplicationContext());
// Session manager
session = new SessionManager(getApplicationContext());
// Check if user is already logged in or not
if (session.isLoggedIn()) {
// User is already logged in. Take him to main activity
Intent intent = new Intent(LoginActivity.this, MainActivity.class);
startActivity(intent);
finish();
}
// Login button Click Event
btnLogin.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
String email = inputEmail.getText().toString().trim();
String password = inputPassword.getText().toString().trim();
// Check for empty data in the form
if (!email.isEmpty() && !password.isEmpty()) {
// login user
checkLogin(email, password);
} else {
// Prompt user to enter credentials
Toast.makeText(getApplicationContext(),
"Please enter the credentials!", Toast.LENGTH_LONG)
.show();
}
}
});
// Link to Register Screen
btnLinkToRegister.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
Intent i = new Intent(getApplicationContext(),
RegisterActivity.class);
startActivity(i);
finish();
}
});
}
/**
* function to verify login details in mysql db
* */
private void checkLogin(final String email, final String password) {
// Tag used to cancel the request
String tag_string_req = "req_login";
pDialog.setMessage("Logging in ...");
showDialog();
StringRequest strReq = new StringRequest(Method.POST,
AppConfig.URL_LOGIN, new Response.Listener<String>() {
@Override
public void onResponse(String response) {
Log.d(TAG, "Login Response: " + response.toString());
hideDialog();
try {
JSONObject jObj = new JSONObject(response);
boolean error = jObj.getBoolean("error");
// Check for error node in json
if (!error) {
// user successfully logged in
// Create login session
session.setLogin(true);
// Now store the user in SQLite
String uid = jObj.getString("uid");
JSONObject user = jObj.getJSONObject("user");
String name = user.getString("name");
String email = user.getString("email");
String created_at = user.getString("created_at");
// Inserting row in users table
db.addUser(name, email, uid, created_at);
// Launch main activity
Intent intent = new Intent(LoginActivity.this,
MainActivity.class);
startActivity(intent);
finish();
} else {
// Error in login. Get the error message
String errorMsg = jObj.getString("error_msg");
Toast.makeText(getApplicationContext(),
errorMsg, Toast.LENGTH_LONG).show();
}
} catch (JSONException e) {
// JSON error
e.printStackTrace();
Toast.makeText(getApplicationContext(), "Json error: " + e.getMessage(), Toast.LENGTH_LONG).show();
}
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
Log.e(TAG, "Login Error: " + error.getMessage());
Toast.makeText(getApplicationContext(),
error.getMessage(), Toast.LENGTH_LONG).show();
hideDialog();
}
}) {
@Override
protected Map<String, String> getParams() {
// Posting parameters to login url
Map<String, String> params = new HashMap<String, String>();
params.put("email", email);
params.put("password", password);
return params;
}
};
// Adding request to request queue
AppController.getInstance().addToRequestQueue(strReq, tag_string_req);
}
private void showDialog() {
if (!pDialog.isShowing())
pDialog.show();
}
private void hideDialog() {
if (pDialog.isShowing())
pDialog.dismiss();
}
}
我的logcat
04-22 13:41:55.092 14473-14521/com.example.shy.wel E/Surface: getSlotFromBufferLocked: unknown buffer: 0x7facc84b6ad0
04-22 13:41:55.117 14473-14473/com.example.shy.wel W/System.err: org.json.JSONException: Value <br of type java.lang.String cannot be converted to JSONObject
04-22 13:41:55.117 14473-14473/com.example.shy.wel W/System.err: at org.json.JSON.typeMismatch(JSON.java:111)
04-22 13:41:55.117 14473-14473/com.example.shy.wel W/System.err: at org.json.JSONObject.<init>(JSONObject.java:160)
04-22 13:41:55.118 14473-14473/com.example.shy.wel W/System.err: at org.json.JSONObject.<init>(JSONObject.java:173)
04-22 13:41:55.118 14473-14473/com.example.shy.wel W/System.err: at com.example.shy.wel.activity.LoginActivity$3.onResponse(LoginActivity.java:129)
04-22 13:41:55.118 14473-14473/com.example.shy.wel W/System.err: at com.example.shy.wel.activity.LoginActivity$3.onResponse(LoginActivity.java:120)
04-22 13:41:55.118 14473-14473/com.example.shy.wel W/System.err: at com.android.volley.toolbox.StringRequest.deliverResponse(StringRequest.java:60)
04-22 13:41:55.118 14473-14473/com.example.shy.wel W/System.err: at com.android.volley.toolbox.StringRequest.deliverResponse(StringRequest.java:30)
04-22 13:41:55.118 14473-14473/com.example.shy.wel W/System.err: at com.android.volley.ExecutorDelivery$ResponseDeliveryRunnable.run(ExecutorDelivery.java:99)
04-22 13:41:55.119 14473-14473/com.example.shy.wel W/System.err: at android.os.Handler.handleCallback(Handler.java:739)
04-22 13:41:55.119 14473-14473/com.example.shy.wel W/System.err: at android.os.Handler.dispatchMessage(Handler.java:95)
04-22 13:41:55.119 14473-14473/com.example.shy.wel W/System.err: at android.os.Looper.loop(Looper.java:148)
04-22 13:41:55.119 14473-14473/com.example.shy.wel W/System.err: at android.app.ActivityThread.main(ActivityThread.java:5417)
04-22 13:41:55.119 14473-14473/com.example.shy.wel W/System.err: at java.lang.reflect.Method.invoke(Native Method)
04-22 13:41:55.119 14473-14473/com.example.shy.wel W/System.err: at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
04-22 13:41:55.119 14473-14473/com.example.shy.wel W/System.err: at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
04-22 13:41:55.123 1606-1779/system_process W/InputMethodManagerService: Window already focused, ignoring focus gain of: com.android.internal.view.IInputMethodClient$Stub$Proxy@b10ec75 attribute=null, token = android.os.BinderProxy@afd2b1e
04-22 13:41:55.174 14473-14521/com.example.shy.wel W/EGL_emulation: eglSurfaceAttrib not implemented
04-22 13:41:55.174 14473-14521/com.example.shy.wel W/OpenGLRenderer: Failed to set EGL_SWAP_BEHAVIOR on surface 0x7facbe4a2500, error=EGL_SUCCESS
04-22 13:41:58.629 14473-14521/com.example.shy.wel E/Surface: getSlotFromBufferLocked: unknown buffer: 0x7facc84b6c90
最佳答案
代码看起来不错。问题可能出在 JSON 中。尝试此页面 JSON Formatter and Validator 上生成的 JSON .
祝你好运!
关于Android，String无法转换为JSONObject，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/36799891/