Java 注册函数的NetworkOnMainThreadException

我是Android编程新手，我正在尝试用php、mysql和sqlite创建一个注册和登录函数。单击“注册”或“登录”按钮后出现此错误。我该如何解决这个问题

FATAL EXCEPTION: main
 android.os.NetworkOnMainThreadException
      at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1133)
      at libcore.io.BlockGuardOs.connect(BlockGuardOs.java:84)
      at libcore.io.IoBridge.connectErrno(IoBridge.java:127)
      at libcore.io.IoBridge.connect(IoBridge.java:112)
      at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:192)
      at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:459)
      at java.net.Socket.connect(Socket.java:842)
      at org.apache.http.conn.scheme.PlainSocketFactory.connectSocket(PlainSocketFactory.java:119)
      at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:144)
      at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164)
      at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119)
      at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:360)
      at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555)
      at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487)
      at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465)
      at my.fyp.classifieds.library.JSONParser.getJSONFromUrl(JSONParser.java:42)
      at my.fyp.classifieds.library.UserFunctions.registerUser(UserFunctions.java:59)
      at my.fyp.inticlassifieds.Register$1.onClick(Register.java:80)
      at android.view.View.performClick(View.java:4240)
      at android.view.View$PerformClick.run(View.java:17721)
      at android.os.Handler.handleCallback(Handler.java:730)
      at android.os.Handler.dispatchMessage(Handler.java:92)
      at android.os.Looper.loop(Looper.java:137)
      at android.app.ActivityThread.main(ActivityThread.java:5103)
      at java.lang.reflect.Method.invokeNative(Native Method)
      at java.lang.reflect.Method.invoke(Method.java:525)
      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
      at dalvik.system.NativeStart.main(Native Method)

我不确定是哪个类导致了错误。这是Register类：

public class Register extends Activity {
Button btnRegister, btnLinkToLogin;
EditText inputEmail;
EditText inputPassword, inputCPassword;
EditText inputContact;
TextView registerErrorMsg;

// JSON Response node names
private static String KEY_SUCCESS = "success";
private static String KEY_ERROR = "error";
private static String KEY_ERROR_MSG = "error_msg";
private static String KEY_CONTACT = "contact";
private static String KEY_EMAIL = "email";
private static String KEY_CREATED_AT = "created_at";

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_register);

    // Importing all assets like buttons, text fields     
    inputEmail = (EditText) findViewById(R.id.registerEmail);
    inputPassword = (EditText) findViewById(R.id.registerPassword);
    inputCPassword = (EditText) findViewById(R.id.confirmPassword);
    inputContact = (EditText) findViewById(R.id.registerContact);
    btnRegister = (Button) findViewById(R.id.btnRegister);
    btnLinkToLogin = (Button) findViewById(R.id.btnLinkToLogin);
    registerErrorMsg = (TextView) findViewById(R.id.register_error);

    // Register Button Click event
    btnRegister.setOnClickListener(new View.OnClickListener() {         
        public void onClick(View view) {
            String password = inputPassword.getText().toString();
            String confirmpass = inputCPassword.getText().toString();

            //Check all fields      
            if(inputContact.length()<10)
            {
                Toast.makeText(Register.this,"Please Enter correct mobile number", Toast.LENGTH_LONG).show();
                return;
            }
             if(inputPassword.length()<6)
             {              
                Toast.makeText(Register.this,"Please Enter minimum 6 characters in password", Toast.LENGTH_LONG).show();
                return;
             } 
             if(!password.equals(confirmpass))
             {
                 Toast.makeText(Register.this,"Password does not match", Toast.LENGTH_LONG).show();
                 return;
             }
             if(inputEmail.length()<6)
             {              
                Toast.makeText(Register.this,"Please Enter valid email", Toast.LENGTH_LONG).show();
                return;
             }

            String contact = inputContact.getText().toString();
            String email = inputEmail.getText().toString();
            //String password = inputPassword.getText().toString();
            UserFunctions userFunction = new UserFunctions();
            JSONObject json = userFunction.registerUser(email,contact,password);

            // check for login response
            try {
                if (json.getString(KEY_SUCCESS) != null) {
                    registerErrorMsg.setText("");
                    String res = json.getString(KEY_SUCCESS); 
                    if(Integer.parseInt(res) == 1){
                        // user successfully registred
                        // Store user details in SQLite Database
                        DatabaseHandler db = new DatabaseHandler(getApplicationContext());
                        JSONObject json_user = json.getJSONObject("user");

                        // Clear all previous data in database
                        userFunction.logoutUser(getApplicationContext());
                        db.addUser(json_user.getString(KEY_EMAIL), json_user.getString(KEY_CONTACT), json_user.getString(KEY_CREATED_AT));                        
                        // Launch Dashboard Screen
                        Intent dashboard = new Intent(getApplicationContext(), MainMenu.class);
                        // Close all views before launching Dashboard
                        dashboard.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                        startActivity(dashboard);
                        // Close Registration Screen
                        finish();
                    }else{
                        // Error in registration
                        registerErrorMsg.setText("Error occured in registration");
                    }
                }
            } catch (JSONException e) {
                e.printStackTrace();
            }
        }


    });

    // Link to Login Screen
   /* public void btnLinkToLogin(View view) {
        Intent i = new Intent (this, LoginActivity.class);
        startActivity (i);
        finish();
    }*/

  btnLinkToLogin.setOnClickListener(new View.OnClickListener() {

       public void onClick(View view) {
            Intent i = new Intent(getApplicationContext(),LoginActivity.class);
            startActivity(i);
            // Close Registration View
            finish();
        }
    });
}}

公共类寄存器扩展活动{
按钮BTN注册表，btnLinkToLogin；
编辑文本输入电子邮件；
编辑文本输入密码，输入密码；
编辑文本输入联系人；
TextView注册表errormsg；
//JSON响应节点名称
私有静态字符串密钥\u SUCCESS=“SUCCESS”；
私有静态字符串密钥\u ERROR=“ERROR”；
私有静态字符串密钥\u ERROR\u MSG=“ERROR\u MSG”；
私有静态字符串密钥\u CONTACT=“CONTACT”；
私有静态字符串密钥\u EMAIL=“EMAIL”；
私有静态字符串密钥\u CREATED\u AT=“CREATED\u AT”；
@凌驾
创建时的公共void（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
setContentView（R.layout.activity\u寄存器）；
//导入按钮、文本字段等所有资源
inputEmail=（EditText）findViewById（R.id.registerEmail）；
inputPassword=（EditText）findViewById（R.id.registerPassword）；
inputCPassword=（EditText）findViewById（R.id.confirmPassword）；
inputContact=（EditText）findViewById（R.id.registerContact）；
btnRegister=（按钮）findViewById（R.id.btnRegister）；
btnLinkToLogin=（按钮）findViewById（R.id.btnLinkToLogin）；
registerErrorMsg=（TextView）findViewById（R.id.register\u错误）；
//注册按钮点击事件
btnRegister.setOnClickListener（新视图.OnClickListener（）{
公共void onClick（视图）{
字符串密码=inputPassword.getText（）.toString（）；
字符串confirmpass=inputCPassword.getText（）.toString（）；
//检查所有字段
if（inputContact.length（）//处理此问题的惰性方法是检查：
//您可以在创建时输入以下代码

StrictMode.ThreadPolicy policy=新建StrictMode.ThreadPolicy.Builder（）.permitAll（）.build（）；
StrictMode.setThreadPolicy（policy）；
当您尝试在主线程上执行网络活动时，会发生NetworkOnMainThreadException。请为网络活动创建新线程。我相信是这样一行：
jsonParser.getJSONFromUrl（）
导致问题。查看此链接。它解释了如何在ANR上的
线程
或
异步任务
而不是
UIThread
上进行
网络
调用，以及触发它的原因：我应该将异步任务放在哪里？作为内部类还是单独的类，以满足您的要求为准
public class UserFunctions {

private JSONParser jsonParser;

private static String loginURL = "http://10.0.2.2/project/index.php";
private static String registerURL = "http://10.0.2.2/project/index.php";

private static String login_tag = "login";
private static String register_tag = "register";

// constructor
public UserFunctions(){
    jsonParser = new JSONParser();
}

/**
 * function make Login Request
 * @param email
 * @param password
 * */
public JSONObject loginUser(String email, String password){
    // Building Parameters
    List<NameValuePair> params = new ArrayList<NameValuePair>();
    params.add(new BasicNameValuePair("tag", login_tag));
    params.add(new BasicNameValuePair("email", email));
    params.add(new BasicNameValuePair("password", password));
    JSONObject json = jsonParser.getJSONFromUrl(loginURL, params);
    // return json
    // Log.e("JSON", json.toString());
    return json;
}

/**
 * function make Login Request
 * @param name
 * @param email
 * @param password
 * */
public JSONObject registerUser(String email, String contact, String password){
    // Building Parameters
    List<NameValuePair> params = new ArrayList<NameValuePair>();
    params.add(new BasicNameValuePair("tag", register_tag));
    params.add(new BasicNameValuePair("email", email));
    params.add(new BasicNameValuePair("contact", contact));
    params.add(new BasicNameValuePair("password", password));

    // getting JSON Object
    JSONObject json = jsonParser.getJSONFromUrl(registerURL, params);
    // return json
    return json;
}

/**
 * Function get Login status
 * */
public boolean isUserLoggedIn(Context context){
    DatabaseHandler db = new DatabaseHandler(context);
    int count = db.getRowCount();
    if(count > 0){
        // user logged in
        return true;
    }
    return false;
}

/**
 * Function to logout user
 * Reset Database
 * */
public boolean logoutUser(Context context){
    DatabaseHandler db = new DatabaseHandler(context);
    db.resetTables();
    return true;
}}