java.lang.RuntimeException:Can'；t在未调用Looper.prepare（）的线程内创建处理程序为什么？
当我运行第一个活动时，没有出现错误 但是当我尝试运行第二个活动错误时 “java.lang.RuntimeException:无法在未调用Looper.prepare（）的线程内创建处理程序” 无活套问题的活动java.lang.RuntimeException:Can'；t在未调用Looper.prepare（）的线程内创建处理程序为什么？,java,android,multithreading,Java,Android,Multithreading,当我运行第一个活动时，没有出现错误 但是当我尝试运行第二个活动错误时 “java.lang.RuntimeException:无法在未调用Looper.prepare（）的线程内创建处理程序” 无活套问题的活动 package com.example.androidnotizer; import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.State
package com.example.androidnotizer;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
public class LoginActivity extends Activity {
public static final String URL="jdbc:mysql://10.0.2.2/notizer";
public static final String USER="root";
public static final String PASSWORD="apple";
public static final String Driver_Class="com.mysql.jdbc.Driver";
public static final int RED=-65536;
Handler handler = new Handler();
Thread background;
String uid,pass;
int count=0;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
TextView tv = (TextView)findViewById(R.id.textView4);
tv.setText("");
Button login = (Button) findViewById(R.id.button1);
login.setOnClickListener(new OnClickListener(){
@Override
public void onClick(View arg0) {
EditText et1 = (EditText)findViewById(R.id.editText1);
EditText et2 = (EditText)findViewById(R.id.editText2);
uid=et1.getText().toString();
pass=et2.getText().toString();
TextView tv = (TextView)findViewById(R.id.textView4);
tv.setText("");
count=0;
doLogin();
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.login,menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.action_signup:
Intent i = new Intent(LoginActivity.this,SignUpActivity.class);
startActivity(i);
}
return true;
}
public void doLogin(){
background = new Thread(new Runnable(){
@Override
public void run(){
try{
Class.forName(Driver_Class);
Connection con = DriverManager.getConnection(URL, USER, PASSWORD);
Statement st = con.createStatement();
ResultSet rs =st.executeQuery("select * from login where user_id='"+ uid +"' and password='"+ pass +"'");
while(rs.next()){
count++;
}
}catch(Exception e){
e.printStackTrace();
}
Runnable r=new Runnable() {
@Override
public void run() {
if(count==0){
Toast.makeText(getApplicationContext(), "Unsuccessful Login", Toast.LENGTH_SHORT).show();
TextView tv = (TextView)findViewById(R.id.textView4);
tv.setText("Wrong user_id or password");
tv.setTextColor(RED);
}
else{
Intent i = new Intent(LoginActivity.this,NoticeActivity.class);
startActivity(i);
}
}
};
handler.post(r);
}
}
);
background.start();
}
}
package com.example.androidnotizer;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.Statement;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
import android.util.SparseBooleanArray;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.Toast;
public class StudentSignUpActivity extends Activity implements OnClickListener {
public static final String URL="jdbc:mysql://10.0.2.2/notizer";
public static final String USER="root";
public static final String PASSWORD="apple";
public static final String Driver_Class="com.mysql.jdbc.Driver";
Handler handler = new Handler();
Thread background;
Button button,combi;
ListView listView;
ArrayAdapter<String> adapter;
String fname,lname,mname,gender,mobile,designation,passPapers,roll,department,year;
int count=0;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_student_sign_up);
Intent intent =getIntent();
fname = intent.getStringExtra("fname");
mname = intent.getStringExtra("mname");
lname = intent.getStringExtra("lname");
gender = intent.getStringExtra("gender");
mobile = intent.getStringExtra("mobile");
designation = intent.getStringExtra("designation");
roll = intent.getStringExtra("roll");
department = intent.getStringExtra("department");
year = intent.getStringExtra("year");
findViewById();
String[] sports = getResources().getStringArray(R.array.papers_array);
adapter = new ArrayAdapter<String>(this,android.R.layout.simple_list_item_multiple_choice, sports);
listView.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE);
listView.setAdapter(adapter);
button.setOnClickListener(this);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.student_sign_up, menu);
return true;
}
private void findViewById() {
listView = (ListView) findViewById(R.id.dept_listView1);
button = (Button) findViewById(R.id.done);
}
@Override
public void onClick(View arg0) {
SparseBooleanArray checked = listView.getCheckedItemPositions();
passPapers="";
for (int i = 0; i < checked.size(); i++) {
int position = checked.keyAt(i);
if (checked.valueAt(i))
if((i+1) < checked.size()){
passPapers=passPapers+String.valueOf(adapter.getItem(position))+",";
}
else{
passPapers=passPapers+String.valueOf(adapter.getItem(position));
}
}
doSignUp();
}
public void doSignUp(){
Toast.makeText(getApplicationContext(),"Inside doSignUp()",Toast.LENGTH_LONG).show();
background = new Thread(new Runnable(){
@Override
public void run(){
try{
Toast.makeText(getApplicationContext(),"Inside try",Toast.LENGTH_LONG).show();
Class.forName(Driver_Class);
Connection con = DriverManager.getConnection(URL, USER, PASSWORD);
Statement st = con.createStatement();
//st.executeUpdate("insert into student(roll_no,fname,mname,lname,gender,mobile_no,department,year,pass_papers,desigantion) values('"+ roll +"','"+ fname +"','"+ mname +"','"+ lname +"','"+ gender +"','"+ mobile +"','"+ department +"','"+ year +"','"+ passPapers +"','"+ designation +"')");
st.executeUpdate("insert into login(user_id,password) values('"+ roll +"','"+ roll +"')");
count=1;
}catch(Exception e){
count=0;
e.printStackTrace();
Toast.makeText(getApplicationContext(),e.toString(),Toast.LENGTH_LONG).show();
}
Runnable r=new Runnable() {
@Override
public void run() {
if(count==1){
Toast.makeText(getApplicationContext(), "Successful Sign Up\nYour user_id : " + roll + "\nand password : " + roll, Toast.LENGTH_LONG).show();
Intent i = new Intent(StudentSignUpActivity.this,NoticeActivity.class);
startActivity(i);
}
else{
Toast.makeText(getApplicationContext(), "Unsuccessful Sign Up\nTry Again", Toast.LENGTH_LONG).show();
Intent i = new Intent(StudentSignUpActivity.this,SignUpActivity.class);
startActivity(i);
}
}
};
handler.post(r);
}
}
);
background.start();
}
}
package com.example.androidnotizer;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
public class LoginActivity extends Activity {
public static final String URL="jdbc:mysql://10.0.2.2/notizer";
public static final String USER="root";
public static final String PASSWORD="apple";
public static final String Driver_Class="com.mysql.jdbc.Driver";
public static final int RED=-65536;
Handler handler = new Handler();
Thread background;
String uid,pass;
int count=0;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
TextView tv = (TextView)findViewById(R.id.textView4);
tv.setText("");
Button login = (Button) findViewById(R.id.button1);
login.setOnClickListener(new OnClickListener(){
@Override
public void onClick(View arg0) {
EditText et1 = (EditText)findViewById(R.id.editText1);
EditText et2 = (EditText)findViewById(R.id.editText2);
uid=et1.getText().toString();
pass=et2.getText().toString();
TextView tv = (TextView)findViewById(R.id.textView4);
tv.setText("");
count=0;
doLogin();
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.login,menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.action_signup:
Intent i = new Intent(LoginActivity.this,SignUpActivity.class);
startActivity(i);
}
return true;
}
public void doLogin(){
background = new Thread(new Runnable(){
@Override
public void run(){
try{
Class.forName(Driver_Class);
Connection con = DriverManager.getConnection(URL, USER, PASSWORD);
Statement st = con.createStatement();
ResultSet rs =st.executeQuery("select * from login where user_id='"+ uid +"' and password='"+ pass +"'");
while(rs.next()){
count++;
}
}catch(Exception e){
e.printStackTrace();
}
Runnable r=new Runnable() {
@Override
public void run() {
if(count==0){
Toast.makeText(getApplicationContext(), "Unsuccessful Login", Toast.LENGTH_SHORT).show();
TextView tv = (TextView)findViewById(R.id.textView4);
tv.setText("Wrong user_id or password");
tv.setTextColor(RED);
}
else{
Intent i = new Intent(LoginActivity.this,NoticeActivity.class);
startActivity(i);
}
}
};
handler.post(r);
}
}
);
background.start();
}
}
package com.example.androidnotizer;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.Statement;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
import android.util.SparseBooleanArray;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.Toast;
public class StudentSignUpActivity extends Activity implements OnClickListener {
public static final String URL="jdbc:mysql://10.0.2.2/notizer";
public static final String USER="root";
public static final String PASSWORD="apple";
public static final String Driver_Class="com.mysql.jdbc.Driver";
Handler handler = new Handler();
Thread background;
Button button,combi;
ListView listView;
ArrayAdapter<String> adapter;
String fname,lname,mname,gender,mobile,designation,passPapers,roll,department,year;
int count=0;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_student_sign_up);
Intent intent =getIntent();
fname = intent.getStringExtra("fname");
mname = intent.getStringExtra("mname");
lname = intent.getStringExtra("lname");
gender = intent.getStringExtra("gender");
mobile = intent.getStringExtra("mobile");
designation = intent.getStringExtra("designation");
roll = intent.getStringExtra("roll");
department = intent.getStringExtra("department");
year = intent.getStringExtra("year");
findViewById();
String[] sports = getResources().getStringArray(R.array.papers_array);
adapter = new ArrayAdapter<String>(this,android.R.layout.simple_list_item_multiple_choice, sports);
listView.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE);
listView.setAdapter(adapter);
button.setOnClickListener(this);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.student_sign_up, menu);
return true;
}
private void findViewById() {
listView = (ListView) findViewById(R.id.dept_listView1);
button = (Button) findViewById(R.id.done);
}
@Override
public void onClick(View arg0) {
SparseBooleanArray checked = listView.getCheckedItemPositions();
passPapers="";
for (int i = 0; i < checked.size(); i++) {
int position = checked.keyAt(i);
if (checked.valueAt(i))
if((i+1) < checked.size()){
passPapers=passPapers+String.valueOf(adapter.getItem(position))+",";
}
else{
passPapers=passPapers+String.valueOf(adapter.getItem(position));
}
}
doSignUp();
}
public void doSignUp(){
Toast.makeText(getApplicationContext(),"Inside doSignUp()",Toast.LENGTH_LONG).show();
background = new Thread(new Runnable(){
@Override
public void run(){
try{
Toast.makeText(getApplicationContext(),"Inside try",Toast.LENGTH_LONG).show();
Class.forName(Driver_Class);
Connection con = DriverManager.getConnection(URL, USER, PASSWORD);
Statement st = con.createStatement();
//st.executeUpdate("insert into student(roll_no,fname,mname,lname,gender,mobile_no,department,year,pass_papers,desigantion) values('"+ roll +"','"+ fname +"','"+ mname +"','"+ lname +"','"+ gender +"','"+ mobile +"','"+ department +"','"+ year +"','"+ passPapers +"','"+ designation +"')");
st.executeUpdate("insert into login(user_id,password) values('"+ roll +"','"+ roll +"')");
count=1;
}catch(Exception e){
count=0;
e.printStackTrace();
Toast.makeText(getApplicationContext(),e.toString(),Toast.LENGTH_LONG).show();
}
Runnable r=new Runnable() {
@Override
public void run() {
if(count==1){
Toast.makeText(getApplicationContext(), "Successful Sign Up\nYour user_id : " + roll + "\nand password : " + roll, Toast.LENGTH_LONG).show();
Intent i = new Intent(StudentSignUpActivity.this,NoticeActivity.class);
startActivity(i);
}
else{
Toast.makeText(getApplicationContext(), "Unsuccessful Sign Up\nTry Again", Toast.LENGTH_LONG).show();
Intent i = new Intent(StudentSignUpActivity.this,SignUpActivity.class);
startActivity(i);
}
}
};
handler.post(r);
}
}
);
background.start();
}
}
package com.example.androidnotizer；
导入java.sql.Connection；
导入java.sql.DriverManager；
导入java.sql.Statement；
导入android.app.Activity；
导入android.content.Intent；
导入android.os.Bundle；
导入android.os.Handler；
导入android.util.SparseBooleanArray；
导入android.view.Menu；
导入android.view.view；
导入android.view.view.OnClickListener；
导入android.widget.ArrayAdapter；
导入android.widget.Button；
导入android.widget.ListView；
导入android.widget.Toast；
公共类StudentSignUpActivity扩展了活动实现OnClickListener{
公共静态最终字符串URL=“jdbc:mysql://10.0.2.2/notizer";
公共静态最终字符串USER=“root”；
公共静态最终字符串PASSWORD=“apple”；
公共静态最终字符串驱动程序\u Class=“com.mysql.jdbc.Driver”；
Handler=newhandler（）；
线程背景；
按钮，组合；
列表视图列表视图；
阵列适配器；
字符串fname、lname、mname、性别、手机、名称、护照、卷、部门、年份；
整数计数=0；
@凌驾
创建时受保护的void（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
setContentView（R.layout.activity\u student\u sign\u）；
Intent=getIntent（）；
fname=intent.getStringExtra（“fname”）；
mname=intent.getStringExtra（“mname”）；
lname=intent.getStringExtra（“lname”）；
性别=意图。getStringExtra（“性别”）；
mobile=intent.getStringExtra（“移动”）；
名称=意图。getStringExtra（“名称”）；
滚动=意图。getStringExtra（“滚动”）；
department=intent.getStringExtra（“department”）；
年份=意向。getStringExtra（“年度”）；
findViewById（）；
String[]sports=getResources（）.getStringArray（R.array.papers\u数组）；
adapter=new ArrayAdapter（这是android.R.layout.simple\u list\u item\u multiple\u choice，sports）；
listView.setChoiceMode（listView.CHOICE\u MODE\u MULTIPLE）；
setAdapter（适配器）；
setOnClickListener（此）；
}
@凌驾
公共布尔onCreateOptions菜单（菜单）{
//为菜单充气；这会将项目添加到操作栏（如果存在）。
getMenuInflater（）.充气（右菜单。学生注册，菜单）；
返回true；
}
私有void findViewById（）{
listView=（listView）findViewById（R.id.dept\u listView1）；
按钮=（按钮）findViewById（R.id.done）；
}
@凌驾
公共void onClick（视图arg0）{
SparseBooleanArray checked=listView.GetCheckEditePositions（）；
护照=”；
对于（int i=0；i12-10 06:49:48.823: E/AndroidRuntime(5021): FATAL EXCEPTION: Thread-344
12-10 06:49:48.823: E/AndroidRuntime(5021): java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()
12-10 06:49:48.823: E/AndroidRuntime(5021): at android.os.Handler.<init>(Handler.java:197)
12-10 06:49:48.823: E/AndroidRuntime(5021): at android.os.Handler.<init>(Handler.java:111)
12-10 06:49:48.823: E/AndroidRuntime(5021): at android.widget.Toast$TN.<init>(Toast.java:324)
12-10 06:49:48.823: E/AndroidRuntime(5021): at android.widget.Toast.<init>(Toast.java:91)
12-10 06:49:48.823: E/AndroidRuntime(5021): at android.widget.Toast.makeText(Toast.java:238)
12-10 06:49:48.823: E/AndroidRuntime(5021): at com.example.androidnotizer.StudentSignUpActivity$1.run(StudentSignUpActivity.java:104)
12-10 06:49:48.823: E/AndroidRuntime(5021): at java.lang.Thread.run(Thread.java:841)
12-10 06:49:48.823:E/AndroidRuntime（5021）：致命异常：线程344
12-10 06:49:48.823:E/AndroidRuntime（5021）：java.lang.RuntimeException:无法在未调用Looper.prepare（）的线程内创建处理程序
12-10 06:49:48.823:E/AndroidRuntime（5021）：位于android.os.Handler.（Handler.java:197）
12-10 06:49:48.823:E/AndroidRuntime（5021）：位于android.os.Handler.（Handler.java:111）
12-10 06:49:48.823:E/AndroidRuntime（5021）：在android.widget.Toast$TN.（Toast.java:324）
12-10 06:49:48.823:E/AndroidRuntime（5021）：在android.widget.Toast（Toast.java:91）
12-10 06:49:48.823:E/AndroidRuntime（5021）：在android.widget.Toast.makeText（Toast.java:238）上
12