"Unfortunately app_name has stopped working"

Question

The emulator does not respond to this code.

It gives the error as "Unfortunatey, Act has stopped ". I tried the same code with just one field as student name and it worked well but with two fields as student name and location its not responding. Pls do help me out.

MainActivity.java

package com.act;

            import java.util.List;

            import android.app.ListActivity;
            import android.os.Bundle;
            import android.view.View;
        import android.widget.ArrayAdapter;
            import android.widget.EditText;
            public class MainActivity extends ListActivity {

              private StudentOperations studentDBoperation;

                @Override
                public void onCreate(Bundle savedInstanceState) {
                    super.onCreate(savedInstanceState);
                    setContentView(R.layout.activity_main);
                      studentDBoperation = new StudentOperations(this);
                    studentDBoperation.open();

                    List values = studentDBoperation.getAllStudents();

                    // Use the SimpleCursorAdapter to show the
                   // elements in a ListView
                    ArrayAdapter adapter = new ArrayAdapter(this,
                 android.R.layout.simple_list_item_1, values);
                   setListAdapter(adapter);
                }

                public void addUser(View view) {
                      ArrayAdapter adapter = (ArrayAdapter) getListAdapter();
                      EditText text = (EditText) findViewById(R.id.editText1);
                      EditText text2 = (EditText) findViewById(R.id.editText2);

                   Student stud = studentDBoperation.addStudent(text.getText().toString(),text2.getText().toString());
                      adapter.add(stud);

                }
                  public void deleteFirstUser(View view) {
                      ArrayAdapter adapter = (ArrayAdapter) getListAdapter();
                   Student stud = null;
                        if (getListAdapter().getCount() > 0) {
                        stud = (Student) getListAdapter().getItem(0);
                        studentDBoperation.deleteStudent(stud);
                        adapter.remove(stud);
                   }
                    }

                @Override
               protected void onResume() {
                   studentDBoperation.open();
                   super.onResume();
               }
               @Override
                protected void onPause() {
                        studentDBoperation.close();
                        super.onPause();
                }

                        }

DataBaseWrapper.java

 package com.act;

                import android.content.Context;
            import android.database.sqlite.SQLiteDatabase;
            import android.database.sqlite.SQLiteOpenHelper;
                    public class DataBaseWrapper extends SQLiteOpenHelper {

                    public static final String STUD = "Stud";
                    public static final String STUDENT_ID = "_id";
                    public static final String STUDENT_NAME = "_name";
                    public static final String STUDENT_LOC = "_loc";

                    private static final String DATABASE_NAME = "Students.db";
                    private static final int DATABASE_VERSION = 1;
                            // creation SQLite statement
                    private static final String DATABASE_CREATE = "create table " + STUD
                        + "(" + STUDENT_ID + " integer primary key autoincrement, "
                            + STUDENT_NAME + " text not null," 
                            + STUDENT_LOC + "text not null );";
                            public DataBaseWrapper(Context context) {
                        super(context, DATABASE_NAME, null, DATABASE_VERSION);
                    }

                    @Override
                public void onCreate(SQLiteDatabase db) {
                        db.execSQL(DATABASE_CREATE);

                    }

                    @Override
                public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
                        // you should do some logging in here
                    // ..

                    db.execSQL("DROP TABLE IF EXISTS " + STUD);
                    onCreate(db);
                    }

                        }

Student.java

package com.act;
            public class Student {
                private int id;
                private String name;
    private String loc;
                public long getId() {
                return id;
            }
                    public void setId(int id) {
                    this.id = id;
                }



                public String getName() {
                return this.name;
                }

                public void setName(String name) {
                    this.name = name;
            }


                public String getLoc() {
                    return this.loc;
                    }

                    public void setLoc(String loc) {
                        this.loc = loc;
                }
                @Override
                public String toString() {
                return name;
                }
            }

StudentOperations.java

package com.act;
    import java.util.ArrayList;
    import java.util.List;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
public class StudentOperations {
// Database fields
private DataBaseWrapper dbHelper;
private String[] STUDENT_TABLE_COLUMNS = { DataBaseWrapper.STUDENT_ID,       DataBaseWrapper.STUDENT_NAME,DataBaseWrapper.STUDENT_LOC };
private SQLiteDatabase database;
public StudentOperations(Context context) {
   dbHelper = new DataBaseWrapper(context);
            }
public void open() throws SQLException {
    database = dbHelper.getWritableDatabase();
            }
                public void close() {
                dbHelper.close();
            }
                public Student addStudent(String name, String loc) {
                    ContentValues values = new ContentValues();

                values.put(DataBaseWrapper.STUDENT_NAME, name);
                values.put(DataBaseWrapper.STUDENT_LOC,loc);
                    long studId = database.insert(DataBaseWrapper.STUD, null, values);

                // now that the student is created return it ...
            Cursor cursor = database.query(DataBaseWrapper.STUD,
                        STUDENT_TABLE_COLUMNS, DataBaseWrapper.STUDENT_ID + " = "
                                + studId, null, null, null, null);

                cursor.moveToFirst();

                Student newComment = parseStudent(cursor);
                cursor.close();
            return newComment;
            }

            public void deleteStudent(Student comment) {
                long id = comment.getId();
                System.out.println("Comment deleted with id: " + id);
           database.delete(DataBaseWrapper.STUD, DataBaseWrapper.STUDENT_ID
                    + " = " + id, null);
            }
                public List getAllStudents() {
            List students = new ArrayList();

                Cursor cursor = database.query(DataBaseWrapper.STUD,
                   STUDENT_TABLE_COLUMNS, null, null, null, null, null);

            cursor.moveToFirst();
            while (!cursor.isAfterLast()) {
                Student student = parseStudent(cursor);
                students.add(student);
                    cursor.moveToNext();
          }

                cursor.close();
                return students;
        }

            private Student parseStudent(Cursor cursor) {
                Student student = new Student();
            student.setId((cursor.getInt(0)));
                student.setName(cursor.getString(1));
                student.setLoc(cursor.getString(2));
                return student;
            }
        }

XML code activity_main.xml

 <?xml version="1.0" encoding="utf-8"?>
                <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
                    android:layout_width="wrap_content"
                    android:layout_height="match_parent"
                    android:orientation="vertical" >
                <EditText
                    android:id="@+id/editText1"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:layout_alignParentLeft="true"
                        android:layout_alignParentTop="true"
                        android:ems="10" >

                        <requestFocus />
                    </EditText>

                <Button
                        android:id="@+id/addBtn"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:layout_below="@+id/editText1"
                        android:onClick="addUser"
                        android:text="Add New" />

                    <Button
                        android:id="@+id/deleteBtn"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:layout_toRightOf="@+id/addBtn"
                        android:layout_below="@+id/editText1"
                        android:onClick="deleteFirstUser"
                        android:text="Delete First" />

                    <ListView
                        android:id="@android:id/list"
                        android:layout_width="match_parent"
                        android:layout_height="212dp"
                        android:layout_alignParentLeft="true"
                        android:layout_below="@+id/deleteBtn" >
                    </ListView>

                    <EditText
                        android:id="@+id/editText2"
                        android:layout_width="match_parent"
                        android:layout_height="wrap_content" />

                </LinearLayout>

LOGCAT:

  02-27 05:13:53.349: D/dalvikvm(1057): GC_FOR_ALLOC freed 52K, 6% free 2878K/3036K, paused 35ms, total 37ms
    02-27 05:13:53.389: D/dalvikvm(1057): GC_FOR_ALLOC freed 4K, 6% free 2972K/3136K, paused 26ms, total 26ms
    02-27 05:13:53.399: I/dalvikvm-heap(1057): Grow heap (frag case) to 4.074MB for 1127536-byte allocation
    02-27 05:13:53.509: D/dalvikvm(1057): GC_FOR_ALLOC freed <1K, 4% free 4073K/4240K, paused 108ms, total 108ms
    02-27 05:13:53.650: E/SQLiteLog(1057): (1) near ")": syntax error
    02-27 05:13:53.650: D/AndroidRuntime(1057): Shutting down VM
    02-27 05:13:53.650: W/dalvikvm(1057): threadid=1: thread exiting with uncaught exception (group=0x414c4700)
    02-27 05:13:53.670: E/AndroidRuntime(1057): FATAL EXCEPTION: main
    02-27 05:13:53.670: E/AndroidRuntime(1057): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.act/com.act.MainActivity}: android.database.sqlite.SQLiteException: near ")": syntax error (code 1): , while compiling: create table Stud(_id integer primary key autoincrement, _name text not null,);
    02-27 05:13:53.670: E/AndroidRuntime(1057):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2211)
    02-27 05:13:53.670: E/AndroidRuntime(1057):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2261)
    02-27 05:13:53.670: E/AndroidRuntime(1057):     at android.app.ActivityThread.access$600(ActivityThread.java:141)
    02-27 05:13:53.670: E/AndroidRuntime(1057):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1256)
    02-27 05:13:53.670: E/AndroidRuntime(1057):     at android.os.Handler.dispatchMessage(Handler.java:99)
    02-27 05:13:53.670: E/AndroidRuntime(1057):     at android.os.Looper.loop(Looper.java:137)
    02-27 05:13:53.670: E/AndroidRuntime(1057):     at android.app.ActivityThread.main(ActivityThread.java:5103)
    02-27 05:13:53.670: E/AndroidRuntime(1057):     at java.lang.reflect.Method.invokeNative(Native Method)
    02-27 05:13:53.670: E/AndroidRuntime(1057):     at java.lang.reflect.Method.invoke(Method.java:525)
    02-27 05:13:53.670: E/AndroidRuntime(1057):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
    02-27 05:13:53.670: E/AndroidRuntime(1057):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
    02-27 05:13:53.670: E/AndroidRuntime(1057):     at dalvik.system.NativeStart.main(Native Method)
    02-27 05:13:53.670: E/AndroidRuntime(1057): Caused by: android.database.sqlite.SQLiteException: near ")": syntax error (code 1): , while compiling: create table Stud(_id integer primary key autoincrement, _name text not null,);
    02-27 05:13:53.670: E/AndroidRuntime(1057):     at android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method)
    02-27 05:13:53.670: E/AndroidRuntime(1057):     at android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:889)
    02-27 05:13:53.670: E/AndroidRuntime(1057):     at android.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:500)
    02-27 05:13:53.670: E/AndroidRuntime(1057):     at android.database.sqlite.SQLiteSession.prepare(SQLiteSession.java:588)
    02-27 05:13:53.670: E/AndroidRuntime(1057):     at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:58)
    02-27 05:13:53.670: E/AndroidRuntime(1057):     at android.database.sqlite.SQLiteStatement.<init>(SQLiteStatement.java:31)
    02-27 05:13:53.670: E/AndroidRuntime(1057):     at android.database.sqlite.SQLiteDatabase.executeSql(SQLiteDatabase.java:1672)
    02-27 05:13:53.670: E/AndroidRuntime(1057):     at android.database.sqlite.SQLiteDatabase.execSQL(SQLiteDatabase.java:1603)
    02-27 05:13:53.670: E/AndroidRuntime(1057):     at com.act.DataBaseWrapper.onCreate(DataBaseWrapper.java:26)
    02-27 05:13:53.670: E/AndroidRuntime(1057):     at android.database.sqlite.SQLiteOpenHelper.getDatabaseLocked(SQLiteOpenHelper.java:252)
    02-27 05:13:53.670: E/AndroidRuntime(1057):     at android.database.sqlite.SQLiteOpenHelper.getWritableDatabase(SQLiteOpenHelper.java:164)
    02-27 05:13:53.670: E/AndroidRuntime(1057):     at com.act.StudentOperations.open(StudentOperations.java:19)
    02-27 05:13:53.670: E/AndroidRuntime(1057):     at com.act.MainActivity.onCreate(MainActivity.java:19)
    02-27 05:13:53.670: E/AndroidRuntime(1057):     at android.app.Activity.performCreate(Activity.java:5133)
    02-27 05:13:53.670: E/AndroidRuntime(1057):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
    02-27 05:13:53.670: E/AndroidRuntime(1057):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2175)
    02-27 05:13:53.670: E/AndroidRuntime(1057):     

Answer 1

Check this line

02-27 05:13:53.670: E/AndroidRuntime(1057): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.act/com.act.MainActivity}: android.database.sqlite.SQLiteException: near ")": syntax error (code 1): , while compiling: create table Stud(_id integer primary key autoincrement, _name text not null,);

Change this line create table Stud(_id integer primary key autoincrement, _name text not null,);

as

create table Stud(_id integer primary key autoincrement, _name text not null); 

Answer 2

I think you missed space at STUDENT_LOC + "text not null ); between text not null so replace it with this STUDENT_LOC + " text not null ); so your whole query should like this, try it like below.

And also you missed to close the " at ed of STUDENT_LOC Please verify it.

private static final String DATABASE_CREATE = "create table " + STUD
                        + "(" + STUDENT_ID + " integer primary key autoincrement, "
                            + STUDENT_NAME + " text not null," 
                            + STUDENT_LOC + " text not null " )";
                            public DataBaseWrapper(Context context) {
                        super(context, DATABASE_NAME, null, DATABASE_VERSION);
                    }