Hashtable key value pair add put get pair Java Android example
How add pair of strings to Hashtable, how get pair key value from Hashtable, how split string, basic Java Android example.
MainClass.java
MainClass.java
import java.util.Enumeration;
import java.util.Hashtable;
public class MainClass {
public static void main(String[] arg) {
// english;germany dictionary
String[] arrayOfString = { "one;eine", "two;zwei", "three;drei" };
Hashtable<String, String> hashTable = new Hashtable<String, String>();
for(String s: arrayOfString){
String[] array = s.split(";");
String sKey ="", sValue="";
if(array.length > 1){
sKey = array[0]; sValue = array[1];
hashTable.put(sKey, sValue);
}
}
Enumeration<String> enumer = hashTable.keys();
while (enumer.hasMoreElements()) {
String keyFromTable = (String) enumer.nextElement();
// get Returns the value to which the specified key is mapped,
// or null if this map contains no mapping for the key
System.out.println(keyFromTable + " = " + hashTable.get(keyFromTable));
}
}
}
/*
two = zwei
one = eine
three = drei
*/
396LW NO topic_id
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Click to Android version combobox - drop down menu and select your version, which just using (have instaled). For example: You updated ADT by SDK manager, but forget to update Android version. You can use lower version from drop down menu, which using your project, or do update of Android by SDK manager.
Switch statement with numbers and array of strings Java example.
Possible:
public class MainClass {
public static void main(String[] arg) {
String[] arrayOfString = { "One", "Two", "Three", "Four" };
int i = 2;
switch (i) {
case 1: {
System.out.println(arrayOfString[i]);
break;
}
case 2: {
System.out.println(arrayOfString[i]);
break;
}
case 3: {
System.out.println(arrayOfString[i]);
break;
}
default: {
System.out.println("Enter a valid value.");
}
} // END of switch
}
}
/*
* Three
*/
Possible:
case 1:
System.out.println(arrayOfString[i]);
break;
// i love this notation
case 1:{
System.out.println(arrayOfString[i]);
}break;
case 1:{
System.out.println(arrayOfString[i]);
break;
}
Sensor, getSystemService(), getSensorList(), getDefaultDisplay(), WindowManager,
Surface.ROTATION_0, onAccuracyChanged() Android sample.
Surface.ROTATION_0, onAccuracyChanged() Android sample.
public class _MotionActivity extends Activity implements SensorEventListener {
private float mSensorX;
private float mSensorY;
private Display mDisplay;
private SensorManager sm;
private PowerManager mPowerManager;
private WindowManager mWindowManager;
TextView textview;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Get an instance of the SensorManager
sm = (SensorManager) getSystemService(SENSOR_SERVICE);
if(sm.getSensorList(Sensor.TYPE_ACCELEROMETER).size()!=0){
Sensor s = sm.getSensorList(Sensor.TYPE_ACCELEROMETER).get(0);
sm.registerListener(this,s, SensorManager.SENSOR_DELAY_NORMAL);
}
// Get an instance of the PowerManager
mPowerManager = (PowerManager) getSystemService(POWER_SERVICE);
// Get an instance of the WindowManager
mWindowManager = (WindowManager) getSystemService(WINDOW_SERVICE);
mDisplay = mWindowManager.getDefaultDisplay();
setContentView(R.layout.main);
textview = (TextView)findViewById(R.id.textView1);
}
@Override
public void onSensorChanged(SensorEvent event) {
if (event.sensor.getType() != Sensor.TYPE_ACCELEROMETER)
return;
switch (mDisplay.getRotation()) {
case Surface.ROTATION_0:
mSensorX = event.values[0];
mSensorY = event.values[1];
textview.setText(String.valueOf( mSensorX));
break;
case Surface.ROTATION_90:
mSensorX = -event.values[1];
mSensorY = event.values[0];
textview.setText(String.valueOf( mSensorX));
break;
case Surface.ROTATION_180:
mSensorX = -event.values[0];
mSensorY = -event.values[1];
textview.setText(String.valueOf( mSensorX));
break;
case Surface.ROTATION_270:
mSensorX = event.values[1];
mSensorY = -event.values[0];
textview.setText(String.valueOf( mSensorX));
break;
}
}
@Override
public void onAccuracyChanged(Sensor sensor, int accuracy) {
// TODO Auto-generated method stub
}
@Override
protected void onResume() {
super.onResume();
if(sm.getSensorList(Sensor.TYPE_ACCELEROMETER).size()!=0){
Sensor s = sm.getSensorList(Sensor.TYPE_ACCELEROMETER).get(0);
sm.registerListener(this,s, SensorManager.SENSOR_DELAY_NORMAL);
}
}
@Override
protected void onPause() {
sm.unregisterListener(this);
super.onStop();
}
}
Not request focus EditText if startup Android - hide keyboard if startup.
Remove:
Create a LinearLayout and set the:
attributes android:focusable="true" android:focusableInTouchMode="true"
Remove:
Create a LinearLayout and set the:
attributes android:focusable="true" android:focusableInTouchMode="true"
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:focusable="true"
android:focusableInTouchMode="true"
android:orientation="vertical" >
</LinearLayout>
Problemi is in e.getMessage() what can return null and Log.e (String tag, String msg) will throws an new exception !!!!
Problem and solution:
LogCat:
Or you can using this code:
Problem and solution:
try {
int [] i = {1};
int z = i[5];
} catch (ArrayIndexOutOfBoundsException e) {
String s = e.toString(); // s == java.lang.ArrayIndexOutOfBoundsException
// try to testing String s for null value
if(s != null)
Log.e("bla", s);
else
Log.e("bla", "My error text 1");
String s2 = e.getMessage(); // s2 == null !!!!!!!
// you need to testing String s2 for null value , or you get FATAL EXCEPTION: main
// and application will be crashed
String s2 = e.getMessage(); // s2 == null !!!!!!!
if(s2 != null)
Log.e("bla2", e.getMessage());
else
Log.e("bla2", "My error text 2");
// this is OK
e.printStackTrace();
}
LogCat:
E/bla(855): java.lang.ArrayIndexOutOfBoundsException
E/bla2(855): My error text 2
W/System.err(855): java.lang.ArrayIndexOutOfBoundsException
W/System.err(855): at cz.okhelp.motion._MotionActivity.onTouchEvent(_MotionActivity.java:54)
W/System.err(855): at android.app.Activity.dispatchTouchEvent(Activity.java:2099)
W/System.err(855): at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:1675)
W/System.err(855): at android.view.ViewRoot.deliverPointerEvent(ViewRoot.java:2194)
W/System.err(855): at android.view.ViewRoot.handleMessage(ViewRoot.java:1878)
W/System.err(855): at android.os.Handler.dispatchMessage(Handler.java:99)
W/System.err(855): at android.os.Looper.loop(Looper.java:123)
W/System.err(855): at android.app.ActivityThread.main(ActivityThread.java:3683)
W/System.err(855): at java.lang.reflect.Method.invokeNative(Native Method)
W/System.err(855): at java.lang.reflect.Method.invoke(Method.java:507)
W/System.err(855): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
W/System.err(855): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
W/System.err(855): at dalvik.system.NativeStart.main(Native Method)
Or you can using this code:
try {
int [] i = {1};
int z = i[5];
} catch (Exception e) {
StringBuilder sb = new StringBuilder().append(e.getClass().getSimpleName());
if (e.getMessage() != null) {
sb.append("
");
sb.append(e.getMessage());
}
Log.e("err", sb.toString()); // E/err(336): ArrayIndexOutOfBoundsException
// this code write out all message
Log.e("myError", "methodName", e);
}
// E/myError(371): methodName
// E/myError(371): java.lang.ArrayIndexOutOfBoundsException
// E/myError(371): at cz.okhelp.motion._MotionActivity.onTouchEvent(_MotionActivity.java:54)
// E/myError(371): at android.app.Activity.dispatchTouchEvent(Activity.java:2099)
// E/myError(371): at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:1675)
// E/myError(371): at android.view.ViewRoot.deliverPointerEvent(ViewRoot.java:2194)
// E/myError(371): at android.view.ViewRoot.handleMessage(ViewRoot.java:1878)
// E/myError(371): at android.os.Handler.dispatchMessage(Handler.java:99)
// E/myError(371): at android.os.Looper.loop(Looper.java:123)
// E/myError(371): at android.app.ActivityThread.main(ActivityThread.java:3683)
// E/myError(371): at java.lang.reflect.Method.invokeNative(Native Method)
// E/myError(371): at java.lang.reflect.Method.invoke(Method.java:507)
// E/myError(371): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
// E/myError(371): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
// E/myError(371): at dalvik.system.NativeStart.main(Native Method)
Editace: 2013-12-09 10:56:37
Počet článků v kategorii: 396
Url:hashtable-key-value-pair-add-put-get-pair-java-android-example
