A Java example to check if a provided date is within a range of 3 momths before and after current date. The idea is quite simple, just use Calendar class to roll the month back and forward to create a “date range”, and use the Date.before() and Date.after() to check if the Date is within […]
This article shows how to use the Java 8 DateTimeFormatter to check if a date format is valid in Java. Below are the requirements for a valid date. Year format, 1900, 2099 Month format, 1, 01, 2, 02… 12 Day format, 1, 01… 31 Leap year, February 29 days. Common year, February 28 days. Month […]
This article shows you how to use try-with-resources in Java. Table of contents: 1 Java try-with-resources before and after 2. try-with-resources with single resource 3. try-with-resources with multiple resources 3.1 JDBC example. 4. Custom resource with AutoCloseable interface 5. Resource open and closing order 6. Java 9 – final or effectively final variables Download Source […]
In Java, we use FileInputStream to read bytes from a file, such as an image file or binary file. Topics FileInputStream – Read a file FileInputStream – Remaining bytes FileInputStream – Better performance FileInputStream vs BufferedInputStream InputStreamReader – Convert FileInputStream to Reader FileInputStream – Read a Unicode file Note However, all the below examples use […]
In Android, ListView let you arranges components in a vertical scrollable list. In this tutorial, we will show you 2 ListView examples : Normal way to display components in ListView. Custom array adapter to customize the item display in ListView. P.S This project is developed in Eclipse 3.7, and tested with Android 2.3.3. 1. Normal […]
Recently, received many emails for mkyong.com tutorials, about how to deploy the project to Tomcat, build the project with Maven, and also how to import it into Eclipse IDE. Actually, almost all the mkyong.com tutorials are developed in Eclipse IDE (3.6 or 3.7), build with Maven (version 2 or 3) and deploy to Tomcat. At […]
In Android, you can configure the starting activity (default activity) of your application via following “intent-filter” in “AndroidManifest.xml“. See following code snippet to configure a activity class “logoActivity” as the default activity. File : AndroidManifest.xml <activity android:label="Logo" android:name=".logoActivity" > <intent-filter > <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> For example, let said you have […]
By default, Android SDK or Eclipse ADT plugin are not bundle with any Android’s source code for debugging. In Eclipse IDE, step into any Android class will prompt no source code attach, see following screen : Solution According to this official Android source code article, it’s shocked that we need to use “repo” to download […]
In Android, an activity is represent a single screen. Most applications have multiple activities to represent different screens, for example, one activity to display a list of the application settings, another activity to display the application status. Note Refer to this official Android activity article to understand more about Android activity. In this tutorial, we […]
In Android, TableLayout let you arranges components in rows and columns, just like the standard table layout in HTML, <tr> and <td>. In this tutorial, we show you how to use TableLayout to arrange button, textview and edittext in rows and columns format, and also demonstrates the use of “android:layout_span” to span view in 2 […]
In Android, RelativeLayout let you position your component base on the nearby (relative or sibling) component’s position. It’s the most flexible layout, that allow you to position your component to display in anywhere you want (if you know how to “relative” it). In RelativeLayout, you can use “above, below, left and right” to arrange the […]
In Android, you always put either “wrap_content” or “fill_parent” on component’s attribute “layout_width” and “layout_height“, did you wonder what’s the different? See following definition : wrap_content – The component just want to display big enough to enclose its content only. fill_parent – The component want to display as big as its parent, and fill in […]
In Android, LinearLayout is a common layout that arranges “component” in vertical or horizontal order, via orientation attribute. In additional, the highest “weight” component will fill up the remaining space in LinearLayout. In this tutorial, we show you how to use LinearLayout to display 3 buttons in vertical and horizontal order, and also how “weight” […]
Here’s a code snippet to show you how to use “android.content.Intent” to open an specify URL in Android’s web browser. button.setOnClickListener(new OnClickListener() { @Override public void onClick(View arg0) { Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse("https://mkyong.com")); startActivity(intent); } }); Note For full example, please refer to this – Android button example. References Android Button JavaDoc Android […]
In Android, just use “android.widget.Button” class to display a normal button. In this tutorial, we show you how to display a normal button, add a click listener, when user click on the button, open an URL in your Android’s internet browser. P.S This project is developed in Eclipse 3.7, and tested with Android 2.3.3. Note […]
In last Android tutorial, you use “ImageButton” to display a “Button” with a customized background image easily. However, you can do more than that just a simple image, Android allow you to change the button’s image depends on different states like button is focused or button is pressed. This example is referenced from this Android […]
In Android, you can use “android.widget.ImageButton” to display a normal “Button“, with a customized background image. In this tutorial, we show you how to display a button with a background image named “android_button.png“, when user click on it, display a short message. As simple as that. Note You may also like this Android ImageButton selector […]
In Maven 2, if you didn’t specify the version for each plugins that used in pom.xml, it will pick the latest plugin version automatically, which is very convenient. However, in Maven 3, if you didn’t explicitly specify the plugin version, it will prompt you warning message. Read this “Maven 3 compatibility” for detail. For example, […]
In Android, you can use “android.widget.ImageView” class to display an image file. Image file is easy to use but hard to master, because of the various screen and dpi in Android devices. Note Please refer to this official Android’s “Drawable Resource” and “Screen Support” article for better understand of how image works in Android. In […]
In Android, progress bar is useful to tell user that the task is takes longer time to finish. In this tutorial, we show you how to display a progress bar dialog to tell user that your task is running, and also how to increase the progress bar status until the task is completed. Note Refer […]
In Android, the AnalogClock is a two-handed clock, one for hour indicator and the other for minute indicator. The DigitalClock is look like your normal digital watch on hand, which display hours, minutes and seconds in digital format. Both AnalogClock and DigitalClock are UNABLE to modify the time, if you want to change the time, […]
In Android, you can use “android.widget.TimePicker” class to render a time picker component to select hour and minute in a pre-defined user interface. In this tutorial, we show you how to render time picker component via android.widget.TimePicker in current page, and also in dialog box via android.app.TimePickerDialog. In addition, we also show you how to […]
In Android, you can use “android.widget.DatePicker” class to render a date picker component to select day, month and year in a pre-defined user interface. In this tutorial, we show you how to render date picker component in current page via android.widget.DatePicker, and also in dialog box via android.app.DatePickerDialog. In addition, we also show you how […]
In Android, you can use “android.widget.Spinner” class to render a dropdown box selection list. Note Spinner is a widget similar to a drop-down list for selecting items. In this tutorial, we show you how to do the following tasks : Render a Spinner in XML, and load the selection items via XML file also. Render […]
In Android, you can use “android.widget.RatingBar” to display rating bar component in stars icon. The user is able to touch, drag or click on the stars to set the rating value easily. In this tutorial, we show you how to use XML to display a rating bar, few textviews and a button. When user click […]
In Android, you can use “android.widget.EditText“, with inputType=”textPassword” to render a password component. In this tutorial, we show you how to use XML to create a password field, label field and a normal button. When you click on the button, the password value will be displayed as a floating message (toast message). P.S This project […]
In Android, the “android.widget.ToggleButton” is a special class to render a button which has only two states, for example, “on and “off”. It’s best alternative to radio buttons to turn on or turn off a function. In this tutorial, we show you how to use XML to create two toggle buttons and a normal button, […]
In Android, you can use “android.widget.RadioButton” class to render radio button, and those radio buttons are usually grouped by android.widget.RadioGroup. If RadioButtons are in group, when one RadioButton within a group is selected, all others are automatically deselected. In this tutorial, we show you how to use XML to create two radio buttons, and grouped […]
In Android, you can use “android.widget.CheckBox” class to render a checkbox. In this tutorial, we show you how to create 3 checkboxes in XML file, and demonstrates the use of listener to check the checkbox state – checked or unchecked. P.S This project is developed in Eclipse 3.7, and tested with Android 2.3.3. 1. Custom […]
In Android, you can use “EditText” class to create an editable textbox to accept user input. This tutorial show you how to create a textbox in XML file, and demonstrates the use of key listener to display message typed in the textbox. P.S This project is developed in Eclipse, and tested with Android 2.3.3. 1. […]
Problem Android development with Eclipse IDE, sometime it hit following “adb” error message and caused the application fail to start? [2011-11-22 15:17:07 – HelloWorld] —————————— [2011-11-22 15:17:07 – HelloWorld] Android Launch! [2011-11-22 15:17:07 – HelloWorld] The connection to adb is down, and a severe error has occured. [2011-11-22 15:17:07 – HelloWorld] You must restart adb […]
For security concern, many users like to disable JavaScript in their web browser, and it raise a big problem in many website which depends on JavaScript to function well. The easy and simple solution is using the HTML “noscript” tag to display different content if JavaScript is disabled. See following full “noscript” example : If […]
See following example to get the real server file path via servletRequest.getRealPath(“/”). However, warning is prompt and complained that this method is deprecated. import javax.servlet.http.HttpServletRequest; public class DisplayAction { private HttpServletRequest servletRequest; public String execute() { //The method getRealPath(String) from the type ServletRequest is deprecated String filePath = servletRequest.getRealPath("/"); } @Override public void setServletRequest(HttpServletRequest arg0) […]
In this tutorial, we show you how to create a simple “hello world” Android project in Eclipse IDE + ADT plugin, and run it with Android Virtual Device (AVD). The Eclipse ADT plugin provided easy Android project creation and management, components drag and drop, auto-complete and many useful features to speed up your Android development […]
In some cases, your JavaScript may need to depend on a particular variable to “define” or “exists”, in order to process on the next step. Note I don’t recommend to do so, as JavaScript shouldn’t involve any business logic, it should be purely basic validation or UI enhancement, but, many still like to code complex […]
In JavaScript, there are two ways to check if a variable is a number : isNaN() – Stands for “is Not a Number”, if variable is not a number, it return true, else return false. typeof – If variable is a number, it will returns a string named “number”. Note Normally, people use isNaN() to […]
In this tutorial, we show you how to link an external JavaScript file (file extension end with .js) to web page. Note In HTML, you can either embed JavaScript on web page or external JavaScript file, or implemented both ways together. 1. External JavaScript file Create a new file end with “.js” file extension, and […]
Google Maps API support four map types : ROADMAP – Displays normal street/road map (default map type). TERRAIN – Display normal street/road map based on terrain information. SATELLITE – Display satellite images only. HYBRID – Mixed normal and satellite views, display street/road views on top of the satellite images. Note Normally, you just use either […]
A simple hello world guide to display Google Maps on a web page, via Google Maps Javascript API v3. In this tutorial, we show you how to display a map centered on “Malim Nawar, Malaysia” (my hometown), and use “marker (small icon)” to identify the location on the map. Full example… <html> <head> <title>Google Map […]
Spring Security tutorials, secure your web application with authentication and access control.
