Volley framework in the Java library
Introduction to the use of Volley framework in the Java library
Volley is a Android library provided by Google for network requests. It simplifies the process of network requests and effectively solves some common problems in network communication in Android development.Volley provides an API that is easy to use and has powerful functions, which can quickly make network requests and load pictures.
The characteristics of Volley include the following aspects:
1. Asynchronous processing of network requests: Volley uses asynchronous tasks to handle network requests to avoid stuttering caused by network operations in the main thread, and improve the response speed of application.
2. Request queue management: Volley uses the request queue to manage the network request, which can sort, cancel and prioritize the request to ensure that the request is executed in the order of expected.
3. Image loading and cache: Volley has built -in picture loading function and provides a picture cache mechanism. You can automatically manage the download, cache and display of the picture, and improve the application of the application of the application.
4. Request retry mechanism: Volley has the function of requesting retry. When the network request fails, you can automatically send the request to improve the success rate of request.
The use of the Volley framework in the Java class library is introduced through some example code:
1. Introduce Volley dependence:
Add the following dependencies to the project's build.gradle file:
dependencies {
implementation 'com.android.volley:volley:1.2.0'
}
2. Spot a GET request:
String url = "https://api.example.com/data";
RequestQueue queue = Volley.newRequestQueue(context);
StringRequest stringRequest = new StringRequest(Request.Method.GET, url, response -> {
// Request successful callback processing
Log.d("Response", response);
}, error -> {
// Requires the recovery process of failure
Log.e("Error", error.toString());
});
queue.add(stringRequest);
3. Lift a post request:
String url = "https://api.example.com/data";
RequestQueue queue = Volley.newRequestQueue(context);
StringRequest stringRequest = new StringRequest(Request.Method.POST, url, response -> {
// Request successful callback processing
Log.d("Response", response);
}, error -> {
// Requires the recovery process of failure
Log.e("Error", error.toString());
}) {
// Set the request parameter
@Override
protected Map<String, String> getParams() {
Map<String, String> params = new HashMap<>();
params.put("username", "example");
params.put("password", "password123");
return params;
}
};
queue.add(stringRequest);
4. Load network pictures:
String imageUrl = "https://example.com/image.jpg";
ImageView imageView = findViewById(R.id.imageView);
RequestQueue queue = Volley.newRequestQueue(context);
ImageRequest imageRequest = new ImageRequest(imageUrl, response -> {
// The picture loaded successfully recovery processing
imageView.setImageBitmap(response);
}, 0, 0, ImageView.ScaleType.FIT_XY, Bitmap.Config.RGB_565, error -> {
// The back loading failure recovery processing
Log.e("Error", error.toString());
});
queue.add(imageRequest);
It can be seen through the above example, the Volley framework provides a simple and easy -to -use interface, which can easily load network requests and pictures.Its powerful functions and good performance enable developers to handle network communication more efficiently and provide users with a better experience.
