The technical principles and practices of logging output formatting in logback android framework
The LOGBACK Android framework is one of the most widely used Android log frameworks, which provides a powerful log processing function.Among them, the formatting of log output is an important aspect of log records, which can make log information more easy to read and organize.This article will introduce the technical principles and practice of logging formatting in the logback android framework, and provide some Java code examples.
1. Technical principles
The LOGBACK Android framework uses the PatternLayout mode layout class to achieve the formatting of the log output.The PatternLayout class specifies the log output format by defining a series of place occupies, which will be replaced by the actual log data.Here are some commonly used place occupies:
1. %D: The timestamp of the output log can be controlled by different formats.
2. %Thread: Output thread name.
3. %-5LEVEL: Output log level, using -5 can ensure that each level label is 5 characters wide.
4. %logger {10}: The name of the output log recorder shows only the first 10 characters.
5. %MSG: Output log message.
6. %n: Output a platform for independent changes.
By combining these placeholders together, the output format of the log can be flexibly defined.For example, "[ %Thread] %-5Level %Logger {10} - %msg %n" specifies the output format of the log.
Practice example
In order to demonstrate the practice of log output formatting in the logback android framework, we can create a simple Android application and use the logback android framework in the application to record the log.The following is an example code:
First, add dependencies to logback-anndroid in the App/Build.gradle file:
gradle
dependencies {
implementation 'com.github.tony19:logback-android-core:1.1.1-11'
implementation 'com.github.tony19:logback-android-classic:1.1.1-11'
}
Then, the logback is initialized in the application entrance Activity or Application class, and the output format is set to the format we need:
import android.app.Application;
import ch.qos.logback.classic.Level;
import ch.qos.logback.classic.LoggerContext;
import ch.qos.logback.classic.android.LogcatAppender;
import ch.qos.logback.classic.encoder.PatternLayoutEncoder;
import org.slf4j.LoggerFactory;
public class MyApplication extends Application {
@Override
public void onCreate() {
super.onCreate();
// Get loggerContext
LoggerContext loggerContext = (LoggerContext) LoggerFactory.getILoggerFactory();
// Set the log level
loggerContext.getLogger("ROOT").setLevel(Level.DEBUG);
// Create logcatappender
LogcatAppender logcatAppender = new LogcatAppender();
logcatAppender.setEncoder(createEncoder(loggerContext));
logcatAppender.start();
// Add logcataPpender to loggerContext
loggerContext.getLogger("ROOT").addAppender(logcatAppender);
}
private PatternLayoutEncoder createEncoder(LoggerContext loggerContext) {
PatternLayoutEncoder encoder = new PatternLayoutEncoder();
encoder.setContext(loggerContext);
encoder.setPattern("[%thread] %-5level %logger{10} - %msg%n");
encoder.start();
return encoder;
}
}
In the above code, we obtained the LoggerContext object through LoggerFactory, and set the log level to Debug.Create a logcatappender and specify the format.
In any place in the application, we can use the log record log, for example:
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class MainActivity extends AppCompatActivity {
private static final Logger LOG = LoggerFactory.getLogger(MainActivity.class);
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
LOG.debug("This is a debug log message");
LOG.info("This is an info log message");
LOG.warn("This is a warning log message");
LOG.error("This is an error log message");
}
}
In the above sample code, we used LOG to record different levels of logs in MainActivity.
3. Summary
The log output formatting technology in the logback Android framework is implemented by the PatternLayout class. Developers can use the output format of the log in the logo.In practice, we can set the parameters of the PatternLayouTenCoder class to define the output format of the log.The logback android framework is a powerful Android log framework that provides rich configuration options and flexible log processing capabilities.By correcting the logging format of the log, we can make the log information easier to read and manage.
