nomis/slf4j-android

SLF4J binding for the Android logger

SLF4J binding for the Android logger

• Does not support SLF4J markers, these will be ignored.
• Compatible with API version 1.

Configuration

• Loads properties from /uk/uuid/slf4j/android/config.properties.
• Configuration can be applied per logger prefix or set the default by omitting the logger prefix.
  • Set the tag for the specified logger prefix: tag.logger-prefix=TagName
  • Set the log level for the specified logger prefix: level.logger-prefix=SUPPRESS|ERROR|WARN|INFO|DEBUG|VERBOSE|NATIVE
  • Show the logger name in short, compact, long format, or show caller stack frame: showName.logger-prefix=false|short|compact|long|caller
  • Show the current thread: showThread.logger-prefix=true|false
• With no tag configured, logger names are automatically compacted to fit the Android 23 character tag limit.
• The default configuration does not show the logger name or the current thread.
• The default log level is NATIVE (use the Android log level for the tag).
  • The Android log level for each tag is cached at the time the logger is constructed.

Example Configuration File

tag=ExampleApplication
showThread=true
showName=short

Maven Central

• Available as uk.uuid.slf4j:slf4j-android.
• The configuration file when using the standard project layout should be located at src/main/resources/uk/uuid/slf4j/android/config.properties.
• Note: There is a bug in android-maven-plugin that makes the runtime scope unusable.

Maven Usage Example

pom.xml:

<dependency>
   <groupId>org.slf4j</groupId>
   <artifactId>slf4j-api</artifactId>
   <version>2.0.7</version>
</dependency>

<dependency>
   <groupId>uk.uuid.slf4j</groupId>
   <artifactId>slf4j-android</artifactId>
   <version>2.0.7-0</version>
</dependency>

Gradle Example

build.gradle:

dependencies {
   compile 'org.slf4j:slf4j-api:2.0.7'
   compile 'uk.uuid.slf4j:slf4j-android:2.0.7-0'
}

slf4j-android's Issues

Thank you!

The "official" SLF4J Android is still 1.6.4.

I hope you can propose to slf4j.org to use your implementation instead :-)

crash in android 2.2: String.isEmpty() and Locale.ROOT not found

slf4j uses methods that are not implemented in android 2.2

• method java.lang.String.isEmpty()
  • referenced from method eu.lp0.slf4j.android.LoggerFactory.getConfig
  • referenced from method eu.lp0.slf4j.android.LoggingConfig.
  • could be easily replaced by ((string == null) || (string.length() == 0))
• Static field java.util.Locale.ROOT
  • referenced 2 times from LoggingConfig.LoggingConfig()
  • could be easily replaced by Locale.US

runtime:

• android 2.2 on emulator
• lib 'org.slf4j', name: 'slf4j-api', version:'1.7.7'
• lib 'eu.lp0.slf4j:slf4j-android:1.7.6-0'

here is the debug output.

I/dalvikvm﹕ Could not find method java.lang.String.isEmpty, referenced from method eu.lp0.slf4j.android.LoggerFactory.getConfig
W/dalvikvm﹕ VFY: unable to resolve virtual method 524: Ljava/lang/String;.isEmpty ()Z
D/dalvikvm﹕ VFY: replacing opcode 0x6e at 0x0010
D/dalvikvm﹕ VFY: dead code 0x0013-0044 in Leu/lp0/slf4j/android/LoggerFactory;.getConfig (Ljava/lang/String;)Leu/lp0/slf4j/android/LoggerConfig;
I/dalvikvm﹕ Could not find method java.lang.String.isEmpty, referenced from method eu.lp0.slf4j.android.LoggingConfig.
W/dalvikvm﹕ VFY: unable to resolve virtual method 524: Ljava/lang/String;.isEmpty ()Z
D/dalvikvm﹕ VFY: replacing opcode 0x6e at 0x006e
D/dalvikvm﹕ DexOpt: couldn't find static field
W/dalvikvm﹕ VFY: unable to resolve static field 195 (ROOT) in Ljava/util/Locale;
D/dalvikvm﹕ VFY: replacing opcode 0x62 at 0x00ce
I/dalvikvm﹕ Could not find method java.lang.String.isEmpty, referenced from method eu.lp0.slf4j.android.LoggingConfig.
W/dalvikvm﹕ VFY: unable to resolve virtual method 524: Ljava/lang/String;.isEmpty ()Z
D/dalvikvm﹕ VFY: replacing opcode 0x6e at 0x00e1
D/dalvikvm﹕ DexOpt: couldn't find static field
W/dalvikvm﹕ VFY: unable to resolve static field 195 (ROOT) in Ljava/util/Locale;
D/dalvikvm﹕ VFY: replacing opcode 0x62 at 0x0120
I/dalvikvm﹕ Could not find method java.lang.String.isEmpty, referenced from method eu.lp0.slf4j.android.LoggingConfig.
W/dalvikvm﹕ VFY: unable to resolve virtual method 524: Ljava/lang/String;.isEmpty ()Z
D/dalvikvm﹕ VFY: replacing opcode 0x6e at 0x0133

W/dalvikvm﹕ Exception Ljava/lang/NoSuchMethodError; thrown during Lde/k3b/android/cellinfo/demo/CellInfoDemoActivity;.
W/dalvikvm﹕ Class init failed in newInstance call (Lde/k3b/android/cellinfo/demo/CellInfoDemoActivity;)
E/AndroidRuntime﹕ FATAL EXCEPTION: main
    java.lang.ExceptionInInitializerError
            ...
            at dalvik.system.NativeStart.main(Native Method)
     Caused by: java.lang.NoSuchMethodError: java.lang.String.isEmpty
            at eu.lp0.slf4j.android.LoggerFactory.getConfig(LoggerFactory.java:143)
            at eu.lp0.slf4j.android.LoggerFactory.getLogger(LoggerFactory.java:64)
            at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:277)
            at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:288)
            at de.k3b.android.cellinfo.demo.CellInfoDemoActivity.(CellInfoDemoActivity.java:34)

...

README.md references Maven Central version that does not exist

The usage instructions reference version 1.7.25-0 on Maven Central, which does not exist. The most recent version available is 1.7.22-0 (http://search.maven.org/#search%7Cgav%7C1%7Cg%3A%22eu.lp0.slf4j%22%20AND%20a%3A%22slf4j-android%22).

Looking at the most recent commit, I assume it was a find and replace mistake.

Getting exception when add it to android studio 2.1.3

i getting Exception as below:
Error:Error converting bytecode to dex:
Cause: com.android.dex.DexException: Multiple dex files define Lorg/slf4j/impl/StaticLoggerBinder;

I am Using Android studio 2.1.3 and java 8

Fatal exception on logging `null`

logger.info(null) on Android throws

java.lang.NullPointerException: println needs a message
at android.util.Log.println_native(Native Method)
at android.util.Log.println(Log.java:357)
at org.slf4j.impl.AndroidLoggerAdapter.logInternal(Unknown)
at org.slf4j.impl.AndroidLoggerAdapter.log(Unknown)
at org.slf4j.impl.AndroidLoggerAdapter.info(Unknown)

but works fine on other server adapters under SLF4J.

Can it support MDC

if it support MDC, will help developer integrate trace chain