0.2: added mandatory context supplier

Author: jacek99

README.md

@@ -133,6 +133,17 @@ and you would get:
     Error occurred during batch processing [email protected] tenantId=SOME_TENANT_ID errorMessage="ORA-14094: Oracle Hates You" hostname=DEV_SERVER1
     ...followed by regular full stack trace of the exception...
 
+## Specifying mandatory context key/value pairs
+
+If you have specific key/value pairs that you would like logged automatically with every log entry (host nanem and service name are a good example),
+then you just have to specify a mandatory context lambda:
+
+    StructLog4J.setMandatoryContextSupplier(() -> new Object[]{
+        "hostname", InetAddress.getLocalHost().getHostName(),
+        "serviceName","MyService"});
+
+Now these mandatory key/value pairs will be logged automatically on **every** log entry, without the need to specify them manually.
+
 # License
 
 MIT License.

gradle.properties

@@ -1,6 +1,6 @@
 org.gradle.daemon=true
 
-version = 0.1.0
+version = 0.2.0
 
 group = structlog4j
 

structlog4j-api/src/main/java/com/github/structlog4j/ILogger.java

@@ -6,9 +6,18 @@
  * @author Jacek Furmankiewicz
  */
 public interface ILogger {
+
+    //logging APIs
     public void error(String message, Object...params);
     public void warn(String message, Object...params);
     public void info(String message, Object...params);
     public void debug(String message, Object...params);
     public void trace(String message, Object...params);
+
+    // logging level checks, usually never needed but we add them for completion
+    public boolean isErrorEnabled();
+    public boolean isWarnEnabled();
+    public boolean isInfoEnabled();
+    public boolean isDebugEnabled();
+    public boolean isTraceEnabled();
 }

structlog4j-api/src/main/java/com/github/structlog4j/IToLog.java

@@ -8,6 +8,7 @@
  *
  * @author Jacek Furmankiewicz
  */
+@FunctionalInterface
 public interface IToLog {
 
     /**

structlog4j-api/src/main/java/com/github/structlog4j/SLogger.java

@@ -6,6 +6,8 @@
 import org.slf4j.LoggerFactory;
 import org.slf4j.event.Level;
 
+import java.util.Optional;
+
 /**
  * Concrete implementation of the ILogger interface
  *
@@ -64,6 +66,31 @@ public void trace(String message, Object... params) {
         }
     }
 
+    @Override
+    public boolean isErrorEnabled() {
+        return slfjLogger.isErrorEnabled();
+    }
+
+    @Override
+    public boolean isWarnEnabled() {
+        return slfjLogger.isWarnEnabled();
+    }
+
+    @Override
+    public boolean isInfoEnabled() {
+        return slfjLogger.isInfoEnabled();
+    }
+
+    @Override
+    public boolean isDebugEnabled() {
+        return slfjLogger.isDebugEnabled();
+    }
+
+    @Override
+    public boolean isTraceEnabled() {
+        return slfjLogger.isTraceEnabled();
+    }
+
     private void log(Level level, String message, Object...params) {
         try {
             // just in case...
@@ -116,6 +143,12 @@ private void log(Level level, String message, Object...params) {
                 }
             }
 
+            // add mandatory context, if specified
+            Optional<IToLog> mandatory = StructLog4J.getMandatoryContextSupplier();
+            if (mandatory.isPresent()) {
+                handleIToLog(formatter,bld,mandatory.get());
+            }
+
             formatter.end(bld);
 
             // actual logging via SLF4J

structlog4j-api/src/main/java/com/github/structlog4j/StructLog4J.java

@@ -4,6 +4,8 @@
 import com.github.structlog4j.format.KeyValuePairFormatter;
 import lombok.experimental.UtilityClass;
 
+import java.util.Optional;
+
 /**
  * Common settings
  *
@@ -13,6 +15,7 @@
 public class StructLog4J {
 
     private IFormatter formatter = KeyValuePairFormatter.getInstance();
+    private Optional<IToLog> mandatoryContextSupplier = Optional.empty();
 
     // thread local StringBuilder used for all log concatenation
     final ThreadLocal<StringBuilder> BLD = new ThreadLocal<StringBuilder>() {
@@ -26,6 +29,8 @@ public StringBuilder get() {
             super.get().setLength(0);
             return super.get();
         }
+
+        FunctionalInterface t;
     };
 
     /**
@@ -37,8 +42,29 @@ public void setFormatter(IFormatter formatter) {
         StructLog4J.formatter = formatter;
     }
 
-    // Returns the current encoder - internal only
+    /**
+     * Allows to pas in a lambda that will be invoked on every log entry to add additional mandatory
+     * key/value pairs (e.g. hostname, service name, etc). Saves the hassle of having to specify it explicitly
+     * on every log invocation
+     * @param mandatoryContextSupplier Lambda that will executed on every log entry.
+     */
+    public void setMandatoryContextSupplier(IToLog mandatoryContextSupplier) {
+        StructLog4J.mandatoryContextSupplier = Optional.of(mandatoryContextSupplier);
+    }
+
+    // internal
     IFormatter getFormatter() {
         return formatter;
     }
+
+    // internal
+    Optional<IToLog> getMandatoryContextSupplier() {
+        return mandatoryContextSupplier;
+    }
+
+    // internal testing support
+    void clearMandatoryContextSupplier() {
+        mandatoryContextSupplier = Optional.empty();
+    }
+
 }

structlog4j-api/src/test/java/com/github/structlog4j/BasicKeyValuePairTests.java

@@ -25,6 +25,8 @@ public class BasicKeyValuePairTests {
 
     @Before
     public void setup() {
+        StructLog4J.clearMandatoryContextSupplier();
+
         log = (SLogger) SLoggerFactory.getLogger(BasicKeyValuePairTests.class);
         entries = ((TestLogger)log.getSlfjLogger()).getEntries();
     }
@@ -191,6 +193,7 @@ public void kitchenSinkTest() {
 
     @Test
     public void allLevelsTest() {
+
         log.error("Error",iToLog);
         log.warn("Warning",iToLog);
         log.info("Information",iToLog);
@@ -215,4 +218,42 @@ public void allLevelsTest() {
         assertEquals(entries.toString(),"Trace userName=\"Test User\" tenantId=TEST_TENANT",entries.get(4).getMessage());
 
     }
+
+    @Test
+    public void kitchenSinkWithMandatoryContextTest() {
+
+        BusinessObjectContext ctx = new BusinessObjectContext("Country","CA");
+        Throwable rootCause = new RuntimeException("This is the root cause of the error");
+        Throwable t = new RuntimeException("Major exception",rootCause);
+
+        // define mandatory context lambfa
+        StructLog4J.setMandatoryContextSupplier(() -> new Object[]{"hostname","Titanic","serviceName","MyService"});
+
+        // mix and match in different order to ensure it all works
+        log.error("This is an error",iToLog,ctx,"key1",1L,"key2","Value 2",t);
+        log.error("This is an error",t,iToLog,ctx,"key1",1L,"key2","Value 2");
+        log.error("This is an error",iToLog,"key1",1L,t,ctx,"key2","Value 2");
+
+        assertEquals(entries.toString(),3,entries.size());
+        for(LogEntry entry : entries) {
+            assertEquals(entries.toString(), Level.ERROR,entry.getLevel());
+            assertTrue(entries.toString(), entry.getError().isPresent());
+        }
+
+        // all messages should have mandatory context fields specified at the end
+
+        // first
+        assertEquals(entries.toString(),"This is an error userName=\"Test User\" tenantId=TEST_TENANT entityName=Country entityId=CA key1=1 key2=\"Value 2\" errorMessage=\"This is the root cause of the error\" hostname=Titanic serviceName=MyService",
+                entries.get(0).getMessage());
+        // second
+        assertEquals(entries.toString(),"This is an error errorMessage=\"This is the root cause of the error\" userName=\"Test User\" tenantId=TEST_TENANT entityName=Country entityId=CA key1=1 key2=\"Value 2\" hostname=Titanic serviceName=MyService",
+                entries.get(1).getMessage());
+        // third
+        assertEquals(entries.toString(),"This is an error userName=\"Test User\" tenantId=TEST_TENANT key1=1 errorMessage=\"This is the root cause of the error\" entityName=Country entityId=CA key2=\"Value 2\" hostname=Titanic serviceName=MyService",
+                entries.get(2).getMessage());
+    }
+
+
+
+
 }

structlog4j-api/src/test/java/com/github/structlog4j/ErrorKeyValuePairTests.java

@@ -3,7 +3,6 @@
 import static org.junit.Assert.*;
 
 import com.github.structlog4j.samples.TestSecurityContext;
-import oracle.jrockit.jfr.jdkevents.ThrowableTracer;
 import org.junit.Before;
 import org.junit.Test;
 import org.slf4j.impl.LogEntry;
@@ -21,6 +20,8 @@ public class ErrorKeyValuePairTests {
 
     @Before
     public void setup() {
+        StructLog4J.clearMandatoryContextSupplier();
+
         log = (SLogger) SLoggerFactory.getLogger(BasicKeyValuePairTests.class);
         entries = ((TestLogger)log.getSlfjLogger()).getEntries();
     }