Make slf4j optional, fall back on j.u.logging

In order to avoid the hard dependency on slf4j, this patch
abstracts the Logger interface and LoggerFactory factory to fall
back on a java.util.logging-based implementation if slf4j is not
present.

Fixes #1094

Makefile

@@ -14,7 +14,6 @@ DOCKER_RUN_OPTS=--rm
 MVN:=mvn
 CODESIGN:=docker run $(DOCKER_RUN_OPTS) -v $$PWD:/workdir gotson/rcodesign sign
 SRC:=src/main/java
-JAVA_CLASSPATH:=$(TARGET)/classpath/slf4j-api.jar
 SQLITE_OUT:=$(TARGET)/$(sqlite)-$(OS_NAME)-$(OS_ARCH)
 SQLITE_OBJ?=$(SQLITE_OUT)/sqlite3.o
 SQLITE_ARCHIVE:=$(TARGET)/$(sqlite)-amal.zip
@@ -44,19 +43,15 @@ $(SQLITE_UNPACKED): $(SQLITE_ARCHIVE)
 	(mv $(TARGET)/tmp.$(version)/$(SQLITE_AMAL_PREFIX) $(TARGET) && rmdir $(TARGET)/tmp.$(version)) || mv $(TARGET)/tmp.$(version)/ $(TARGET)/$(SQLITE_AMAL_PREFIX)
 	touch $@
 
-$(JAVA_CLASSPATH):
-	@mkdir -p $(@D)
-	curl -L -f -o$@ https://search.maven.org/remotecontent?filepath=org/slf4j/slf4j-api/1.7.36/slf4j-api-1.7.36.jar
-
 $(TARGET)/common-lib/org/sqlite/%.class: src/main/java/org/sqlite/%.java
 	@mkdir -p $(@D)
 	$(JAVAC) -source 1.6 -target 1.6 -sourcepath $(SRC) -d $(TARGET)/common-lib $<
 
 jni-header: $(TARGET)/common-lib/NativeDB.h
 
-$(TARGET)/common-lib/NativeDB.h: src/main/java/org/sqlite/core/NativeDB.java $(JAVA_CLASSPATH)
+$(TARGET)/common-lib/NativeDB.h: src/main/java/org/sqlite/core/NativeDB.java
 	@mkdir -p $(TARGET)/common-lib
-	$(JAVAC) -cp $(JAVA_CLASSPATH) -d $(TARGET)/common-lib -sourcepath $(SRC) -h $(TARGET)/common-lib src/main/java/org/sqlite/core/NativeDB.java
+	$(JAVAC) -d $(TARGET)/common-lib -sourcepath $(SRC) -h $(TARGET)/common-lib src/main/java/org/sqlite/core/NativeDB.java
 	mv target/common-lib/org_sqlite_core_NativeDB.h target/common-lib/NativeDB.h
 
 test:

Makefile.common

@@ -9,24 +9,20 @@ JAVAC := "$$JAVA_HOME/bin/javac"
 JAVAH := "$$JAVA_HOME/bin/javah"
 
 TARGET := target
-SRC:=src/main/java
 OSINFO_CLASS := org.sqlite.util.OSInfo
 OSINFO_PROG := lib/org/sqlite/util/OSInfo.class
-JAVA_CLASSPATH:=$(TARGET)/classpath/slf4j-api.jar
 
 ## building OSInfo.java
 ifeq ("$(wildcard $(OSINFO_PROG))","")
 $(info Building OSInfo tool)
-$(shell mkdir -p $(TARGET)/classpath)
-$(shell curl -L -f -o$(JAVA_CLASSPATH) https://search.maven.org/remotecontent?filepath=org/slf4j/slf4j-api/1.7.36/slf4j-api-1.7.36.jar)
-$(shell $(JAVAC) -cp $(JAVA_CLASSPATH) -sourcepath $(SRC) -d lib src/main/java/org/sqlite/util/OSInfo.java)
+$(shell $(JAVAC) -cp src/main/java -d lib src/main/java/org/sqlite/util/OSInfo.java)
 endif
 
 ifndef OS_NAME
-OS_NAME := $(shell $(JAVA) -cp lib:$(JAVA_CLASSPATH) $(OSINFO_CLASS) --os)
+OS_NAME := $(shell $(JAVA) -cp lib $(OSINFO_CLASS) --os)
 endif
 ifndef OS_ARCH
-OS_ARCH := $(shell $(JAVA) -cp lib:$(JAVA_CLASSPATH) $(OSINFO_CLASS) --arch)
+OS_ARCH := $(shell $(JAVA) -cp lib $(OSINFO_CLASS) --arch)
 endif
 
 # Windows uses different path separators
@@ -59,7 +55,7 @@ ifeq (,$(findstring $(strip $(target)),$(known_targets)))
   target := Default
 endif
 
-$(info Will build using target: $(target) (detected os: $(OS_NAME), arch: $(OS_ARCH)))
+$(info Will build using target: $(target) (detected os: $(OS_NAME) arch: $(OS_ARCH)))
 
 # cross-compilation toolchain prefix (e.g. "arm-linux-gnueabi-")
 CROSS_PREFIX :=

README.adoc

@@ -29,19 +29,18 @@ SQLite JDBC is a library for accessing SQLite databases through the JDBC API. Fo
 
 . <<Download,Download>> `sqlite-jdbc-{project-version}.jar`
 then append this jar file into your classpath.
-. https://search.maven.org/remotecontent?filepath=org/slf4j/slf4j-api/1.7.36/slf4j-api-1.7.36.jar[Download] `slf4j-api-1.7.36.jar` then append this jar file into your classpath.
 . Open a SQLite database connection from your code. (see the example below)
 
 === Example usage
 
-Assuming `sqlite-jdbc-{project-version}.jar` and `slf4j-api-1.7.36.jar` are placed in the current directory.
+Assuming `sqlite-jdbc-{project-version}.jar` is placed in the current directory.
 
 [source,shell,subs="attributes+"]
 ----
 > javac Sample.java
-> java -classpath ".;sqlite-jdbc-{project-version}.jar;slf4j-api-1.7.36.jar" Sample   # in Windows
+> java -classpath ".;sqlite-jdbc-{project-version}.jar" Sample   # in Windows
 or
-> java -classpath ".:sqlite-jdbc-{project-version}.jar:slf4j-api-1.7.36.jar" Sample   # in macOS or Linux
+> java -classpath ".:sqlite-jdbc-{project-version}.jar" Sample   # in macOS or Linux
 name = leo
 id = 1
 name = yui

pom.xml

@@ -415,6 +415,7 @@
             <groupId>org.slf4j</groupId>
             <artifactId>slf4j-api</artifactId>
             <version>1.7.36</version>
+            <scope>compile</scope>
         </dependency>
         <!--
         This dependency makes compilation on non-GraalVM versions possible.

src/main/java/org/sqlite/JDBC.java

@@ -18,12 +18,12 @@
 
 import java.sql.*;
 import java.util.Properties;
-import java.util.logging.Logger;
-import org.slf4j.LoggerFactory;
 import org.sqlite.jdbc4.JDBC4Connection;
+import org.sqlite.util.Logger;
+import org.sqlite.util.LoggerFactory;
 
 public class JDBC implements Driver {
-    private static final org.slf4j.Logger logger = LoggerFactory.getLogger(JDBC.class);
+    private static final Logger logger = LoggerFactory.getLogger(JDBC.class);
     public static final String PREFIX = "jdbc:sqlite:";
 
     static {
@@ -49,7 +49,7 @@ public boolean jdbcCompliant() {
         return false;
     }
 
-    public Logger getParentLogger() throws SQLFeatureNotSupportedException {
+    public java.util.logging.Logger getParentLogger() throws SQLFeatureNotSupportedException {
         // TODO
         return null;
     }

src/main/java/org/sqlite/SQLiteJDBCLoader.java

@@ -39,9 +39,9 @@
 import java.util.Properties;
 import java.util.UUID;
 import java.util.stream.Stream;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 import org.sqlite.util.LibraryLoaderUtil;
+import org.sqlite.util.Logger;
+import org.sqlite.util.LoggerFactory;
 import org.sqlite.util.OSInfo;
 import org.sqlite.util.StringUtils;
 

src/main/java/org/sqlite/core/NativeDB.java

@@ -19,14 +19,14 @@
 import java.nio.ByteBuffer;
 import java.nio.charset.StandardCharsets;
 import java.sql.SQLException;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 import org.sqlite.BusyHandler;
 import org.sqlite.Collation;
 import org.sqlite.Function;
 import org.sqlite.ProgressHandler;
 import org.sqlite.SQLiteConfig;
 import org.sqlite.SQLiteJDBCLoader;
+import org.sqlite.util.Logger;
+import org.sqlite.util.LoggerFactory;
 
 /** This class provides a thin JNI layer over the SQLite3 C API. */
 public final class NativeDB extends DB {

src/main/java/org/sqlite/jdbc3/JDBC3DatabaseMetaData.java

@@ -21,12 +21,12 @@
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 import java.util.stream.Collectors;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 import org.sqlite.SQLiteConnection;
 import org.sqlite.core.CoreDatabaseMetaData;
 import org.sqlite.core.CoreStatement;
 import org.sqlite.jdbc3.JDBC3DatabaseMetaData.ImportedKeyFinder.ForeignKey;
+import org.sqlite.util.Logger;
+import org.sqlite.util.LoggerFactory;
 import org.sqlite.util.QueryUtils;
 import org.sqlite.util.StringUtils;
 

src/main/java/org/sqlite/jdbc3/JDBC3Statement.java

@@ -8,14 +8,14 @@
 import java.sql.SQLWarning;
 import java.sql.Statement;
 import java.util.Arrays;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 import org.sqlite.ExtendedCommand;
 import org.sqlite.ExtendedCommand.SQLExtension;
 import org.sqlite.SQLiteConnection;
 import org.sqlite.core.CoreStatement;
 import org.sqlite.core.DB;
 import org.sqlite.core.DB.ProgressObserver;
+import org.sqlite.util.Logger;
+import org.sqlite.util.LoggerFactory;
 
 public abstract class JDBC3Statement extends CoreStatement {
 

src/main/java/org/sqlite/util/OSInfo.java

@@ -31,8 +31,6 @@
 import java.util.HashMap;
 import java.util.Locale;
 import java.util.stream.Stream;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 /**
  * Provides OS name and architecture name.

src/test/java/org/sqlite/architecture/CodingRulesTest.java

@@ -35,8 +35,6 @@ void no_access_to_standard_streams(JavaClasses importedClasses) {
 
     @ArchTest private final ArchRule no_jodatime = NO_CLASSES_SHOULD_USE_JODATIME;
 
-    @ArchTest private final ArchRule no_java_util_logging = NO_CLASSES_SHOULD_USE_JAVA_UTIL_LOGGING;
-
     @ArchTest
     private final ArchRule no_driver_manager_println =
             noClasses()