improve JDBC docs

Author: mlin

docs/guide_db.md

@@ -21,6 +21,7 @@ First complete the [installation instructions](index.md).
 === "Java"
     ```java
     import java.sql.*;
+    import org.sqlite.SQLiteConfig;
     import net.mlin.genomicsqlite.GenomicSQLite;
     ```
 
@@ -102,14 +103,14 @@ First complete the [installation instructions](index.md).
 
 === "Java"
     ```java
-    java.util.Properties config = new java.util.Properties();
-    config.setProperty("genomicsqlite.config_json", "{}");
-    // Properties may originate from org.sqlite.SQLiteConfig.toProperties()
-    // with genomicsqlite.config_json added in.
+    SQLiteConfig config = new SQLiteConfig();
+    // config.setReadOnly(true)
+    // (or other sqlite-jdbc settings as needed)
+    java.util.Properties props = config.toProperties();
+    props.setProperty("genomicsqlite.config_json", "{}");
 
     Connection dbconn = DriverManager.getConnection(
-      "jdbc:genomicsqlite:" + dbfileName,
-      config
+      "jdbc:genomicsqlite:" + dbfileName, props
     );
     ```
 

docs/index.md

@@ -65,7 +65,23 @@ It's usually easiest to obtain the extension as a pre-compiled shared library (L
       </dependency>
     </dependencies>
     ```
-    Or, download the JAR from [GitHub Releases](https://github.com/mlin/GenomicSQLite/releases) and place it in your classpath, along with [sqlite-jdbc](https://github.com/xerial/sqlite-jdbc)'s JAR which is also required. The package loads a bundled shared library by default. To override the bundled file, set environment variable `LIBGENOMICSQLITE` to a filename.
+
+    Or to your `build.gradle`:
+    ```groovy
+    repositories {
+      maven {
+        url 'https://raw.githubusercontent.com/wiki/mlin/GenomicSQLite/mvn-repo/'
+      }
+    }
+
+    dependencies {
+      compile group: 'net.mlin', name: 'genomicsqlite-jdbc', version: 'vX.Y.Z'
+    }
+    ```
+
+    Alternatively, download the JAR from [GitHub Releases](https://github.com/mlin/GenomicSQLite/releases) and place it in your classpath, along with [sqlite-jdbc](https://github.com/xerial/sqlite-jdbc)'s JAR which is also required. The package loads a bundled shared library by default. To override the bundled file, set environment variable `LIBGENOMICSQLITE` to a filename.
+
+    To bundle GenomicSQLite and sqlite-jdbc inside an "Uber JAR" for your application, you may need to enable the [ServicesResourceTransformer for Maven Shade](https://maven.apache.org/plugins/maven-shade-plugin/examples/resource-transformers.html#ServicesResourceTransformer) or [mergeServiceFiles() for Gradle Shadow](https://stackoverflow.com/questions/32887966/shadow-plugin-gradle-what-does-mergeservicefiles-do), to ensure the JDBC drivers will be registered automatically when the "Uber JAR" loads.
 
     Recommendation: *also* install the Python package, which includes a useful command-line shell and smoke-test script.