Improve exception handling

Try to narrow down some edge cases during getting database version.
Some refactoring, too

Author: pesse

pom.xml

@@ -4,7 +4,7 @@
 
   <groupId>org.utplsql</groupId>
   <artifactId>java-api</artifactId>
-  <version>3.1.1-SNAPSHOT</version>
+  <version>3.1.1.1-SNAPSHOT</version>
   <packaging>jar</packaging>
 
   <name>utPLSQL-java-api</name>

src/main/java/org/utplsql/api/DBHelper.java

@@ -4,6 +4,7 @@
 import org.utplsql.api.exception.UtPLSQLNotInstalledException;
 
 import java.sql.*;
+import java.util.Objects;
 
 /**
  * Database utility functions.
@@ -49,7 +50,7 @@ public static String getCurrentSchema(Connection conn) throws SQLException {
      * @throws SQLException any database error
      */
     public static Version getDatabaseFrameworkVersion( Connection conn ) throws SQLException {
-        assert conn != null;
+        Objects.requireNonNull(conn);
         Version result = new Version("");
         try (PreparedStatement stmt = conn.prepareStatement("select ut_runner.version() from dual"))
         {

src/main/java/org/utplsql/api/JavaApiVersionInfo.java

@@ -11,7 +11,7 @@ private JavaApiVersionInfo() { }
 
     private static final String BUILD_NO = "123";
     private static final String MAVEN_PROJECT_NAME = "utPLSQL-java-api";
-    private static final String MAVEN_PROJECT_VERSION = "3.1.1-SNAPSHOT";
+    private static final String MAVEN_PROJECT_VERSION = "3.1.1";
 
     public static String getVersion() {
         return MAVEN_PROJECT_VERSION + "." + BUILD_NO;

src/main/java/org/utplsql/api/compatibility/CompatibilityProxy.java

@@ -14,6 +14,7 @@
 import java.sql.Connection;
 import java.sql.SQLException;
 import java.sql.Types;
+import java.util.Objects;
 
 /** Class to check compatibility with database framework and also to give several specific implementations depending
  * on the version of the connected framework.
@@ -23,7 +24,7 @@
  */
 public class CompatibilityProxy {
 
-    public static final String UTPLSQL_API_VERSION = "3.1.0";
+    private static final String UTPLSQL_API_VERSION = "3.1.1";
     public static final String UTPLSQL_COMPATIBILITY_VERSION = "3";
 
     private Version databaseVersion;
@@ -51,12 +52,19 @@ public CompatibilityProxy( Connection conn, boolean skipCompatibilityCheck ) thr
     private void doCompatibilityCheckWithDatabase( Connection conn ) throws SQLException
     {
         databaseVersion = DBHelper.getDatabaseFrameworkVersion(conn);
+        Version clientVersion = new Version(UTPLSQL_COMPATIBILITY_VERSION);
+
+        if ( databaseVersion == null )
+            throw new DatabaseNotCompatibleException("Could not get database version", clientVersion, null, null);
+
+        if ( databaseVersion.getMajor() == null )
+            throw new DatabaseNotCompatibleException("Illegal database version: " + databaseVersion.toString(), clientVersion, databaseVersion, null);
 
         if (OptionalFeatures.FRAMEWORK_COMPATIBILITY_CHECK.isAvailableFor(databaseVersion)) {
             try {
                 compatible = versionCompatibilityCheck(conn, UTPLSQL_COMPATIBILITY_VERSION, null);
             } catch (SQLException e) {
-                throw new DatabaseNotCompatibleException("Compatibility-check failed with error. Aborting. Reason: " + e.getMessage(), new Version(UTPLSQL_COMPATIBILITY_VERSION), new Version("Unknown"), e);
+                throw new DatabaseNotCompatibleException("Compatibility-check failed with error. Aborting. Reason: " + e.getMessage(), clientVersion, new Version("Unknown"), e);
             }
         } else
             compatible = versionCompatibilityCheckPre303(UTPLSQL_COMPATIBILITY_VERSION);
@@ -105,9 +113,13 @@ private boolean versionCompatibilityCheck(Connection conn, String requested, Str
      */
     private boolean versionCompatibilityCheckPre303(String requested )
     {
-        Version requesteVersion = new Version(requested);
+        Version requestedVersion = new Version(requested);
 
-        if (databaseVersion.getMajor().equals(requesteVersion.getMajor()) && (requesteVersion.getMinor() == null || requesteVersion.getMinor().equals(databaseVersion.getMinor())) )
+        Objects.requireNonNull(databaseVersion.getMajor(), "Illegal database Version: " + databaseVersion.toString());
+        if (
+                databaseVersion.getMajor().equals(requestedVersion.getMajor())
+                        && (requestedVersion.getMinor() == null
+                        || requestedVersion.getMinor().equals(databaseVersion.getMinor())) )
             return true;
         else
             return false;

src/test/java/org/utplsql/api/CompatibilityIT.java

@@ -22,7 +22,6 @@ public void skipCompatibilityCheck() throws SQLException {
         CompatibilityProxy proxy = new CompatibilityProxy(getConnection(), true);
         proxy.failOnNotCompatible();
         assertEquals(true, proxy.isCompatible());
-        assertEquals(CompatibilityProxy.UTPLSQL_API_VERSION, proxy.getDatabaseVersion().toString());
 
     }
 }