[SQLLINE-183] Add wrapper around DatabaseMetaData, to make SQLLine le…

…ss susceptible to errors in underlying JDBC driver

Wrapper uses reflection, and handles method-not-supported exceptions.
In future it could perhaps handle other exceptions, and do caching.

Add a test emulating hive behaviour with method not supported.

Add "strictJdbc" property to mark whether we should use default values
when hitting not-supported/not-implemented methods of DatabaseMetaData.

src/docbkx/manual.xml

@@ -3026,6 +3026,16 @@ java.sql.SQLException: ORA-00942: table or view does not exist
           <literal>true</literal>.
         </para>
       </sect1>
+      <sect1 id="setting_silent">
+        <title>silent</title>
+        <para>
+            If <literal>false</literal>, then use default values
+            defined by <literal>java.sql.DatabaseMetaData</literal>
+            in case an implementation of this interface fails with
+            e.g. "Method not supported", otherwise it also fails.
+            Defaults to <literal>false</literal>.
+        </para>
+      </sect1>
       <sect1 id="setting_silent">
         <title>silent</title>
         <para>

src/main/java/sqlline/BuiltInProperty.java

@@ -65,6 +65,7 @@ public enum BuiltInProperty implements SqlLineProperty {
   SHOW_HEADER("showHeader", Type.BOOLEAN, true),
   SHOW_NESTED_ERRS("showNestedErrs", Type.BOOLEAN, false),
   SHOW_WARNINGS("showWarnings", Type.BOOLEAN, true),
+  STRICT_JDBC("strictJdbc", Type.BOOLEAN, false),
   TIME_FORMAT("timeFormat", Type.STRING, DEFAULT),
   TIMEOUT("timeout", Type.INTEGER, -1),
   TIMESTAMP_FORMAT("timestampFormat", Type.STRING, DEFAULT),

src/main/java/sqlline/Commands.java

@@ -200,14 +200,12 @@ public void metadata(
         return;
       }
 
-      Object res = sqlLine.getReflector().invoke(sqlLine.getDatabaseMetaData(),
-          DatabaseMetaData.class, cmd, argList);
+      final Object res = sqlLine.getReflector()
+          .invoke(sqlLine.getDatabaseMetaData(), DatabaseMetaDataWrapper.class,
+              cmd, argList);
       if (res instanceof ResultSet) {
-        ResultSet rs = (ResultSet) res;
-        try {
+        try (ResultSet rs = (ResultSet) res) {
           sqlLine.print(rs, callback);
-        } finally {
-          rs.close();
         }
       } else if (res != null) {
         sqlLine.output(res.toString());

src/main/java/sqlline/DatabaseConnection.java

@@ -25,7 +25,7 @@
 class DatabaseConnection {
   private final SqlLine sqlLine;
   Connection connection;
-  DatabaseMetaData meta;
+  DatabaseMetaDataWrapper meta;
   private final String driver;
   private final String url;
   private final Properties info;
@@ -128,7 +128,7 @@ boolean connect() throws SQLException {
     // Instead, we use the driver instance to make the connection
 
     connection = theDriver.connect(url, info);
-    meta = connection.getMetaData();
+    meta = new DatabaseMetaDataWrapper(sqlLine, connection.getMetaData());
 
     try {
       sqlLine.debug(
@@ -219,7 +219,7 @@ Schema getSchema() {
     return schema;
   }
 
-  DatabaseMetaData getDatabaseMetaData() {
+  DatabaseMetaDataWrapper getDatabaseMetaData() {
     return meta;
   }