chore(jdbc): suppress expected compiler warnings

libsql-conformance/pom.xml

@@ -163,6 +163,23 @@
                     </execution>
                 </executions>
             </plugin>
+            <plugin>
+                <!-- The vendored xerial tests use deprecated JDBC API on purpose.
+                     Suppress the deprecation detail and javac's summary note for the test compile. -->
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <executions>
+                    <execution>
+                        <id>default-testCompile</id>
+                        <configuration>
+                            <compilerArgs combine.children="append">
+                                <arg>-Xlint:-deprecation</arg>
+                                <arg>-XDsuppressNotes</arg>
+                            </compilerArgs>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-surefire-plugin</artifactId>

libsql-jdbc/src/main/java/com/github/magnusp/libsql/jdbc/LibsqlPreparedStatement.java

@@ -52,6 +52,9 @@ public class LibsqlPreparedStatement extends LibsqlStatement implements Prepared
     // Sequential list indexed by JDBC parameter position; no map or boxing overhead.
     private final List<Value> parameters = new ArrayList<>();
 
+    // ParameterMetaDataView only stores this reference and calls checkClosed() after construction,
+    // so no subclass method can run against a half-built statement.
+    @SuppressWarnings("this-escape")
     public LibsqlPreparedStatement(LibsqlConnection connection, String sql) {
         super(connection);
         this.sql = sql;

libsql-jdbc/src/test/java/com/github/magnusp/libsql/jdbc/LibsqlPreparedStatementTest.java

@@ -409,6 +409,8 @@ void unsetParametersBindNullArguments() throws SQLException {
                 .containsExactly(Value.of(7L), Value.ofNull());
     }
 
+    // The deprecated Unicode stream setter is part of the local-conversion contract.
+    @SuppressWarnings("deprecation")
     @Test
     void streamSettersBindLocalConversions() throws SQLException {
         RecordingConnection connection = new RecordingConnection(NO_ROWS);

libsql-jdbc/src/test/java/com/github/magnusp/libsql/jdbc/LibsqlResultSetTest.java

@@ -457,6 +457,8 @@ void findColumnRejectsNullLabel() {
                 .hasMessageContaining("null");
     }
 
+    // The deprecated Unicode stream getters are part of the unsupported-method contract.
+    @SuppressWarnings("deprecation")
     @Test
     void everyUnsupportedMethodThrowsSqlFeatureNotSupportedException() throws SQLException {
         LibsqlResultSet rs = resultSet(new Value.Integer(1));