[core] Add hashCode to AbstractFileStoreTable for consistency with equals (#7616)

Author: wayneli-vt

paimon-core/src/main/java/org/apache/paimon/table/AbstractFileStoreTable.java

@@ -796,4 +796,9 @@ public boolean equals(Object o) {
         AbstractFileStoreTable that = (AbstractFileStoreTable) o;
         return Objects.equals(path, that.path) && Objects.equals(tableSchema, that.tableSchema);
     }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(path, tableSchema);
+    }
 }

paimon-core/src/test/java/org/apache/paimon/table/AppendOnlySimpleTableTest.java

@@ -1565,6 +1565,33 @@ public void testBatchOrderWithCompaction() throws Exception {
         }
     }
 
+    @Test
+    public void testEqualsAndHashCode() throws Exception {
+        // Test same table equals and hashCode consistency
+        FileStoreTable table1 = createFileStoreTable();
+        FileStoreTable table2 = table1.copy(table1.schema());
+        assertThat(table1.equals(table2)).isTrue();
+        assertThat(table1.hashCode()).isEqualTo(table2.hashCode());
+
+        // Test with different options
+        Map<String, String> optionsWithMock = new HashMap<>(table1.schema().options());
+        optionsWithMock.put("mockKey", "mockValue");
+        TableSchema schemaWithMock = table1.schema().copy(optionsWithMock);
+        FileStoreTable tableWithMock = table1.copy(schemaWithMock);
+
+        assertThat(table1.equals(tableWithMock)).isFalse();
+        assertThat(table1.hashCode()).isNotEqualTo(tableWithMock.hashCode());
+
+        // Test same options should be equal
+        Map<String, String> sameOptionsWithMock = new HashMap<>(table1.schema().options());
+        sameOptionsWithMock.put("mockKey", "mockValue");
+        TableSchema sameSchemaWithMock = table1.schema().copy(sameOptionsWithMock);
+        FileStoreTable sameTableWithMock = table1.copy(sameSchemaWithMock);
+
+        assertThat(tableWithMock.equals(sameTableWithMock)).isTrue();
+        assertThat(tableWithMock.hashCode()).isEqualTo(sameTableWithMock.hashCode());
+    }
+
     private void writeData() throws Exception {
         writeData(options -> {});
     }

paimon-core/src/test/java/org/apache/paimon/table/PrimaryKeySimpleTableTest.java

@@ -2473,6 +2473,33 @@ public void testForceLookupCompaction(CoreOptions.MergeEngine mergeEngine) throw
                                 "1|10|100|binary|varbinary|mapKey:mapVal|multiset"));
     }
 
+    @Test
+    public void testEqualsAndHashCode() throws Exception {
+        // Test same table equals and hashCode consistency
+        FileStoreTable table1 = createFileStoreTable();
+        FileStoreTable table2 = table1.copy(table1.schema());
+        assertThat(table1.equals(table2)).isTrue();
+        assertThat(table1.hashCode()).isEqualTo(table2.hashCode());
+
+        // Test with different options
+        Map<String, String> optionsWithMock = new HashMap<>(table1.schema().options());
+        optionsWithMock.put("mockKey", "mockValue");
+        TableSchema schemaWithMock = table1.schema().copy(optionsWithMock);
+        FileStoreTable tableWithMock = table1.copy(schemaWithMock);
+
+        assertThat(table1.equals(tableWithMock)).isFalse();
+        assertThat(table1.hashCode()).isNotEqualTo(tableWithMock.hashCode());
+
+        // Test same options should be equal
+        Map<String, String> sameOptionsWithMock = new HashMap<>(table1.schema().options());
+        sameOptionsWithMock.put("mockKey", "mockValue");
+        TableSchema sameSchemaWithMock = table1.schema().copy(sameOptionsWithMock);
+        FileStoreTable sameTableWithMock = table1.copy(sameSchemaWithMock);
+
+        assertThat(tableWithMock.equals(sameTableWithMock)).isTrue();
+        assertThat(tableWithMock.hashCode()).isEqualTo(sameTableWithMock.hashCode());
+    }
+
     private void assertReadChangelog(int id, FileStoreTable table) throws Exception {
         // read the changelog at #{id}
         table = table.copy(singletonMap(CoreOptions.SCAN_SNAPSHOT_ID.key(), String.valueOf(id)));