feat: added new methods for inserting properties at specific positions

src/main/java/org/codejive/properties/Properties.java

@@ -389,6 +389,50 @@ public String put(String key, String value) {
         return values.put(key, value);
     }
 
+    /**
+     * Associates the specified value with the specified key at the position indicated by the
+     * cursor. The cursor must point to the start of a line, or to the end of the token list. If the
+     * key already exists, its value is replaced at its existing position.
+     *
+     * @param pos position at which to insert the property
+     * @param key key with which the specified value is to be associated
+     * @param value value to be associated with the specified key
+     * @return the previous value associated with key, or null if there was no mapping for key
+     * @throws IllegalArgumentException if the cursor is not at a valid insertion position
+     */
+    public String put(Cursor pos, String key, String value) {
+        Objects.requireNonNull(pos, "pos");
+        if (key == null || value == null) {
+            throw new NullPointerException();
+        }
+        String rawValue = escapeValue(value);
+        if (values.containsKey(key)) {
+            replaceValue(key, rawValue, value);
+        } else {
+            String rawKey = escapeKey(key);
+            addNewKeyValue(pos, rawKey, key, rawValue, value);
+        }
+        return values.put(key, value);
+    }
+
+    /**
+     * Associates the specified value with the specified key at the position indicated by the
+     * cursor. The cursor must point to the start of a line, or to the end of the token list. If the
+     * key already exists, its value is replaced at its existing position. If any comment lines are
+     * supplied they will be prepended to the property.
+     *
+     * @param pos position at which to insert the property
+     * @param key key with which the specified value is to be associated
+     * @param value value to be associated with the specified key
+     * @param comment comment lines to be associated with the specified key
+     * @return the previous value associated with key, or null if there was no mapping for key
+     */
+    public String putCommented(Cursor pos, String key, String value, String... comment) {
+        String old = put(pos, key, value);
+        setComment(key, comment);
+        return old;
+    }
+
     /**
      * Associates the specified value with the specified key in this properties table. If the
      * properties previously contained a mapping for the key, the old value is replaced. If any

src/test/java/org/codejive/properties/TestProperties.java

@@ -797,6 +797,31 @@ void testPutNew() throws IOException, URISyntaxException {
         assertThat(sw.toString()).isEqualTo(readAll(getResource("/test-putnew.properties")));
     }
 
+    @Test
+    void testPutAtPosition() throws IOException {
+        Properties p = Properties.loadProperties(new StringReader("alpha=1\nbeta=2\n"));
+
+        assertThat(p.put(p.beforeProperty("beta"), "middle", "3")).isNull();
+
+        StringWriter sw = new StringWriter();
+        p.store(sw);
+        assertThat(sw.toString()).isEqualTo("alpha=1\nmiddle=3\nbeta=2\n");
+        assertThat(p).containsEntry("middle", "3");
+    }
+
+    @Test
+    void testPutAtInvalidPosition() throws IOException {
+        Properties p = Properties.loadProperties(new StringReader("alpha=1\nbeta=2\n"));
+
+        Cursor separator = p.indexOf("beta").next();
+        assertThat(p.put(separator, "middle", "3")).isNull();
+
+        StringWriter sw = new StringWriter();
+        p.store(sw);
+        assertThat(sw.toString()).isEqualTo("alpha=1\nmiddle=3\nbeta=2\n");
+        assertThat(p).containsEntry("middle", "3");
+    }
+
     @Test
     void testPutNewTest2() throws IOException, URISyntaxException {
         Path f = getResource("/test2.properties");