java: use reflection to get private methods

Author: drinckes

java/src/main/java/com/google/openlocationcode/OpenLocationCode.java

@@ -200,7 +200,7 @@ public OpenLocationCode(double latitude, double longitude, int codeLength) {
    * @param codeLength The requested number of digits.
    * @return The OLC for the location.
    */
-  static String encodeIntegers(long lat, long lng, int codeLength) {
+  private static String encodeIntegers(long lat, long lng, int codeLength) {
     // Limit the maximum number of digits in the code.
     codeLength = Math.min(codeLength, MAX_DIGIT_COUNT);
     // Check that the code length requested is valid.

java/src/test/java/com/google/openlocationcode/EncodingTest.java

@@ -6,6 +6,7 @@
 import java.io.FileInputStream;
 import java.io.InputStream;
 import java.io.InputStreamReader;
+import java.lang.reflect.Method;
 import java.util.ArrayList;
 import java.util.List;
 
@@ -72,9 +73,14 @@ public void testEncodeFromLatLong() {
   }
 
   @Test
-  public void testDegreesToIntegers() {
+  public void testDegreesToIntegers() throws Exception {
+    // The method to test is private, we use reflection to get it to avoid changing the visibility.
+    OpenLocationCode olcClass = new OpenLocationCode(null);
+    Method privateMethod = OpenLocationCode.class.getDeclaredMethod("degreesToIntegers", int.class, int.class);
+    privateMethod.setAccessible(true);
+
     for (TestData testData : testDataList) {
-      long[] got = OpenLocationCode.degreesToIntegers(testData.latitudeDegrees, testData.longitudeDegrees);
+      long[] got = (long[]) privateMethod.invoke(olcClass, testData.latitudeDegrees, testData.longitudeDegrees);
       Assert.assertEquals(
           String.format("Latitude %f integer conversion is incorrect", testData.latitudeDegrees),
           testData.latitudeInteger,
@@ -87,14 +93,20 @@ public void testDegreesToIntegers() {
   }
 
   @Test
-  public void testEncodeIntegers() {
+  public void testEncodeIntegers() throws Exception {
+    // The method to test is private, we use reflection to get it to avoid changing the visibility.
+    OpenLocationCode olcClass = new OpenLocationCode(null);
+    Method privateMethod = OpenLocationCode.class.getDeclaredMethod("encodeIntegers", int.class, int.class);
+    privateMethod.setAccessible(true);
+
     for (TestData testData : testDataList) {
+      String got = (String) privateMethod.invoke(olcClass, testData.latitudeInteger, testData.longitudeInteger, testData.length);
       Assert.assertEquals(
           String.format(
               "Latitude %d, longitude %d and length %d were wrongly encoded.",
               testData.latitudeInteger, testData.longitudeInteger, testData.length),
           testData.code,
-          OpenLocationCode.encodeIntegers(testData.latitudeInteger, testData.longitudeInteger, testData.length));
+          got);
     }
   }
 }