A first pass to correctly convert between c char strings to Java Strings.

src/main/headers/generic.h

@@ -22,6 +22,63 @@ extern void mark_failed_with_errno(JNIEnv *env, const char* message, jobject res
  */
 extern void mark_failed_with_code(JNIEnv *env, const char* message, int error_code, jobject result);
 
+typedef struct wchar_struct {
+    // Not NULL terminated
+    wchar_t* chars;
+    // number of characters in the string
+    size_t len;
+    jstring source;
+    JNIEnv *env;
+} wchar_str;
+
+/*
+ * Converts the given Java string to a wchar_str. Should call wchar_str_free() when finished.
+ *
+ * Returns NULL on failure.
+ */
+extern wchar_str*
+java_to_wchar_str(JNIEnv *env, jstring string, jobject result);
+
+/*
+ * Releases resources used by the given string.
+ */
+extern void wchar_str_free(wchar_str* str);
+
+/*
+ * Converts the given wchar_t string to a Java string.
+ *
+ * Returns NULL on failure.
+ */
+extern jstring wchar_to_java(JNIEnv* env, const wchar_t* chars, size_t len, jobject result);
+
+typedef struct char_struct {
+    // NULL terminated
+    char* chars;
+    // Number of chars in the string, excluding the NULL terminator
+    size_t len;
+    jstring source;
+    JNIEnv *env;
+} char_str;
+
+/*
+ * Converts the given Java string to a char_str. Should call char_str_free() when finished.
+ *
+ * Returns NULL on failure.
+ */
+extern char_str* java_to_char_str(JNIEnv *env, jstring string, jobject result);
+
+/*
+ * Releases resources used by the given string.
+ */
+extern void char_str_free(char_str* str);
+
+/*
+ * Converts the given NULL terminated char string to a Java string.
+ *
+ * Returns NULL on failure.
+ */
+extern jstring char_to_java(JNIEnv* env, const char* chars, jobject result);
+
 #ifdef __cplusplus
 }
 #endif