Add support Java bindings

This add support for Java bindings in the bindings/java directory.

bindings/java/rs_src/errors.rs

@@ -0,0 +1,35 @@
+use jni::errors::{Error, JniError};
+
+#[derive(Debug, Clone)]
+pub struct CustomError {
+    pub message: String,
+}
+
+/// This struct defines error codes that correspond to the constants defined in the
+/// Java package `org.github.tursodatabase.exceptions.ErrorCode`.
+///
+/// These error codes are used to handle and represent specific error conditions
+/// that may occur within the Rust code and need to be communicated to the Java side.
+#[derive(Clone)]
+pub struct ErrorCode;
+
+impl ErrorCode {
+    pub const CONNECTION_FAILURE: i32 = -1;
+
+    pub const STATEMENT_IS_DML: i32 = -1;
+}
+
+impl From<jni::errors::Error> for CustomError {
+    fn from(value: Error) -> Self {
+        CustomError {
+            message: value.to_string(),
+        }
+    }
+}
+
+impl From<CustomError> for JniError {
+    fn from(value: CustomError) -> Self {
+        eprintln!("Error occurred: {:?}", value.message);
+        JniError::Other(-1)
+    }
+}