From 4afcff940551079617e8f4116e52bb0ef9df7fcc Mon Sep 17 00:00:00 2001
From: Kamal Wickramanayake <kamal@inbox.lk>
Date: Sat, 25 Apr 2026 21:53:33 +0530
Subject: Added Spring Framework sample code

---
 .../main/java/com/example/fp/UserManagerImpl.java  | 78 ++++++++++++++++++++++
 1 file changed, 78 insertions(+)
 create mode 100644 spring-framework/07-user-jdbc-ds-transaction/src/main/java/com/example/fp/UserManagerImpl.java

(limited to 'spring-framework/07-user-jdbc-ds-transaction/src/main/java/com/example/fp/UserManagerImpl.java')

diff --git a/spring-framework/07-user-jdbc-ds-transaction/src/main/java/com/example/fp/UserManagerImpl.java b/spring-framework/07-user-jdbc-ds-transaction/src/main/java/com/example/fp/UserManagerImpl.java
new file mode 100644
index 0000000..ad2a58d
--- /dev/null
+++ b/spring-framework/07-user-jdbc-ds-transaction/src/main/java/com/example/fp/UserManagerImpl.java
@@ -0,0 +1,78 @@
+package com.example.fp;
+
+import java.math.BigInteger;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.util.List;
+
+import com.example.fp.dao.UserDAO;
+
+public class UserManagerImpl implements UserManager {
+
+	private UserDAO userDAO;
+
+	public void setUserDAO(UserDAO userDAO) {
+		this.userDAO = userDAO;
+	}
+
+	@Override
+	public void create(User user) {
+		user.setPassword(calculatePasswordHash(user.getPassword()));
+		userDAO.create(user);
+	}
+
+	@Override
+	public User find(int uid) {
+		return userDAO.find(uid);
+	}
+
+	@Override
+	public List<User> findAll() {
+		return userDAO.findAll();
+	}
+
+	@Override
+	public void delete(int uid) {
+		userDAO.delete(uid);
+	}
+
+	@Override
+	public void update(User user) {
+		userDAO.update(user);
+	}
+
+	@Override
+	public void setPassword(int uid, String plainTextPassword) {
+		User user = userDAO.find(uid);
+
+		user.setPassword(calculatePasswordHash(plainTextPassword));
+
+		userDAO.update(user);
+	}
+
+	public static String calculatePasswordHash(String plainText) {
+
+		try {
+			// Static getInstance method is called with hashing MD5
+			MessageDigest md = MessageDigest.getInstance("MD5");
+
+			// digest() method is called to calculate message digest
+			// of an input digest() return array of byte
+			byte[] messageDigest = md.digest(plainText.getBytes());
+
+			// Convert byte array into signum representation
+			BigInteger no = new BigInteger(1, messageDigest);
+
+			// Convert message digest into hex value
+			String hashtext = no.toString(16);
+			while (hashtext.length() < 32) {
+				hashtext = "0" + hashtext;
+			}
+			
+			return hashtext;
+		} catch (NoSuchAlgorithmException e) {
+			// For specifying wrong message digest algorithms
+			throw new RuntimeException(e);
+		}
+	}
+}
\ No newline at end of file
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