Added spring-boot sample applications

6 files changed, 238 insertions, 0 deletions

diff --git a/spring-boot/03-bank-jdbc-rest/src/main/java/com/example/spring/bank/account/Account.java b/spring-boot/03-bank-jdbc-rest/src/main/java/com/example/spring/bank/account/Account.java
new file mode 100644
index 0000000..4a84f09
--- /dev/null
+++ b/spring-boot/03-bank-jdbc-rest/src/main/java/com/example/spring/bank/account/Account.java
@@ -0,0 +1,21 @@
+package com.example.spring.bank.account;
+
+import java.math.BigDecimal;
+
+public class Account {
+	private int accountNumber;
+	private BigDecimal balance;
+	
+	public int getAccountNumber() {
+		return accountNumber;
+	}
+	public void setAccountNumber(int accountNumber) {
+		this.accountNumber = accountNumber;
+	}
+	public BigDecimal getBalance() {
+		return balance;
+	}
+	public void setBalance(BigDecimal balance) {
+		this.balance = balance;
+	}
+}
diff --git a/spring-boot/03-bank-jdbc-rest/src/main/java/com/example/spring/bank/account/AccountController.java b/spring-boot/03-bank-jdbc-rest/src/main/java/com/example/spring/bank/account/AccountController.java
new file mode 100644
index 0000000..9d229fe
--- /dev/null
+++ b/spring-boot/03-bank-jdbc-rest/src/main/java/com/example/spring/bank/account/AccountController.java
@@ -0,0 +1,23 @@
+package com.example.spring.bank.account;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+@RequestMapping("/account")
+public class AccountController {
+
+	@Autowired
+	private AccountManager accountManager;
+	
+	@GetMapping("/{accno}")
+	public Account getAccount(@PathVariable Integer accno) {
+		Account account = accountManager.find(accno);
+		
+		return account;
+	}
+	
+}
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diff --git a/spring-boot/03-bank-jdbc-rest/src/main/java/com/example/spring/bank/account/AccountManager.java b/spring-boot/03-bank-jdbc-rest/src/main/java/com/example/spring/bank/account/AccountManager.java
new file mode 100644
index 0000000..492ecf9
--- /dev/null
+++ b/spring-boot/03-bank-jdbc-rest/src/main/java/com/example/spring/bank/account/AccountManager.java
@@ -0,0 +1,21 @@
+package com.example.spring.bank.account;
+
+import java.math.BigDecimal;
+
+public interface AccountManager {
+
+	public Account create();
+	
+	public Account find(int accountNumber);
+	
+	public Account deposit(int accountNumber, BigDecimal amount);
+	public Account withdraw(int accountNumber, BigDecimal amount);
+	
+	public void delete(int accountNumber);
+	
+	/** Returns the first account */
+	public Account transfer(int accountNumber1, int accountNumber2, BigDecimal amount);
+
+	public void chargeForLowBalance(BigDecimal minimumBalance, BigDecimal amount);
+	
+}
diff --git a/spring-boot/03-bank-jdbc-rest/src/main/java/com/example/spring/bank/account/AccountManagerImpl.java b/spring-boot/03-bank-jdbc-rest/src/main/java/com/example/spring/bank/account/AccountManagerImpl.java
new file mode 100644
index 0000000..d205e02
--- /dev/null
+++ b/spring-boot/03-bank-jdbc-rest/src/main/java/com/example/spring/bank/account/AccountManagerImpl.java
@@ -0,0 +1,78 @@
+package com.example.spring.bank.account;
+
+import java.math.BigDecimal;
+import java.util.Iterator;
+import java.util.List;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+@Service
+public class AccountManagerImpl implements AccountManager {
+
+	@Autowired
+	private AccountRepository accountDAO;
+	
+	@Override
+	@Transactional
+	public void chargeForLowBalance(BigDecimal minimumBalance, BigDecimal amount) {
+		List<Account> accounts = accountDAO.findAccountsWithLowBalance(minimumBalance);
+		for (Iterator<Account> iterator = accounts.iterator(); iterator.hasNext();) {
+			Account account = (Account) iterator.next();
+			// Check if the balance will go beyond 0. If yes, set the balance to 0
+			account.setBalance(account.getBalance().subtract(amount));
+			accountDAO.update(account);
+		}
+	}
+
+	@Override
+	@Transactional
+	public Account create() {
+		return accountDAO.createAccount();
+	}
+
+	@Override
+	public Account find(int accountNumber) {
+		return accountDAO.getAccount(accountNumber);
+	}
+	
+	@Override
+	@Transactional
+	public void delete(int accountNumber) {
+		accountDAO.delete(accountNumber);
+	}
+
+	@Override
+	@Transactional
+	public Account deposit(int accountNumber, BigDecimal amount) {
+		Account account = accountDAO.getAccount(accountNumber);
+		account.setBalance(account.getBalance().add(amount));
+		accountDAO.update(account);
+		
+		return account;
+	}
+
+	@Override
+	public Account withdraw(int accountNumber, BigDecimal amount) {
+		Account account = accountDAO.getAccount(accountNumber);
+		account.setBalance(account.getBalance().subtract(amount));
+		accountDAO.update(account);
+		
+		return account;
+	}
+	
+	@Override
+	@Transactional
+	public Account transfer(int accountNumber1, int accountNumber2, BigDecimal amount) {
+		Account account1 = accountDAO.getAccount(accountNumber1);
+		account1.setBalance(account1.getBalance().subtract(amount));
+		accountDAO.update(account1);
+		
+		Account account2 = accountDAO.getAccount(accountNumber2);
+		account2.setBalance(account2.getBalance().add(amount));
+		accountDAO.update(account2);
+		
+		return account1;
+	}
+}
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diff --git a/spring-boot/03-bank-jdbc-rest/src/main/java/com/example/spring/bank/account/AccountRepository.java b/spring-boot/03-bank-jdbc-rest/src/main/java/com/example/spring/bank/account/AccountRepository.java
new file mode 100644
index 0000000..2b5c3d0
--- /dev/null
+++ b/spring-boot/03-bank-jdbc-rest/src/main/java/com/example/spring/bank/account/AccountRepository.java
@@ -0,0 +1,13 @@
+package com.example.spring.bank.account;
+
+import java.math.BigDecimal;
+import java.util.List;
+
+public interface AccountRepository {
+	public Account createAccount();
+	public Account getAccount(int accountNumber);
+	public void update(Account account);
+	public void delete(int accountNumber);
+	public List<Account> findAllAccounts();
+	public List<Account> findAccountsWithLowBalance(BigDecimal lessThanAmount);
+}
diff --git a/spring-boot/03-bank-jdbc-rest/src/main/java/com/example/spring/bank/account/JDBCAccountRepository.java b/spring-boot/03-bank-jdbc-rest/src/main/java/com/example/spring/bank/account/JDBCAccountRepository.java
new file mode 100644
index 0000000..9ad846e
--- /dev/null
+++ b/spring-boot/03-bank-jdbc-rest/src/main/java/com/example/spring/bank/account/JDBCAccountRepository.java
@@ -0,0 +1,82 @@
+package com.example.spring.bank.account;
+
+import java.math.BigDecimal;
+import java.sql.Connection;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import java.util.List;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.jdbc.core.JdbcTemplate;
+import org.springframework.jdbc.core.PreparedStatementCreator;
+import org.springframework.jdbc.core.RowMapper;
+import org.springframework.jdbc.support.GeneratedKeyHolder;
+import org.springframework.jdbc.support.KeyHolder;
+import org.springframework.stereotype.Repository;
+
+@Repository
+public class JDBCAccountRepository implements AccountRepository {
+
+	@Autowired
+	private JdbcTemplate jdbcTemplate;
+	
+	@Override
+	public Account createAccount() {
+		final String INSERT_SQL = "insert into account (balance) values(0)";
+
+		KeyHolder keyHolder = new GeneratedKeyHolder();
+		jdbcTemplate.update(
+		    new PreparedStatementCreator() {
+		        public PreparedStatement createPreparedStatement(Connection connection) throws SQLException {
+		            PreparedStatement ps =
+		                connection.prepareStatement(INSERT_SQL, new String[] {"account_number"});
+		            //  ps.setString(1, name);
+		            return ps;
+		        }
+		    }, keyHolder);
+
+		Account account = new Account();
+		// keyHolder.getKey() now contains the generated key
+		account.setAccountNumber(keyHolder.getKey().intValue());
+		account.setBalance(new BigDecimal("0.0"));
+
+		return account;
+	}
+
+	@Override
+	public void delete(int accountNumber) {
+		jdbcTemplate.update("delete from account where account_number = ?", Integer.valueOf(accountNumber));
+	}
+
+	@Override
+	public List<Account> findAccountsWithLowBalance(BigDecimal lessThanAmount) {
+		return this.jdbcTemplate.query( "select * from account where balance < ?", new Object[] {lessThanAmount.doubleValue()}, new AccountMapper());
+	}
+
+	@Override
+	public List<Account> findAllAccounts() {
+		return this.jdbcTemplate.query( "select * from account", new AccountMapper());
+	}
+
+	@Override
+	public Account getAccount(int accountNumber) {
+		return this.jdbcTemplate.queryForObject( "select * from account where account_number = ?", new Object[] {accountNumber}, new AccountMapper());
+	}
+
+	@Override
+	public void update(Account account) {
+		this.jdbcTemplate.update("update account set balance = ? where account_number = ?", account.getBalance(), account.getAccountNumber());
+	}
+
+	
+	private static final class AccountMapper implements RowMapper<Account> {
+
+	    public Account mapRow(ResultSet rs, int rowNum) throws SQLException {
+	        Account account = new Account();
+	        account.setAccountNumber(rs.getInt("account_number"));
+	        account.setBalance(rs.getBigDecimal("balance"));
+	        return account;
+	    }        
+	}
+}
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