Added a sample project that shows how to create and use jar files.

7 files changed, 106 insertions, 0 deletions

diff --git a/java/07-simple-objects-better-use-jar/myaccountslib/.gitignore b/java/07-simple-objects-better-use-jar/myaccountslib/.gitignore
new file mode 100644
index 0000000..e493dd6
--- /dev/null
+++ b/java/07-simple-objects-better-use-jar/myaccountslib/.gitignore
@@ -0,0 +1,2 @@
+bin
+dist
diff --git a/java/07-simple-objects-better-use-jar/myaccountslib/README b/java/07-simple-objects-better-use-jar/myaccountslib/README
new file mode 100644
index 0000000..94d053e
--- /dev/null
+++ b/java/07-simple-objects-better-use-jar/myaccountslib/README
@@ -0,0 +1,12 @@
+# NOTE:
+# On Windows,
+#   1. Use \ as the directory seperator.
+
+# Compile:
+mkdir bin
+javac --source-path src/ -d bin/ src/*.java
+
+# Build jar file:
+mkdir dist
+cd bin
+jar cf ../dist/myaccountslib.jar *.class
diff --git a/java/07-simple-objects-better-use-jar/myaccountslib/src/Account.java b/java/07-simple-objects-better-use-jar/myaccountslib/src/Account.java
new file mode 100644
index 0000000..4b26eca
--- /dev/null
+++ b/java/07-simple-objects-better-use-jar/myaccountslib/src/Account.java
@@ -0,0 +1,26 @@
+public class Account {
+	
+	/* Declaring fields  - represent state */
+	
+	int accountNumber;
+	double balance;
+
+	public Account(int accountNumber, double balance) {
+		this.accountNumber = accountNumber;
+		this.balance = balance;
+	}
+
+	public int getAccountNumber() {
+		return accountNumber;
+	}
+	public void setAccountNumber(int accountNumber) {
+		this.accountNumber = accountNumber;
+	}
+	public double getBalance() {
+		return balance;
+	}
+	public void setBalance(double balance) {
+		this.balance = balance;
+	}
+	
+}
diff --git a/java/07-simple-objects-better-use-jar/myaccountslib/src/AccountManager.java b/java/07-simple-objects-better-use-jar/myaccountslib/src/AccountManager.java
new file mode 100644
index 0000000..5a3368c
--- /dev/null
+++ b/java/07-simple-objects-better-use-jar/myaccountslib/src/AccountManager.java
@@ -0,0 +1,39 @@
+import java.util.HashMap;
+import java.util.Map;
+
+public class AccountManager {
+
+    private Map<Integer, Account> accounts = new HashMap<>();
+
+	/*
+		This is a called a constructor. It gets executed when an object of this class is
+		created.	
+	*/
+    public AccountManager() {
+		// For testing, create some account objects.
+		// In a real systems, account data will be in a storage system like a database.
+
+		Account account = new Account(1, 10.0);
+        accounts.put(account.getAccountNumber(), account);
+
+		account = new Account(2, 20.0);
+        accounts.put(account.getAccountNumber(), account);
+        
+		account = new Account(3, 10.0);
+        accounts.put(account.getAccountNumber(), account);
+    }
+
+	public void withdraw(int accountId, double amount) {
+		Account account = accounts.get(accountId);
+		account.setBalance(account.getBalance() - amount);
+	}
+
+	public void deposit(int accountId, double amount) {
+		Account account = accounts.get(accountId);
+		account.setBalance(account.getBalance() + amount);
+	}
+
+	public double getBalance(int accountId) {
+		return accounts.get(accountId).getBalance();
+	}
+}
diff --git a/java/07-simple-objects-better-use-jar/myapp/.gitignore b/java/07-simple-objects-better-use-jar/myapp/.gitignore
new file mode 100644
index 0000000..6b468b6
--- /dev/null
+++ b/java/07-simple-objects-better-use-jar/myapp/.gitignore
@@ -0,0 +1 @@
+*.class
diff --git a/java/07-simple-objects-better-use-jar/myapp/AccountApp.java b/java/07-simple-objects-better-use-jar/myapp/AccountApp.java
new file mode 100644
index 0000000..3399770
--- /dev/null
+++ b/java/07-simple-objects-better-use-jar/myapp/AccountApp.java
@@ -0,0 +1,16 @@
+public class AccountApp {
+
+	/**
+	 * @param args
+	 */
+	public static void main(String[] args) {
+		AccountManager accountManager = new AccountManager();
+
+		System.out.println(accountManager.getBalance(2));
+
+		accountManager.deposit(2, 2.0);
+
+		System.out.println(accountManager.getBalance(2));
+	}
+
+}
diff --git a/java/07-simple-objects-better-use-jar/myapp/README b/java/07-simple-objects-better-use-jar/myapp/README
new file mode 100644
index 0000000..80ed401
--- /dev/null
+++ b/java/07-simple-objects-better-use-jar/myapp/README
@@ -0,0 +1,10 @@
+# NOTE:
+# On Windows,
+#   1. Instead of using ':' as the classpath seperator, use ';'.
+#   2. Use \ as the directory seperator.
+
+# Compile
+javac -cp ../myaccountslib/dist/myaccountslib.jar:. AccountApp.java 
+
+# Run
+java -cp ../myaccountslib/dist/myaccountslib.jar:. AccountApp