"Singleton Pattern Solution"

src/main/java/com/scaler/lld/design/assignments/builder/DatabaseConfigurationBuilder.java

@@ -1,6 +1,105 @@
 package com.scaler.lld.design.assignments.builder;
 
 @WithBuilder
-public class DatabaseConfigurationBuilder {
+public class  DatabaseConfigurationBuilder {
+
+    // NO SETTER IN OUTER CLASS
+
+    private String databaseUrl;
+    private String username;
+    private String password;
+    private int maxConnections;
+    private boolean enableCache;
+    private boolean isReadOnly;
+
+    public String getDatabaseUrl() {
+        return databaseUrl;
+    }
+
+    public String getUsername() {
+        return username;
+    }
+
+    public String getPassword() {
+        return password;
+    }
+
+    public int getMaxConnections() {
+        return maxConnections;
+    }
+
+    public boolean isEnableCache() {
+        return enableCache;
+    }
+
+    public boolean isReadOnly() {
+        return isReadOnly;
+    }
+
+    public static Builder builder()
+    {
+        return new Builder();
+    }
+
+
+
+
+    public static class Builder
+    {
+       private DatabaseConfigurationBuilder obj;
+
+        public Builder() {
+            obj = new DatabaseConfigurationBuilder();
+        }
+
+        public Builder setDatabaseUrl(String databaseUrl) {
+            this.obj.databaseUrl = databaseUrl;
+            return this;
+        }
+
+        public Builder setUsername(String username) {
+            this.obj.username = username;
+            return this;
+        }
+
+        public Builder setPassword(String password) {
+            this.obj.password = password;
+            return this;
+
+        }
+
+        public Builder setMaxConnections(int maxConnections) {
+            this.obj.maxConnections = maxConnections;
+            return this;
+        }
+
+        public Builder setEnableCache(boolean enableCache) {
+            this.obj.enableCache = enableCache;
+            return this;
+
+        }
+
+        public Builder setReadOnly(boolean isReadOnly) {
+            this.obj.isReadOnly = isReadOnly;
+            return this;
+        }
+
+        public DatabaseConfigurationBuilder build(){
+            DatabaseConfigurationBuilder db=new DatabaseConfigurationBuilder();
+            db.databaseUrl=this.obj.databaseUrl;
+            db.enableCache=this.obj.enableCache;
+            db.isReadOnly=this.obj.isReadOnly;
+            db.maxConnections=this.obj.maxConnections;
+            db.password=this.obj.password;
+            db.username=this.obj.username;
+            return db;
+        }
+
+
+
+
+
+
+    }
 
 }

src/main/java/com/scaler/lld/design/assignments/prototype/Configuration.java

@@ -1,6 +1,6 @@
 package com.scaler.lld.design.assignments.prototype;
 
-public class Configuration {
+public class Configuration<T> implements ClonableObject<T>{
     private String themeColor;
     private Boolean autoSave;
     private String language;
@@ -19,6 +19,27 @@ public Configuration(String themeColor, Boolean autoSave, String language, Boole
         this.type = type;
     }
 
+    public Configuration()
+    {
+
+    }
+    public Configuration(Configuration c)
+    {
+
+        this.themeColor=c.themeColor;
+        this.autoSave = c.autoSave;
+        this.language = c.language;
+        this.darkMode = c.darkMode;
+        this.fontSize = c.fontSize;
+        this.fontFamily = c.fontFamily;
+        this.type = c.type;
+
+    }
+    @Override
+    public T cloneObject()
+    {
+        return (T)(new Configuration(this));
+    }
     public String getThemeColor() {
         return themeColor;
     }

src/main/java/com/scaler/lld/design/assignments/prototype/ConfigurationPrototypeRegistryImpl.java

@@ -0,0 +1,35 @@
+package com.scaler.lld.design.assignments.prototype;
+import java.util.HashMap;
+import java.util.Map;
+public class ConfigurationPrototypeRegistryImpl implements ConfigurationPrototypeRegistry{
+
+    Map<ConfigurationType,Configuration> map;
+    public ConfigurationPrototypeRegistryImpl()
+    {
+        map=new HashMap<>();
+    }
+    @Override
+    public void addPrototype(Configuration user) {
+
+        map.put(user.getType(),user);
+
+
+    }
+
+    @Override
+    public Configuration getPrototype(ConfigurationType type) {
+        return map.get(type);
+    }
+
+    @Override
+    public Configuration clone(ConfigurationType type) {
+
+        Configuration obj=map.getOrDefault(type,null);
+
+        if(obj!=null)
+        return (Configuration) obj.cloneObject();
+
+        return null;
+
+    }
+}

src/main/java/com/scaler/lld/design/assignments/singleton/FileBasedConfigurationManagerImpl.java

@@ -2,49 +2,78 @@
 
 public class FileBasedConfigurationManagerImpl extends FileBasedConfigurationManager {
 
+    private static FileBasedConfigurationManager INSTANCE=null;
+
+    private FileBasedConfigurationManagerImpl()
+    {
+
+    }
+
     @Override
     public String getConfiguration(String key) {
         // TODO Auto-generated method stub
-        throw new UnsupportedOperationException("Unimplemented method 'getConfiguration'");
+        //throw new UnsupportedOperationException("Unimplemented method 'getConfiguration'");
+        return this.properties.getProperty(key);
     }
 
     @Override
     public <T> T getConfiguration(String key, Class<T> type) {
         // TODO Auto-generated method stub
-        throw new UnsupportedOperationException("Unimplemented method 'getConfiguration'");
+        //throw new UnsupportedOperationException("Unimplemented method 'getConfiguration'");
+        T ans=null;
+        String val=this.properties.getProperty(key);
+        if(val!=null)
+        ans=convert(val,type);
+        return ans;
     }
 
     @Override
     public void setConfiguration(String key, String value) {
         // TODO Auto-generated method stub
-        throw new UnsupportedOperationException("Unimplemented method 'setConfiguration'");
+        //throw new UnsupportedOperationException("Unimplemented method 'setConfiguration'");
+        this.properties.setProperty(key,value);
     }
 
     @Override
     public <T> void setConfiguration(String key, T value) {
         // TODO Auto-generated method stub
-        throw new UnsupportedOperationException("Unimplemented method 'setConfiguration'");
+        //throw new UnsupportedOperationException("Unimplemented method 'setConfiguration'");
+        this.properties.setProperty(key,(value+""));
     }
 
     @Override
     public void removeConfiguration(String key) {
         // TODO Auto-generated method stub
-        throw new UnsupportedOperationException("Unimplemented method 'removeConfiguration'");
+        //throw new UnsupportedOperationException("Unimplemented method 'removeConfiguration'");
+
+        this.properties.remove(key);
     }
 
     @Override
     public void clear() {
         // TODO Auto-generated method stub
-        throw new UnsupportedOperationException("Unimplemented method 'clear'");
+        //throw new UnsupportedOperationException("Unimplemented method 'clear'");
+        this.properties.clear();
     }
 
     public static FileBasedConfigurationManager getInstance() {
         // TODO Auto-generated method stub
-        return null;
+        if(INSTANCE==null)
+        {
+            synchronized(FileBasedConfigurationManager.class)
+            {
+                if(INSTANCE==null)
+                {
+                    INSTANCE=new FileBasedConfigurationManagerImpl();
+                }
+            }
+        }
+        return INSTANCE;
     }
 
     public static void resetInstance() {
         // TODO Auto-generated method stub
+        INSTANCE=null;
     }
 
 }