Add error handling

7 files changed, 160 insertions, 89 deletions

diff --git a/src/main/java/dev/submelon/pantry/CustomControllerAdvice.java b/src/main/java/dev/submelon/pantry/CustomControllerAdvice.java
new file mode 100644
index 0000000..dad961b
--- /dev/null
+++ b/src/main/java/dev/submelon/pantry/CustomControllerAdvice.java
@@ -0,0 +1,46 @@
+package dev.submelon.pantry;
+
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.ControllerAdvice;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+import java.io.PrintWriter;
+import java.io.StringWriter;
+import java.util.NoSuchElementException;
+
+@ControllerAdvice
+class CustomControllerAdvice {
+    @ExceptionHandler(NoSuchElementException.class)
+    public ResponseEntity<ErrorResponse> handleNullPointerExceptions(
+        NoSuchElementException e
+    ) {
+        HttpStatus status = HttpStatus.NOT_FOUND;
+
+        return new ResponseEntity<>(
+            new ErrorResponse(status, e.getMessage()),
+            status
+        );
+    }
+
+    @ExceptionHandler(Exception.class)
+    public ResponseEntity<ErrorResponse> handleExceptions(
+        Exception e
+    ) {
+        HttpStatus status = HttpStatus.INTERNAL_SERVER_ERROR;
+
+        // converting the stack trace to String
+        StringWriter stringWriter = new StringWriter();
+        PrintWriter printWriter = new PrintWriter(stringWriter);
+        e.printStackTrace(printWriter);
+        String stackTrace = stringWriter.toString();
+
+        return new ResponseEntity<>(
+            new ErrorResponse(
+              status, 
+              e.getMessage(), 
+              stackTrace // specifying the stack trace in case of 500s
+            ),
+            status
+        );
+    }
+}
diff --git a/src/main/java/dev/submelon/pantry/ErrorResponse.java b/src/main/java/dev/submelon/pantry/ErrorResponse.java
new file mode 100644
index 0000000..c5b1dbe
--- /dev/null
+++ b/src/main/java/dev/submelon/pantry/ErrorResponse.java
@@ -0,0 +1,58 @@
+package dev.submelon.pantry;
+
+import com.fasterxml.jackson.annotation.JsonFormat;
+import lombok.Getter;
+import lombok.Setter;
+import org.springframework.http.HttpStatus;
+import java.util.Date;
+
+@Getter
+@Setter
+public class ErrorResponse {
+    // customizing timestamp serialization format
+    @JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "dd-MM-yyyy hh:mm:ss")
+    private Date timestamp;
+
+    private int code;
+
+    private String status;
+
+    private String message;
+
+    private String stackTrace;
+
+    private Object data;
+
+    public ErrorResponse() {
+        timestamp = new Date();
+    }
+
+    public ErrorResponse(HttpStatus httpStatus, String message) {
+        this();
+    
+        this.code = httpStatus.value();
+        this.status = httpStatus.name();
+        this.message = message;
+    }
+
+    public ErrorResponse(
+        HttpStatus httpStatus,
+        String message,
+        String stackTrace
+    ) {
+        this(httpStatus, message);
+
+        this.stackTrace = stackTrace;
+    }
+
+    public ErrorResponse(
+        HttpStatus httpStatus,
+        String message,
+        String stackTrace,
+        Object data
+    ) {
+        this(httpStatus, message, stackTrace);
+
+        this.data = data;
+    }
+}
diff --git a/src/main/java/dev/submelon/pantry/Item.java b/src/main/java/dev/submelon/pantry/Item.java
deleted file mode 100644
index a17f5a1..0000000
--- a/src/main/java/dev/submelon/pantry/Item.java
+++ /dev/null
@@ -1,75 +0,0 @@
-package dev.submelon.pantry;
-
-import javax.persistence.Column;
-import javax.persistence.Entity;
-import javax.persistence.GeneratedValue;
-import javax.persistence.GenerationType;
-import javax.persistence.Id;
-
-@Entity
-public class Item {
-    @Id
-    @GeneratedValue(strategy=GenerationType.AUTO)
-    private Integer id;
-
-    @Column(nullable=false)
-    private String name;
-
-    private String description;
-    
-    @Column(unique=true, nullable=false)
-    private String shortid;
-
-    @Column(nullable=false)
-    private double quantity;
-    
-    public Item() {
-    }
-    
-    public Item(String name, String description, String shortid, double quantity) {
-        this.name = name;
-        this.description = description;
-        this.shortid = shortid;
-        this.quantity = quantity;
-    }
-
-    public Integer getId() {
-        return id;
-    }
-
-    public void setId(Integer id) {
-        this.id = id;
-    }
-
-    public String getName() {
-        return name;
-    }
-
-    public void setName(String name) {
-        this.name = name;
-    }
-
-    public String getDescription() {
-        return description;
-    }
-
-    public void setDescription(String description) {
-        this.description = description;
-    }
-
-    public String getShortid() {
-        return shortid;
-    }
-
-    public void setShortid(String shortid) {
-        this.shortid = shortid;
-    }
-
-    public double getQuantity() {
-        return quantity;
-    }
-
-    public void setQuantity(double quantity) {
-        this.quantity = quantity;
-    }
-}
diff --git a/src/main/java/dev/submelon/pantry/ItemRepository.java b/src/main/java/dev/submelon/pantry/ItemRepository.java
deleted file mode 100644
index 01451e3..0000000
--- a/src/main/java/dev/submelon/pantry/ItemRepository.java
+++ /dev/null
@@ -1,7 +0,0 @@
-package dev.submelon.pantry;
-
-import org.springframework.data.repository.CrudRepository;
-
-public interface ItemRepository extends CrudRepository<Item, Integer> {
-    Item findByShortid(String shortid);
-}
diff --git a/src/main/java/dev/submelon/pantry/PantryItem.java b/src/main/java/dev/submelon/pantry/PantryItem.java
new file mode 100644
index 0000000..36850bf
--- /dev/null
+++ b/src/main/java/dev/submelon/pantry/PantryItem.java
@@ -0,0 +1,40 @@
+package dev.submelon.pantry;
+
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+
+@Entity
+@Getter
+@Setter
+@NoArgsConstructor
+public class PantryItem {
+    @Id
+    @GeneratedValue(strategy=GenerationType.AUTO)
+    private Integer id;
+
+    @Column(nullable=false)
+    private String name;
+
+    private String description;
+    
+    @Column(unique=true, nullable=false)
+    private String shortid;
+
+    @Column(nullable=false)
+    private double quantity;
+    
+    public PantryItem(String name, String description, String shortid, double quantity) {
+        this.name = name;
+        this.description = description;
+        this.shortid = shortid;
+        this.quantity = quantity;
+    }
+
+}
diff --git a/src/main/java/dev/submelon/pantry/ItemController.java b/src/main/java/dev/submelon/pantry/PantryItemController.java
index 7021f0a..37a71e9 100644
--- a/src/main/java/dev/submelon/pantry/ItemController.java
+++ b/src/main/java/dev/submelon/pantry/PantryItemController.java
@@ -11,33 +11,33 @@ import org.springframework.web.bind.annotation.ResponseBody;
 
 @Controller
 @RequestMapping(path="/items")
-public class ItemController {
+public class PantryItemController {
     @Autowired
-    private ItemRepository itemRepository;
+    private PantryItemRepository itemRepository;
 
     @PostMapping(path="/add")
     @ResponseBody
     Integer addNewItem(@RequestParam String name, @RequestParam String description, @RequestParam String shortid, @RequestParam double quantity) {
-        Item item = new Item();
+        PantryItem item = new PantryItem();
         item.setName(name);
         item.setDescription(description);
         item.setShortid(shortid);
         item.setQuantity(quantity);
 
-        Item updatedItem = itemRepository.save(item);
+        PantryItem updatedItem = itemRepository.save(item);
         return updatedItem.getId();
     }
 
     @GetMapping(path="")
     @ResponseBody
-    Iterable<Item> getAllItems() {
+    Iterable<PantryItem> getAllItems() {
         return itemRepository.findAll();
     }
     
     @GetMapping(path="/{shortid}")
     @ResponseBody
-    Item getByShortid(@PathVariable String shortid) {
-        return itemRepository.findByShortid(shortid);
+    PantryItem getByShortid(@PathVariable String shortid) {
+        return itemRepository.findByShortid(shortid).get();
     }
     
 }
diff --git a/src/main/java/dev/submelon/pantry/PantryItemRepository.java b/src/main/java/dev/submelon/pantry/PantryItemRepository.java
new file mode 100644
index 0000000..7808186
--- /dev/null
+++ b/src/main/java/dev/submelon/pantry/PantryItemRepository.java
@@ -0,0 +1,9 @@
+package dev.submelon.pantry;
+
+import java.util.Optional;
+
+import org.springframework.data.repository.CrudRepository;
+
+public interface PantryItemRepository extends CrudRepository<PantryItem, Integer> {
+    Optional<PantryItem> findByShortid(String shortid);
+}