context: add default value to Context value methods

- ref #3761

Author: jknack

jooby/src/main/java/io/jooby/Context.java

@@ -185,6 +185,15 @@ private static Selector single() {
    */
   Value flash(@NonNull String name);
 
+  /**
+   * Get a flash attribute.
+   *
+   * @param name Attribute's name.
+   * @param defaultValue Default's value. Value won't be persisted to flash context.
+   * @return Flash attribute.
+   */
+  Value flash(@NonNull String name, @NonNull String defaultValue);
+
   /**
    * Find a session or creates a new session.
    *
@@ -201,6 +210,16 @@ private static Selector single() {
    */
   Value session(@NonNull String name);
 
+  /**
+   * Find a session attribute using the given name. If there is no session or attribute under that
+   * name a missing value is returned.
+   *
+   * @param name Attribute's name.
+   * @param defaultValue Default's value. Value won't be persisted to session context.
+   * @return Session's attribute or missing.
+   */
+  Value session(@NonNull String name, @NonNull String defaultValue);
+
   /**
    * Find an existing session.
    *
@@ -216,6 +235,15 @@ private static Selector single() {
    */
   Value cookie(@NonNull String name);
 
+  /**
+   * Get a cookie matching the given name.
+   *
+   * @param name Cookie's name.
+   * @param defaultValue Default's value. Value won't be persisted to response context.
+   * @return Cookie value.
+   */
+  Value cookie(@NonNull String name, @NonNull String defaultValue);
+
   /**
    * Request cookies.
    *
@@ -366,6 +394,25 @@ default String getContextPath() {
    */
   Value query(@NonNull String name);
 
+  /**
+   * Get a query parameter that matches the given name.
+   *
+   * <pre>{@code
+   * {
+   *   get("/search", ctx -> {
+   *     String q = ctx.query("q").value();
+   *     ...
+   *   });
+   *
+   * }
+   * }</pre>
+   *
+   * @param name Parameter name.
+   * @param defaultValue Default value.
+   * @return A query value.
+   */
+  Value query(@NonNull String name, @NonNull String defaultValue);
+
   /**
    * Query string with the leading <code>?</code> or empty string. This is the raw query string,
    * without decoding it.
@@ -417,6 +464,15 @@ default String getContextPath() {
    */
   Value header(@NonNull String name);
 
+  /**
+   * Get a header that matches the given name.
+   *
+   * @param name Header name. Case insensitive.
+   * @param defaultValue Default value.
+   * @return A header value or missing value, never a <code>null</code> reference.
+   */
+  Value header(@NonNull String name, @NonNull String defaultValue);
+
   /**
    * Header as single-value map.
    *

jooby/src/main/java/io/jooby/DefaultContext.java

@@ -130,6 +130,12 @@ default Value flash(@NonNull String name) {
     return Value.create(getValueFactory(), name, flash().get(name));
   }
 
+  @Override
+  default Value flash(@NonNull String name, @NonNull String defaultValue) {
+    var value = flash(name);
+    return value.isMissing() ? Value.value(getValueFactory(), name, defaultValue) : value;
+  }
+
   @Override
   default Value session(@NonNull String name) {
     Session session = sessionOrNull();
@@ -139,6 +145,12 @@ default Value session(@NonNull String name) {
     return Value.missing(getValueFactory(), name);
   }
 
+  @Override
+  default Value session(@NonNull String name, @NonNull String defaultValue) {
+    var value = session(name);
+    return value.isMissing() ? Value.value(getValueFactory(), name, defaultValue) : value;
+  }
+
   @Override
   default Session session() {
     Session session = sessionOrNull();
@@ -177,10 +189,14 @@ default Object forward(@NonNull String path) {
 
   @Override
   default Value cookie(@NonNull String name) {
-    String value = cookieMap().get(name);
-    return value == null
-        ? Value.missing(getValueFactory(), name)
-        : Value.value(getValueFactory(), name, value);
+    var value = cookieMap().get(name);
+    return Value.create(getValueFactory(), name, value);
+  }
+
+  @Override
+  default Value cookie(@NonNull String name, @NonNull String defaultValue) {
+    var value = cookie(name);
+    return value.isMissing() ? Value.value(getValueFactory(), name, defaultValue) : value;
   }
 
   /**
@@ -253,6 +269,11 @@ default Value query(@NonNull String name) {
     return query().get(name);
   }
 
+  @Override
+  default Value query(@NonNull String name, @NonNull String defaultValue) {
+    return query().getOrDefault(name, defaultValue);
+  }
+
   @Override
   default String queryString() {
     return query().queryString();
@@ -273,6 +294,11 @@ default Value header(@NonNull String name) {
     return header().get(name);
   }
 
+  @Override
+  default Value header(@NonNull String name, @NonNull String defaultValue) {
+    return header().getOrDefault(name, defaultValue);
+  }
+
   @Override
   default Map<String, String> headerMap() {
     return header().toMap();

jooby/src/main/java/io/jooby/ForwardingContext.java

@@ -700,11 +700,21 @@ public Value flash(@NonNull String name) {
     return ctx.flash(name);
   }
 
+  @Override
+  public Value flash(@NonNull String name, @NonNull String defaultValue) {
+    return ctx.flash(name, defaultValue);
+  }
+
   @Override
   public Value session(@NonNull String name) {
     return ctx.session(name);
   }
 
+  @Override
+  public Value session(@NonNull String name, @NonNull String defaultValue) {
+    return ctx.session(name, defaultValue);
+  }
+
   @Override
   public Session session() {
     return ctx.session();
@@ -720,6 +730,11 @@ public Value cookie(@NonNull String name) {
     return ctx.cookie(name);
   }
 
+  @Override
+  public Value cookie(@NonNull String name, @NonNull String defaultValue) {
+    return ctx.cookie(name, defaultValue);
+  }
+
   @Override
   public Map<String, String> cookieMap() {
     return ctx.cookieMap();
@@ -803,6 +818,11 @@ public Value query(@NonNull String name) {
     return ctx.query(name);
   }
 
+  @Override
+  public Value query(@NonNull String name, @NonNull String defaultValue) {
+    return ctx.query(name, defaultValue);
+  }
+
   @Override
   public String queryString() {
     return ctx.queryString();
@@ -828,6 +848,11 @@ public Value header(@NonNull String name) {
     return ctx.header(name);
   }
 
+  @Override
+  public Value header(@NonNull String name, @NonNull String defaultValue) {
+    return ctx.header(name, defaultValue);
+  }
+
   @Override
   public Map<String, String> headerMap() {
     return ctx.headerMap();

jooby/src/main/java/io/jooby/annotation/CookieParam.java

@@ -28,4 +28,11 @@
    * @return Parameter name. Defaults to method parameter name.
    */
   String name() default "";
+
+  /**
+   * Default value.
+   *
+   * @return Default value.
+   */
+  String value() default "";
 }

jooby/src/main/java/io/jooby/annotation/FlashParam.java

@@ -28,4 +28,11 @@
    * @return Parameter name. Defaults to method parameter name.
    */
   String name() default "";
+
+  /**
+   * Default value.
+   *
+   * @return Default value.
+   */
+  String value() default "";
 }

jooby/src/main/java/io/jooby/annotation/FormParam.java

@@ -36,4 +36,11 @@
    * @return Parameter name. Defaults to method parameter name.
    */
   String name() default "";
+
+  /**
+   * Default value.
+   *
+   * @return Default value.
+   */
+  String value() default "";
 }

jooby/src/main/java/io/jooby/annotation/HeaderParam.java

@@ -33,4 +33,11 @@
    * @return Parameter name. Defaults to method parameter name.
    */
   String name() default "";
+
+  /**
+   * Default value.
+   *
+   * @return Default value.
+   */
+  String value() default "";
 }

jooby/src/main/java/io/jooby/annotation/QueryParam.java

@@ -28,4 +28,11 @@
    * @return Parameter name. Defaults to method parameter name.
    */
   String name() default "";
+
+  /**
+   * Default value.
+   *
+   * @return Default value.
+   */
+  String value() default "";
 }

jooby/src/main/java/io/jooby/annotation/SessionParam.java

@@ -33,4 +33,11 @@
    * @return Session attribute's name. Defaults to method parameter name.
    */
   String name() default "";
+
+  /**
+   * Default value.
+   *
+   * @return Default value.
+   */
+  String value() default "";
 }