[HttpProblem] common validation shorthands

docs/asciidoc/problem-details.adoc

@@ -46,18 +46,25 @@ problem.details {
 
 ==== Creating problems
 
-`HttpProblem` class represents the `RFC 7807` model. It is the main entity you need to work with to produce the problem.
+javadoc:problem.HttpProblem[] class represents the `RFC 7807` model. It is the main entity you need to work with to produce the problem.
 
 ===== Static helpers
 
-There are several handy static methods to produce a simple `HttpProblem`:
+There are several handy static methods to produce a simple javadoc:problem.HttpProblem[]:
 
-- `HttpProblem.valueOf(StatusCode status)` - will pick the title by status code.
+- javadoc:problem.HttpProblem[valueOf, io.jooby.StatusCode] - will pick the title by status code.
 Don't overuse it, the problem should have meaningful `title` and `detail` when possible.
-- `HttpProblem.valueOf(StatusCode status, String title)` - with custom `title`
-- `HttpProblem.valueOf(StatusCode status, String title, String detail)` - with `title` and `detail`
+- javadoc:problem.HttpProblem[valueOf, io.jooby.StatusCode, java.lang.String] - with custom `title`
+- javadoc:problem.HttpProblem[valueOf, io.jooby.StatusCode, java.lang.String, java.lang.String] - with `title` and `detail`
 
-`HttpProblem` extends `RuntimeException` so you can naturally throw it (as you do with exceptions):
+and a couple of shorthands for the most common validation codes:
+
+- javadoc:problem.HttpProblem[badRequest, java.lang.String, java.lang.String] - for _400 Bad Request_
+- javadoc:problem.HttpProblem[notFound, java.lang.String, java.lang.String] - for _404 Not Found_
+- javadoc:problem.HttpProblem[unprocessableEntity, java.lang.String, java.lang.String] - for _422 Unprocessable Entity_
+- javadoc:problem.HttpProblem[internalServerError] - for _500 Internal Server Error_
+
+javadoc:problem.HttpProblem[] extends `RuntimeException` so you can naturally throw it (as you do with exceptions):
 
 .Java
 [source,java,role="primary"]
@@ -130,7 +137,7 @@ throw HttpProblem.builder()
 
 `RFC 7807` has a simple extension model: APIs are free to add any other properties to the problem details object, so all properties other than the five ones listed above are extensions.
 
-However, variadic root level fields are usually not very convenient for (de)serialization (especially in statically typed languages). That's why `HttpProblem` implementation grabs all extensions under a single root field `parameters`. You can add parameters using builder like this:
+However, variadic root level fields are usually not very convenient for (de)serialization (especially in statically typed languages). That's why javadoc:problem.HttpProblem[] implementation grabs all extensions under a single root field `parameters`. You can add parameters using builder like this:
 
 [source,java]
 ----
@@ -165,7 +172,7 @@ Resulting response:
 
 ==== Adding headers
 
-Some `HTTP` codes (like `413` or `426`) require additional response headers, or it may be required by third-party system/integration. `HttpProblem` support additional headers in response:
+Some `HTTP` codes (like `413` or `426`) require additional response headers, or it may be required by third-party system/integration. javadoc:problem.HttpProblem[] support additional headers in response:
 
 [source,java]
 ----
@@ -211,12 +218,12 @@ In response:
 
 [TIP]
 ====
-If you need to enrich errors with more information feel free to extend `HttpProblem.Error` and make your custom errors model.
+If you need to enrich errors with more information feel free to extend javadoc:problem.HttpProblem.Error[] and make your custom errors model.
 ====
 
 ==== Custom `Exception` to `HttpProblem`
 
-Apparently, you may already have many custom `Exception` classes in the codebase, and you want to make them `Problem Details` compliant without complete re-write. You can achieve this by implementing `HttpProblemMappable` interface. It allows you to control how exceptions should be transformed into `HttpProblem` if default behaviour doesn't suite your needs:
+Apparently, you may already have many custom `Exception` classes in the codebase, and you want to make them `Problem Details` compliant without complete re-write. You can achieve this by implementing javadoc:problem.HttpProblemMappable[] interface. It allows you to control how exceptions should be transformed into javadoc:problem.HttpProblem if default behaviour doesn't suite your needs:
 
 [source,java]
 ----
@@ -235,7 +242,7 @@ public class MyException implements HttpProblemMappable {
 
 ==== Custom Problems
 
-Extending `HttpProblem` and utilizing builder functionality makes it really easy:
+Extending javadoc:problem.HttpProblem[] and utilizing builder functionality makes it really easy:
 
 [source,java]
 ----

docs/pom.xml

@@ -1,4 +1,3 @@
-
 <?xml version="1.0" encoding="UTF-8"?>
 <project xmlns="http://maven.apache.org/POM/4.0.0"
          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
@@ -11,7 +10,7 @@
 
   <properties>
     <application.class>io.jooby.adoc.DocApp</application.class>
-    <jooby.version>3.7.0</jooby.version>
+    <jooby.version>4.0.3</jooby.version>
     <maven.compiler.source>17</maven.compiler.source>
     <maven.compiler.target>17</maven.compiler.target>
     <maven.compiler.release>17</maven.compiler.release>

docs/src/main/java/io/jooby/adoc/DocApp.java

@@ -12,6 +12,7 @@
 import java.util.List;
 
 import io.jooby.LoggingService;
+import io.jooby.Server;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.slf4j.bridge.SLF4JBridgeHandler;
@@ -28,10 +29,6 @@ public class DocApp extends Jooby {
   }
 
   {
-    ServerOptions server = new ServerOptions();
-    server.setPort(4000);
-    setServerOptions(server);
-
     Path site = DocGenerator.basedir().resolve("asciidoc").resolve("site");
     assets("/*", site);
 
@@ -52,7 +49,10 @@ public static void main(String[] args) throws Exception {
 
     DocGenerator.generate(basedir, false, Arrays.asList(args).contains("v1"), true);
 
-    runApp(args, DocApp::new);
+    Server server = Server.loadServer();
+    server.setOptions(new ServerOptions().setPort(4000));
+
+    runApp(args, server, DocApp::new);
 
     Path outdir = basedir.resolve("asciidoc").resolve("site");
 

jooby/src/main/java/io/jooby/problem/HttpProblem.java

@@ -55,18 +55,136 @@ private static String createMessage(String title, String detail) {
     return Objects.isNull(detail) ? title : title + ": " + detail;
   }
 
+  /**
+   * Creates an HttpProblem with the specified status code and custom title.
+   *
+   * @param status the HTTP status code for this problem
+   * @param title  the title describing the type of problem
+   * @return an HttpProblem instance with the specified status and title
+   */
   public static HttpProblem valueOf(StatusCode status, String title) {
     return builder().title(title).status(status).build();
   }
 
+  /**
+   * Creates an HttpProblem with the specified status code, custom title, and detail.
+   *
+   * @param status the HTTP status code for this problem
+   * @param title  the title describing the type of problem
+   * @param detail a human-readable explanation specific to this occurrence of the problem
+   * @return an HttpProblem instance with the specified status, title, and detail
+   */
   public static HttpProblem valueOf(StatusCode status, String title, String detail) {
     return builder().title(title).status(status).detail(detail).build();
   }
 
+  /**
+   * Creates an HttpProblem with the specified status code using the default title.
+   * The title is automatically set to the status code's reason phrase.
+   *
+   * @param status the HTTP status code for this problem
+   * @return an HttpProblem instance with the specified status and default title
+   */
   public static HttpProblem valueOf(StatusCode status) {
     return builder().title(status.reason()).status(status).build();
   }
 
+  /**
+   * Creates an HttpProblem with BAD_REQUEST status (400) and custom title and detail.
+   *
+   * @param title  the title describing the type of problem
+   * @param detail a human-readable explanation specific to this occurrence of the problem
+   * @return an HttpProblem instance with BAD_REQUEST status
+   */
+  public static HttpProblem badRequest(String title, String detail) {
+    return builder()
+        .title(title)
+        .status(StatusCode.BAD_REQUEST)
+        .detail(detail)
+        .build();
+  }
+
+  /**
+   * Creates an HttpProblem with BAD_REQUEST status (400) using the default title.
+   * The title is automatically set to the status code's reason phrase.
+   *
+   * @param detail a human-readable explanation specific to this occurrence of the problem
+   * @return an HttpProblem instance with BAD_REQUEST status
+   */
+  public static HttpProblem badRequest(String detail) {
+    return builder()
+        .title(StatusCode.BAD_REQUEST.reason())
+        .status(StatusCode.BAD_REQUEST)
+        .detail(detail)
+        .build();
+  }
+
+  /**
+   * Creates an HttpProblem with NOT_FOUND status (404) and custom title and detail.
+   *
+   * @param title  the title describing the type of problem
+   * @param detail a human-readable explanation specific to this occurrence of the problem
+   * @return an HttpProblem instance with NOT_FOUND status
+   */
+  public static HttpProblem notFound(String title, String detail) {
+    return builder()
+        .title(title)
+        .status(StatusCode.NOT_FOUND)
+        .detail(detail)
+        .build();
+  }
+
+  /**
+   * Creates an HttpProblem with NOT_FOUND status (404) using the default title.
+   * The title is automatically set to the status code's reason phrase.
+   *
+   * @param detail a human-readable explanation specific to this occurrence of the problem
+   * @return an HttpProblem instance with NOT_FOUND status
+   */
+  public static HttpProblem notFound(String detail) {
+    return builder()
+        .title(StatusCode.NOT_FOUND.reason())
+        .status(StatusCode.NOT_FOUND)
+        .detail(detail)
+        .build();
+  }
+
+  /**
+   * Creates an HttpProblem with UNPROCESSABLE_ENTITY status (422) and custom title and detail.
+   *
+   * @param title  the title describing the type of problem
+   * @param detail a human-readable explanation specific to this occurrence of the problem
+   * @return an HttpProblem instance with UNPROCESSABLE_ENTITY status
+   */
+  public static HttpProblem unprocessableEntity(String title, String detail) {
+    return builder()
+        .title(title)
+        .status(StatusCode.UNPROCESSABLE_ENTITY)
+        .detail(detail)
+        .build();
+  }
+
+  /**
+   * Creates an HttpProblem with UNPROCESSABLE_ENTITY status (422) using the default title.
+   * The title is automatically set to the status code's reason phrase.
+   *
+   * @param detail a human-readable explanation specific to this occurrence of the problem
+   * @return an HttpProblem instance with UNPROCESSABLE_ENTITY status
+   */
+  public static HttpProblem unprocessableEntity(String detail) {
+    return builder()
+        .title(StatusCode.UNPROCESSABLE_ENTITY.reason())
+        .status(StatusCode.UNPROCESSABLE_ENTITY)
+        .detail(detail)
+        .build();
+  }
+
+  /**
+   * Creates an HttpProblem with SERVER_ERROR status (500) using predefined title and detail.
+   * This is typically used for unexpected server errors or misconfigurations.
+   *
+   * @return an HttpProblem instance with SERVER_ERROR status and predefined error message
+   */
   public static HttpProblem internalServerError() {
     return builder()
         .title(INTERNAL_ERROR_TITLE)
@@ -199,7 +317,8 @@ public static class Builder {
     private final Map<String, Object> headers = new LinkedHashMap<>();
     private final List<Error> errors = new LinkedList<>();
 
-    Builder() {}
+    Builder() {
+    }
 
     public Builder type(@Nullable final URI type) {
       this.type = type;
@@ -242,7 +361,7 @@ public Builder errors(final List<? extends Error> errors) {
     }
 
     /**
-     * @param key additional info parameter name
+     * @param key   additional info parameter name
      * @param value additional info parameter value
      * @return this for chaining
      */
@@ -269,19 +388,42 @@ public HttpProblem build() {
     }
   }
 
+  /**
+   * Represents an individual error within an HTTP Problem response.
+   * This class encapsulates error details following RFC 7807/RFC 9457 standards
+   * for providing structured error information in API responses.
+   */
   public static class Error {
     private final String detail;
     private final String pointer;
 
+    /**
+     * Creates a new Error instance with the specified detail and pointer.
+     *
+     * @param detail  a human-readable explanation of the specific error
+     * @param pointer a JSON Pointer (RFC 6901) that identifies the location
+     *                in the request document where the error occurred
+     */
     public Error(String detail, String pointer) {
       this.detail = detail;
       this.pointer = pointer;
     }
 
+    /**
+     * Returns the human-readable explanation of this specific error.
+     *
+     * @return the error detail message
+     */
     public String getDetail() {
       return detail;
     }
 
+    /**
+     * Returns a reference that identifies the location where this error occurred.
+     * This is typically a JSON Pointer (RFC 6901).
+     *
+     * @return the pointer to the location of the error
+     */
     public String getPointer() {
       return pointer;
     }