From 940fabe5f5ccff6c8261d47e938da35260a80e10 Mon Sep 17 00:00:00 2001
From: Tapan Avasthi <tapan.k.avasthi@gmail.com>
Date: Thu, 7 Nov 2019 19:06:32 +0530
Subject: [PATCH] BAEL-3284: Guide to Flash Attributes in a Spring Web
 Application (#8070)

---
 .../flash_attributes/Application.java         | 14 ++++++
 .../controllers/PoemSubmission.java           | 49 ++++++++++++++++++
 .../baeldung/flash_attributes/model/Poem.java | 39 +++++++++++++++
 .../src/main/resources/application.properties |  8 ++-
 .../src/main/resources/templates/submit.html  | 50 +++++++++++++++++++
 .../src/main/resources/templates/success.html | 15 ++++++
 6 files changed, 174 insertions(+), 1 deletion(-)
 create mode 100644 spring-mvc-simple-2/src/main/java/com/baeldung/flash_attributes/Application.java
 create mode 100644 spring-mvc-simple-2/src/main/java/com/baeldung/flash_attributes/controllers/PoemSubmission.java
 create mode 100644 spring-mvc-simple-2/src/main/java/com/baeldung/flash_attributes/model/Poem.java
 create mode 100644 spring-mvc-simple-2/src/main/resources/templates/submit.html
 create mode 100644 spring-mvc-simple-2/src/main/resources/templates/success.html

diff --git a/spring-mvc-simple-2/src/main/java/com/baeldung/flash_attributes/Application.java b/spring-mvc-simple-2/src/main/java/com/baeldung/flash_attributes/Application.java
new file mode 100644
index 0000000000..0472ba4e7b
--- /dev/null
+++ b/spring-mvc-simple-2/src/main/java/com/baeldung/flash_attributes/Application.java
@@ -0,0 +1,14 @@
+package com.baeldung.flash_attributes;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.boot.web.servlet.support.SpringBootServletInitializer;
+
+@SpringBootApplication
+public class Application extends SpringBootServletInitializer {
+
+    public static void main(String[] args) {
+        SpringApplication.run(Application.class, args);
+    }
+
+}
diff --git a/spring-mvc-simple-2/src/main/java/com/baeldung/flash_attributes/controllers/PoemSubmission.java b/spring-mvc-simple-2/src/main/java/com/baeldung/flash_attributes/controllers/PoemSubmission.java
new file mode 100644
index 0000000000..6264ea0531
--- /dev/null
+++ b/spring-mvc-simple-2/src/main/java/com/baeldung/flash_attributes/controllers/PoemSubmission.java
@@ -0,0 +1,49 @@
+package com.baeldung.flash_attributes.controllers;
+
+import com.baeldung.flash_attributes.model.Poem;
+import org.springframework.stereotype.Controller;
+import org.springframework.ui.Model;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.ModelAttribute;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.servlet.mvc.support.RedirectAttributes;
+import org.springframework.web.servlet.support.RequestContextUtils;
+import org.springframework.web.servlet.view.RedirectView;
+import java.util.Map;
+
+import javax.servlet.http.HttpServletRequest;
+
+@Controller
+public class PoemSubmission {
+
+    @GetMapping("/poem/success")
+    public String getSuccess(HttpServletRequest request) {
+        Map<String, ?> inputFlashMap = RequestContextUtils.getInputFlashMap(request);
+        if (inputFlashMap != null) {
+            Poem poem = (Poem) inputFlashMap.get("poem");
+            return "success";
+        } else {
+            return "redirect:/poem/submit";
+        }
+    }
+
+    @PostMapping("/poem/submit")
+    public RedirectView submitPost(
+        HttpServletRequest request, 
+        @ModelAttribute Poem poem, 
+        RedirectAttributes redirectAttributes) {
+        if (Poem.isValidPoem(poem)) {
+            redirectAttributes.addFlashAttribute("poem", poem);
+            return new RedirectView("/poem/success", true);
+        } else {
+            return new RedirectView("/poem/submit", true);
+        }
+    }
+
+    @GetMapping("/poem/submit")
+    public String submitGet(Model model) {
+        model.addAttribute("poem", new Poem());
+        return "submit";
+    }
+
+}
\ No newline at end of file
diff --git a/spring-mvc-simple-2/src/main/java/com/baeldung/flash_attributes/model/Poem.java b/spring-mvc-simple-2/src/main/java/com/baeldung/flash_attributes/model/Poem.java
new file mode 100644
index 0000000000..bff65456c1
--- /dev/null
+++ b/spring-mvc-simple-2/src/main/java/com/baeldung/flash_attributes/model/Poem.java
@@ -0,0 +1,39 @@
+package com.baeldung.flash_attributes.model;
+
+import org.apache.logging.log4j.util.Strings;
+
+public class Poem {
+    private String title;
+    private String author;
+    private String body;
+
+    public static boolean isValidPoem(Poem poem) {
+        return poem != null && Strings.isNotBlank(poem.getAuthor()) && Strings.isNotBlank(poem.getBody())
+          && Strings.isNotBlank(poem.getTitle());
+    }
+
+    public String getTitle() {
+        return this.title;
+    }
+
+    public void setTitle(String title) {
+        this.title = title;
+    }
+
+    public String getBody() {
+        return this.body;
+    }
+
+    public void setBody(String body) {
+        this.body = body;
+    }
+
+    public String getAuthor() {
+        return this.author;
+    }
+
+    public void setAuthor(String author) {
+        this.author = author;
+    }
+
+}
diff --git a/spring-mvc-simple-2/src/main/resources/application.properties b/spring-mvc-simple-2/src/main/resources/application.properties
index d29338d3d3..aca20f4e3c 100644
--- a/spring-mvc-simple-2/src/main/resources/application.properties
+++ b/spring-mvc-simple-2/src/main/resources/application.properties
@@ -1,3 +1,9 @@
 spring.main.allow-bean-definition-overriding=true
+
 spring.mail.host=localhost
-spring.mail.port=8025
\ No newline at end of file
+spring.mail.port=8025
+
+spring.thymeleaf.cache=false
+spring.thymeleaf.enabled=true 
+spring.thymeleaf.prefix=classpath:/templates/
+spring.thymeleaf.suffix=.html
diff --git a/spring-mvc-simple-2/src/main/resources/templates/submit.html b/spring-mvc-simple-2/src/main/resources/templates/submit.html
new file mode 100644
index 0000000000..0ed0107c20
--- /dev/null
+++ b/spring-mvc-simple-2/src/main/resources/templates/submit.html
@@ -0,0 +1,50 @@
+<!DOCTYPE HTML>
+<html xmlns:th="http://www.thymeleaf.org">
+<head>
+    <title>Poetry Contest: Submission</title>
+</head>
+<body>
+
+<form action="#" method="post" th:action="@{/poem/submit}" th:object="${poem}">
+
+    <table border='0' cellpadding='2' cellspacing='2' width='480px'>
+
+        <tr>
+            <td align='center'>
+                <label for="author">Author:</label>
+            </td>
+            <td>
+                <input th:field="*{author}" type="text"/>
+            </td>
+        </tr>
+
+        <tr>
+            <td align='center'>
+                <label for="title">Poem Title:</label>
+            </td>
+            <td>
+                <input th:field="*{title}" type="text"/>
+            </td>
+        </tr>
+
+        <tr>
+            <td align='center'>
+                <label for="body">Poem:</label>
+            </td>
+            <td>
+                <textarea cols="30" rows="30" th:field="*{body}"/>
+            </td>
+        </tr>
+
+        <tr>
+            <td align='center'>
+                <input type="submit" value="Submit Poem">
+            </td>
+        </tr>
+
+
+    </table>
+</form>
+
+</body>
+</html>
\ No newline at end of file
diff --git a/spring-mvc-simple-2/src/main/resources/templates/success.html b/spring-mvc-simple-2/src/main/resources/templates/success.html
new file mode 100644
index 0000000000..f845350ffb
--- /dev/null
+++ b/spring-mvc-simple-2/src/main/resources/templates/success.html
@@ -0,0 +1,15 @@
+<!DOCTYPE HTML>
+<html xmlns:th="http://www.thymeleaf.org">
+<head>
+    <title>Poetry Contest: Thank You</title>
+</head>
+<body>
+<h1 th:if="${poem}">
+    <p th:text="${'You have successfully submitted poem titled - '+ poem?.title}"/>
+    Click <a th:href="@{/poem/submit}"> here</a> to submit more.
+</h1>
+<h1 th:unless="${poem}">
+    Click <a th:href="@{/poem/submit}"> here</a> to submit a poem.
+</h1>
+</body>
+</html>
\ No newline at end of file