add freemarker demog

java-realworld/sample/pom.xml

@@ -51,6 +51,10 @@
             <artifactId>mybatis-spring-boot-starter</artifactId>
             <version>3.0.3</version>
         </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-freemarker</artifactId>
+        </dependency>
 
         <dependency>
             <groupId>org.springframework.boot</groupId>

java-realworld/sample/src/main/java/com/example/demo/controller/freemakerdemo/FreeMakerDemo.java

@@ -0,0 +1,79 @@
+package com.example.demo.controller.freemakerdemo;
+
+import jakarta.servlet.http.HttpServletResponse;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Controller;
+import org.springframework.ui.Model;
+import org.springframework.ui.freemarker.FreeMarkerTemplateUtils;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.ModelAttribute;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+
+import freemarker.template.Configuration;
+import freemarker.template.Template;
+
+import java.io.IOException;
+import java.io.PrintWriter;
+
+@Controller
+@RequestMapping("/freemarker")
+public class FreeMakerDemo {
+    @Autowired
+    private Configuration freemarkerConfig;
+
+    @GetMapping("/template")
+    public void template(String name, Model model, HttpServletResponse response) throws Exception {
+        Template tpl = freemarkerConfig.getTemplate("no-return-template.ftl");
+        model.addAttribute("name", name);
+        String templateText = FreeMarkerTemplateUtils.processTemplateIntoString(tpl, model);
+        response.setContentType("text/html;charset=utf-8");
+        PrintWriter writer = response.getWriter();
+        writer.write(templateText);
+        writer.flush();
+        writer.close();
+    }
+
+    @GetMapping("/welcome")
+    public String welcome(@RequestParam String name, Model model) {
+        if (name == null || name.isEmpty()) {
+            model.addAttribute("name", "Welcome to Safe FreeMarker Demo, try <code>/freemarker/safe/welcome?name=Hacker<>`");
+        } else {
+            model.addAttribute("name", name);
+        }
+        return "welcome";
+    }
+
+    @GetMapping("/welcome-safe")
+    public String safeWelcome(@RequestParam String name, Model model) {
+        if (name == null || name.isEmpty()) {
+            model.addAttribute("name", "Welcome to Safe FreeMarker Demo, try <code>/freemarker/safe/welcome-safe?name=Hacker<>`");
+            return "welcome";
+        } else {
+            model.addAttribute("name", name);
+        }
+        return "welcome-safe";
+    }
+
+    @GetMapping("/welcome-no-model")
+    public String welcomeNoModel() {
+        return "welcome";
+    }
+
+    @GetMapping("/welcome-no-ftl")
+    public String welcomeNoFTL() {
+        return "welcome-no-existed-totally";
+    }
+
+    @ModelAttribute("defaultName")
+    public String getDefaultName() {
+        return "default name for FreeMarker Demo";
+    }
+
+    @GetMapping("/welcome-default-model")
+    public String welcomeDefaultModel() {
+        return "welcome2";
+    }
+
+
+}

java-realworld/sample/src/main/java/com/example/demo/controller/freemakerdemo/README.md

@@ -0,0 +1,9 @@
+# Java Freemaker
+
+使用 Springboot Freemaker Starter 启动后，在 Controller Method 中，返回一个 String 则为 freemaker template 的模版名称（文件名）。
+
+找到文件名比较关键。
+
+一般作为一个 Controller 来说，他的方法是一个纯 Literal String，例如为 $ret，则需要在数据库中搜索 f`${ret}\.\w+` 类似的文件存在，一般来说这个文件中的 ${...} 是可以供 SSTI 的点。
+
+一般的模版注入的审计都类似这种情况，Java 中出现裸 TPL 的渲染和调用的机会不多，框架会包裹一系列的用法。

java-realworld/sample/src/main/resources/application.properties

@@ -5,9 +5,14 @@ spring.datasource.url=jdbc:sqlite:database.db
 spring.datasource.driver-class-name=org.sqlite.JDBC
 spring.jpa.database-platform=org.hibernate.dialect.SQLiteDialect
 
+# sqlmap mapper
 mybatis.mapper-locations=classpath:mapper/*.xml
 mybatis.type-aliases-package=com.example.demo.model
 
+# freemaker
+spring.freemarker.template-loader-path=classpath:/templates/
+spring.freemarker.suffix=.ftl
+
 # auto update
 spring.jpa.hibernate.ddl-auto=update
 

java-realworld/sample/src/main/resources/templates/no-return-template.ftl

@@ -0,0 +1,9 @@
+<!DOCTYPE html>
+<html>
+<head>
+    <title>Welcome</title>
+</head>
+<body>
+<h1>Welcome ${name}! If you see this, this is loaded by freemarkerConfig, not Controller Method Return</h1>
+</body>
+</html>

java-realworld/sample/src/main/resources/templates/welcome-safe.ftl

@@ -0,0 +1,9 @@
+<!DOCTYPE html>
+<html>
+<head>
+    <title>Welcome</title>
+</head>
+<body>
+<h1>Welcome ${name?html}!</h1>
+</body>
+</html>

java-realworld/sample/src/main/resources/templates/welcome.ftl

@@ -0,0 +1,9 @@
+<!DOCTYPE html>
+<html>
+<head>
+    <title>Welcome</title>
+</head>
+<body>
+<h1>Welcome ${name}!</h1>
+</body>
+</html>

java-realworld/sample/src/main/resources/templates/welcome2.ftl

@@ -0,0 +1,9 @@
+<!DOCTYPE html>
+<html>
+<head>
+    <title>Welcome</title>
+</head>
+<body>
+<h1>Welcome ${defaultName}!</h1>
+</body>
+</html>