**1. pom中引入spring-boot-starter-security依賴** ```xml <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-security</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> <dependency> <groupId>org.springframework.security</groupId> <artifactId>spring-security-test</artifactId> <scope>test</scope> </dependency> </dependencies> ``` **2. controller層** ```java @RestController public class IndexController { @RequestMapping("/index") public String index() { return "Hello World!"; } } ``` **3. 啟動項目并訪問：http://localhost:8080/index** 如果沒有登錄，Spring Security 會自動重定向到默認的登錄頁面 http://localhost:8080/login ，如下。  輸入用戶名和密碼登錄。注意，每次啟動項目密碼都會發生變化，密碼會打印到控制臺中，用戶名默認為`user`。 ``` Using generated security password: be53ad37-3a68-4ca0-8c73-32a774661e9e ```