Spring boot之SpringApplicationBuilder，@@Configuration注解，@Component注解 _Configuration

【Spring boot之SpringApplicationBuilder，@@Configuration注解，@Component注解】吾生也有涯,而知也无涯。这篇文章主要讲述Spring boot之SpringApplicationBuilder，@@Configuration注解，@Component注解相关的知识，希望能为你提供帮助。
SpringApplicationBuilder：
该方法的作用是可以把项目打包成war包
需要配置启动类，pom.xml文件等，具体见：http://blog.csdn.net/linzhiqiang0316/article/details/52601292

@SpringBootApplication public class FavoritesApplication extends SpringBootServletInitializer{/** * 如此配置打包后可以用tomcat下使用 * @param application * @return */ @Override protected SpringApplicationBuilder configure(SpringApplicationBuilder application) { return application.sources(FavoritesApplication.class); }public static void main(String[] args) { SpringApplication.run(FavoritesApplication.class, args); } }

@Configuration注解：
从Spring3.0，@Configuration用于定义配置类，可替换xml配置文件，被注解的类内部包含有一个或多个被@Bean注解的方法，这些方法将会被AnnotationConfigApplicationContext或AnnotationConfigWebApplicationContext类进行扫描，并用于构建bean定义，初始化Spring容器。

@Configuration public class WebConfiguration{@Bean public FilterRegistrationBean filterRegistration() {FilterRegistrationBean registration = new FilterRegistrationBean(); registration.setFilter(new SecurityFilter()); registration.addUrlPatterns("/*"); registration.addInitParameter("paramName", "paramValue"); registration.setName("MyFilter"); registration.setOrder(1); return registration; }}

public class SecurityFilter implements Filter {protected Logger logger = Logger.getLogger(this.getClass()); private static Set< String> GreenUrlSet = new HashSet< String> (); @Autowired private UserRepository userRepository; @Override public void init(FilterConfig arg0) throws ServletException { // TODO Auto-generated method stub GreenUrlSet.add("/login"); GreenUrlSet.add("/register"); GreenUrlSet.add("/index"); GreenUrlSet.add("/forgotPassword"); GreenUrlSet.add("/newPassword"); GreenUrlSet.add("/tool"); }@Override public void doFilter(ServletRequest srequest, ServletResponse sresponse, FilterChain filterChain) throws IOException, ServletException { // TODO Auto-generated method stub HttpServletRequest request = (HttpServletRequest) srequest; String uri = request.getRequestURI(); if (request.getSession().getAttribute(Const.LOGIN_SESSION_KEY) == null) { Cookie[] cookies = request.getCookies(); if (containsSuffix(uri)|| GreenUrlSet.contains(uri) || containsKey(uri)) { logger.debug("don‘t checkurl , " + request.getRequestURI()); filterChain.doFilter(srequest, sresponse); return; }else if (cookies!=null) { boolean flag = true; for (int i = 0; i < cookies.length; i++) { Cookie cookie = cookies[i]; if (cookie.getName().equals(Const.LOGIN_SESSION_KEY)) { if(StringUtils.isNotBlank(cookie.getValue())){ flag = false; }else{ break; } String value = https://www.songbingjia.com/android/getUserId(cookie.getValue()); Long userId = 0l; if (userRepository == null) { BeanFactory factory = WebApplicationContextUtils.getRequiredWebApplicationContext(request.getServletContext()); userRepository = (UserRepository) factory.getBean("userRepository"); } if(StringUtils.isNotBlank(value)){ userId = Long.parseLong(value); } User user = userRepository.findOne(userId); String html = ""; if(null == user){ html = "< script type=\"text/javascript\"> window.location.href=https://www.songbingjia.com/"_BP_login\"< /script> "; }else{ logger.info("userId :" + user.getId()); request.getSession().setAttribute(Const.LOGIN_SESSION_KEY, user); String referer = this.getRef(request); if(referer.indexOf("/collect?") > = 0 || referer.indexOf("/lookAround/standard/") > = 0 || referer.indexOf("/lookAround/simple/") > = 0){ filterChain.doFilter(srequest, sresponse); return; }else{ html = "< script type=\"text/javascript\"> window.location.href=https://www.songbingjia.com/"_BP_\"< /script> "; } } html = html.replace("_BP_", Const.BASE_PATH); sresponse.getWriter().write(html); /** * HttpServletResponse response = (HttpServletResponse) sresponse; response.sendRedirect("/"); */ } } if(flag){ //跳转到登陆页面 String referer = this.getRef(request); logger.debug("security filter, deney, " + request.getRequestURI()); String html = ""; if(referer.contains("/collect?") || referer.contains("/lookAround/standard/") || referer.contains("/lookAround/simple/")){ html = "< script type=\"text/javascript\"> window.location.href=https://www.songbingjia.com/"_BP_login\"< /script> "; }else{ html = "< script type=\"text/javascript\"> window.location.href=https://www.songbingjia.com/"_BP_index\"< /script> "; } html = html.replace("_BP_", Const.BASE_PATH); sresponse.getWriter().write(html); } }else{ //跳转到登陆页面 String referer = this.getRef(request); logger.debug("security filter, deney, " + request.getRequestURI()); String html = ""; if(referer.contains("/collect?") || referer.contains("/lookAround/standard/") || referer.contains("/lookAround/simple/")){ html = "< script type=\"text/javascript\"> window.location.href=https://www.songbingjia.com/"_BP_login\"< /script> "; }else{ html = "< script type=\"text/javascript\"> window.location.href=https://www.songbingjia.com/"_BP_index\"< /script> "; } html = html.replace("_BP_", Const.BASE_PATH); sresponse.getWriter().write(html); //HttpServletResponse response = (HttpServletResponse) sresponse; //response.sendRedirect("/"); } }else{ filterChain.doFilter(srequest, sresponse); } }/** * @param url * @return * @author neo * @date 2016-5-4 */ private boolean containsSuffix(String url) { if (url.endsWith(".js") || url.endsWith(".css") || url.endsWith(".jpg") || url.endsWith(".gif") || url.endsWith(".png") || url.endsWith(".html") || url.endsWith(".eot") || url.endsWith(".svg") || url.endsWith(".ttf") || url.endsWith(".woff") || url.endsWith(".ico") || url.endsWith(".woff2")) { return true; } else { return false; } }/** * @param url * @return * @author neo * @date 2016-5-4 */ private boolean containsKey(String url) {if (url.contains("/media/") || url.contains("/login")||url.contains("/user/login") || url.contains("/register")||url.contains("/user/regist")||url.contains("/index") || url.contains("/forgotPassword")||url.contains("/user/sendForgotPasswordEmail") || url.contains("/newPassword")||url.contains("/user/setNewPassword") || (url.contains("/collector") & & !url.contains("/collect/detail/")) || url.contains("/collect/standard/")||url.contains("/collect/simple/") || url.contains("/user")||url.contains("/favorites")||url.contains("/comment") || url.startsWith("/lookAround/standard/") || url.startsWith("/lookAround/simple/") || url.startsWith("/user/") || url.startsWith("/feedback") || url.startsWith("/standard/") || url.startsWith("/collect/standard/lookAround/") || url.startsWith("/collect/simple/lookAround/")) { return true; } else { return false; } }@Override public void destroy() { // TODO Auto-generated method stub }publicString codeToString(String str) { String strString = str; try { byte tempB[] = strString.getBytes("ISO-8859-1"); strString = new String(tempB); return strString; } catch (Exception e) { return strString; } }public String getRef(HttpServletRequest request){ String referer = ""; String param = this.codeToString(request.getQueryString()); if(StringUtils.isNotBlank(request.getContextPath())){ referer = referer + request.getContextPath(); } if(StringUtils.isNotBlank(request.getServletPath())){ referer = referer + request.getServletPath(); } if(StringUtils.isNotBlank(param)){ referer = referer + "?" + param; } request.getSession().setAttribute(Const.LAST_REFERER, referer); return referer; }public String getUserId(String value){ try { String userId = Des3EncryptionUtil.decode(Const.DES3_KEY,value); userId = userId.substring(0,userId.indexOf(Const.PASSWORD_KEY)); return userId; }catch (Exception e){ logger.error("解析cookie异常：",e); } return null; } }

@Component：
关于Spring的@Component、@Repository、@Service、@Controller四个注解的区别，查阅了spring的官方文档：http://spring.io/search，文档中只是说了组件的注解要在组件处，service的注解要用在service处，但是他们的定义却没有区别。
问题:
1.那既然没有区别，为什么要分开来定义四个注解呢？
2.既然如他定义中说的，使用具体场景如下：

@Repository注解：用于标注数据访问组件，即DAO组件 @Service注解：用于标注业务层组件 @Controller注解：用于标注控制层组件（如struts中的action） @Component注解：泛指组件，当组件不好归类的时候，我们可以使用这个注解进行标注。

@Service
public class UserServiceImpl implements UserService { }
@Repository
public class UserDaoImpl implements UserDao { } getBean的默认名称是类名（头字母小写），如果想自定义，可以@Service(“***”)
这样来指定，这种bean默认是单例的，如果想改变，可以使用@Service(“beanName”)
@Scope(“prototype”)来改变。可以使用以下方式指定初始化方法和销毁方法（方法名任意）： @PostConstruct public void init() { }
总结：
1.用IDEA时，dao层没有注解idea会在service实现层的声明这个dao报错，加上这些注解之后就不会提示错误了，但是可以运行没有问题。
2.以上注解的作用基本相同，不同是标注这是什么层面，经过测试在dao层使用controller注解也可以正常运行。