SpringMVC 集成 JWT验证方式
JWT官网: https://jwt.io/
这里以java的ssm框架为例,集成jwt。
1.pom.xml 导入jwt的包
<!-- jwt --> <dependency> <groupId>com.auth0</groupId> <artifactId>java-jwt</artifactId> <version>2.2.0</version> </dependency>
2.编写jwt的工具类,包含加密解密功能
import com.auth0.jwt.JWTSigner; import com.auth0.jwt.JWTVerifier; import com.auth0.jwt.internal.com.fasterxml.jackson.databind.ObjectMapper; import java.util.HashMap; import java.util.Map; public class JWT { private static final String SECRET = "XX#$%()(#*!()!KL<><MQLMNQNQJQK sdfkjsdrow32234545fdf>?N<:{LWPW"; private static final String EXP = "exp"; private static final String PAYLOAD = "payload"; //加密,传入一个对象和有效期 public static <T> String sign(T object, long maxAge) { try { final JWTSigner signer = new JWTSigner(SECRET); final Map<String, Object> claims = new HashMap<String, Object>(); ObjectMapper mapper = new ObjectMapper(); String jsonString = mapper.writeValueAsString(object); claims.put(PAYLOAD, jsonString); claims.put(EXP, System.currentTimeMillis() + maxAge); return signer.sign(claims); } catch(Exception e) { return null; } } //解密,传入一个加密后的token字符串和解密后的类型 public static<T> T unsign(String jwt, Class<T> classT) { final JWTVerifier verifier = new JWTVerifier(SECRET); try { final Map<String,Object> claims= verifier.verify(jwt); if (claims.containsKey(EXP) && claims.containsKey(PAYLOAD)) { long exp = (Long)claims.get(EXP); long currentTimeMillis = System.currentTimeMillis(); if (exp > currentTimeMillis) { String json = (String)claims.get(PAYLOAD); ObjectMapper objectMapper = new ObjectMapper(); return objectMapper.readValue(json, classT); } } return null; } catch (Exception e) { return null; } } }
3.jwt有了,ssm要如何去利用,用户验证的第一步是登录,登录时根据用户传来的username和password到数据库验证身份,如果合法,便给该用户jwt加密生成token
//处理登录 @RequestMapping(value="login", produces = "application/json; charset=utf-8") public @ResponseBody ResponseData login(HttpServletRequest request, @RequestParam( "email") String email, @RequestParam("password") String password) { Login login = new Login(); login.setEmail(email); login.setPassword(password); ResponseData responseData = ResponseData.ok(); //先到数据库验证 Integer loginId = userService.checkLogin(login); if(null != loginId) { User user = userService.getUserByLoginId(loginId); login.setId(loginId); //给用户jwt加密生成token String token = JWT.sign(login, 60L* 1000L* 30L); //封装成对象返回给客户端 responseData.putDataValue("loginId", login.getId()); responseData.putDataValue("token", token); responseData.putDataValue("user", user); } else{ responseData = ResponseData.customerError(); } return responseData; }
4.在用户登录时,把loginId和token返回给前台,以后用户每次请求时,都得带上这两个参数,后台拿到token后解密出loginId,与用户传递过来的loginId比较,如果相同,则说明用户身份合法。因为是每个登录过后的每个请求,这里用springmvc的拦截器做
<mvc:interceptors> <mvc:interceptor> <!-- 匹配的是url路径, 如果不配置或/**,将拦截所有的Controller --> <mvc:mapping path="/**" /> <!-- /register 和 /login 不需要拦截--> <mvc:exclude-mapping path="/register" /> <mvc:exclude-mapping path="/login" /> <bean class="com.xforce.charles.interceptor.TokenInterceptor"></bean> </mvc:interceptor> <!-- 当设置多个拦截器时,先按顺序调用preHandle方法,然后逆序调用每个拦截器的postHandle和afterCompletion方法 --> </mvc:interceptors>
5.拦截器代码
import java.io.PrintWriter; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.springframework.web.servlet.HandlerInterceptor; import org.springframework.web.servlet.ModelAndView; import com.alibaba.fastjson.JSONObject; import com.xforce.charles.model.Admin; import com.xforce.charles.model.Login; import com.xforce.charles.util.JWT; import com.xforce.charles.util.ResponseData; public class TokenInterceptor implements HandlerInterceptor{ public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception arg3) throws Exception { } public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView model) throws Exception { } //拦截每个请求 public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception { response.setCharacterEncoding("utf-8"); String token = request.getParameter("token"); ResponseData responseData = ResponseData.ok(); //token不存在 if(null != token) { Login login = JWT.unsign(token, Login.class); String loginId = request.getParameter("loginId"); //解密token后的loginId与用户传来的loginId不一致,一般都是token过期 if(null != loginId && null != login) { if(Integer.parseInt(loginId) == login.getId()) { return true; } else { responseData = ResponseData.forbidden(); responseMessage(response, response.getWriter(), responseData); return false; } } else { responseData = ResponseData.forbidden(); responseMessage(response, response.getWriter(), responseData); return false; } } else { responseData = ResponseData.forbidden(); responseMessage(response, response.getWriter(), responseData); return false; } } //请求不通过,返回错误信息给客户端 private void responseMessage(HttpServletResponse response, PrintWriter out, ResponseData responseData) { responseData = ResponseData.forbidden(); response.setContentType("application/json; charset=utf-8"); String json = JSONObject.toJSONString(responseData); out.print(json); out.flush(); out.close(); } }
6.注意点:用@ResponseBody返回json数据时,有时会有乱码,需要在springmvc的配置文件里面加以下配置(spring4以上)
<mvc:annotation-driven>
<mvc:message-converters register-defaults="true">
<bean class="org.springframework.http.converter.StringHttpMessageConverter">
<property name="supportedMediaTypes" value = "text/plain;charset=UTF-8" />
</bean>
</mvc:message-converters>
</mvc:annotation-driven>
7.最后分享一个类,用于返回给客户端的万能类,我觉得它可以满足一般的接口
import java.util.HashMap; import java.util.Map; public class ResponseData { private final String message; private final int code; private final Map<String, Object> data = new HashMap<String, Object>(); public String getMessage() { return message; } public int getCode() { return code; } public Map<String, Object> getData() { return data; } public ResponseData putDataValue(String key, Object value) { data.put(key, value); return this; } private ResponseData(int code, String message) { this.code = code; this.message = message; } public static ResponseData ok() { return new ResponseData(200, "Ok"); } public static ResponseData notFound() { return new ResponseData(404, "Not Found"); } public static ResponseData badRequest() { return new ResponseData(400, "Bad Request"); } public static ResponseData forbidden() { return new ResponseData(403, "Forbidden"); } public static ResponseData unauthorized() { return new ResponseData(401, "unauthorized"); } public static ResponseData serverInternalError() { return new ResponseData(500, "Server Internal Error"); } public static ResponseData customerError() { return new ResponseData(1001, "customer Error"); } }