今天就跟大家聊聊有关Java项目如何实现前后端分离,可能很多人都不太了解,为了让大家更加了解,小编给大家总结了以下内容,希望大家根据这篇文章可以有所收获。
构建springboot项目
我的目录结构:(结果未按标准书写,仅作说明)
不管用什么IDE,最后我们只看pom.xml里的依赖:
为了尽可能简单,就不连数据库了,登陆时用固定的。
devtools:用于修改代码后自动重启;
jjwt:加密这么麻烦的事情可以用现成的,查看https://github.com/jwtk/jjwt
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.2.RELEASE</version>
<relativePath /> <!-- lookup parent from repository -->
</parent>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<!-- JJWT -->
<dependency>
<groupId>io.jsonwebtoken</groupId>
<artifactId>jjwt</artifactId>
<version>0.6.0</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
登录
这里的加密密钥是:base64EncodedSecretKey
import java.util.Date;
import javax.servlet.ServletException;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
import io.jsonwebtoken.Jwts;
import io.jsonwebtoken.SignatureAlgorithm;
@RestController
@RequestMapping("/")
public class HomeController {
@PostMapping("/login")
public String login(@RequestParam("username") String name, @RequestParam("password") String pass)
throws ServletException {
String token = "";
if (!"admin".equals(name)) {
throw new ServletException("找不到该用户");
}
if (!"1234".equals(pass)) {
throw new ServletException("密码错误");
}
token = Jwts.builder().setSubject(name).claim("roles", "user").setIssuedAt(new Date())
.signWith(SignatureAlgorithm.HS256, "base64EncodedSecretKey").compact();
return token;
}
}
测试token
现在就可以测试生成的token了,我们采用postman:
过滤器
这肯定是必须的呀,当然,也可以用AOP。
过滤要保护的url,同时在过滤器里进行token验证
token验证:
public class JwtFilter extends GenericFilterBean {
@Override
public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain)
throws IOException, ServletException {
HttpServletRequest request = (HttpServletRequest) req;
HttpServletResponse response = (HttpServletResponse) res;
String authHeader = request.getHeader("Authorization");
if ("OPTIONS".equals(request.getMethod())) {
response.setStatus(HttpServletResponse.SC_OK);
chain.doFilter(req, res);
} else {
if (authHeader == null || !authHeader.startsWith("Bearer ")) {
throw new ServletException("不合法的Authorization header");
}
// 取得token
String token = authHeader.substring(7);
try {
Claims claims = Jwts.parser().setSigningKey("base64EncodedSecretKey").parseClaimsJws(token).getBody();
request.setAttribute("claims", claims);
} catch (Exception e) {
throw new ServletException("Invalid Token");
}
chain.doFilter(req, res);
}
}
}
要保护的url:/user下的:
@SpringBootApplication
public class AuthServerApplication {
@Bean
public FilterRegistrationBean jwtFilter() {
FilterRegistrationBean rbean = new FilterRegistrationBean();
rbean.setFilter(new JwtFilter());
rbean.addUrlPatterns("/user/*");// 过滤user下的链接
return rbean;
}
public static void main(String[] args) {
SpringApplication.run(AuthServerApplication.class, args);
}
}
UserController
这个是必须经过过滤才可以访问的:
@RestController
@RequestMapping("/user")
public class UserController {
@GetMapping("/success")
public String success() {
return "恭喜您登录成功";
}
@GetMapping("/getEmail")
public String getEmail() {
return "xxxx@qq.com";
}
}
关键测试
假设我们的Authorization错了,肯定是通不过的:
当输入刚才服务器返回的正确token:
允许跨域请求
现在来说前端和后端是两个服务器了,所以需要允许跨域:
@Configuration
public class CorsConfig {
@Bean
public FilterRegistrationBean corsFilter() {
UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
CorsConfiguration config = new CorsConfiguration();
config.setAllowCredentials(true);
config.addAllowedOrigin("*");
config.addAllowedHeader("*");
config.addAllowedMethod("OPTION");
config.addAllowedMethod("GET");
config.addAllowedMethod("POST");
config.addAllowedMethod("PUT");
config.addAllowedMethod("HEAD");
config.addAllowedMethod("DELETE");
source.registerCorsConfiguration("/**", config);
FilterRegistrationBean bean = new FilterRegistrationBean(new CorsFilter(source));
bean.setOrder(0);
return bean;
}
@Bean
public WebMvcConfigurer mvcConfigurer() {
return new WebMvcConfigurerAdapter() {
@Override
public void addCorsMappings(CorsRegistry registry) {
registry.addMapping("/**").allowedMethods("GET", "PUT", "POST", "GET", "OPTIONS");
}
};
}
}
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