Java微信授权登录小程序接口流程

<dependencies>  
    <dependency>  
        <groupId>org.springframework.boot</groupId>  
        <artifactId>spring-boot-starter-web</artifactId>  
    </dependency>  
    <dependency>  
        <groupId>com.github.binarywang</groupId>  
        <artifactId>weixin-java-mp</artifactId>  
        <version>最新版本号</version>  
    </dependency>  
    <!-- 其他依赖 -->  
</dependencies>

import com.github.binarywang.wxpay.bean.request.WxPayUnifiedOrderRequest;  
import com.github.binarywang.wxpay.service.WxPayService;  
import me.chanjar.weixin.mp.api.WxMpService;  
import me.chanjar.weixin.mp.bean.result.WxMpOAuth2AccessToken;  
import org.springframework.beans.factory.annotation.Autowired;  
import org.springframework.web.bind.annotation.GetMapping;  
import org.springframework.web.bind.annotation.RequestParam;  
import org.springframework.web.bind.annotation.RestController;  
@RestController  
public class WeChatController {  
    @Autowired  
    private WxMpService wxMpService; // 假设你已经配置好了这个Bean  
    @GetMapping("/login")  
    public String login(@RequestParam("code") String code) throws Exception {  
        // 使用code换取sessionKey和openId  
        WxMpOAuth2AccessToken accessToken = wxMpService.oauth2getAccessToken(code);  
        String openId = accessToken.getOpenId();  
        // 这里可以生成JWT并返回给前端  
        // 示例中不直接生成JWT，仅返回openId作为演示  
        return "Login successful, openId: " + openId;  
    }  
}

<dependencies>  
    <!-- Spring Boot 起步依赖 -->  
    <dependency>  
        <groupId>org.springframework.boot</groupId>  
        <artifactId>spring-boot-starter-web</artifactId>  
    </dependency>  
    <!-- 微信Java SDK -->  
    <dependency>  
        <groupId>com.github.binarywang</groupId>  
        <artifactId>weixin-java-mp</artifactId>  
        <version>你的版本号</version>  
    </dependency>  
    <!-- 其他依赖... -->  
</dependencies>

@Configuration  
public class WechatConfig {  
    @Value("${wechat.appid}")  
    private String appid;  
    @Value("${wechat.secret}")  
    private String secret;  
    @Bean  
    public WxMpService wxMpService() {  
        WxMpInMemoryConfigStorage config = new WxMpInMemoryConfigStorage();  
        config.setAppId(appid);  
        config.setSecret(secret);  
        WxMpServiceImpl wxMpService = new WxMpServiceImpl();  
        wxMpService.setWxMpConfigStorage(config);  
        return wxMpService;  
    }  
}

@RestController  
@RequestMapping("/api/wechat")  
public class WechatController {  
    @Autowired  
    private WxMpService wxMpService;  
    @GetMapping("/login")  
    public ResponseEntity<String> login(@RequestParam("code") String code) {  
        try {  
            // 使用code换取access_token和openid等信息  
            WxMpOAuth2AccessToken accessToken = wxMpService.oauth2getAccessToken(code);  
            String openId = accessToken.getOpenId();  
            String sessionKey = accessToken.getSessionKey(); // 注意：session_key在有些版本的SDK中可能叫做sessionKey  
            // 这里可以生成JWT或进行其他业务逻辑处理  
            // ...  
            // 返回给前端的响应（实际项目中可能不会直接返回这些信息）  
            Map<String, String> result = new HashMap<>();  
            result.put("openid", openId);  
            // 如果需要，也可以返回sessionKey，但通常不建议直接返回给前端  
            // result.put("sessionKey", sessionKey);  
            return ResponseEntity.ok(JSON.toJSONString(result)); // 假设你使用了阿里巴巴的fastjson库  
        } catch (WxErrorException e) {  
            // 处理微信API调用异常  
            return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body("微信登录失败: " + e.getMessage());  
        }  
    }  
}