[Vue]使用Vite設定代理(Proxy)，轉發請求給後端Spring Boot

import { fileURLToPath, URL } from 'node:url'

import { defineConfig } from 'vite'
import vue from '@vitejs/plugin-vue'

// https://vitejs.dev/config/
export default defineConfig({
  plugins: [
    vue(),
  ],
  resolve: {
    alias: {
      '@': fileURLToPath(new URL('./src', import.meta.url))
    }
  },
  server: {
    proxy: {
      // 將所有以 /api 開頭的請求轉發到後端服務器
      '/api': {
        target: 'http://localhost:8080',
        changeOrigin: true,
        rewrite: (path) => path.replace(/^\/api/, ''),
      },
    },
  }
})

<template>
  <div>
    <button @click="fetchHello">Click me</button>
    <p>{{ message }}</p>
  </div>
</template>

<script>
import axios from 'axios';

export default {
  data() {
    return {
      message: '',
    };
  },
  methods: {
    async fetchHello() {
      try {
        const response = await axios.get('/api/hello');
        console.log('Response data:', response.data); // 返回資料
        this.message = response.data;
      } catch (error) {
        if (error.response) {
          // 狀態碼不是 2xx
          console.error('Error response:', error.response);
        } else if (error.request) {
          // 已發出 request ，但沒有回應
          console.error('Error request:', error.request);
        } else {
          // 其他錯誤
          console.error('Error:', error.message);
        }
        this.message = 'Error fetching the API';
      }
    },
  },
};
</script>

<style scoped>
button {
  padding: 10px 20px;
  font-size: 16px;
}
</style>

<script setup lang="ts">
import { RouterLink, RouterView } from 'vue-router'
import HelloWorld from './components/HelloWorld.vue'
import HelloButton from './components/HelloButton.vue';
</script>

<template>
  <header>
    <img alt="Vue logo" class="logo" src="@/assets/logo.svg" width="125" height="125" />

    <div class="wrapper">
      <HelloWorld msg="這是一個 Vue 專案!" />
      <HelloButton />
      <nav>
        <RouterLink to="/">Home</RouterLink>
        <RouterLink to="/about">About</RouterLink>
      </nav>
    </div>
  </header>

  <RouterView />
</template>

<style scoped>
header {
  line-height: 1.5;
  max-height: 100vh;
}

.logo {
  display: block;
  margin: 0 auto 2rem;
}

nav {
  width: 100%;
  font-size: 12px;
  text-align: center;
  margin-top: 2rem;
}

nav a.router-link-exact-active {
  color: var(--color-text);
}

nav a.router-link-exact-active:hover {
  background-color: transparent;
}

nav a {
  display: inline-block;
  padding: 0 1rem;
  border-left: 1px solid var(--color-border);
}

nav a:first-of-type {
  border: 0;
}

@media (min-width: 1024px) {
  header {
    display: flex;
    place-items: center;
    padding-right: calc(var(--section-gap) / 2);
  }

  .logo {
    margin: 0 2rem 0 0;
  }

  header .wrapper {
    display: flex;
    place-items: flex-start;
    flex-wrap: wrap;
  }

  nav {
    text-align: left;
    margin-left: -1rem;
    font-size: 1rem;

    padding: 1rem 0;
    margin-top: 1rem;
  }
}
</style>

import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.CorsRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

@Configuration
public class WebConfig implements WebMvcConfigurer {
    @Override
    public void addCorsMappings(CorsRegistry registry) {
        registry.addMapping("/**")
                .allowedOrigins("http://localhost:5173")
                .allowedMethods("GET", "POST", "PUT", "DELETE", "OPTIONS")
                .allowedHeaders("*")
                .allowCredentials(true);
    }
}

@RestController
public class HelloController {

    @GetMapping("/hello")
    public String hello() {
        return "Hello World!";
    }

}