文件上传和下载

controller 

package com.imooc.web.controller;

import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Date;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.io.IOUtils;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import com.imooc.dto.FileInfo;
@RestController
@RequestMapping("/file")
public class FileController {
	private String folder = "C:\\Users\\65448\\Desktop\\spring-security-main\\imooc-security-demo\\src\\main\\java\\com\\imooc\\web\\controller";
	@PostMapping
	public FileInfo upload(MultipartFile file) throws Exception {

		System.out.println(file.getName());
		System.out.println(file.getOriginalFilename());
		System.out.println(file.getSize());
		File localFile = new File(folder, new Date().getTime() + ".txt");
		file.transferTo(localFile);
		return new FileInfo(localFile.getAbsolutePath());
	}
	@GetMapping("/{id}")
	public void download(@PathVariable String id, HttpServletRequest request, HttpServletResponse response) throws Exception {
		try (InputStream inputStream = new FileInputStream(new File(folder, id + ".txt"));
				OutputStream outputStream = response.getOutputStream();) {
			response.setContentType("application/x-download");
			response.addHeader("Content-Disposition", "attachment;filename=test.txt");
			
			IOUtils.copy(inputStream, outputStream);
			outputStream.flush();
		} 

	}

}

　　测试类

package com.imooc.web.controller;

import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.http.MediaType;
import org.springframework.mock.web.MockMultipartFile;
import org.springframework.test.context.junit4.SpringRunner;
import org.springframework.test.web.servlet.MockMvc;
import org.springframework.test.web.servlet.request.MockMvcRequestBuilders;
import org.springframework.test.web.servlet.result.MockMvcResultMatchers;
import org.springframework.test.web.servlet.setup.MockMvcBuilders;
import org.springframework.web.context.WebApplicationContext;

import java.time.LocalDateTime;
import java.time.ZoneId;
import java.util.Date;

import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.*;
import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.delete;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;


@RunWith(SpringRunner.class)
@SpringBootTest
public class UserControllerTest {

    @Autowired
    private WebApplicationContext wac;
    // 伪造http请求 测试
    private MockMvc mockMvc;

    /**
     * 执行测试用例之前会先执行
     */
    @Before
    public void setup() {
        mockMvc = MockMvcBuilders.webAppContextSetup(wac).build();
    }

    @Test
    public void whenUploadSuccess() throws Exception {
        String result = mockMvc.perform(fileUpload("/file")
                .file(new MockMultipartFile("file", "test.txt", "multipart/form-data", "hello upload".getBytes("UTF-8"))))
                .andExpect(status().isOk())
                .andReturn().getResponse().getContentAsString();
        System.out.println(result);
    }
}