使用ResponseEntity实现文件下载

使用ResponseEntity实现对jar内部和外部的数据文件实现下载。
ResponseEntity的泛型可以设置自定义返回值，也可以使用自带的返回值。

import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.InputStreamResource;
import org.springframework.core.io.Resource;
import org.springframework.http.HttpHeaders;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;

@RestController
@RequestMapping("/test")
public class TestController {

    // 设置返回值
    class MyResult<T>{
        private int code;
        private String msg;
        private T data;

        public int getCode() {
            return code;
        }

        public void setCode(int code) {
            this.code = code;
        }

        public String getMsg() {
            return msg;
        }

        public void setMsg(String msg) {
            this.msg = msg;
        }

        public T getData() {
            return data;
        }

        public void setData(T data) {
            this.data = data;
        }
    }

    @PostMapping("/download/out")
    public ResponseEntity<Object> downloadOut(){

        try {
            // Set the file name
            String fileName = "my.xlsx";

            // 工程的目录
            String prefixPath = System.getProperty("user.dir");
            // 文件路径
            String filePath = "/data/"+fileName;

            // 设置头信息
            HttpHeaders headers = new HttpHeaders();
            // 设置文件名称
            headers.setContentDispositionFormData("attachment", fileName);

            // 转化文件
            Path path = Paths.get(prefixPath + "/" + filePath);
            Resource resource = new InputStreamResource(Files.newInputStream(path));

            // 设置返回值
            return ResponseEntity.ok()
                    .headers(headers)
                    .contentLength(Files.size(path))
                    .contentType(MediaType.APPLICATION_OCTET_STREAM)
                    .body(resource);
        } catch (IOException e) {
            System.out.println("下载文件失败");

            MyResult<String> result = new MyResult<>();
            result.setCode(-1);
            result.setMsg("下载文件失败");

            // 返回实体值
            return ResponseEntity.ok(result);
        }
    }

    @PostMapping("/download/in")
    public ResponseEntity<Object> downloadIn(){

        System.out.println("test");
        try {
            // Set the file name
            String fileName = "my.xlsx";

            // 文件路径
            String filePath = "/data/"+fileName;

            // 设置头信息
            HttpHeaders headers = new HttpHeaders();
            // 设置文件名称
            headers.setContentDispositionFormData("attachment", fileName);

            System.out.println(filePath);

            // 获取资源jar包下的数据文件
            ClassPathResource classPathResource = new ClassPathResource(filePath);
            Resource resource = new InputStreamResource(classPathResource.getInputStream());

            // 设置返回值
            return ResponseEntity.ok()
                    .headers(headers)
                    .contentLength(classPathResource.contentLength())
                    .contentType(MediaType.APPLICATION_OCTET_STREAM)
                    .body(resource);
        } catch (IOException e) {
            System.out.println("下载文件失败");

            MyResult<String> result = new MyResult<>();
            result.setCode(-2);
            result.setMsg("下载文件失败");

            // 返回实体值
            return ResponseEntity.ok(result);
        }

    }

}
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133