Tech&WK_programming_Java Web

purpose: 记录开发过程中的需要注意的点

Spring boot 项目下静态资源访问的配置

默认是 templates, 自定义 static

1. SpEL 在配置引用字段，注意大小写敏感

2. collection application config

View Code

3. bean 很多的大型项目，需要将 application-context 层次设计

Spring async web

WebAsyncTask<T>

 1 @RestController
 2 @RequestMapping("/async/webAsyncTask")
 3 public class WebAsyncTaskCtr {
 4 
 5     @GetMapping
 6     public WebAsyncTask<String> getResponse() throws Exception{
 7         System.out.println((Thread.currentThread().getName() + ", web server main thread start."));
 8 
 9         Callable<String> callable = () -> {
10             System.out.println((Thread.currentThread().getName() + ", sub thread started."));
11             TimeUnit.SECONDS.sleep(5);
12             System.out.println((Thread.currentThread().getName() + ", sub thread end."));
13 
14             return "webAsyncTask callable action.";
15         };
16 
17         WebAsyncTask<String> webAsyncTask = new WebAsyncTask<>(6000, callable);
18 
19         webAsyncTask.onCompletion(() -> System.out.println("Program process completed back invocation"));
20         webAsyncTask.onTimeout(() ->"Program time out back invocation");
21         webAsyncTask.onError(() -> "Program error occurred.");
22 
23         System.out.println(Thread.currentThread().getName() + ", web server main thread end.");
24         return webAsyncTask;
25     }
26 }

View Code

Spring web test

1. @RunWith(SpringRunner.class)

@WebMvcTest( [ contract-controller.class] )

 1 package org.techroad.springboot.practice.netSource.mvcAsysnc;
 2 
 3 import org.junit.Test;
 4 import org.junit.runner.RunWith;
 5 import org.springframework.beans.factory.annotation.Autowired;
 6 import org.springframework.boot.test.autoconfigure.web.servlet.WebMvcTest;
 7 import org.springframework.http.MediaType;
 8 import org.springframework.test.context.junit4.SpringRunner;
 9 import org.springframework.test.web.servlet.MockMvc;
10 import org.springframework.test.web.servlet.MvcResult;
11 import org.springframework.test.web.servlet.result.MockMvcResultHandlers;
12 
13 import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.asyncDispatch;
14 import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
15 import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.*;
16 
17 @RunWith(SpringRunner.class)
18 @WebMvcTest(WebAsyncTaskCtr.class)
19 public class WebAsyncTaskCtrTest {
20 
21     @Autowired
22     private MockMvc mockMvc;
23 
24     @Test
25     public void getResponse() throws Exception {
26 
27         MvcResult mvcResult = mockMvc.perform(get("/async/webAsyncTask"))
28                 .andExpect(request().asyncStarted())
29                 .andDo(MockMvcResultHandlers.log())
30                 .andReturn();
31 
32         mockMvc.perform(asyncDispatch(mvcResult))
33                 .andExpect(status().isOk())
34                 .andExpect(content().contentTypeCompatibleWith(MediaType.TEXT_PLAIN))
35                 .andExpect(content().string("webAsyncTask callable action."));
36     }
37 }

1. aync task executor

2. ResponseBodyEmitter

 1 import org.springframework.web.bind.annotation.GetMapping;
 2 import org.springframework.web.bind.annotation.RestController;
 3 import org.springframework.web.servlet.mvc.method.annotation.ResponseBodyEmitter;
 4 import org.springframework.web.servlet.mvc.method.annotation.SseEmitter;
 5 
 6 import java.io.IOException;
 7 import java.util.List;
 8 import java.util.concurrent.ExecutorService;
 9 import java.util.concurrent.Executors;
10 
11 @RestController
12 public class ResponseBodyEmitterMock {
13 
14     private final MockEmitterService service;
15 
16     public ResponseBodyEmitterMock(MockEmitterService service){
17         this.service = service;
18     }
19 
20     @GetMapping("/mock")
21     public ResponseBodyEmitter entities(){
22         ResponseBodyEmitter emitter = new ResponseBodyEmitter();
23         ExecutorService executorService = Executors.newSingleThreadExecutor();
24         executorService.execute(
25                 () -> {
26                     List<MockEntity> entityList = service.findAll();
27                     try{
28                         for(MockEntity e : entityList){
29                             // delay()
30                             emitter.send(e);
31                         }
32                         emitter.complete();
33                     }catch (IOException e){
34                         emitter.completeWithError(e);
35                     }
36                 });
37         executorService.shutdown();
38         return emitter;
39     }
40 
41     // Content-type head -> text/event-stream , 事件流，可以保持打开状态并接受事件通知
42     // 编写的每个对象都通过 HttpMessageConvert 转换为 JSON 对象
43     // 每个对象都作为事件数据写入 data 字段中。
44 
45     // id , event 事件类型， data 事件数据， retry 事件流重启连接的时间。
46 
47     @GetMapping("/mockSse")
48     public SseEmitter orders(){
49         SseEmitter emitter = new SseEmitter();
50         ExecutorService executorService = Executors.newSingleThreadExecutor();
51         executorService.execute(
52                 () -> {
53                     List<MockEntity> entities = service.findAll();
54                     try {
55                         for (MockEntity e : entities) {
56                             // delay();
57                             emitter.send(e);
58                         }
59                         emitter.complete();
60                     } catch (Exception e) {
61                         emitter.completeWithError(e);
62                     }
63                 });
64         executorService.shutdown();
65         return  emitter;
66     }
67 
68     @GetMapping("/mockConfigSseEventBuilder")
69     public SseEmitter sseEmitterBuilder(){
70         SseEmitter sseEmitter = new SseEmitter();
71         ExecutorService executorService = Executors.newSingleThreadExecutor();
72         executorService.execute(
73                 () -> {
74                     List<MockEntity> entities = service.findAll();
75                     try{
76                         for(MockEntity e : entities){
77                             // delay()
78                             SseEmitter.SseEventBuilder eventBuilder = sseEmitter.event();
79                             // 可填充 id 和 event 字段
80                             sseEmitter.send(
81                                     eventBuilder
82                                     .data(e)
83                                     .name("specify")
84                                     .id("uuid"));
85                         }
86                         sseEmitter.complete();
87                     }catch (IOException e){
88                         sseEmitter.completeWithError(e);
89                     }
90                 }
91         );
92         executorService.shutdown();
93         return sseEmitter;
94     }