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视频链接
1.数据类设计
包结构以及前端资源
Java Bean：
Video和Play
Video：
package com.miles.module5.dto;
import java.time.LocalDateTime;
import java.util.List;
/**
* Created with IntelliJ IDEA.
*
* @author : Wzq
* @version : 1.0
* @Project : HeiMa-Project1
* @Package : com.miles.module5.dto
* @ClassName : Video.java
* @createTime : 2022/8/6 11:54
* @Email : zqwang21@163.com
* @Description :
*/
public class Video {
private String bv;//视频编号
private String title;
private LocalDateTime publishTime;
private String cover;//封面
private String introduction;
private List<String> tagList;
private List<Play> playList;
private String type;//转载or原创
private String category;//分区
public Video(String bv, String title, LocalDateTime publishTime, String cover, String introduction, List<String> tagList, List<Play> playList, String type, String category) {
this.bv = bv;
this.title = title;
this.publishTime = publishTime;
this.cover = cover;
this.introduction = introduction;
this.tagList = tagList;
this.playList = playList;
this.type = type;
this.category = category;
}
public String getBv() {
return bv;
}
public void setBv(String bv) {
this.bv = bv;
}
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
public LocalDateTime getPublishTime() {
return publishTime;
}
public void setPublishTime(LocalDateTime publishTime) {
this.publishTime = publishTime;
}
public String getCover() {
return cover;
}
public void setCover(String cover) {
this.cover = cover;
}
public String getIntroduction() {
return introduction;
}
public void setIntroduction(String introduction) {
this.introduction = introduction;
}
public List<String> getTagList() {
return tagList;
}
public void setTagList(List<String> tagList) {
this.tagList = tagList;
}
public List<Play> getPlayList() {
return playList;
}
public void setPlayList(List<Play> playList) {
this.playList = playList;
}
public String getType() {
return type;
}
public void setType(String type) {
this.type = type;
}
public String getCategory() {
return category;
}
public void setCategory(String category) {
this.category = category;
}
}
Play：
public class Play {
private String id;//视频编号
private String title;
private LocalTime duration;
private String url;
public Play() {
}
public Play(String id, String title, LocalTime duration, String url) {
this.id = id;
this.title = title;
this.duration = duration;
this.url = url;
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
public LocalTime getDuration() {
return duration;
}
public void setDuration(LocalTime duration) {
this.duration = duration;
}
public String getUrl() {
return url;
}
public void setUrl(String url) {
this.url = url;
}
}
相关知识点
日期时间类： LocalDateTime-年月日时分秒，LocalTime-时分秒，LocalDate-年月日
1.获取当前时间
2.方便加减
3.把字符串表示的时间转换为对象时间
代码Demo：
public class TestDateTime {
public static void main(String[] args) {
LocalDateTime localDateTime = LocalDateTime.of(2022,8,6,12,12,35);
LocalTime localTime = LocalTime.of(11,22,33);
System.out.println(localDateTime.plusDays(21));
System.out.println(localTime.plusHours(10));
System.out.println(LocalDateTime.now());
String dateTime = "2022-08-27T12:12:35";
LocalDateTime l = LocalDateTime.parse(dateTime);
System.out.println(l.getYear());
System.out.println(l.getMonth());
System.out.println(l.getDayOfMonth());
}
}
2.数据展示
playList：
代码实现：
List<Play> plays = List.of(
new Play("P1", "二分查找-演示", LocalTime.parse("00:05:46"), "1_1.mp4"),
new Play("P2", "二分查找-实现", LocalTime.parse("00:06:47"), "1_2.mp4")
);
List<Play> plays = List.of(
new Play("P1", "Jva中的线程技术", LocalTime.parse("00:09:45"), "2_1.mp4"),
new Play("P2", "代码演示1", LocalTime.parse("00:07:05"), "2_2.mp4"),
new Play("P3", "代码演示2", LocalTime.parse("00:05:01"), "2_3.mp4")
);
VideoController：
package com.miles.module6.controller;
import com.miles.module6.dto.Play;
import com.miles.module6.dto.Video;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import java.time.LocalDateTime;
import java.time.LocalTime;
import java.util.List;
/**
* Created with IntelliJ IDEA.
*
* @author : Wzq
* @version : 1.0
* @Project : HeiMa-Project1
* @Package : com.miles.module5.controller
* @ClassName : VideoController.java
* @createTime : 2022/8/6 12:22
* @Email : zqwang21@163.com
* @Description :
*/
@Controller
public class VideoController {
@RequestMapping("/video/1")
@ResponseBody
public Video t1(){
List<Play> plays = List.of(
new Play("P1", "二分查找-演示", LocalTime.parse("00:05:46"), "1_1.mp4"),
new Play("P2", "二分查找-实现", LocalTime.parse("00:06:47"), "1_2.mp4")
);
return new Video("1","面试专题-基础篇", LocalDateTime.now(),"1.png","祝你面试游刃有余",
List.of("面试","Java","计算机技术"),plays,"自制","科技-计算机技术");
}
@RequestMapping("/video/2")
@ResponseBody
public Video t2(){
List<Play> plays = List.of(
new Play("P1", "Jva中的线程技术", LocalTime.parse("00:09:45"), "2_1.mp4"),
new Play("P2", "代码演示1", LocalTime.parse("00:07:05"), "2_2.mp4"),
new Play("P3", "代码演示2", LocalTime.parse("00:05:01"), "2_3.mp4")
);
return new Video("2","面试专题-并发篇", LocalDateTime.now(),"2.png","祝你面试游刃有余",
List.of("面试","Java","计算机技术"),plays,"自制","科技-计算机技术");
}
}
重启服务器，查看页面效果：
3.路径参数
多个路径映射到一个方法
@RequestMapping("/video/{bv}")
2.@PathVariable:表示该方法参数要从路径中获得
@PathVariable String bv
代码改进：
@Controller
public class VideoController {
@RequestMapping("/video/{bv}")
@ResponseBody
public Video t(@PathVariable String bv) {
if (bv.equals("1")) {
List<Play> plays = List.of(
new Play("P1", "二分查找-演示", LocalTime.parse("00:05:46"), "1_1.mp4"),
new Play("P2", "二分查找-实现", LocalTime.parse("00:06:47"), "1_2.mp4")
);
return new Video("1", "面试专题-基础篇", LocalDateTime.now(), "1.png", "祝你面试游刃有余",
List.of("面试", "Java", "计算机技术"), plays, "自制", "科技-计算机技术");
}
if (bv.equals("2")) {
List<Play> plays = List.of(
new Play("P1", "Jva中的线程技术", LocalTime.parse("00:09:45"), "2_1.mp4"),
new Play("P2", "代码演示1", LocalTime.parse("00:07:05"), "2_2.mp4"),
new Play("P3", "代码演示2", LocalTime.parse("00:05:01"), "2_3.mp4")
);
return new Video("2", "面试专题-并发篇", LocalDateTime.now(), "2.png", "祝你面试游刃有余",
List.of("面试", "Java", "计算机技术"), plays, "自制", "科技-计算机技术");
}
return null;
}
}
3.读取文件数据
目前代码缺点：
1.数据是写死的
2.把现有代码转到service中
数据文件：
相关知识点
读取文件数据 Files
代码Demo：
public class TestFile {
public static void main(String[] args) throws IOException {
List<String> data = Files.readAllLines(Path.of("data", "p.csv"));
for (String line : data) {
System.out.println(line);
}
}
}
运行结果：
分割字符串 split后存到数组
public class TestFile {
public static void main(String[] args) throws IOException {
List<String> data = Files.readAllLines(Path.of("data", "p.csv"));
for (String line : data) {
//System.out.println(line);
String[] s = line.split(",");
System.out.println(s[0]);
}
}
}
业务逻辑类设计
VideoService：
查询：根据视频编号，查询Video对象
@Service
public class VideoService1 {
//查询：根据视频编号，查询Video对象
public Video find(String bv){
try {
List<String> data = Files.readAllLines(Path.of("data", "p.csv"));
for (String line : data) {
String[] s = line.split(",");
if (s[0].equals(bv)) {
String[] tags = s[7].split("_");
//读取选集文件
List<String> vdata = Files.readAllLines(Path.of("data", "v_" + bv + ".csv"));
List<Play> list = new ArrayList<>();
for (String vline : vdata) {
String[] ss = vline.split(",");
list.add(new Play(ss[0],ss[1], LocalTime.parse(ss[3]),ss[2]));
}
return new Video(s[0], s[3], LocalDateTime.parse(s[6]), s[4], s[5], Arrays.asList(tags), list, s[1], s[2]);
}
}
return null;
} catch (IOException e) {
throw new RuntimeException(e);
}
}
}
相关知识点
1.读取文件
2.slpit方法
3.字符串拼接
VideoController：
public class VideoController {
@RequestMapping("/video/{bv}")
@ResponseBody
public Video t(@PathVariable String bv) throws IOException {
return videoService1.find(bv);
}
@Autowired
private VideoService1 videoService1;
}
相关知识点
1.@PathVariable
2.@Autowired 依赖注入
页面效果：
IDEA抽取方法快捷键
ctrl+Alt+M
文件读取时机
当前问题：
每次请求服务时，都会重新读一遍所有文件
改进：编写一个初始化函数，把需要读取的文件预先读取，这样只需读取一遍即可
关键字：@PostConstructor
改进后代码：
@Service
public class VideoService1 {
@PostConstruct
public void init(){
try {
List<String> data = Files.readAllLines(Path.of("data", "p.csv"));
for (String line : data) {
String[] s = line.split(",");
String[] tags = s[7].split("_");
List<Play> list = getPlayList(s[0]);
Video video =new Video(s[0], s[3], LocalDateTime.parse(s[6]), s[4], s[5], Arrays.asList(tags), list, s[1], s[2]);
map.put(s[0],video);
}
} catch (IOException e) {
throw new RuntimeException(e);
}
}
Map<String,Video> map = new HashMap<>();
//查询：根据视频编号，查询Video对象
public Video find(String bv){
Video video=map.get(bv);
return video;
}
//读取选集文件
private List<Play> getPlayList(String bv) {
try {
List<String> vdata = Files.readAllLines(Path.of("data", "v_" + bv + ".csv"));
List<Play> list = new ArrayList<>();
for (String vline : vdata) {
String[] ss = vline.split(",");
list.add(new Play(ss[0],ss[1], LocalTime.parse(ss[3]),ss[2]));
}
return list;
} catch (IOException e) {
throw new RuntimeException(e);
}
}
}
相关知识点
1.@PostConstructor
2.用map作为桥梁，声明一个<String,Video>类型的map，在获取文件数据后，存入到map中，然后通过map的get方法，实现根据视频编号，查询Video对象的效果
