创建springboot(五)文章发表项目

文章发表

实现发表文章的功能
流程:
1:用户在首页点击发表文章的超链接来到发表文章页面
2:在页面输入文章标题和文章内容并点击发表按钮
3:服务端将该文章保存后响应发表结果页面(成功或失败)
实现:
1:在static下新建对应的页面
1.1:writeArticle.html 发表文章页面
页面form表单action指定的值"/writeArticle"
1.2:article_success.html 发表成功提示页面
1.3:article_fail.html 发表失败提示页面
2:在controller包下新建处理文章相关的业务类:ArticleController
并定义处理发表文章的方法:writeArticle()
注意:@Controller注解和@RequestMapping注解不要忘记!!!
3:在entity包下新建表示文章的对象:Article并实现序列化接口
4:在writeArticle方法中将表单提交上来的标题和文章内容以Article对象形式序列化到目录articles
下文件名格式:标题.obj
保存后响应发表成功。如果标题或内容没有输入则响应发表失败页面。

1.新增文章

package cn.tedu.springboot220602.controller;

import cn.tedu.springboot220602.entity.Article;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectOutputStream;

@Controller
public class ArticleController {
    private static File ArticleDir;
    static {
        ArticleDir=new File("./articles");
        if (!ArticleDir.exists()){
            ArticleDir.mkdirs();
        }
    }

    /**
     * 发表文章
     * @param request
     * @param response
     */
    @RequestMapping("/writeArticle")
    private void writeArticle(HttpServletRequest request, HttpServletResponse response){
        String title = request.getParameter("title");
        String author = request.getParameter("author");
        String content = request.getParameter("content");
        //如果输入内容为空或空格
        if(title==null||title.trim().isEmpty()||
        author==null||author.trim().isEmpty()||
        content==null||content.trim().isEmpty()
        ){
            try {
                response.sendRedirect("/article_fail.html");
            } catch (IOException e) {
                e.printStackTrace();
            }
            return;
        }
        File file=new File(ArticleDir,title+".obj");
        if(file.exists()){
            try {
                response.sendRedirect("/article_fail.html");
            } catch (IOException e) {
                e.printStackTrace();
            }
            return;
        }
        try (FileOutputStream fos=new FileOutputStream(file);
             ObjectOutputStream oos=new ObjectOutputStream(fos);){
            Article article=new Article(title,author,content);
            oos.writeObject(article);
        } catch (IOException e) {
            e.printStackTrace();
        }
        try {
            response.sendRedirect("/article_success.html");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

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package cn.tedu.springboot220602.entity;

import java.io.Serializable;

public class Article implements Serializable {
    public static final long serialVersionUID = 42L;
    private String title;
    private String author;
    private String content;

    public Article() {
    }

    public Article(String title, String author, String content) {
        this.title = title;
        this.author = author;
        this.content = content;
    }

    public static long getSerialVersionUID() {
        return serialVersionUID;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getAuthor() {
        return author;
    }

    public void setAuthor(String author) {
        this.author = author;
    }

    public String getContent() {
        return content;
    }

    public void setContent(String content) {
        this.content = content;
    }
}

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2.展示和删除文章

package cn.tedu.springboot220602.controller;

import cn.tedu.springboot220602.entity.Article;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.util.ArrayList;
import java.util.List;

@Controller
public class ArticleController {
    private static File ArticleDir;
    static {
        ArticleDir=new File("./articles");
        if (!ArticleDir.exists()){
            ArticleDir.mkdirs();
        }
    }
    @RequestMapping("/deleteArticle")
    private void delete(HttpServletRequest request,HttpServletResponse response){
        String title = request.getParameter("title");
        File file=new File(ArticleDir,title+".obj");
        if(file.exists()){
            file.delete();
            try {
                response.sendRedirect("/articleList");
            } catch (IOException e) {
                e.printStackTrace();
            }
            return;
        }
    }

    //文章列表
    @RequestMapping("/articleList")
    private void articleList(HttpServletRequest request,HttpServletResponse response){
        File[] subs = ArticleDir.listFiles(f -> f.getName().endsWith(".obj"));
        List<Article> articleList=new ArrayList<>();
        for (File file:subs) {
            try (FileInputStream fis=new FileInputStream(file);
                 ObjectInputStream ois=new ObjectInputStream(fis);
                 ){
                Article article=(Article)ois.readObject();
                articleList.add(article);
            } catch (IOException | ClassNotFoundException e) {
                e.printStackTrace();
            }
        }
        //向浏览器写信息
        response.setContentType("text/html;charset=utf-8");
        try (PrintWriter pw = response.getWriter();){

            pw.println("");
            pw.println("");
            pw.println("");
            pw.println("");
            pw.println("");
            pw.println("");
            pw.println("");
            pw.println("");
            pw.println("");
            pw.println("");
            pw.println("");
            pw.println("");
            pw.println("");for(Article article:articleList){
                pw.println("");
                pw.println("");
                pw.println("");
                pw.println("");
                pw.println("");}
            pw.println("
标题
作者
操作
            
"+article.getTitle()+"
"+article.getAuthor()+"
删除
            
");
            pw.println("");
            pw.println("");
            pw.println("");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    /**
     * 发表文章
     * @param request
     * @param response
     */
    @RequestMapping("/writeArticle")
    private void writeArticle(HttpServletRequest request, HttpServletResponse response){
        String title = request.getParameter("title");
        String author = request.getParameter("author");
        String content = request.getParameter("content");
        //如果输入内容为空或空格
        if(title==null||title.trim().isEmpty()||
        author==null||author.trim().isEmpty()||
        content==null||content.trim().isEmpty()
        ){
            try {
                response.sendRedirect("/article_fail.html");
            } catch (IOException e) {
                e.printStackTrace();
            }
            return;
        }
        File file=new File(ArticleDir,title+".obj");
        if(file.exists()){
            try {
                response.sendRedirect("/article_fail.html");
            } catch (IOException e) {
                e.printStackTrace();
            }
            return;
        }
        try (FileOutputStream fos=new FileOutputStream(file);
             ObjectOutputStream oos=new ObjectOutputStream(fos);){
            Article article=new Article(title,author,content);
            oos.writeObject(article);
        } catch (IOException e) {
            e.printStackTrace();
        }
        try {
            response.sendRedirect("/article_success.html");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}
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