本文实例讲述了基于jsp+servlet实现的简单博客系统。分享给大家供大家参考。具体如下:

没有用框架写的 小博客, 代码大量重复。

个人感觉重复代码对于新手还是有好处的,我也是新手,见谅。

完整实例代码点击此处本站下载

1. servlet


/*

 * To change this template, choose Tools | Templates

 * and open the template in the editor.

 */

package Servlet;

import blog.BlogBean;

import blog.BlogRepositoryJDBC;

import blog.PagerUtil;

import java.io.IOException;

import java.io.PrintWriter;

import java.net.URLDecoder;

import java.util.List;

import javax.enterprise.context.RequestScoped;

import javax.enterprise.context.SessionScoped;

import javax.inject.Inject;

import javax.inject.Named;

import javax.servlet.ServletException;

import javax.servlet.annotation.WebServlet;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

@WebServlet(name = "PageListServlet", urlPatterns = {"/page/*", ""})

public class ListAllServlet extends HttpServlet {

  @Inject

  private BlogRepositoryJDBC blogdao;

  @Inject

  private PagerUtil pagerUtil;

  protected void processRequest(HttpServletRequest request, HttpServletResponse response)

      throws ServletException, IOException {

    int pg;

    String s = request.getRequestURI();

    String searchContent = request.getParameter("search");

    if (s.matches(request.getContextPath() + "/page/" + "\\d")) {

      String pgnum = s.replaceAll(request.getContextPath() + "/page/", "");

      pg = Integer.parseInt(pgnum);

    } else if (s.matches(request.getContextPath() + "/")) {

      pg = 1;

    } else {

      getServletContext().getRequestDispatcher("/errorpage.jsp").forward(request, response);

      return;

    }

    List<BlogBean> bloglist;

    boolean isNullRequest = (searchContent == null || "".equals(searchContent));

    if (isNullRequest) {

      bloglist = blogdao.getBloglist();

    } else {

      bloglist = blogdao.listBlogByKey(searchContent);

    }

    if (!pagerUtil.isValidPg(bloglist, pg)) {

      getServletContext().getRequestDispatcher("/errorpage.jsp").forward(request, response);

      return;

    }

    pagerUtil.fillValue(bloglist, pg);

    String pageURLBase = getServletContext().getContextPath();

    String pageURLparam = isNullRequest ? "" : "?search=" + searchContent;

    request.setAttribute("pageURLBase", pageURLBase);

    request.setAttribute("pageURLparam", pageURLparam);

    request.setAttribute("bloglist", bloglist);

    getServletContext().getRequestDispatcher("/blog.jsp").forward(request, response);

  }

  @Override

  protected void doGet(HttpServletRequest request, HttpServletResponse response)

      throws ServletException, IOException {

    processRequest(request, response);

  }

  @Override

  protected void doPost(HttpServletRequest request, HttpServletResponse response)

      throws ServletException, IOException {

    processRequest(request, response);

  }

  @Override

  public String getServletInfo() {

    return "Short description";

  }// </editor-fold>

}



2. dao


package blog;

import java.sql.Connection;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

import java.sql.SQLException;

import java.sql.Statement;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.Date;

import java.util.HashMap;

import java.util.HashSet;

import java.util.List;

import java.util.Map;

import java.util.Set;

import java.util.logging.Level;

import java.util.logging.Logger;

import javax.annotation.PostConstruct;

import javax.annotation.Resource;

import javax.enterprise.context.ApplicationScoped;

import javax.inject.Inject;

import javax.inject.Named;

import javax.sql.DataSource;

@ApplicationScoped

@Named

public class BlogRepositoryJDBC implements BlogRepository {

  @Resource(lookup = "jdbc/sample")

  private DataSource ds;

  private ArrayList<BlogBean> bloglist;

  private Set<String> tagSet;

  private Set<String> categorySet;

  private Map<String,Integer> dateMap;

  @PostConstruct

  private void init() {

    refreshCache();

  }

  @Override

  public int addBlog(BlogBean blogi) {

    String sql = "INSERT INTO POSTS VALUES (?,?,?,?,?)";

    Connection conn = null;

    PreparedStatement ps = null;

    int out = 0;

    try {

      conn = ds.getConnection();

      ps = conn.prepareStatement(sql);

      ps.setString(1, blogi.getBlogTitle());

      ps.setString(2, blogi.getCategory());

      ps.setString(3, blogi.getTag());

      ps.setDate(4, new java.sql.Date(blogi.getPostDate().getTime()));

      ps.setString(5, blogi.getContent());

      out = ps.executeUpdate();

    } catch (SQLException ex) {

      Logger.getLogger(BlogRepositoryJDBC.class.getName()).log(Level.SEVERE, null, ex);

    } finally {

      closeEverything(conn, ps, null);

    }

    refreshCache();

    return out;

  }

  @Override

  public int deleteBlog(String blogName) {

    String sql = "DELETE FROM POSTS WHERE HEAD = ?";

    Connection conn = null;

    PreparedStatement ps = null;

    int out = 0;

    try {

      conn = ds.getConnection();

      ps = conn.prepareStatement(sql);

      ps.setString(1, blogName);

      out = ps.executeUpdate();

    } catch (SQLException ex) {

      Logger.getLogger(BlogRepositoryJDBC.class.getName()).log(Level.SEVERE, null, ex);

    } finally {

      closeEverything(conn, ps, null);

    }

    refreshCache();

    return out;

  }

  @Override

  public int updateBlog(BlogBean blog, String oldhead) {

    String sql = "UPDATE POSTS SET HEAD=?,CATEGORY=?,TAG=?,POSTDATE=?,CONTENT=? WHERE HEAD=?";

    PreparedStatement ps = null;

    Connection conn = null;

    int out = 0;

    try {

      conn = ds.getConnection();

      ps = conn.prepareStatement(sql);

      ps.setString(1, blog.getBlogTitle());

      ps.setString(2, blog.getCategory());

      ps.setString(3, blog.getTag());

      ps.setDate(4, new java.sql.Date(blog.getPostDate().getTime()));

      ps.setString(5, blog.getContent());

      ps.setString(6, oldhead);

      out = ps.executeUpdate();

    } catch (SQLException ex) {

      Logger.getLogger(BlogRepositoryJDBC.class.getName()).log(Level.SEVERE, null, ex);

    } finally {

      closeEverything(conn, ps, null);

    }

    refreshCache();

    return out;

  }

  @Override

  public List<BlogBean> ListAllBlog() {

    bloglist = new ArrayList<BlogBean>();

    BlogBean blog;

    String sql = "SELECT * FROM POSTS ORDER BY POSTDATE DESC";

    Connection conn = null;

    Statement ss = null;

    ResultSet rs = null;

    int out = 0;

    try {

      conn = ds.getConnection();

      ss = conn.createStatement();

      rs = ss.executeQuery(sql);

      while (rs.next()) {

        blog = new BlogBean();

        blog.setBlogTitle(rs.getString(1));

        blog.setCategory(rs.getString(2));

        blog.setTag(rs.getString(3));

        blog.setPostDate(rs.getDate(4));

        blog.setContent(rs.getString(5));

        bloglist.add(blog);

      }

    } catch (SQLException ex) {

      Logger.getLogger(BlogRepositoryJDBC.class.getName()).log(Level.SEVERE, null, ex);

    } finally {

      closeEverything(conn, ss, rs);

    }

    return bloglist;

  }

  @Override

  public List listBlogByKey(String keyword) {

    List<BlogBean> list = new ArrayList<BlogBean>();

    BlogBean blog;

    String sql = "SELECT * FROM POSTS WHERE HEAD LIKE ? ORDER BY POSTDATE DESC";

    Connection conn = null;

    PreparedStatement ps = null;

    ResultSet rs = null;

    int out = 0;

    try {

      conn = ds.getConnection();

      ps = conn.prepareStatement(sql);

      ps.setString(1, "%" + keyword + "%");

      rs = ps.executeQuery();

      while (rs.next()) {

        blog = new BlogBean();

        blog.setBlogTitle(rs.getString(1));

        blog.setCategory(rs.getString(2));

        blog.setTag(rs.getString(3));

        blog.setPostDate(rs.getDate(4));

        blog.setContent(rs.getString(5));

        list.add(blog);

      }

    } catch (SQLException ex) {

      Logger.getLogger(BlogRepositoryJDBC.class.getName()).log(Level.SEVERE, null, ex);

    } finally {

      closeEverything(conn, ps, rs);

    }

    return list;

  }

  @Override

  public List listBlogByContent(String keyword) {

    List<BlogBean> list = new ArrayList<BlogBean>();

    BlogBean blog;

    String sql = "SELECT * FROM POSTS WHERE CONTENT LIKE ? ORDER BY POSTDATE DESC";

    PreparedStatement ps = null;

    ResultSet rs = null;

    Connection conn = null;

    int out = 0;

    try {

      conn = ds.getConnection();

      ps = conn.prepareStatement(sql);

      ps.setString(1, "%" + keyword + "%");

      rs = ps.executeQuery();

      while (rs.next()) {

        blog = new BlogBean();

        blog.setBlogTitle(rs.getString(1));

        blog.setCategory(rs.getString(2));

        blog.setTag(rs.getString(3));

        blog.setPostDate(rs.getDate(4));

        blog.setContent(rs.getString(5));

        list.add(blog);

      }

    } catch (SQLException ex) {

      Logger.getLogger(BlogRepositoryJDBC.class.getName()).log(Level.SEVERE, null, ex);

    } finally {

      closeEverything(conn, ps, rs);

    }

    return list;

  }

  public Set listAllTags() {

    tagSet = new HashSet<String>();

    String sql = "SELECT TAG FROM POSTS ";

    Connection conn = null;

    Statement ss = null;

    ResultSet rs = null;

    try {

      conn = ds.getConnection();

      ss = conn.createStatement();

      rs = ss.executeQuery(sql);

      while (rs.next()) {

        String tags = rs.getString(1);

        String[] Arraytags = tags.split(",");

        tagSet.addAll(Arrays.asList(Arraytags));

      }

    } catch (SQLException ex) {

      Logger.getLogger(BlogRepositoryJDBC.class.getName()).log(Level.SEVERE, null, ex);

    } finally {

      closeEverything(conn, ss, rs);

    }

    return tagSet;

  }

  public List listBlogByTag(String keyword) {

    List<BlogBean> list = new ArrayList<BlogBean>();

    BlogBean blog;

    String sql = "SELECT * FROM POSTS WHERE TAG LIKE ? ORDER BY POSTDATE DESC";

    Connection conn = null;

    PreparedStatement ps = null;

    ResultSet rs = null;

    int out = 0;

    try {

      conn = ds.getConnection();

      ps = conn.prepareStatement(sql);

      ps.setString(1, "%" + keyword + "%");

      rs = ps.executeQuery();

      while (rs.next()) {

        blog = new BlogBean();

        blog.setBlogTitle(rs.getString(1));

        blog.setCategory(rs.getString(2));

        blog.setTag(rs.getString(3));

        blog.setPostDate(rs.getDate(4));

        blog.setContent(rs.getString(5));

        list.add(blog);

      }

    } catch (SQLException ex) {

      Logger.getLogger(BlogRepositoryJDBC.class.getName()).log(Level.SEVERE, null, ex);

    } finally {

      closeEverything(conn, ps, rs);

    }

    return list;

  }

    public List listBlogByDate(String keyword) {

    List<BlogBean> list = new ArrayList<BlogBean>();

    BlogBean blog;

    String sql = "SELECT * FROM POSTS WHERE POSTDATE = ? ORDER BY POSTDATE DESC";

    Connection conn = null;

    PreparedStatement ps = null;

    ResultSet rs = null;

    int out = 0;

    try {

      conn = ds.getConnection();

      ps = conn.prepareStatement(sql);

      ps.setString(1, keyword );

      rs = ps.executeQuery();

      while (rs.next()) {

        blog = new BlogBean();

        blog.setBlogTitle(rs.getString(1));

        blog.setCategory(rs.getString(2));

        blog.setTag(rs.getString(3));

        blog.setPostDate(rs.getDate(4));

        blog.setContent(rs.getString(5));

        list.add(blog);

      }

    } catch (SQLException ex) {

      Logger.getLogger(BlogRepositoryJDBC.class.getName()).log(Level.SEVERE, null, ex);

    } finally {

      closeEverything(conn, ps, rs);

    }

    return list;

  }

  public Set listAllCategory() {

    categorySet = new HashSet<String>();

    String sql = "SELECT CATEGORY FROM POSTS";

    Connection conn = null;

    Statement ss = null;

    ResultSet rs = null;

    try {

      conn = ds.getConnection();

      ss = conn.createStatement();

      rs = ss.executeQuery(sql);

      while (rs.next()) {

        String category = rs.getString(1);

        categorySet.add(category);

      }

    } catch (SQLException ex) {

      Logger.getLogger(BlogRepositoryJDBC.class.getName()).log(Level.SEVERE, null, ex);

    } finally {

      closeEverything(conn, ss, rs);

    }

    return categorySet;

  }

  public List listBlogByCategory(String keyword) {

    List<BlogBean> list = new ArrayList<BlogBean>();

    BlogBean blog;

    String sql = "SELECT * FROM POSTS WHERE CATEGORY LIKE ?";

    Connection conn = null;

    PreparedStatement ps = null;

    ResultSet rs = null;

    int out = 0;

    try {

      conn = ds.getConnection();

      ps = conn.prepareStatement(sql);

      ps.setString(1, "%" + keyword + "%");

      rs = ps.executeQuery();

      while (rs.next()) {

        blog = new BlogBean();

        blog.setBlogTitle(rs.getString(1));

        blog.setCategory(rs.getString(2));

        blog.setTag(rs.getString(3));

        blog.setPostDate(rs.getDate(4));

        blog.setContent(rs.getString(5));

        list.add(blog);

      }

    } catch (SQLException ex) {

      Logger.getLogger(BlogRepositoryJDBC.class.getName()).log(Level.SEVERE, null, ex);

    } finally {

      closeEverything(conn, ps, rs);

    }

    return list;

  }

  private void fillDateMap(){

    String sql = "SELECT POSTDATE,COUNT(POSTDATE) FROM POSTS GROUP BY POSTDATE";

     Connection conn = null;

    Statement ss = null;

    ResultSet rs = null;

    dateMap = new HashMap<String,Integer>();

    try {

      conn = ds.getConnection();

      ss = conn.createStatement();

       rs=ss.executeQuery(sql);  

      while (rs.next()) {

        dateMap.put(rs.getString(1), rs.getInt(2));

      }

    } catch (SQLException ex) {

      Logger.getLogger(BlogRepositoryJDBC.class.getName()).log(Level.SEVERE, null, ex);

    } finally {

      closeEverything(conn, ss, rs);

    }

  }

  public void test(){

        for(Map.Entry<String,Integer> dd: dateMap.entrySet()){

           dd.getKey();

           dd.getValue();

        }

  }

  public void refreshCache() {

    ListAllBlog();

    listAllTags();

    listAllCategory();

    fillDateMap();

  }

  public ArrayList<BlogBean> getBloglist() {

    return bloglist;

  }

  public Set<String> getTagSet() {

    return tagSet;

  }

  public Set<String> getCategorySet() {

    return categorySet;

  }

  public Map<String, Integer> getDateMap() {

    return dateMap;

  }

  private void closeEverything(Connection conn, Statement ps, ResultSet rs) {

    if (rs != null) {

      try {

        rs.close();

      } catch (SQLException ex) {

      }

    }

    if (ps != null) {

      try {

        ps.close();

      } catch (SQLException ex) {

      }

    }

    if (conn != null) {

      try {

        conn.close();

      } catch (SQLException ex) {

      }

    }

  }

}



3. 运行效果截图:

希望本文所述对大家的JSP程序设计有所帮助。

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