如何基于jsp+servlet实现博客系统？

来源：www.45fan.com 2016-06-03 09:13:39

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：

如何基于jsp+servlet实现博客系统？

希望本文所述对大家的JSP程序设计有所帮助。

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如何基于jsp+servlet实现博客系统？

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