基于jsp+servlet实现的简单博客系统实例(附源码)

所属分类：网络编程 / JSP编程阅读数： 1967

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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：