基于jsp+servlet实现的简单博客系统实例(附源码)

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。

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。