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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