Java牛客项目课_仿牛客网讨论区_第三章
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文章目录
第三章
3.1、Trie树过滤敏感词
敏感词文件：sensitive-words.txt
赌博
嫖娼
吸毒
开票
过滤敏感词工具类SensitiveFilter.java
注释：Bean在服务启动时初始化，然后被@PostConstruct注释的方法被调用。所以SensitiveFilter类中的init()方法在程序一启动时就被调用。
package com.nowcoder.community.util;
import org.apache.commons.lang3.CharUtils;
import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;
import javax.annotation.PostConstruct;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.HashMap;
import java.util.Map;
@Component
public class SensitiveFilter {
private static final Logger logger = LoggerFactory.getLogger(SensitiveFilter.class);
// 替换符
private static final String REPLACEMENT = "***";
// 根节点
private TrieNode rootNode = new TrieNode();
@PostConstruct
public void init() {
try (
InputStream is = this.getClass().getClassLoader().getResourceAsStream("sensitive-words.txt");
BufferedReader reader = new BufferedReader(new InputStreamReader(is));
) {
String keyword;
while ((keyword = reader.readLine()) != null) {
// 添加到前缀树
this.addKeyword(keyword);
}
} catch (IOException e) {
logger.error("加载敏感词文件失败: " + e.getMessage());
}
}
// 将一个敏感词添加到前缀树中
private void addKeyword(String keyword) {
TrieNode tempNode = rootNode;
for (int i = 0; i < keyword.length(); i++) {
char c = keyword.charAt(i);
TrieNode subNode = tempNode.getSubNode(c);
if (subNode == null) {
// 初始化子节点
subNode = new TrieNode();
tempNode.addSubNode(c, subNode);
}
// 指向子节点,进入下一轮循环
tempNode = subNode;
// 设置结束标识
if (i == keyword.length() - 1) {
tempNode.setKeywordEnd(true);
}
}
}
/**
* 过滤敏感词
*
* @param text 待过滤的文本
* @return 过滤后的文本
*/
public String filter(String text) {
if (StringUtils.isBlank(text)) {
return null;
}
// 指针1
TrieNode tempNode = rootNode;
// 指针2
int begin = 0;
// 指针3
int position = 0;
// 结果
StringBuilder sb = new StringBuilder();
while (position < text.length()) {
char c = text.charAt(position);
// 跳过符号
if (isSymbol(c)) {
// 若指针1处于根节点,将此符号计入结果,让指针2向下走一步
if (tempNode == rootNode) {
sb.append(c);
begin++;
}
// 无论符号在开头或中间,指针3都向下走一步
position++;
continue;
}
// 检查下级节点
tempNode = tempNode.getSubNode(c);
if (tempNode == null) {
// 以begin开头的字符串不是敏感词
sb.append(text.charAt(begin));
// 进入下一个位置
position = ++begin;
// 重新指向根节点
tempNode = rootNode;
} else if (tempNode.isKeywordEnd()) {
// 发现敏感词,将begin~position字符串替换掉
sb.append(REPLACEMENT);
// 进入下一个位置
begin = ++position;
// 重新指向根节点
tempNode = rootNode;
} else {
// 检查下一个字符
position++;
}
}
// 将最后一批字符计入结果
sb.append(text.substring(begin));
return sb.toString();
}
// 判断是否为符号
private boolean isSymbol(Character c) {
// 0x2E80~0x9FFF 是东亚文字范围
return !CharUtils.isAsciiAlphanumeric(c) && (c < 0x2E80 || c > 0x9FFF);
}
// 前缀树
private class TrieNode {
// 关键词结束标识
private boolean isKeywordEnd = false;
// 子节点(key是下级字符,value是下级节点)
private Map<Character, TrieNode> subNodes = new HashMap<>();
public boolean isKeywordEnd() {
return isKeywordEnd;
}
public void setKeywordEnd(boolean keywordEnd) {
isKeywordEnd = keywordEnd;
}
// 添加子节点
public void addSubNode(Character c, TrieNode node) {
subNodes.put(c, node);
}
// 获取子节点
public TrieNode getSubNode(Character c) {
return subNodes.get(c);
}
}
}
测试，SensitiveTests.java
package com.nowcoder.community;
import com.nowcoder.community.util.SensitiveFilter;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringRunner;
@RunWith(SpringRunner.class)
@SpringBootTest
@ContextConfiguration(classes = CommunityApplication.class)
public class SensitiveTests {
@Autowired
private SensitiveFilter sensitiveFilter;
@Test
public void testSensitiveFilter() {
String text = "这里可以赌博,可以嫖娼,可以吸毒,可以开票,哈哈哈!";
text = sensitiveFilter.filter(text);
System.out.println(text);
text = "这里可以☆赌☆博☆,可以☆嫖☆娼☆,可以☆吸☆毒☆,可以☆开☆票☆,哈哈哈!";
text = sensitiveFilter.filter(text);
System.out.println(text);
}
}
3.6、AJAX发布帖子
pom.xml
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.58</version>
</dependency>
CommunityUtil.java ：
public class CommunityUtil {
public static String getJSONString(int code, String msg, Map<String, Object> map) {
JSONObject json = new JSONObject();
json.put("code", code);
json.put("msg", msg);
if (map != null) {
for (String key : map.keySet()) {
json.put(key, map.get(key));
}
}
return json.toJSONString();
}
public static String getJSONString(int code, String msg) {
return getJSONString(code, msg, null);
}
public static String getJSONString(int code) {
return getJSONString(code, null, null);
}
public static void main(String[] args) {
Map<String, Object> map = new HashMap<>();
map.put("name", "zhangsan");
map.put("age", 25);
System.out.println(getJSONString(0, "ok", map));
}
}
测试部分，测试ajax：
AlphaController.java测试
@Controller
@RequestMapping("/alpha")
public class AlphaController {
// ajax示例
@RequestMapping(path = "/ajax", method = RequestMethod.POST)
@ResponseBody
public String testAjax(String name, int age) {
System.out.println(name);
System.out.println(age);
return CommunityUtil.getJSONString(0, "操作成功!");
}
}
测试页面，/html/ajax-demo.html
注释：$.ajax();可以简化为$.post();和$.get();。
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>AJAX</title>
</head>
<body>
<p>
<input type="button" value="发送" onclick="send();">
</p>
<script src="https://code.jquery.com/jquery-3.3.1.min.js" crossorigin="anonymous"></script>
<script>
function send() {
$.post(
"/community/alpha/ajax",
{"name":"张三","age":23},
function(data) {
console.log(typeof(data));
console.log(data);
data = $.parseJSON(data);
console.log(typeof(data));
console.log(data.code);
console.log(data.msg);
}
);
}
</script>
</body>
</html>
测试结果：
采用AJAX请求，实现发布帖子的功能
discusspost-mapper.xml
<insert id="insertDiscussPost" parameterType="DiscussPost">
insert into discuss_post(<include refid="insertFields"></include>)
values(#{userId},#{title},#{content},#{type},#{status},#{createTime},#{commentCount},#{score})
</insert>
Service，DiscussPostService.java：
注释：
HtmlUtils.htmlEscape("<div>");得到<div>
HtmlUtils.htmlUnescape("<div>");得到<div>
public int addDiscussPost(DiscussPost post) {
if (post == null) {
throw new IllegalArgumentException("参数不能为空!");
}
// 转义HTML标记
post.setTitle(HtmlUtils.htmlEscape(post.getTitle()));
post.setContent(HtmlUtils.htmlEscape(post.getContent()));
// 过滤敏感词
post.setTitle(sensitiveFilter.filter(post.getTitle()));
post.setContent(sensitiveFilter.filter(post.getContent()));
return discussPostMapper.insertDiscussPost(post);
}
Controller，0803最终版的的DiscussPostController.java：
@Controller
@RequestMapping("/discuss")
public class DiscussPostController implements CommunityConstant {
@Autowired
private DiscussPostService discussPostService;
@Autowired
private HostHolder hostHolder;
@RequestMapping(path = "/add", method = RequestMethod.POST)
@ResponseBody
public String addDiscussPost(String title, String content) {
User user = hostHolder.getUser();
if (user == null) {
return CommunityUtil.getJSONString(403, "你还没有登录哦!");
}
DiscussPost post = new DiscussPost();
post.setUserId(user.getId());
post.setTitle(title);
post.setContent(content);
post.setCreateTime(new Date());
discussPostService.addDiscussPost(post);
// 报错的情况,将来统一处理.
return CommunityUtil.getJSONString(0, "发布成功!");
}
}
0803版的index.js，就是点击发布按钮后的操作
$(function(){
$("#publishBtn").click(publish);
});
function publish() {
$("#publishModal").modal("hide");
// 发送AJAX请求之前,将CSRF令牌设置到请求的消息头中.
// var token = $("meta[name='_csrf']").attr("content");
// var header = $("meta[name='_csrf_header']").attr("content");
// $(document).ajaxSend(function(e, xhr, options){
// xhr.setRequestHeader(header, token);
// });
// 获取标题和内容
var title = $("#recipient-name").val();
var content = $("#message-text").val();
// 发送异步请求(POST)
$.post(
CONTEXT_PATH + "/discuss/add",
{"title":title,"content":content},
function(data) {
data = $.parseJSON(data);
// 在提示框中显示返回消息
$("#hintBody").text(data.msg);
// 显示提示框
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