java高級部分：
1.多線程：線程并發（多個線程操作共享變量）；
鎖機制，關鍵字有synchronize(并發線程安全，可鎖對象和方法),wait，notify
（悲觀）死鎖，,wait，notify,notifyAll;
2.網絡編程：UDP數據廣播（數據發送者只需向交換機發送一個拷貝，交換機負責將這個信息制作n個拷貝發送給所有機器）
Http協議（HyperText Transfer Protocol）
Json數據格式，語法規則：JSON對象{"屬性名":"屬性值"}
JSON數組["元素1","元素2"...]
JSON插件：- Json-lib
- Gson
- Jackson
- FastJSON - alibaba
；
數據庫部分：（采用mysql5.5數據庫，以及navicat圖形工具對其操作）
3.系統以及mysql常用命令
系統命令（以管理員身份運行）

： #啟動服務
net start mysql

#停止服務
net stop mysql


#進入mysql命令行
mysql -uroot -p密碼

#退出mysql命令行
exit


#修改密碼
mysqladmin -uroot -p123456 password 密碼
#備份數據庫實例 mysqldump -uroot -proot mydb > d:/mydb.sql
#備份表 mysqldump -uroot -proot mydb tbuser > d:/tbuser.sql

Mysql常用命令

： --顯示數據庫實例
show databases;

--創建數據庫實例
create database mydb;

--使用數據庫實例
user mydb;

--顯示實例中所有數據庫表
show tables;

SQL語句

auto_increment：設置列自增，可用于主鍵列以及非空唯一列(not null unique)

unsigned：設置無符號列(列值不允許為負數)

zerofill：設置零填充列(當列數據長度不到定義長度時，數值前補0)

4.SQL語句：
DDL（數據庫定義語言：用來建立數據庫、數據庫對象和定義其列）：create、desc（查看表結構）、alter、drop
DML （數據庫操縱語言：增刪改查）：select、insert、delete、update；
DCL（數據庫控制語言：控制權限）revork，grant；
5.（完整性條件）約束：1. 主鍵約束
2. 外鍵約束
3. 不為空約束
4. 唯一約束
5. 檢查約束(mysql暫不支持)

6.數據類型、運算符
7.查詢（重點）：SELECT 查詢列1,查詢列2,...
FROM 目標表

【WHERE 查詢條件】

【GROUP BY 列名稱】

【HAVING 查詢條件】

【ORDER BY 列名稱 ASCDESC】

【LIMIT [偏移行,]記錄行數】

單表查詢：模糊查詢（“%”，“_”），聚合函數
多表查詢：等值連接，外連接
mysql函數的使用。

import java.io.Serializable;/** * 工作詳情類 * @author NIUXUYUAN */public class Jobs implements Serializable{	/**	 * 	 */	private static final long serialVersionUID = 1L;	private String id;          //id	private String experience;  //工作經驗	private String city;        //工作地點	private String industry;    //行業	private String detail;      //工作詳情	private String company;     //公司	private String jobname;     //職位	public Jobs(String id, String experience, String city, String industry, String detail, String company,			String jobname) {		super();		this.id = id;		this.experience = experience;		this.city = city;		this.industry = industry;		this.detail = detail;		this.company = company;		this.jobname = jobname;	}		@Override	public String toString() {		return "Jobs [id=" + id + ", experience=" + experience + ", city=" + city + ", industry=" + industry				+ ", detail=" + detail + ", company=" + company + ", jobname=" + jobname + "]";	}		public String toString(int i) {		return experience+city+industry+detail+company+jobname;	}	public Jobs() {		// TODO Auto-generated constructor stub	}	public String getId() {		return id;	}	public void setId(String id) {		this.id = id;	}	public String getExperience() {		return experience;	}	public void setExperience(String experience) {		this.experience = experience;	}	public String getCity() {		return city;	}	public void setCity(String city) {		this.city = city;	}	public String getIndustry() {		return industry;	}	public void setIndustry(String industry) {		this.industry = industry;	}	public String getDetail() {		return detail;	}	public void setDetail(String detail) {		this.detail = detail;	}	public String getCompany() {		return company;	}	public void setCompany(String company) {		this.company = company;	}	public String getJobname() {		return jobname;	}	public void setJobname(String jobname) {		this.jobname = jobname;	}	}

import java.io.BufferedReader;import java.io.File;import java.io.FileInputStream;import java.io.FileNotFoundException;import java.io.FileOutputStream;import java.io.IOException;import java.io.InputStreamReader;import java.io.ObjectInputStream;import java.io.ObjectOutputStream;import java.util.ArrayList;import java.util.List;public class AddJobs {	static List<Jobs> list = new ArrayList<>();	File file = new File("jobs");		/**	 * 輸入數據	 * @throws IOException	 */	public void input() throws IOException {	     BufferedReader br = new BufferedReader(new InputStreamReader(System.in));	     System.out.println("以id/experience/education/city/industry/detail/company/jobname格式填入：");	     String msg = "";	     while(!(msg = br.readLine()).equalsIgnoreCase("quit")) {	    	 add(msg);	     }	     br.close();	}	/**	 * 將數據變為Jobs對象存入list集合	 * @param msg	 */	private void add(String msg) {		String[] s = msg.split("/");		Jobs job = new Jobs(s[0], s[1], s[2], s[3], s[4], s[5], s[6]);		list.add(job);	}		private void checkFile() throws FileNotFoundException, IOException, ClassNotFoundException {		if(file.length()>0) {		ObjectInputStream ois = new ObjectInputStream(new FileInputStream(file));		List<Jobs> temp = (List<Jobs>)ois.readObject();		if(temp!=null) {			list.clear();			for(Jobs t:temp) {				list.add(t);			}		}		ois.close();		}	}	public static void main(String[] args) throws FileNotFoundException, IOException, ClassNotFoundException {		AddJobs aj = new AddJobs();		if(!aj.file.exists()) {			aj.file.createNewFile();		}		aj.checkFile();		aj.input();		ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream(aj.file));		oos.writeObject(list);		oos.close();	}}

import java.io.BufferedReader;import java.io.File;import java.io.FileInputStream;import java.io.FileNotFoundException;import java.io.IOException;import java.io.InputStreamReader;import java.io.ObjectInputStream;import java.util.ArrayList;import java.util.List;public class Query {	static List<Jobs> list = new ArrayList<>();	File file = new File("jobs");	/**	 * 查看file文件，將數據導入list集合	 * @throws FileNotFoundException	 * @throws IOException	 * @throws ClassNotFoundException	 */	private void checkFile() throws FileNotFoundException, IOException, ClassNotFoundException {		if(file.length()>0) {		ObjectInputStream ois = new ObjectInputStream(new FileInputStream(file));		List<Jobs> temp = (List<Jobs>)ois.readObject();		if(temp!=null) {			list.clear();			for(Jobs t:temp) {				list.add(t);			}		}		ois.close();		}	}		public void check() throws IOException {		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));		System.out.println("請輸入experience/education/city/industry/detail/company/jobname的某些信息");		String msg = br.readLine();		String[] s = msg.split("/");		String regex = "";		for (String str : s) {			regex += "[//s//S]*" + str + "[//s//S]*";		}		List<Jobs> temp = new ArrayList<>();		for (Jobs j : list) {			msg = j.toString(1);			if(msg.matches(regex)) {				temp.add(j);			}		}		System.out.println("結果");		for (Jobs jobs : temp) {			System.out.println(jobs);		}	}	public static void main(String[] args) throws FileNotFoundException, ClassNotFoundException, IOException {		Query q = new Query();		q.checkFile();		q.check();	}}