{ "user": {
      "username": "admin",
      "password": "1234"}
};

# 以前的登录url
/signup?username=abc&password=123456

POST /accounts

{
"username": "abc",
"password": "123456"
}

GET /favicon.ico HTTP/1.1
Host: www.xiedaimala.com
Connection: keep-alive
Pragma: no-cache
Cache-Control: no-cache
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3497.100 Safari/537.36
Accept: image/webp,image/apng,image/*,*/*;q=0.8
Accept-Encoding: gzip, deflate
Accept-Language: en,zh-CN;q=0.9,zh;q=0.8,ja;q=0.7,zh-TW;q=0.6
Cookie: _ga=GA1.2.963880079.1538204516; _gid=GA1.2.932523408.1538204516; _gat=1; Hm_lvt_f89e0235da0841927341497d774e7b15=1538204517,1538205893; Hm_lpvt_f89e0235da0841927341497d774e7b15=1538205893

HTTP/1.1 200 OK
Date: Sat, 29 Sep 2018 07:24:53 GMT
Content-Type: image/vnd.microsoft.icon
Content-Length: 3638
Connection: keep-alive
Server: nginx/1.6.2
Last-Modified: Thu, 24 May 2018 05:56:53 GMT
ETag: "e36-56ced517f0753"
Cache-Control: max-age=2592000, public
X-ORCA-Accelerator: HIT from 006.mul.lax01.us.krill.zenlogic.net
X-Cache: HIT from 006.mul.lax01.us.krill.zenlogic.net
Accept-Ranges: bytes

package user;

import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;

import java.util.*;
/*
   操作相关注解 @PostMapping, @GetMapping, @PutMapping, Deletemapping
   参数相关注解 @RequestBody, @PathVariable
*/
@RestController
public class UserController {
    private final Map<String,User> map = new HashMap<String,User>();

    UserController(){
        map.put("aaa",new User("aaa",11));
        map.put("bbb",new User("bbb",22));
        map.put("ccc",new User("ccc",33));
    }

    @GetMapping("/users")
    public List<User> getUsers() {
        Set<String> keys = map.keySet();
        List<User> res = new ArrayList<>();
        for (String name:keys) {
            res.add(map.get(name));
        }
        return res;
    }

    @GetMapping("/users/{name}")
    public User getUserByName(@PathVariable("name") String name) {
        if(map.containsKey(name)){
            return map.get(name);
        }else{
            return null;
        }
    }

    @PostMapping("/users")
    public User AddUser(@RequestBody User user) {
        String name = user.getName();
        map.put(name,user);
        return user;
    }

    @PutMapping("/users/{name}")
    public User UpdateUser(@PathVariable("name") String name ,@RequestBody User user) {
        map.get(name).setAge(user.getAge());
        return user;
    }
    @DeleteMapping("/users/{name}")
    public User DelUserByName(@PathVariable("name") String name){
        if(map.containsKey(name)){
            return map.remove(name);
        }else{
            return null;
        }
    }
}

package user;

import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;

import java.util.*;
/*
   操作相关注解 @PostMapping, @GetMapping, @PutMapping, Deletemapping
   参数相关注解 @RequestBody, @PathVariable
*/
@RestController
public class UserController {
    private final Map<String,User> map = new HashMap<>();

    UserController(){
        map.put("aaa",new User("aaa",11));
        map.put("bbb",new User("bbb",22));
        map.put("ccc",new User("ccc",33));
    }

    @GetMapping("/users")
    ResponseEntity<List<User>> getUsers(){
        Set<String> keys = map.keySet();
        List<User> res = new ArrayList<>();
        for (String name:keys) {
            res.add(map.get(name));
        }
        return new ResponseEntity<>(res, HttpStatus.OK);
    }

    @GetMapping("/users/{name}")
    public ResponseEntity<User> getUserByName(@PathVariable("name") String name) {
        if(map.containsKey(name)){
            return new ResponseEntity<>(map.get(name),HttpStatus.OK);
        }else{
            return new ResponseEntity<>(HttpStatus.NOT_FOUND);
        }
    }

    @PostMapping("/users")
    public ResponseEntity<User>  AddUser(@RequestBody User user) {
        String name = user.getName();
        if(map.containsKey(name)){
            return new ResponseEntity<>(HttpStatus.NOT_FOUND);
        }else{
            map.put(name,user);
            return new ResponseEntity<>(map.get(name),HttpStatus.CREATED);
        }
    }



    @PutMapping("/users/{name}")
    public ResponseEntity<User> UpdateUser(@PathVariable("name") String name ,@RequestBody User user) {
        if(map.containsKey(name)){
            User updateUser = map.get(name);
            updateUser.setAge(user.getAge());
            return new ResponseEntity<>(map.get(name),HttpStatus.OK);
        }else{
            return new ResponseEntity<>(HttpStatus.NOT_FOUND);
        }
    }

    @DeleteMapping("/users/{name}")
    public ResponseEntity<User> DelUserByName(@PathVariable("name") String name){
        if(map.containsKey(name)){
            return new ResponseEntity<>(map.remove(name),HttpStatus.OK);
        }else{
            return new ResponseEntity<>(HttpStatus.NOT_FOUND);
        }
    }
}

package hello;

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

import java.util.concurrent.atomic.AtomicLong;

@RestController
public class GreetingController {

    private static final String template = "Hello, %s!";
    private final AtomicLong counter = new AtomicLong(); // 原子操作, 因为Spring默认是支持多线程的

    @RequestMapping("/greeting")
    public Greeting greeting(@RequestParam(value="name", defaultValue = "World") String name) {
        return new Greeting(counter.incrementAndGet(), String.format(template, name));
    }
}

package hello;

public class Greeting {

    private final long id;
    private final String content;

    public Greeting(long id, String content) {
        this.id = id;
        this.content = content;
    }

    public long getId() {
        return id;
    }

    public String getContent() {
        return content;
    }
}

package hello;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class Application {

    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }
}

scp -r [远程机器配置缩写]:[远程目录] [本地目录] 

scp -r [本地目录] [远程机器配置缩写]:[远程目录]

scp [本地文件] [远程机器配置缩写]:[远程目录]

scp -r [本地目录] [远程机器配置缩写]:[远程目录]

scp --> ssh copy

ssh -i "id_rsa.pem" ubuntu@ec2-54-193-62-229.us-west-1.compute.amazonaws.com -t "tmux"

ssh -i "id_rsa.pem" ubuntu@ec2-54-193-62-229.us-west-1.compute.amazonaws.com -t "tmux attach"

Host aws
    HostName ec2-54-193-62-229.us-west-1.compute.amazonaws.com
    User ubuntu
    IdentityFile "~/.ssh/id_rsa"

ssh [-p 端口] [用户名]@[远程服务器IP地址]

如果省略端口设置, 使用ssh默认端口22
如果省略用户名设置, 使用当前系统登录用户的用户名
ip地址不能省略

Host ubuntu
    HostName 10.211.55.5
    User hacker
    IdentityFile "~/.ssh/hacker.pem"

# 缩写登录命令:
ssh ubuntu

public class CurrentThreadDemo {
    public static void main(String args[]) {
        Thread t = Thread.currentThread();
        System.out.println("Current thread: " + t);
        // change the name of the thread
        t.setName("My Thread");
        System.out.println("After name change: " + t);
        try {
            for (int n = 5; n > 0; n--) {
                System.out.println(n);
                Thread.sleep(1000);
            }
        } catch (InterruptedException e) {
            System.out.println("Main thread interrupted");
        }
    }
}

// Create a second thread by extending Thread
class NewThread extends Thread {
    NewThread() {
        // Create a new, second thread
        super("Demo Thread");
        System.out.println("Child thread: " + this);
        start(); // Start the thread
    }

    // This is the entry point for the second thread.
    public void run() {
        try {
            for (int i = 5; i > 0; i--) {
                System.out.println("Child Thread: " + i);
                Thread.sleep(500);
            }
        } catch (InterruptedException e) {
            System.out.println("Child interrupted.");
        }
        System.out.println("Exiting child thread.");
    }
}

public class Demo {
    public static void main(String args[]) {
        new NewThread(); // create a new thread
        try {
            for (int i = 5; i > 0; i--) {
                System.out.println("Main Thread: " + i);
                Thread.sleep(1000);
            }
        } catch (InterruptedException e) {
            System.out.println("Main thread interrupted.");
        }
        System.out.println("Main thread exiting.");
    }
}

// Create multiple threads.
class NewThread implements Runnable {
    String name; // name of thread
    Thread t;

    NewThread(String threadname) {
        name = threadname;
        t = new Thread(this, name);
        System.out.println("New thread: " + t);
        t.start(); // Start the thread
    }

    // This is the entry point for thread.
    public void run() {
        try {
            for (int i = 5; i > 0; i--) {
                System.out.println(name + ": " + i);
                Thread.sleep(1000);
            }
        } catch (InterruptedException e) {
            System.out.println(name + "Interrupted");
        }
        System.out.println(name + " exiting.");
    }
}

public class Demo {
    public static void main(String args[]) {
        new NewThread("One"); // start threads
        new NewThread("Two");
        new NewThread("Three");
        try {
            // wait for other threads to end
            Thread.sleep(10000);
        } catch (InterruptedException e) {
            System.out.println("Main thread Interrupted");
        }
        System.out.println("Main thread exiting.");
    }
}

package com.repeat;


public class Work01 {
    public static void main(String[] args) throws InterruptedException {
        Thread t = Thread.currentThread();
        t.setName("main thread");

        MyThread t2 = new MyThread("aaa");
        MyThread2 t3 = new MyThread2("bbb");

        t2.start();
        t3.start();

        for (int i = 1; i <= 100; i++) {
            System.out.println(t.getName() + " running " + i);
            Thread.sleep(50);
        }
    }
}

class MyThread extends Thread{
    private Thread t;
    private String name;

    public MyThread(String name) {
        this.name = name;
    }

    @Override
    public void run() {
        try {
            for (int i = 65; i < 65+26; i++) {
                char a = (char) i;
                System.out.println(name+ " running " + a);
                Thread.sleep(50);
            }
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }

    public void start(){
        t = new Thread (this, name);
        t.start ();
    }
}

class MyThread2 implements Runnable{
    private Thread t;
    private String name;

    public MyThread2(String name) {
        this.name = name;
    }

    @Override
    public void run() {
        try {
            for (int i = 97; i < 97 + 26; i++) {
                char a = (char) i;
                System.out.println(name+ " running " + a);
                Thread.sleep(50);
            }
        } catch (InterruptedException e) {
            e.printStackTrace();
        }

    }

    public void start(){
        t = new Thread (this, name);
        t.start ();
    }
}

package com.repeat;

import java.io.*;
import java.util.Scanner;

public class Work02 {
    public static void main(String[] args) throws IOException {

        while (true){
            // 获取输入
            String input = getInput();
            // 新开线程，写入文件
            new MyFileIoThread( input ).start();

        }
    }

    public static String getInput(){
        Scanner sc = new Scanner(System.in);
        String str = sc.next();
        return str;
    }
}

class MyFileIoThread extends Thread{
    public static int count = 1;
    private String content;

    public MyFileIoThread(String content) {
        this.content = content;
        MyFileIoThread.count++;
        System.out.println(MyFileIoThread.count);
    }

    @Override
    public void run() {
        FileOutputStream output = null;
        try {
            String fileName = MyFileIoThread.count + ".txt";
            output = new FileOutputStream("day015Thread/res/" + fileName);
            OutputStreamWriter writer = new OutputStreamWriter(output,"UTF-8");
            PrintWriter printWriter = new PrintWriter(writer);

            // 模拟写入文件慢的操作
            Thread.sleep(500);
            System.out.println(" file: " + fileName + " 写入成功");

            printWriter.write(content);
            printWriter.close();
            output.close();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
}

exec:java -Dexec.mainClass=你的包名.类名 -Dexec.args

export M2_HOME=/Users/huangjiaxi/Desktop/soft/apache-maven-3.6.1
export PATH=/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin
# 这句一定要在上句下面
export PATH=$PATH:$M2_HOME/bin

<settings xmlns="http://maven.apache.org/SETTINGS/1.0.0"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.0.0
                          https://maven.apache.org/xsd/settings-1.0.0.xsd">

      <mirrors>
        <mirror>  
            <id>alimaven</id>  
            <name>aliyun maven</name>  
            <url>http://maven.aliyun.com/nexus/content/groups/public/</url>  
            <mirrorOf>central</mirrorOf>          
        </mirror>  
      </mirrors>
</settings>
`

https://blog.csdn.net/Liu_xud/article/details/84385755

public class Demo01泛型 {
    // 泛型
    // 定义了hash表 key是 String类型 value是 Integer类型
    static HashMap<String,Integer> counts = new HashMap<>();

    static Stack<String> stringStack = new Stack<>();

    static Stack<Integer> intStack = new Stack<>();


    public static void main(String[] args) {
        stringStack.push("abc");

        String one = stringStack.pop();

        intStack.push(1);
        Integer two = intStack.pop();

        // intStack.push("ssss");  规定了Stack 内的类型是 int的 所以无法 加入 String类型的
    }
}

public class IntStack {
    ArrayList<Integer> store = new ArrayList<>();

    public void push(Integer item){
        store.add(item);
    }

    public Integer pop(){
        Integer tmp = store.get(store.size() - 1);
        store.remove(store.size() - 1);
        return tmp;
    }

    public int size(){
        return store.size();
    }
}

public class StringStack {
    ArrayList<String> store = new ArrayList<>();

    public void push(String item){
        store.add(item);
    }

    public String pop(){
        String tmp = store.get(store.size() - 1);
        store.remove(store.size() - 1);
        return tmp;
    }

    public int size(){
        return store.size();
    }
}

// 自己实现一个泛型，支持任意类型的Stack ，
// 把数据类型变成参数，把重复代码去除了 如 IntStack / StringStack
// T 是 类型参数
public class Stack2<T> {
    ArrayList<T> store = new ArrayList<>();

    public void push(T item){
        store.add(item);
    }

    public T pop(){
        T tmp = store.get(store.size() - 1);
        store.remove(store.size() - 1);
        return tmp;
    }

    public int size(){
        return store.size();
    }
}

// 列表
List<String> arrayList = new ArrayList<>();
List<String> linkedList = new LinkedList<>();

// 操作 在尾部添加
arrayList.add("hello");
arrayList.add("world");
arrayList.add("~~~~");

// 通过索引去访问
arrayList.get(0);

//arrayList.subList(0,5); // 取出 索引从 0 到 5 位置的列表  内容不够就报错

// 通过索引 删除
arrayList.remove(0);

// 访问 列表的长度
int size = arrayList.size();

// for循环里的语法糖

for (String item: arrayList) {
    System.out.println( item );
}

// Set 主要用来去重复
Set<String> set = new HashSet<>();

set.add("a");
set.add("b");
set.add("c");

set.add("a"); // 去重复

for (String item: set) {
    System.out.println( item );
}

在经典的汉诺塔问题中，有 3 个塔和 N 个可用来堆砌成塔的不同大小的盘子。要求盘子必须按照从小到大的顺序从上往下堆 （如，任意一个盘子，其必须堆在比它大的盘子上面）。同时，你必须满足以下限制条件：

(1) 每次只能移动一个盘子。
(2) 每个盘子从堆的顶部被移动后，只能置放于下一个堆中。
(3) 每个盘子只能放在比它大的盘子上面。

请写一段程序，实现将第一个堆的盘子移动到最后一个堆中.

在编程训练网站完成训练: https://www.lintcode.com/problem/mock-hanoi-tower-by-stacks/description

public class Tower {
    private Stack<Integer> disks;
  
    public Tower(int i) {
        // create three towers
        disks = new Stack();
    }
    public void add(int d) {
        // Add a disk into this tower
        if (!disks.isEmpty() && disks.peek() <= d) {
            System.out.println("Error placing disk " + d);
        } else {
            disks.push(d);
        }
    }
    public void moveTopTo(Tower t) {
        // Move the top disk of this tower to the top of t.
        if(t.disks.isEmpty() || (!disks.isEmpty() && t.disks.peek() >= disks.peek())) {
            t.disks.push(disks.pop());
        }
    }
    public void moveDisks(int n, Tower destination, Tower buffer) {
        // Move n Disks from this tower to destination by buffer tower
        if(n <= 0) {
            return;
        } else if(n == 1) {
            moveTopTo(destination);
        } else {
            moveDisks(n-1, buffer, destination);
            moveDisks(1, destination, buffer);
            buffer.moveDisks(n-1, destination, this);
        }
    }
    public Stack<Integer> getDisks() {
        // write your code here
        return disks;
    }
}

Given two strings s and t which consist of only lowercase letters.

String t is generated by random shuffling string s and then add one more letter at a random position.

Find the letter that was added in t.

输入给两个只包含小写字母的字符串 S 和 T.

字符串 T 是在字符串 S 基础上添加一个小写字母, 然后随机打乱之后生成.

请找出那个被加入的小写字母.

示例:

Input:
s = "abcd"
t = "abcde"

Output:
e

Explanation:
'e' is the letter that was added.
在线测试网站: https://leetcode.com/problems/find-the-difference/description

package work;

import java.util.HashMap;
import java.util.HashSet;
import java.util.Set;

public class Test02 {

    public static void main(String[] args) {
        char a = findTheDifference("abc","abcd");
        System.out.println(a);
    }


    public static  char findTheDifference(String s, String t) {
        HashMap<Character,Integer> hash = new HashMap<>();

        String tmp = s + t;
        for(int i = 0;i<tmp.length();i++){
            char current = tmp.charAt(i);
            if(hash.containsKey(current)){
                hash.put(current,hash.get(current) + 1);
            }else{
                hash.put(current,1);
            }
        }

        Set<Character> a = hash.keySet();
        Character res = null;
        for (Character item: a) {
            if(hash.get(item)==1){
                res = item;
                break;
            }
        }
        return res;
    }
}

Design a stack that supports push, pop, top, and retrieving the minimum element in constant time.

push(x) -- Push element x onto stack.
pop() -- Removes the element on top of the stack.
top() -- Get the top element.
getMin() -- Retrieve the minimum element in the stack.
设计一个栈, 支持4种操作: push, pop, top和getMin, 关键是getMin是获取栈中的最小值.

示例:

MinStack minStack = new MinStack();
minStack.push(-2);
minStack.push(0);
minStack.push(-3);
minStack.getMin();   --> Returns -3.
minStack.pop();
minStack.top();      --> Returns 0.
minStack.getMin();   --> Returns -2.
基本代码框架:

class MinStack {

    /** initialize your data structure here. */
    public MinStack() {

    }

    public void push(int x) {

    }

    public void pop() {

    }

    public int top() {

    }

    public int getMin() {

    }
}

package work;

import java.util.ArrayList;

class MinStack {
    private ArrayList<Integer> store;
    /** initialize your data structure here. */
    public MinStack() {
        store = new ArrayList<>();
    }

    public void push(int x) {
        store.add(x);
    }

    public void pop() {
        if(store.size()==0){
            throw new Error("数组元素为空");
        }
        store.remove(store.get(store.size()-1));
    }

    public int top() {
        if(store.size()==0){
            throw new Error("数组元素为空");
        }
        return store.get(store.size()-1);
    }

    public int getMin() {
        if(store.size()==0){
            throw new Error("数组元素为空");
        }

        int res = store.get(0);
        for (int i = 1; i < store.size(); i++) {
            if( res > store.get(i) ){
                res = store.get(i);
            }
        }
        return res;
    }
}

首选项- plugins-搜索 rainbow brackets 彩虹括号

bytecode viewer 字节码查看器
Key Promoter X 快捷键提示插件
Stream java8流调试器，debug 的bar里最后一个按钮