<servlet>    
   <servlet-name>application</servlet-name>    
   <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>  
   <init-param>  
		<param-name>dispatchOptionsRequest</param-name>  
		<param-value>true</param-value>  
   </init-param>    
   <load-on-startup>1</load-on-startup>    
</servlet>    

public class CorsInterceptor extends HandlerInterceptorAdapter {

	@Override
	public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
		addOriginHeader(request, response);
		if ("OPTIONS".equalsIgnoreCase(request.getMethod())) {
			response.setStatus(200);
			return false;
		}	
		return true;
	}

	private void addOriginHeader(HttpServletRequest request, HttpServletResponse response) {
		String origin = request.getHeader("Origin");
		response.addHeader("Access-Control-Allow-Origin", origin);
		response.setHeader("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type");
		response.addHeader("Access-Control-Allow-Credentials", "true");         // 可选，是否允许Cookie
		response.addHeader("Access-Control-Allow-Methods", "POST, GET, OPTIONS");
		response.addHeader("Access-Control-Max-Age", "1728000");
	}
}

@RequestMapping(value = "/test/hello", method = {RequestMethod.GET, RequestMethod.OPTIONS})

sudo passwd root
# 然后输入密码
# 用同样的方式修改默认账户 pi 的密码
sudo passwd pi

sudo service ssh start

raspi-config

apt install vim
apt install samba samba-common-bin
apt install zsh
apt-get install nginx
sh -c "$(curl -fsSL https://raw.github.com/robbyrussell/oh-my-zsh/master/tools/install.sh)"
chsh -s /bin/zsh
apt-get install -y make build-essential libssl-dev zlib1g-dev libbz2-dev \
libreadline-dev libsqlite3-dev wget curl llvm libncurses5-dev libncursesw5-dev \
xz-utils tk-dev
curl -L https://raw.githubusercontent.com/pyenv/pyenv-installer/master/bin/pyenv-installer | bash
apt install mysql-server
apt-get install libmysqlclient-dev

bind 127.0.0.1

requirepass mypassword

sudo service redis-server restart

./redis-cli -h 127.0.0.1 -p 6379 -a mypassword
127.0.0.1:6379> config get requirepass
1) "requirepass"
2) "mypassword"

./redis-cli -h 127.0.0.1 -p 6379
127.0.0.1:6379> auth mypassword
OK
127.0.0.1:6379> config get requirepass
1) "requirepass"
2) "mypassword"

127.0.0.1:6379> config set requirepass mypassword
OK

masterauth master-password

rm -R /etc/nodequery && (crontab -u nodequery -l | grep -v "/etc/nodequery/nq-agent.sh") | crontab -u nodequery - && userdel nodequery

a = 3
a = 'Spam'

a = 3
b = a

a = 'spam'

a = a + 2

L1 = [2,3,4]
L2 = L1
L1[0] = 'spam'

L1 = [2,3,4]
L2 = L1[:]             # 创建了一个 L1 的拷贝
L1[0] = 'spam'          # 此时再修改 L1 则不会对 L2 造成影响

import copy
X = copy.copy(Y)            # make top-level "shadow" copy of any object Y
X = copy.deepcopy(Y)        # make deep copy of any object Y: copy all nested parts

L = [1,2,3]
M = L
L == M                      # Same 这时候判断的是引用是否相同，判定值是否相同
L is M                      # Same is 操作符判断是指向的对象是否相同，更强的相等判断

L = [1,2,3]
M = [1,2,3]
L == M                      # Same 相同的内容
L is M                      # False 不同的对象

X = 42
Y = 42                      # 应该是两个不同的对象
X == Y                      # True
X is Y                      # 相同的对象，caching 在起作用

import sys
sys.getrefcount(1)

>>> import sys
>>> sys.path

import dir1.dir2.mod
from dir1.dir2.mod import x

dir0\dir1\dir2\mod.py

当 Python 导入 Package 时，会自动跑 `__init__.py` 下的内容，所以 `__init__.py` 文件下是天然的存放初始化内容的地方，比如初始化数据库连接等等。

__all__ = ["Error", "encode", "decode"]

@Controller
@RequestMapping("/mvc")
public class mvcController {
    @RequestMapping("/hello")
    public String hello(){
        return "hello";
    }
}

@Controller
@RequestMapping("/rest")
public class RestController {
    @RequestMapping(value="/user/{id}",method=RequestMethod.GET)
    public String get(@PathVariable("id") Integer id){
        System.out.println("get"+id);
        return "/hello";
    }

    @RequestMapping(value="/user/{id}",method=RequestMethod.POST)
    public String post(@PathVariable("id") Integer id){
        System.out.println("post"+id);
        return "/hello";
    }

    @RequestMapping(value="/user/{id}",method=RequestMethod.PUT)
    public String put(@PathVariable("id") Integer id){
        System.out.println("put"+id);
        return "/hello";
    }

    @RequestMapping(value="/user/{id}",method=RequestMethod.DELETE)
    public String delete(@PathVariable("id") Integer id){
        System.out.println("delete"+id);
        return "/hello";
    }
}

@RequestMapping(value = "/register", method = RequestMethod.POST)

@RequestMapping(value="/users/**")   匹配"/users/abc/abc"；
@RequestMapping(value="/product?")   匹配"/product1"或"/producta"，但不匹配"/product"或"/productaa"；
@RequestMapping(value="/product*")   匹配“/productabc”或“/product”，但不匹配“/productabc/abc”；
@RequestMapping(value="/product/*")   匹配“/product/abc”，但不匹配“/productabc”；

@RequestMapping(value="/login.do",params="flag")   代表请求中必须要有名为 flag 的提交项
@RequestMapping(value="/login.do",params="!flag")  代表请求中不能有名为 flag 的提交项
@RequestMapping(value="/login.do",params="flag=hello") 代表请求中必须有名为 flag 的提交项，且值为 hello
@RequestMapping(value="/login.do",params="flag!=hello") 代表请求中如果有名为 flag 的提交项，其值不能为 hello
@RequestMapping(value="/login.do",params={"flag1","flag2=hello"}) 代表请求中必须有名为 flag1 的提交项，同时必须有名为 flag2 的提交项，且 flag2 的值必须为 hello

@RequestMapping(value="/login.do",method=RequestMethod.POST)
@RequestMapping(value="/login.do",method=RequestMethod.GET)
@RequestMapping(value="/login.do", method= {RequestMethod.POST, RequestMethod.GET}"

@RequestMapping(value = "/check", method = RequestMethod.GET)
public
@ResponseBody
String check(@RequestParam(value = "signature", required = true, defaultValue = "") String signature,
             @RequestParam(value = "timestamp", required = true, defaultValue = "") String timestamp,
             @RequestParam(value = "nonce", required = true, defaultValue = "") String nonce,
             @RequestParam(value = "echostr", required = true, defaultValue = "") String echostr,
             HttpServletRequest request,
             HttpServletResponse response
) {
    response.addHeader("Access-Control-Allow-Origin", "*");
    response.setHeader("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept");

    if (checkSignature(signature, timestamp, nonce)) {
        return echostr;
    }
    return "";
}

@ControllerAdvice
public class GlobalExceptionHandler {
    private static Logger logger = LoggerFactory.getLogger(GlobalExceptionHandler.class);

    @ExceptionHandler(value = Exception.class)
    @ResponseBody
    public void exceptionHandler(HttpServletRequest req, Exception e) throws Exception {
        //todo add request info to log
        logger.error("error: {}", e);
        return;
    }

}

@Controller
@RequestMapping("/owners/{ownerId}")
public class RelativePathUriTemplateController {

	@RequestMapping("/pets/{petId}")
	public void findPet(@PathVariable String ownerId, @PathVariable String petId, Model model) {
	// implementation omitted
	}
}

Host
localhost:8080
Accept                  text/html,application/xhtml+xml,application/xml;q=0.9
Accept-Language         fr,en-gb;q=0.7,en;q=0.3
Accept-Encoding         gzip,deflate
Accept-Charset          ISO-8859-1,utf-8;q=0.7,*;q=0.7
Keep-Alive              300

@RequestMapping("/displayHeaderInfo.do")
public void displayHeaderInfo(@RequestHeader("Accept-Encoding") String encoding,                                @RequestHeader("Keep-Alive") long keepAlive)  {
	//...
}

@RequestMapping("/displayHeaderInfo.do")  public void displayHeaderInfo(@CookieValue("JSESSIONID") String cookie)  {      //...    }  即把 JSESSIONID 的值绑定到参数 cookie 上。

@Controller
@RequestMapping("/pets")
@SessionAttributes("pet")
public class EditPetForm {

	@RequestMapping(method = RequestMethod.GET)
	public String setupForm(@RequestParam("petId") int petId, ModelMap model) {
		Pet pet = this.clinic.loadPet(petId);
		model.addAttribute("pet", pet);
		return "petForm";
	}
}

@RequestMapping(value = "/something", method = RequestMethod.PUT)  public void handle(@RequestBody String body, Writer writer) throws IOException {    writer.write(body);  }

@Controller  @RequestMapping("/editPet.do")  @SessionAttributes("pet")  public class EditPetForm {      // ...  }

// Add one attribute  // The return value of the method is added to the model under the name "account"  // You can customize the name via @ModelAttribute("myAccount")    @ModelAttribute  public Account addAccount(@RequestParam String number) {      return accountManager.findAccount(number);  }

@RequestMapping(value="/owners/{ownerId}/pets/{petId}/edit", method = RequestMethod.POST)
public String processSubmit(@ModelAttribute Pet pet) {       }

@RequestMapping ({"/", "/home"})      public String showHomePage(String key){                    logger.debug("key="+key);
return "home";
}

@RequestMapping (method = RequestMethod.POST)  public String doRegister(User user){      if(logger.isDebugEnabled()){          logger.debug("process url[/user], method[post] in "+getClass());          logger.debug(user);      }        return "user";  }

/**
 * Indicates that a method declaration is intended to override a
 * method declaration in a supertype. If a method is annotated with
 * this annotation type compilers are required to generate an error
 * message unless at least one of the following conditions hold:
 * The method does override or implement a method declared in a
 * supertype.
 * The method has a signature that is override-equivalent to that of
 * any public method declared in Object.
 *
 * @author  Peter von der Ahé
 * @author  Joshua Bloch
 * @jls 9.6.1.4 @Override
 * @since 1.5
 */
@Target(ElementType.METHOD)
@Retention(RetentionPolicy.SOURCE)
public @interface Override {
}

/**
 * Indicates how long annotations with the annotated type are to
 * be retained.  If no Retention annotation is present on
 * an annotation type declaration, the retention policy defaults to
 * RetentionPolicy.CLASS.
 */
@Documented
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.ANNOTATION_TYPE)
public @interface Retention {
	/**
	 * Returns the retention policy.
	 * @return the retention policy
	 */
	RetentionPolicy value();
}

public enum RetentionPolicy {
	/**
	 * Annotations are to be discarded by the compiler.
	 */
	SOURCE,
	/**
	 * Annotations are to be recorded in the class file by the compiler
	 * but need not be retained by the VM at run time.  This is the default
	 * behavior.
	 */
	CLASS,
	/**
	 * Annotations are to be recorded in the class file by the compiler and
	 * retained by the VM at run time, so they may be read reflectively.
	 *
	 * @see java.lang.reflect.AnnotatedElement
	 */
	RUNTIME
}

package java.lang.annotation;

/**
 * Indicates the contexts in which an annotation type is applicable. The
 * declaration contexts and type contexts in which an annotation type may be
 * applicable are specified in JLS 9.6.4.1, and denoted in source code by enum
 * constants of java.lang.annotation.ElementType
 * @since 1.5
 * @jls 9.6.4.1 @Target
 * @jls 9.7.4 Where Annotations May Appear
 */
@Documented
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.ANNOTATION_TYPE)
public @interface Target {
	/**
	 * Returns an array of the kinds of elements an annotation type
	 * can be applied to.
	 * @return an array of the kinds of elements an annotation type
	 * can be applied to
	 */
	ElementType[] value();
}

public enum ElementType {
	/** Class, interface (including annotation type), or enum declaration */
	TYPE,
	/** Field declaration (includes enum constants) */
	FIELD,
	/** Method declaration */
	METHOD,
	/** Formal parameter declaration */
	PARAMETER,
	/** Constructor declaration */
	CONSTRUCTOR,
	/** Local variable declaration */
	LOCAL_VARIABLE,
	/** Annotation type declaration */
	ANNOTATION_TYPE,
	/** Package declaration */
	PACKAGE,
	/**
	 * Type parameter declaration
	 * @since 1.8
	 */
	TYPE_PARAMETER,
	/**
	 * Use of a type
	 * @since 1.8
	 */
	TYPE_USE
}

@Target(ElementType.METHOD)
@Retention(RetentionPolicy.SOURCE)
public @interface Override {
}

/**
 * Indicates that annotations with a type are to be documented by javadoc
 * and similar tools by default.  This type should be used to annotate the
 * declarations of types whose annotations affect the use of annotated
 * elements by their clients.  If a type declaration is annotated with
 * Documented, its annotations become part of the public API
 * of the annotated elements.
 */
@Documented
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.ANNOTATION_TYPE)
public @interface Documented {
}

/**
 * 不需要登录注解
 */
@Target({ ElementType.METHOD, ElementType.TYPE })
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface NoLogin {
}

/**
 * 检查登录拦截器
 * 如不需要检查登录可在方法或者 controller 上加上 @NoLogin
 */
public class CheckLoginInterceptor implements HandlerInterceptor {
	private static final Logger logger = Logger.getLogger(CheckLoginInterceptor.class);

	@Override
	public boolean preHandle(HttpServletRequest request, HttpServletResponse response,
							 Object handler) throws Exception {
		if (!(handler instanceof HandlerMethod)) {
			logger.warn("当前操作 handler 不为 HandlerMethod=" + handler.getClass().getName() + ",req="
						+ request.getQueryString());
			return true;
		}
		HandlerMethod handlerMethod = (HandlerMethod) handler;
		String methodName = handlerMethod.getMethod().getName();
		// 判断是否需要检查登录
		NoLogin noLogin = handlerMethod.getMethod().getAnnotation(NoLogin.class);
		if (null != noLogin) {
			if (logger.isDebugEnabled()) {
				logger.debug("当前操作 methodName=" + methodName + "不需要检查登录情况");
			}
			return true;
		}
		noLogin = handlerMethod.getMethod().getDeclaringClass().getAnnotation(NoLogin.class);
		if (null != noLogin) {
			if (logger.isDebugEnabled()) {
				logger.debug("当前操作 methodName=" + methodName + "不需要检查登录情况");
			}
			return true;
		}
		if (null == request.getSession().getAttribute(CommonConstants.SESSION_KEY_USER)) {
			logger.warn("当前操作" + methodName + "用户未登录，ip=" + request.getRemoteAddr());
			response.getWriter().write(JsonConvertor.convertFailResult(ErrorCodeEnum.NOT_LOGIN).toString()); // 返回错误信息
			return false;
		}
		return true;
	}
	@Override
	public void postHandle(HttpServletRequest request, HttpServletResponse response,
						   Object handler, ModelAndView modelAndView) throws Exception {
	}
	@Override
	public void afterCompletion(HttpServletRequest request, HttpServletResponse response,
								Object handler, Exception ex) throws Exception {
	}
}

NoLogin noLogin = handlerMethod.getMethod().getAnnotation(NoLogin.class);

noLogin = handlerMethod.getMethod().getDeclaringClass().getAnnotation(NoLogin.class);

public interface BeanPostProcessor {
	Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException;
	Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException;
}

<context:component-scan base-package="net.aazj.service,net.aazj.aop" />

0x1234 0X1234               # 16 进制 0x 后接 [0-9A-F]
0o177 0O177                 # 8 进制  0o Zero 加大小写的 o 后接 [0-7]
0b101 0B101                 # 2 进制 New in 2.6 > ，后接 [0-1]

S[1:3]          # 'pa'  左边包括，右边不包括
S[1:]           # 'pam' [1:len(S)]
S[:3]           # 'Spa' 等效于 [0:3]
S[:-1]          # 除去最后一个元素
S[:]            # S 全部

S.find('pa')        # 输出字串位置 1
S.replace('pa', 'xy')   # 替换 pa 为 xy 输出到新的字符串，不改变原始字符串

line = 'hello world'
line.split(' ')     # 空格分割，输出列表
line.upper()        # 转为大写
line.isdigit()      # 判断是否为数字，还有 isalpha() isnumeric() isspace() 等等
line.rstrip()       # 移除行尾空白字符比如 `\n`

'%s, eggs, and %s' % ('spam', 'SPAM!')     # Python 格式化表达式
# or
'%s, eggs, and %s' % ('spam', 'SPAM!')     # Python 2.6 and 3.0

>>> import re
>>> match = re.match('Hello[ \t]*(.*)world', 'Hello
>>> match.group(1)
'Python '

>>> match = re.match('/(.*)/(.*)/(.*)', '/usr/home/einverne')
>>> match.groups()
('usr', 'home', 'einverne')

L = [123, 'spam', 1.23]
L[0]
L[:-1]
L + [4,5,6]

L.append('NI')          # 添加
L.pop(2)                # 删除 index 为 2 的元素，并返回
L.insert(1, 'xyz')      # 在 index 之前插入 'xyz'
L.remove('xyz')         # 按照值移除第一个找到的 item

>>> M = [[1, 2, 3],
        [4, 5, 6],
        [7, 8, 9]]
>>> M
[[1, 2, 3], [4, 5, 6], [7, 8, 9]]

>>> M[1]     # 获取第二行
>>> M[1][2]  # 获取第二行第三列

>>> col2 = [row[1] for row in M]   # 获取第二列

>>> [row[1] * 2 for row in M]

>>> [row[1] for row in M if row[1] % 2 == 0]

>>> diag = [M[i][i] for i in range(3)]
>>> [c * 2 for c in 'spam']  # 输出一个列表 ['ss', 'pp', 'aa', 'mm']

{sum(row) for row in M}       # {sum(row) for row in M} 创建一个每一行和的 set
{i : sum(M[i]) for i in range(3)}    # {0: 6, 1: 15, 2: 24} dict

D = {}
D['name'] = 'bob'

>>> rec = {'name': {'first': 'Bob', 'last': 'Smith'},
'job': ['dev', 'mgr'],
'age': 40.5}

>>> rec = 0

if 'f' in D:
    print D['f']

D.get('f', 0)           # 如果 f 存在返回 D['f']，否则返回 0，等效于
D['f'] if 'f' in D else 0

T = (1, 2, 3, 4)
T = ('spam', 3.0, [11, 22, 33])

f = open('data.txt', 'w')
f.write('Hello\n')
f.close()

f = open('data.txt')          # 'r' 可以省略
text = f.read()
f.close()

X = set('spam')
Y = {'h', 'a', 'm'}

X & Y   # 交集
X | Y   # 并集
X - Y   # 差集

import deciaml
d = decimal.Decimal('3.141')

>>> decimal.getcontext().prec = 2
>>> decimal.Decimal('1.00') / decimal.Decimal('3.00')
Decimal('0.33')

>>> from fractions import Fraction
>>> f = Fraction(2, 3)
>>> f + 1
Fraction(5, 3)
>>> f + Fraction(1, 2)
Fraction(7, 6)

if type(L) == type([]):
    print('yes')

if type(L) == list:
    print('yes')

if isinstance(L, list):
    print('yes')