Mac下查看java版本和JDK版本

查看Java版本

java -version

---
➜  ~ java -version
java version "1.8.0_291"
Java(TM) SE Runtime Environment (build 1.8.0_291-b10)
Java HotSpot(TM) 64-Bit Server VM (build 25.291-b10, mixed mode)

查看JDK版本

/usr/libexec/java_home -V

---
➜  ~ /usr/libexec/java_home -V
Matching Java Virtual Machines (2):
    1.8.291.10 (x86_64) "Oracle Corporation" - "Java" /Library/Internet Plug-Ins/JavaAppletPlugin.plugin/Contents/Home
    1.8.0_74 (x86_64) "Oracle Corporation" - "Java SE 8" /Library/Java/JavaVirtualMachines/jdk1.8.0_74.jdk/Contents/Home
/Library/Internet Plug-Ins/JavaAppletPlugin.plugin/Contents/Home

---

IntelliJ IDEA

1. mac IDEA自動生成構造函數

control + fn + enter 選擇 Constructor

另外這個快捷鍵還有其它功能，Getter、Setter、Getter and Setter 、equals() and hashCode() 、toString()等。

---

Maven

1. 命令行編譯

在命令中，進入到pom.xml所在目錄，輸入以下命令：

$ mvn clean package

如果一切順利，即可在target目錄下獲得編譯後自動打包的jar。

---

靜態資源導出問題

    <build>
        <resources>
            <resource>
                <directory>src/main/java</directory>
                <includes>
                    <include>**/*.properties</include>
                    <include>**/*.xml</include>
                </includes>
                <filtering>false</filtering>
            </resource>
            <resource>
                <directory>src/main/resources</directory>
                <includes>
                    <include>**/*.properties</include>
                    <include>**/*.xml</include>
                </includes>
                <filtering>false</filtering>
            </resource>
        </resources>
    </build>

連接數據庫

jdbc.driver=com.mysql.jdbc.Driver
# 如果使用的是MySQL8.0+，增加一個時區的配置 &serverTimezone=Asia/Shanghai
jdbc.url=jdbc:mysql://localhost:3306/test?useSSL=true&useUnicode=true&characterEncoding=utf8&serverTimezone=Asia/Shanghai
jdbc.username=root
jdbc.password=123456

常用配置頭

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans.xsd
       http://www.springframework.org/schema/aop
       http://www.springframework.org/schema/aop/spring-aop.xsd ">

    <import resource="classpath:spring-dao.xml"/>

</beans>

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    

</configuration>

springmvc web.xml配置

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
         version="4.0">

    <display-name>Archetype Created Web Application</display-name>

    <!-- 過濾器解決亂碼   -->
    <filter>
        <filter-name>characterEncodingFilter</filter-name>
        <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
        <init-param>
            <param-name>encoding</param-name>
            <param-value>UTF-8</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>characterEncodingFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

    <!--springmvc的核心控制器-->
    <servlet>
        <servlet-name>SpringMVC</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <!--配置servlet的初始化參數，讀取springMVC的配置文件，創建spring容器-->
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath:springmvc.xml</param-value>
        </init-param>
        <!--配置servlet啓動時加載對象-->
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>SpringMVC</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>

</web-app>

springmvc 配置

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="
        http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/mvc
        http://www.springframework.org/schema/mvc/spring-mvc.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context.xsd">

    <!--配置spring創建容器時掃描的包-->
    <context:component-scan base-package="loong.controller"></context:component-scan>
    <!--  讓spring mvc 不處理靜態資源 .css .js .html   -->
<!--    <mvc:default-servlet-handler/>-->
    <!--開啓註解MVC支持-->
<!--    <mvc:annotation-driven />-->

    <!-- 處理請求返回json字符串的亂碼問題 -->
    <!--解決json 亂碼配置-->
    <mvc:annotation-driven>
        <mvc:message-converters register-defaults="true">
            <bean class="org.springframework.http.converter.StringHttpMessageConverter">
                <constructor-arg value="UTF-8"/>
            </bean>
            <bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
                <property name="objectMapper">
                    <bean class="org.springframework.http.converter.json.Jackson2ObjectMapperFactoryBean">
                        <property name="failOnEmptyBeans" value="false"/>
                    </bean>
                </property>
            </bean>
        </mvc:message-converters>
    </mvc:annotation-driven>

    <!--配置視圖解析器-->
    <bean id="internalResourceViewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/jsp/"></property>
        <property name="suffix" value=".jsp"></property>
    </bean>

</beans>

springmvc的攔截器配置

    <!-- 攔截器配置   -->
    <mvc:interceptors>
        <mvc:interceptor>
            <!--  包括這個請求下的所有的請求          -->
            <mvc:mapping path="/**"/>
            <bean class="loong.intercept.InterceptController"/>
        </mvc:interceptor>
    </mvc:interceptors>

設置和獲取 Cookie

    @RequestMapping("/login")
    public String login(@RequestParam("username") String username,
                        @RequestParam("password") String password,
                        HttpSession session,
                        HttpServletRequest request,
                        HttpServletResponse response) {
        // 把用戶的信息存在session中
        session.setAttribute("userLoginInfo", username);
        // 獲取cookie
        Cookie[] cookies = request.getCookies();
        for (Cookie cookie : cookies) {
            System.out.println(cookie.getName() + ":" + cookie.getValue());
        }
        // 設置cookie
        Cookie cookie = new Cookie("username", username);
        cookie.setHttpOnly(true);
        cookie.setPath("/");
        cookie.setDomain("localhost");
        response.addCookie(cookie);
        return "OK";
    }

---

依賴

文件上傳

        <!-- https://mvnrepository.com/artifact/commons-fileupload/commons-fileupload -->
        <dependency>
            <groupId>commons-fileupload</groupId>
            <artifactId>commons-fileupload</artifactId>
            <version>1.4</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/javax.servlet/javax.servlet-api -->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>4.0.1</version>
            <scope>provided</scope>
        </dependency>

    <!-- 文件上傳配置 -->
    <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
        <!--  請求的編碼格式，必須和jsp的pageEncoding屬性一致，以便正確讀取表單的內容，默認爲ISO-8859-1  -->
        <property name="defaultEncoding" value="utf-8"/>
        <!--  上傳文件大小上限，單位爲字節 （10485760 = 10M）      -->
        <property name="maxUploadSize" value="10485760"/>
        <property name="maxInMemorySize" value="40960"/>
    </bean>

    // 方式1
    // @RequestParam("file") 將name=file控件得到的文件封裝成CommonsMultipartFile對象
    // 批量上傳CommonsMultipartFile則爲數組即可
    @RequestMapping("/upload")
    public String upload(@RequestParam("file") CommonsMultipartFile file,
                         HttpServletRequest request) throws IOException {
        // 獲取文件名
        String uploadFileName = file.getOriginalFilename();

        // 如果文件名爲空， 返回error
        if (uploadFileName.equals("")) {
            return "file is not exsit";
        }
        System.out.println("上傳文件名：" + uploadFileName);

        // 上傳路徑保存設置
        String path = request.getServletContext().getRealPath("/upload");
        // 如果路徑不存在，則創建一個
        File realPath = new File(path);
        if (!realPath.exists()) {
            realPath.mkdir();
        }
        System.out.println("上傳文件保存地址：" + realPath);

        // 文件輸入流
        InputStream is = file.getInputStream();
        // 文件輸出流
        OutputStream os = new FileOutputStream(new File(realPath, uploadFileName));

        // 讀取寫入
        int len = 0;
        byte[] buffer = new byte[1024];
        while ((len = is.read(buffer)) != -1) {
            os.write(buffer,0, len);
            os.flush();
        }
        os.close();
        is.close();

        return "upload-ok";
    }


    // 方式2
    @RequestMapping("/upload2")
    public String upload2(@RequestParam("file")CommonsMultipartFile file,
                          HttpServletRequest request) throws IOException {
        // 上傳路徑保存設置
        String path = request.getServletContext().getRealPath("/upload");
        File realPath = new File(path);
        if (!realPath.exists()) {
            realPath.mkdir();
        }
        // 上傳文件地址
        System.out.println("上傳文件保存地址：" + realPath);

        // 通過CommonsMultiparFile的方法直接寫文件
        file.transferTo(new File(realPath + "/" + file.getOriginalFilename()));

        return "upload-ok";
    }