module main {
    requires teacher;
    requires student;
}

// student module

module student {
    exports top.young.student;
}

// teacher module 
module teacher {
    requires student;
    exports top.young.teacher;
}

public class Main {
    public static void main(String[] args) {
        Stream.of(6,4,7,9,2,1).dropWhile(it -> it >= 3).forEach(System.out::println); // 2 1
    }
}

public class Main {
    public static void main(String[] args) {
        Stream.of(6,4,7,9,2,1).takeWhile(it -> it >= 3).forEach(System.out::println); // 6 4 7 9
    }
}

public class Main {
    public static void main(String[] args) {
      Stream.of(6, 4, null, 9, 2, 1).flatMap(Stream::ofNullable).forEach(System.out::println);//6 4 9 2 1
    }
}

public class Main {
    public static void main(String[] args) {
        Stream.iterate(3, x -> x < 10, x -> x + 3).forEach(System.out::println);// 3 6 9
    }
}

<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">

<!--1.配置类-->
    <bean id="book" class="aop.Book"/>
    <bean id="myBook" class="aop.MyBook"/>
    <!--2.配置aop操作-->
    <aop:config>
        <!--2.1配置切入点-->
        <aop:pointcut id="pointcut1" expression="execution(* aop.Book.add())"/>
        <!--2.2配置切面-->
        <aop:aspect ref="myBook">
            <aop:before method="before1" pointcut-ref="pointcut1"/>
        </aop:aspect>
    </aop:config>

<aop:aspectj-autoproxy> </aop:aspectj-autoproxy>

DriverManagerDataSource dataSource = new DriverManagerDataSource();
        dataSource.setDriverClassName("com.mysql.jdbc.Driver");
        dataSource.setUsername("root");
        dataSource.setUrl("jdbc:mysql://localhost:3306/JdbcDemo");
        dataSource.setPassword("12qwaszx");

JdbcTemplate jdbcTemplate = new JdbcTemplate(dataSource);

    String sql = "INSERT INTO jdbcTest (id, name, password) VALUES (?,?,?)";
    jdbcTemplate.update(sql, "1", "lucy", "1234");

    String sql = "UPDATE jdbcTest\n" +
                "SET name = ?\n" +
                "WHERE id=?";
    jdbcTemplate.update(sql,"cat","1");

    String sql = "DELETE FROM jdbcTest WHERE name=?";
    jdbcTemplate.update(sql,"cat");

    //查询返回某值
    String sql1="SELECT count(*) FROM jdbcTest";
    int count=template.queryForObject(sql1,Integer.class);

    //查询返回对象
    String sql2 = "select * from jdbcTest where name=?";
    //调用jdbcTemplate方法
    User user=template.queryForObject(sql2,new MyRowMapper() , "tom");
    System.out.println(user);

class MyRowMapper implements RowMapper<User> {
    @Override
    public User mapRow(ResultSet resultSet, int i) throws SQLException {
        //从结果集里面把数据得到
        String username = resultSet.getString("name");
        String password = resultSet.getString("password");
        //把数据封装到对象里面
        User user = new User();
        user.setName(username);
        user.setPassword(password);
        return user;
    }
}

        String sql3 = "select * from jdbcTest";
        List<User> list = template.query(sql3, new MyRowMapper());
        System.out.println(list);

package com.c3p0;

/**
 * Created by youngxhui
 * Time is 17-2-19.
 */
public class UserService {

    private UserDao userDao;

    public void setUserDao(UserDao userDao) {
        this.userDao = userDao;
    }
    public void add(){
        userDao.add();
    }
}

package com.c3p0;

import org.springframework.jdbc.core.JdbcTemplate;

/**
 * Created by youngxhui
 * Time is 17-2-19.
 */
public class UserDao {
    private JdbcTemplate jdbcTemplate;
    public void add() {

        String sql="INSERT INTO jdbcTest (id, name, password) VALUES (?,?,?)";
        jdbcTemplate.update(sql, 5, "lili", "123456");

    }

    public void setJdbcTemplate(JdbcTemplate jdbcTemplate) {
        this.jdbcTemplate = jdbcTemplate;
    }
}

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       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">

    <!--配置c3p0的连接池-->
    <bean id="comboPooledDataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="com.mysql.jdbc.Driver"/>
        <property name="jdbcUrl" value="jdbc:mysql://localhost:3306/JdbcDemo"/>
        <property name="user" value="root"/>
        <property name="password" value="12qwaszx"/>
    </bean>

    <bean id="userService" class="com.c3p0.UserService">
        <property name="userDao" ref="userDao"/>
    </bean>

    <bean class="com.c3p0.UserDao" id="userDao">
        <property name="jdbcTemplate" ref="jdbcTemplate"/>
    </bean>

    <bean class="org.springframework.jdbc.core.JdbcTemplate" id="jdbcTemplate">
        <property name="dataSource" ref="comboPooledDataSource"/>
    </bean>
</beans>

### 设置日志等级 ###
log4j.rootLogger=info, stdout
### 输出到控制台 ###
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target=System.err
#log4j.appender.stdout=System.err
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d{ABSOLUTE} %5p %c{1}:%L - %m%n
### 输出到日至文件
log4j.appender.file=org.apache.log4j.FileAppender
log4j.appender.file.File=/home/youngxhui/IdeaProjects/SpringDemo/spring-aop-xml/src/mylog.log
log4j.appender.file.layout=org.apache.log4j.PatternLayout
log4j.appender.file.layout.ConversionPattern=%{ABSOLUTE} %5p %c{1}:%L - %m%n

 <context:component-scan base-package="com.young.anno"/>

@Component(value = "user")
public class User {
    public void add(){
        System.out.println("add....");
    }
}

@Component(value = "user")
@Scope(value = "prototype") 
public class User {
    public void add(){
        System.out.println("add....");
    }
}

<bean id="preperty" class="com.young.property.PrepertyDemo1">
        <constructor-arg name="username" value="zhangsan"/>
</bean>

<bean id="book" class="com.young.property.Book">
        <property name="bookname" value="one"/>
</bean>

public class UserService {
    private UserDao userDao;
    public void add(){
        System.out.println("service");
        userDao.add();
    }

    public void setUserDao(UserDao userDao) {
        this.userDao = userDao;
    }
}

    <bean id="service" class="com.young.ioc.UserService">
        <!--不能写value属性，要写ref,dao配置bean标签的id值-->
        <property name="userDao" ref="userdao"></property>
    </bean>
    <bean id="userdao" class="com.young.ioc.UserDao">

@Service(value = "userservice")
public class UserService {

    @Autowired
    private UserDao userDao;

    public void add(){
        System.out.println("service");
        userDao.add();
    }
}

@Component(value = "userdao")
public class UserDao {
    public void add() {
        System.out.println("UserDao");
    }
}

<!--数组类型-->
        <property name="args">
            <list>
                <value>小马</value>
                <value>小宋</value>
                <value>小王</value>
                <value>小李子</value>
            </list>
        </property>

    <property name="list">
            <list>
                <value>张三</value>
                <value>李四</value>
            </list>
    </property>

    <property name="map">
            <map>
                <entry key="a" value="张三"/>
            </map>
    </property>

    <property name="properties">
            <props>
                <prop key="name">root</prop>
            </props>
    </property>

public class BookDao {
    public void book(){
        System.out.println("bookDao");
    }
}

public class BookDao {
    public void book(){
        System.out.println("bookDao");
    }
}

public class BookService {

    @Resource(name = "bookDao")
    private BookDao bookDao;
    @Resource(name = "ordlerDao")
    private OrderDao ordersDao;
    
    public void service(){
        System.out.println("service");
        bookDao.book();
        ordersDao.buy();
    }
}

<?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:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
    <context:component-scan base-package="com.young.xmlanno"/>
    <bean id="bookservice" class="com.young.xmlanno.BookService"/>
    <bean id="bookDao" class="com.young.xmlanno.BookDao"/>
    <bean id="ordlerDao" class="com.young.xmlanno.OrderDao"/>
</beans>

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class Test {
    @org.junit.Test
    public void testxmlAnno(){
        ApplicationContext context =
                new ClassPathXmlApplicationContext("bea2.xml");
        BookService bookService= (BookService) context.getBean("bookservice");
        bookService.service();
    }
}

public class HelloWorld {
    public void sayHello(){
        System.out.println("Hello");
    }
}

public class HelloWorldTest {
    @Test
    public void sayHello() throws Exception {
        HelloWorld helloWorld = new HelloWorld();
        helloWorld.sayHello();
    }
}

package com.young.maven.model;

public class HelloWorld{
  public String sayHello(){
    return "HelloWorld";
  }
}

package com.young.maven.model;
import org.junit.*;
import org.junit.Assert.*;


public class HelloWorldTest{
  @Test
  public void testHello(){
    Assert.assertEquals("HelloWorld",new HelloWorld().sayHello());
  }
}

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.young.maven</groupId>
    <artifactId>maven-model</artifactId>
    <version>1.0-SNAPSHOT</version>
<dependencies>
  <dependency>
    <groupId>junit</groupId>
    <artifactId>junit</artifactId>
    <version>4.10</version>
  </dependency>
</dependencies>
</project>

<groupId></groupId>
<artifactId></artifactId>
<version></version>

<dependencies>
    <dependency>
        <groupId></groupId>
        <artifactId></artifactId>
        <version></version>
        <type></type>
        <scope>依赖范围</scope>
        <!--设置依赖是否可选-->
        <optional></optional>
        <!--排除依赖传递列表-->
        <exclusions>
            <exclusion>
            </exclusion>
        </exclusions>
    </dependency>
</dependencies>
<dependencyManagement>
  <dependencies>
  
  </dependencies>
</dependencyManagement>
<build>
  <plugins>
    <groupId></groupId>
    <artifactId></artifactId>
  </plugins>
</build>
<parent></parent>
<modules></modules>

    public ArrayList() {
        this.elementData = DEFAULTCAPACITY_EMPTY_ELEMENTDATA;
    }

     public ArrayList(int initialCapacity) {
        if (initialCapacity > 0) {
            this.elementData = new Object[initialCapacity];
        } else if (initialCapacity == 0) {
            this.elementData = EMPTY_ELEMENTDATA;
        } else {
            throw new IllegalArgumentException("Illegal Capacity: "+
                                               initialCapacity);
        }
    }

public ArrayList(Collection<? extends E> c) {
        elementData = c.toArray();
        if ((size = elementData.length) != 0) {
            // c.toArray might (incorrectly) not return Object[] (see 6260652)
            if (elementData.getClass() != Object[].class)
                elementData = Arrays.copyOf(elementData, size, Object[].class);
        } else {
            // replace with empty array.
            this.elementData = EMPTY_ELEMENTDATA;
        }
    }

 public void trimToSize() {
        modCount++;
        if (size < elementData.length) {
            elementData = (size == 0)
              ? EMPTY_ELEMENTDATA
              : Arrays.copyOf(elementData, size);
        }
    }

public void ensureCapacity(int minCapacity) {
        int minExpand = (elementData != DEFAULTCAPACITY_EMPTY_ELEMENTDATA)
            // any size if not default element table
            ? 0
            // larger than default for default empty table. It's already
            // supposed to be at default size.
            : DEFAULT_CAPACITY;

        if (minCapacity > minExpand) {
            ensureExplicitCapacity(minCapacity);
        }

public int indexOf(Object o) {
        if (o == null) {
            for (int i = 0; i < size; i++)
                if (elementData[i]==null)
                    return i;
        } else {
            for (int i = 0; i < size; i++)
                if (o.equals(elementData[i]))
                    return i;
        }
        return -1;
    }

public boolean contains(Object o) {
        return indexOf(o) >= 0;
    }

public class Main {
    public static void main(String[] args) {
        String a = null;
        String b = null;
        System.out.println(a == b);
        System.out.println(a.equals(b));
    }
}

        true
    Exception in thread "main" java.lang.NullPointerException
    	at Main.Main.main(Main.java:14)
    	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    	at java.lang.reflect.Method.invoke(Method.java:498)
    	at com.intellij.rt.execution.application.AppMain.main(AppMain.java:147)
    
    Process finished with exit code 1

public int lastIndexOf(Object o) {
        if (o == null) {
            for (int i = size-1; i >= 0; i--)
                if (elementData[i]==null)
                    return i;
        } else {
            for (int i = size-1; i >= 0; i--)
                if (o.equals(elementData[i]))
                    return i;
        }
       

   /**
     * Returns a shallow copy of this <tt>ArrayList</tt> instance.  (The
     * elements themselves are not copied.)
     *
     * @return a clone of this <tt>ArrayList</tt> instance
     */
 public Object clone() {
        try {
            ArrayList<?> v = (ArrayList<?>) super.clone();
            v.elementData = Arrays.copyOf(elementData, size);
            v.modCount = 0;
            return v;
        } catch (CloneNotSupportedException e) {
            // this shouldn't happen, since we are Cloneable
            throw new InternalError(e);
        }
    }

public boolean add(E e) {
        ensureCapacityInternal(size + 1);  // Increments modCount!!
        elementData[size++] = e;
        return true;
    }

public void add(int index, E element) {
        rangeCheckForAdd(index);

        ensureCapacityInternal(size + 1);  // Increments modCount!!
        System.arraycopy(elementData, index, elementData, index + 1,
                         size - index);
        elementData[index] = element;
        size++;
    }
    
private void rangeCheckForAdd(int index) {
        if (index > size || index < 0)
            throw new IndexOutOfBoundsException(outOfBoundsMsg(index));
    }

public boolean remove(Object o) {
        if (o == null) {
            for (int index = 0; index < size; index++)
                if (elementData[index] == null) {
                    fastRemove(index);
                    return true;
                }
        } else {
            for (int index = 0; index < size; index++)
                if (o.equals(elementData[index])) {
                    fastRemove(index);
                    return true;
                }
        }
        return false;
    }

 public void clear() {
        modCount++;

        // clear to let GC do its work
        for (int i = 0; i < size; i++)
            elementData[i] = null;

        size = 0;
    }

public ListIterator<E> listIterator(int index) {
        if (index < 0 || index > size)
            throw new IndexOutOfBoundsException("Index: "+index);
        return new ListItr(index);
    }