本文共 26376 字，大约阅读时间需要 87 分钟。
package com.bjsxt.others.commons;import java.util.ArrayList;import java.util.List;import org.apache.commons.collections4.Predicate;import org.apache.commons.collections4.PredicateUtils;import org.apache.commons.collections4.functors.EqualPredicate;import org.apache.commons.collections4.functors.NotNullPredicate;import org.apache.commons.collections4.functors.UniquePredicate;import org.apache.commons.collections4.list.PredicatedList;import org.junit.Test;/** 函数式编程 之 Predicate 断言 封装条件或判别式 if..else替代 1、 new EqualPredicate <类型> (值) EqualPredicate.equalPredicate(值); 2、NotNullPredicate.INSTANCE 3、UniquePredicate.uniquePredicate() 4、自定义 new Predicate() +evaluate PredicateUtils.allPredicate andPredicate anyPredicate PredicatedXxx.predicatedXxx(容器,判断) * @author Administrator * */public class Demo01 { /** * @param args */ public static void main(String[] args) { System.out.println("======自定义判断======"); //自定义的判别式 Predicate selfPre =new Predicate (){ @Override public boolean evaluate(String object) { return object.length()>=5 && object.length()<=20; }}; Predicate notNull=NotNullPredicate.notNullPredicate(); Predicate all =PredicateUtils.allPredicate(notNull,selfPre); List list =PredicatedList.predicatedList(new ArrayList (),all); list.add("bjsxt"); list.add(null); list.add("bj"); } /** * 判断唯一 */ public static void unique(){ System.out.println("====唯一性判断===="); Predicate uniquePre =UniquePredicate.uniquePredicate(); List list =PredicatedList.predicatedList(new ArrayList (), uniquePre); list.add(100L); list.add(200L); list.add(100L); //出现重复值，抛出异常 } /** * 判断非空 */ public static void notNull(){ System.out.println("====非空判断===="); //Predicate notNull=NotNullPredicate.INSTANCE; Predicate notNull=NotNullPredicate.notNullPredicate(); //String str ="bjs"; String str =null; System.out.println(notNull.evaluate(str)); //如果非空为true ,否则为false //添加容器值的判断 List list =PredicatedList.predicatedList(new ArrayList (), notNull); list.add(1000L); list.add(null); //验证失败，出现异常 } /** * 比较相等判断 */ @Test public static void equal(){ System.out.println("======相等判断======"); //Predicate pre =new EqualPredicate ("bjsxt"); Predicate pre =EqualPredicate.equalPredicate("bjsxt"); boolean flag =pre.evaluate("bj"); System.out.println(flag); }} package com.bjsxt.others.commons;import java.text.SimpleDateFormat;import java.util.ArrayList;import java.util.Collection;import java.util.Iterator;import java.util.List;import org.apache.commons.collections4.CollectionUtils;import org.apache.commons.collections4.Predicate;import org.apache.commons.collections4.Transformer;import org.apache.commons.collections4.functors.SwitchTransformer;import org.junit.Test;/** 解耦，业务处理与判断进行分类 函数式编程 Transformer 类型转化 1、new Transformer() +transform 2、SwitchTransformer CollectionUtils.collect(容器,转换器) * @author Administrator * */public class Demo02 { /** * @param args */ public static void main(String[] args) { System.out.println("===自定义类型转换=="); //判别式 Predicate isLow=new Predicate (){ @Override public boolean evaluate(Employee emp) { return emp.getSalary()<10000; } }; Predicate isHigh=new Predicate (){ @Override public boolean evaluate(Employee emp) { return emp.getSalary()>=10000; } }; Predicate[] pres ={isLow,isHigh}; //转换 Transformer lowTrans =new Transformer (){ @Override public Level transform(Employee input) { return new Level(input.getName(),"卖身中"); }}; Transformer highTrans =new Transformer (){ @Override public Level transform(Employee input) { return new Level(input.getName(),"养身中"); }}; Transformer[] trans ={lowTrans,highTrans}; //二者进行了关联 Transformer switchTrans =new SwitchTransformer(pres, trans, null); //容器 List list =new ArrayList (); list.add(new Employee("老马",1000000)); list.add(new Employee("老裴",999)); Collection levelList = CollectionUtils.collect(list,switchTrans); //遍历容器 Iterator levelIt =levelList.iterator(); while(levelIt.hasNext()){ System.out.println(levelIt.next()); } } /** * 内置类型的转换 */ @Test public static void inner(){ System.out.println("===内置类型转换 长整形时间日期，转成指定格式的字符串=="); //类型转换器 Transformer trans =new Transformer (){ @Override public String transform(Long input) { return new SimpleDateFormat("yyyy年MM月dd日").format(input); }}; //容器 List list =new ArrayList (); list.add(999999999999L); list.add(300000000L); //工具类 程序猿出钱---开发商---农民工出力 Collection result=CollectionUtils.collect(list, trans); //遍历查看结果 for(String time:result){ System.out.println(time); } }} package com.bjsxt.others.commons;/** * 员工类 * @author Administrator * */public class Employee { private String name; private double salary; //alt +/ public Employee() { } //alt+shift+s o public Employee(String name, double salary) { super(); this.name = name; this.salary = salary; } //alt+shift+s +r tab 回车 shift+tab 回车 public String getName() { return name; } public void setName(String name) { this.name = name; } public double getSalary() { return salary; } public void setSalary(double salary) { this.salary = salary; } @Override public String toString() { return "(码农:"+this.name+",敲砖钱:"+this.salary+")"; } } package com.bjsxt.others.commons;/** * 等级类 * @author Administrator * */public class Level { private String name; private String level; public Level() { // TODO Auto-generated constructor stub } public Level(String name, String level) { super(); this.name = name; this.level = level; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getLevel() { return level; } public void setLevel(String level) { this.level = level; } @Override public String toString() { return "(码农:"+this.name+",水平:"+this.level+")"; }} package com.bjsxt.others.commons;public class Goods { private String name; private double price; //折扣 private boolean discount; public Goods() { // TODO Auto-generated constructor stub } public Goods(String name, double price, boolean discount) { super(); this.name = name; this.price = price; this.discount = discount; } public String getName() { return name; } public void setName(String name) { this.name = name; } public double getPrice() { return price; } public void setPrice(double price) { this.price = price; } public boolean isDiscount() { return discount; } public void setDiscount(boolean discount) { this.discount = discount; } @Override public String toString() { return "(商品:"+this.name+",价格:"+this.price+",是否打折:"+(discount?"是":"否")+")"; } } package com.bjsxt.others.commons;import java.util.ArrayList;import java.util.Iterator;import java.util.List;import org.apache.commons.collections4.Closure;import org.apache.commons.collections4.CollectionUtils;import org.apache.commons.collections4.Predicate;import org.apache.commons.collections4.functors.ChainedClosure;import org.apache.commons.collections4.functors.IfClosure;import org.apache.commons.collections4.functors.WhileClosure;/** 函数式编程 Closure 闭包 封装特定的业务功能 1、Closure 2、IfClosure IfClosure.ifClosure(断言,功能1,功能2) 3、WhileClosure WhileClosure.whileClosure(断言,功能,标识) 4、ChainedClosure.chainedClosure(功能列表); CollectionUtils.forAllDo(容器,功能类对象); * @author Administrator * */public class Demo03 { /** * @param args */ public static void main(String[] args) { //basic(); ifClosure(); //whileClosure(); chainClosure(); } /** * 折上减 先打折商品，进行9折，满百再减20 */ public static void chainClosure(){ List goodsList =new ArrayList (); goodsList.add(new Goods("javase视频",120,true)); goodsList.add(new Goods("javaee视频",100,false)); goodsList.add(new Goods("高新技术视频",80,false)); //满百减20 Closure subtract=new Closure (){ public void execute(Goods goods) { if(goods.getPrice()>=100){ goods.setPrice(goods.getPrice()-20); } }}; //打折 Closure discount=new Closure (){ public void execute(Goods goods) { if(goods.isDiscount()){ goods.setPrice(goods.getPrice()*0.9); } }}; //链式操作 Closure chainClo=ChainedClosure.chainedClosure(discount,subtract); //关联 CollectionUtils.forAllDo(goodsList,chainClo); //查看操作后的数据 for(Goods temp:goodsList){ System.out.println(temp); } } /** * 确保所有的员工工资都大于10000,如果已经超过的不再上涨 */ public static void whileClosure(){ //数据 List empList =new ArrayList (); empList.add(new Employee("bjsxt",20000)); empList.add(new Employee("is",10000)); empList.add(new Employee("good",5000)); //业务功能 每次上涨0.2 Closure cols=new Closure (){ public void execute(Employee emp) { emp.setSalary(emp.getSalary()*1.2); }}; //判断 Predicate empPre=new Predicate (){ @Override public boolean evaluate(Employee emp) { return emp.getSalary()<10000; } }; //false 表示 while结构 先判断后执行 true do..while 先执行后判断 Closure whileCols =WhileClosure.whileClosure(empPre, cols, false); //工具类 CollectionUtils.forAllDo(empList, whileCols) ; //操作后的数据 Iterator empIt=empList.iterator(); while(empIt.hasNext()){ System.out.println(empIt.next()); } } /** * 二选一 如果是打折商品，进行9折，否则满百减20 */ public static void ifClosure(){ List goodsList =new ArrayList (); goodsList.add(new Goods("javase视频",120,true)); goodsList.add(new Goods("javaee视频",100,false)); goodsList.add(new Goods("高新技术视频",80,false)); //满百减20 Closure subtract=new Closure (){ public void execute(Goods goods) { if(goods.getPrice()>=100){ goods.setPrice(goods.getPrice()-20); } }}; //打折 Closure discount=new Closure (){ public void execute(Goods goods) { if(goods.isDiscount()){ goods.setPrice(goods.getPrice()*0.9); } }}; //判断 Predicate pre=new Predicate (){ public boolean evaluate(Goods goods) { return goods.isDiscount(); }}; //二选一 Closure ifClo=IfClosure.ifClosure(pre, discount,subtract); //关联 CollectionUtils.forAllDo(goodsList,ifClo); //查看操作后的数据 for(Goods temp:goodsList){ System.out.println(temp); } } /** * 基本操作 */ public static void basic(){ //数据 List empList =new ArrayList (); empList.add(new Employee("bjsxt",20000)); empList.add(new Employee("is",10000)); empList.add(new Employee("good",5000)); //业务功能 Closure cols=new Closure (){ public void execute(Employee emp) { emp.setSalary(emp.getSalary()*1.2); }}; //工具类 CollectionUtils.forAllDo(empList, cols) ; //操作后的数据 Iterator empIt=empList.iterator(); while(empIt.hasNext()){ System.out.println(empIt.next()); } }} package com.bjsxt.others.commons;import java.util.Collection;import java.util.HashSet;import java.util.Set;import org.apache.commons.collections4.CollectionUtils;/** * 集合操作 * 1、并集 * CollectionUtils.union(); * 2、交集 * CollectionUtils.intersection(); * CollectionUtils.retainAll(); * 3、差集 * CollectionUtils.subtract(); * @author Administrator * */public class Demo04 { /** * @param args */ public static void main(String[] args) { Set set1 =new HashSet (); set1.add(1); set1.add(2); set1.add(3); Set set2 =new HashSet (); set2.add(2); set2.add(3); set2.add(4); //并集 System.out.println("=========并集============"); Collection col =CollectionUtils.union(set1,set2); for(Integer temp:col){ System.out.println(temp); } //交集 System.out.println("=========交集============"); //col =CollectionUtils.intersection(set1, set2); col =CollectionUtils.retainAll(set1, set2); for(Integer temp:col){ System.out.println(temp); } //差集 System.out.println("=========差集============"); col =CollectionUtils.subtract(set1, set2); for(Integer temp:col){ System.out.println(temp); } }} package com.bjsxt.others.commons;import java.util.Queue;import org.apache.commons.collections4.Predicate;import org.apache.commons.collections4.functors.NotNullPredicate;import org.apache.commons.collections4.queue.CircularFifoQueue;import org.apache.commons.collections4.queue.PredicatedQueue;import org.apache.commons.collections4.queue.UnmodifiableQueue;/** Queue队列 1、循环队列:CircularFifoQueue 2、只读队列:不可改变队列 UnmodifiableQueue 3、断言队列:PredicatedQueue.predicatedQueue() * @author Administrator * */public class Demo05 { /** * @param args */ public static void main(String[] args) { //circular(); //readOnly(); predicate(); } /** * 断言队列 */ public static void predicate(){ //循环队列 CircularFifoQueue que =new CircularFifoQueue (2); que.add("a"); que.add("b"); que.add("c"); Predicate notNull=NotNullPredicate.INSTANCE; //包装成对应的队列 Queue que2=PredicatedQueue.predicatedQueue(que, notNull); que2.add(null); } /** * 只读队列 */ public static void readOnly(){ //循环队列 CircularFifoQueue que =new CircularFifoQueue (2); que.add("a"); que.add("b"); que.add("c"); Queue readOnlyQue =UnmodifiableQueue.unmodifiableQueue(que); readOnlyQue.add("d"); } /** * 循环队列 */ public static void circular(){ //循环队列 CircularFifoQueue que =new CircularFifoQueue (2); que.add("a"); que.add("b"); que.add("c"); //查看 for(int i=0;i package com.bjsxt.others.commons;import java.util.ArrayList;import java.util.Iterator;import java.util.List;import org.apache.commons.collections4.BidiMap;import org.apache.commons.collections4.IterableMap;import org.apache.commons.collections4.MapIterator;import org.apache.commons.collections4.Predicate;import org.apache.commons.collections4.bidimap.DualHashBidiMap;import org.apache.commons.collections4.iterators.ArrayListIterator;import org.apache.commons.collections4.iterators.FilterIterator;import org.apache.commons.collections4.iterators.LoopingIterator;import org.apache.commons.collections4.iterators.UniqueFilterIterator;import org.apache.commons.collections4.map.HashedMap;/** 迭代器的扩展 1、MapIterator 以后不再使用map.keySet.iterator访问 IterableMap HashedMap 2、UniqueFilterIterator 去重迭代器 3、FilterIterator 自定义过滤 +Predicate 4、LoopingIterator 循环迭代器 5、ArrayListIterator 数组迭代器 * @author Administrator * */public class Demo06 { /** * @param args */ public static void main(String[] args) { //mapIt(); //uniqueIt(); //filterIt(); //loopIt(); arrayIt(); } /** * 数组迭代器 */ public static void arrayIt(){ System.out.println("===== 数组迭代器 ===="); int[] arr ={1,2,3,4,5}; //数组迭代器 //Iterator it =new ArrayListIterator (arr); //指定起始索引和结束索引 Iterator it =new ArrayListIterator (arr,1,3); while(it.hasNext()){ System.out.println(it.next()); } } /** * 循环迭代器 */ public static void loopIt(){ System.out.println("===== 循环迭代器 ===="); List list =new ArrayList (); list.add("refer"); list.add("dad"); list.add("bjsxt"); list.add("moom"); Iterator it =new LoopingIterator(list); for(int i=0;i<15;i++){ System.out.println(it.next()); } } /** * 自定义迭代器 */ public static void filterIt(){ System.out.println("=====自定义迭代器 ===="); List list =new ArrayList (); list.add("refer"); list.add("dad"); list.add("bjsxt"); list.add("moom"); //自定义条件判断 Predicate pre =new Predicate (){ public boolean evaluate(String value) { //回文判断 return new StringBuilder(value).reverse().toString().equals(value); }}; //去除重复的过滤器 Iterator it =new FilterIterator(list.iterator(),pre); while(it.hasNext()){ System.out.println(it.next()); } } /** * 去重迭代器 */ public static void uniqueIt(){ System.out.println("=====去重迭代器 ===="); List list =new ArrayList (); list.add("a"); list.add("b"); list.add("a"); //去除重复的过滤器 Iterator it =new UniqueFilterIterator(list.iterator()); while(it.hasNext()){ System.out.println(it.next()); } } /** * map迭代器 */ public static void mapIt(){ System.out.println("=====map迭代器===="); IterableMap map =new HashedMap (); map.put("a","bjsxt"); map.put("b", "sxt"); map.put("c", "good"); //使用 MapIterator MapIterator it =map.mapIterator(); while(it.hasNext()){ //一定要it.next() /* it.next(); String key =it.getKey(); */ String key =it.next(); String value =it.getValue(); System.out.println(key+"-->"+value); } }} package com.bjsxt.others.commons;import org.apache.commons.collections4.BidiMap;import org.apache.commons.collections4.MapIterator;import org.apache.commons.collections4.bidimap.DualHashBidiMap;import org.apache.commons.collections4.bidimap.DualTreeBidiMap;/** 双向Map 要求键与值都不能重复 BidiMap inverseBidiMap() 1、DualTreeBidiMap :有序 2、DualHashBidiMap :无序 * @author Administrator * */public class Demo07 { /** * @param args */ public static void main(String[] args) { //hashMap(); treeMap(); } /** * 有序的双向Map */ public static void treeMap(){ System.out.println("=====有序的双向Map===="); BidiMap map =new DualTreeBidiMap (); map.put("bj", "bj@test.com"); map.put("sxt", "sxt@qq.com"); //遍历查看 MapIterator it =map.inverseBidiMap().mapIterator(); while(it.hasNext()){ String key =it.next(); String value =it.getValue(); System.out.println(key+"-->"+value); } } /** * 无序的双向Map */ public static void hashMap(){ System.out.println("=====无序的双向Map===="); BidiMap map =new DualHashBidiMap (); map.put("bj", "bj@test.com"); map.put("sxt", "sxt@qq.com"); //反转 System.out.println(map.inverseBidiMap().get("sxt@qq.com")); //遍历查看 MapIterator it =map.inverseBidiMap().mapIterator(); while(it.hasNext()){ String key =it.next(); String value =it.getValue(); System.out.println(key+"-->"+value); } }} package com.bjsxt.others.commons;import java.util.Iterator;import java.util.Set;import org.apache.commons.collections4.Bag;import org.apache.commons.collections4.bag.HashBag;import org.apache.commons.collections4.bag.TreeBag;/** Bag 包 允许重复 1、HashBag 无序 2、TreeBag 有序 统计单词的出现次数 * @author Administrator * */public class Demo08 { /** * @param args */ public static void main(String[] args) { //hashBag(); //treeBag(); String str ="this is a cat and that is a mice where is the food"; //分割字符串 String[] strArray =str.split(" "); Bag bag =new TreeBag (); for(String temp:strArray){ bag.add(temp); } System.out.println("====统计次数==="); Set keys =bag.uniqueSet(); for(String letter:keys){ System.out.println(letter+"-->"+bag.getCount(letter)); } } /** * 有序 */ public static void treeBag(){ System.out.println("=====有序的包===="); Bag bag =new TreeBag (); bag.add("a"); bag.add("a",5); bag.remove("a", 2); bag.add("b"); bag.add("c"); Iterator it =bag.iterator(); while(it.hasNext()){ System.out.println(it.next()); } } /** * 无序 */ public static void hashBag(){ System.out.println("=====无序的包===="); Bag bag =new HashBag (); bag.add("a"); bag.add("a",5); bag.remove("a", 2); bag.add("b"); bag.add("c"); Iterator it =bag.iterator(); while(it.hasNext()){ System.out.println(it.next()); } }} package collection;import java.util.NoSuchElementException;/** * @author SUNHAN * @Date: 2014年9月29日 */public class SLinkedList { private transient int size=0; private transient Node head=new Node(null,null,null);//用头结点来表示整个链表 public SLinkedList(){//默认构造方法 head.next=head; head.previous=head; } public void add(Object element){//在末尾插入元素 Node Nnode=new Node(element,head,head.previous); Nnode.previous.next=Nnode; Nnode.next.previous=Nnode; size++; } public void addBefore(Object o,Node e){ Node newNode=new Node(o,e,e.previous); newNode.previous.next=newNode; newNode.next.previous=newNode; size++; } public void add(int index,Object o){//俩参数的add()方法 addBefore(o,(index==size?head:node(index))); } private Node node(int index){ if(index<0||index>=size){ throw new IndexOutOfBoundsException("Index: "+index+", Size: "+size); } Node e=head;//从header开始循环 if(index index;i--){ e=e.previous; } } return e; } public Object remove(int index){ Node e=node(index); remove(e); return e.element; } private void remove(Node e){ if(e==head){ throw new NoSuchElementException(); } e.previous.next=e.next; e.next.previous=e.previous; size--; }}class Node { Object element; Node next; Node previous; public Node(Object element,Node next,Node previous){//带仨参的构造函数 this.element=element; this.next=next; this.previous=previous; }} package collection;import java.util.ArrayList;import java.util.HashSet;import java.util.Iterator;import java.util.List;import java.util.Set;/** * @author SUNHAN * @Date: 2014年9月29日 * */public class SIterator { public static void main(String[] args) { Set set=new HashSet(); set.add("aa"); set.add("bb"); set.add("cc"); Iterator iter=set.iterator(); while(iter.hasNext()){ String str=(String) iter.next(); System.err.println(str); } for(Iterator iter1=set.iterator();iter.hasNext();){ String str=(String) iter1.next(); System.err.println(str); } List list=new ArrayList(); list.add("xxx"); list.add("yyy"); list.add("zzz"); for(Object o:list){ System.err.println(o.toString()); } }}