private String level;
public Level() {
}
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 Collections;
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;
/**
* 解耦：将 业务处理与判断进行分离
*
* 函数式编程Transformat 类型转换
* 1.Transformer+CollectionUtils.collect
*
* 2.SwitchTransformer
* CollectionUtils.collect(容器，转换器)
*/
@SuppressWarnings("all")
public class Demo02 {
public static void main(String[] args) {
inner();
define();
}
//内置类型的转化
public static void inner()
{
System.out.println("========《内置类型转换 长整型时间日期，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(99999999L); list.add(30000L); //工具类：程序员出钱<---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); } } //自定义类型转换 public static void define(){ System.out.println("==========《自定义类型转换》==========="); Predicate
isLow = new Predicate
(){ public boolean eva luate(Employee emp) { return emp.getSalary()<=10000; } }; Predicate
isHigh = new Predicate
() { public boolean eva luate(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(),"低薪"); } }; //转换 Transformer
hightrans = new Transformer
() { @Override public Level transform(Employee input) { return new Level(input.getName(),"高薪"); } }; Transformer[] trans = {lowtrans,hightrans}; //二者进行了关联 Transformer switchTrans = new SwitchTransformer<>(pres, trans, null); List
list = new ArrayList<>(); list.add(new Employee("凤姐",10000000)); list.add(new Employee("犀利哥",1000)); Collection
levelList = CollectionUtils.collect(list, switchTrans); //遍历容器 Iterator
levelIt = levelList.iterator(); while(levelIt.hasNext()) { System.out.println(levelIt.next()); } } }
运行结果：
========《内置类型转换 长整型时间日期，转成指定格式的字符串》========
1970年01月02日
1970年01月01日
==========《自定义类型转换》===========
(码农：凤姐,水平:高薪)
(码农：犀利哥,水平:低薪)
三、Closure 闭包封装业务功能
package Collections;
/**
* 员工类
*/
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