[Java基础]函数式接口
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代码如下:
package MyInterfacePack01;
@FunctionalInterface
public interface MyInterface {
void show();
}
package MyInterfacePack01;
public class MyInterfaceDemo {
public static void main(String[] args)
{
MyInterface my= ()->System.out.println("hello world");
my.show();
}
}
代码如下:
package MyInterfacePack01;
public class RunnableDemo {
public static void main(String[] args)
{
startThread(new Runnable() {
@Override
public void run() {
System.out.println(Thread.currentThread().getName()+"线程启动了");
}
});
startThread(()->System.out.println(Thread.currentThread().getName()+"线程启动了"));
}
private static void startThread(Runnable r)
{
new Thread(r).start();
}
}
代码如下:
package MyInterfacePack01;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
public class ComparatorDemo {
public static void main(String[] args)
{
ArrayList<String> array = new ArrayList<String>();
array.add("hello");
array.add("javaaaaa");
array.add("world");
System.out.println("排序前"+array);
Collections.sort(array,getComparator());
System.out.println("排序后"+array);
}
private static Comparator<String> getComparator(){
// Comparator<String> comp = new Comparator<String>() {
// @Override
// public int compare(String s1, String s2) {
// return s1.length()-s2.length();
// }
// };
// return comp;
return (s1,s2)->s1.length()-s2.length();
}
}
代码如下:
package SupplierPack;
import java.util.function.Supplier;
public class SupplierDemo {
public static void main(String[] args)
{
String s = getString(()->{
return "Tom";
});
String s1 = getString(()->"TOM");
System.out.println(s);
System.out.println(s1);
Integer i = getInteger(()->30);
System.out.println(i);
}
private static String getString(Supplier<String> sup)
{
return sup.get();
}
private static Integer getInteger(Supplier<Integer> sup)
{
return sup.get();
}
}
代码如下:
package SupplierPack;
import java.util.function.Supplier;
public class SupplierTest {
public static void main(String[] args)
{
int [] arr = {19,50,28,37,64};
int maxValue = getMax(()->{
int max = arr[0];
for (int i = 1;i<arr.length;i++)
{
if (arr[i] > max)
{
max = arr[i];
}
}
return max;
});
System.out.println(maxValue);
}
private static int getMax(Supplier<Integer> sup)
{
return sup.get();
}
}
代码如下:
package SupplierPack;
import java.util.function.Consumer;
public class ConsumerDemo {
public static void main(String[] args)
{
// operatorString("Tom",(String s)->{
// System.out.println(s);
// });
operatorString("Tom",s->System.out.println(s));
operatorString("Tom",System.out::println);
operatorString("Tom",s->
System.out.println(new StringBuilder(s).reverse().toString())
);
System.out.println("------------------------------------------");
operatorString("Jack",s->System.out.println(s),s->System.out.println(new StringBuilder(s).reverse().toString()));
}
private static void operatorString(String name,Consumer<String> con1,Consumer<String> con2)
{
// con1.accept(name);
// con2.accept(name);
con1.andThen(con2).accept(name);
}
private static void operatorString(String name, Consumer<String> con)
{
con.accept(name);
}
}
代码如下:
package SupplierPack;
import java.util.function.Consumer;
public class ConsumerTest {
public static void main(String[] args)
{
String[] strArray = {"Tom,20","Jack,23","Bom,18"};
printInfo(strArray,(String str)->{
String name = str.split(",")[0];
System.out.print("姓名"+name);
},(String str)->{
int age = Integer.parseInt(str.split(",")[1]);
System.out.println(",年龄"+age);
});
}
public static void printInfo(String[] strArray, Consumer<String> con1,Consumer<String> con2)
{
for (String str:strArray)
{
con1.andThen(con2).accept(str);
}
}
}
代码如下:
package SupplierPack;
import java.util.function.Predicate;
public class PredicateDemo01 {
public static void main(String[] args)
{
boolean b1 = checkString("hello",(String s)->{
return s.length() > 8;
});
boolean b2 = checkString("hello",s->s.length() > 8);
boolean b3 = checkString("helloworld",s->s.length() > 8);
System.out.println(b1);
System.out.println(b2);
System.out.println(b3);
}
private static boolean checkString(String s, Predicate<String> pre)
{
// return pre.test(s);
return pre.negate().test(s);
}
}
package PredicatePack01;
import java.io.StringReader;
import java.util.function.Predicate;
public class PredicateDemo01 {
public static void main(String[] args)
{
boolean b1 = checkString("hello",s->s.length() > 8);
System.out.println(b1);
boolean b2 = checkString("helloworld",s->s.length()> 8);
System.out.println(b2);
boolean b3 = checkString("hello",s->s.length() > 8 ,s->s.length()<15);
System.out.println(b3);
boolean b4 = checkString("helloworld",s->s.length() > 8 , s->s.length() < 15);
System.out.println(b4);
}
private static boolean checkString(String s, Predicate<String> pre1,Predicate<String> pre2)
{
// boolean b1 = pre1.test(s);
// boolean b2 = pre2.test(s);
// boolean b = b1 && b2;
// return b;
// return pre1.and(pre2).test(s);
return pre1.or(pre2).test(s);
}
private static boolean checkString(String s, Predicate<String> pre)
{
return pre.test(s);
}
}
代码如下:
package PredicatePack01;
import java.util.ArrayList;
import java.util.function.Predicate;
public class PredicatePack {
public static void main(String[] args)
{
String[] strArray = {"Tom,30","Jack,34","Bom,49","Lily,34","Mike,33"};
ArrayList<String> array = myFilter(strArray,s->s.split(",")[0].length()>2,s->Integer.parseInt(s.split(",")[1]) > 33);
for (String str:array)
{
System.out.println(str);
}
}
private static ArrayList<String> myFilter(String[] strArray, Predicate<String> pre1,Predicate<String> pre2)
{
ArrayList<String> array = new ArrayList<String>();
for (String str:strArray)
{
if(pre1.and(pre2).test(str))
array.add(str);
}
return array;
}
}
代码如下:
package PredicatePack01;
import java.util.function.Function;
public class FunctionDemo {
public static void main(String[] args)
{
// convert("100",(String s)->{
// return Integer.parseInt(s);
// });
convert("100",s->Integer.parseInt(s));
convert("100",Integer::parseInt);
convert(100,i->String.valueOf(i+566));
convert("100",s->Integer.parseInt(s),i->String.valueOf(i+566));
}
private static void convert(String s,Function<String,Integer> fun1,Function<Integer,String > fun2)
{
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