Java8之Stream流代替For循环操作

public class Emp {
 private String id;
 private String name;
 
 public Emp(String id, String name) {
 this.id=id;
 this.name=name;
 }
 public String getId() {
 return id;
 }
 public void setId(String id) {
 this.id = id;
 }
 public String getName() {
 return name;
 }
 public void setName(String name) {
 this.name = name;
 }
 @Override
 public String toString() {
 return "Emp信息： [id=" + id + ", name=" + name + "]";
 }

List<Emp> emps = new ArrayList<>();
 emps.add(new Emp("00101","张三"));
 emps.add(new Emp("00102","张四"));
 emps.add(new Emp("00103","张五"));
 emps.add(new Emp("00104","张六"));
 emps.add(new Emp("00105","张七"));
 
 for (Emp emp : emps) {
 if (emp.getName().equals("张三")) {
 System.out.println(emp);
 return;
 }
 }

List<Emp> emps = new ArrayList<>();
 emps.add(new Emp("00101","张三"));
 emps.add(new Emp("00102","张四"));
 emps.add(new Emp("00103","张五"));
 emps.add(new Emp("00104","张六"));
 emps.add(new Emp("00105","张七"));
 
 //filter()定义方法，toList()输出为list
 List<Emp> emp=emps.stream().filter(e -> "张三".equals(e.getName())).collect(Collectors.toList());
 emp.forEach(System.out::println);

public static void main(String[] args) {
 Long startTime = System.currentTimeMillis();
 formMethod();
 Long endTime = System.currentTimeMillis();
 System.out.println("result:" + (endTime - startTime)); 
}

public static void formMethod(){
 for (int i = 0; i < 10000; i++) {
  System.out.println("start::::::::::::");
 } 
 }

public static void main(String[] args) {
 List<Integer> list = new ArrayList<Integer>();
 for (int i = 0; i < 10000; i++) {
  list.add(i);
 }
 Long startTime = System.currentTimeMillis();
 foreachMethod(list);
 Long endTime = System.currentTimeMillis();
 System.out.println("result:" + (endTime - startTime));
}

/**
* foreach
* @param list
*/
public static void foreachMethod(List<Integer> list){
 list.forEach(i ->{
  System.out.println("++++++++++++");
 });
}

public static void main(String[] args) {
 List<Integer> list = new ArrayList<Integer>();
 for (int i = 0; i < 10000; i++) {
  list.add(i);
 }
 Long startTime = System.currentTimeMillis();
 streamMethod(list);
 Long endTime = System.currentTimeMillis();
 System.out.println("result:" + (endTime - startTime));
}

/**
* stream 串行处理
* @param list
*/
public static void streamMethod(List<Integer> list){
 list.stream().forEach(i ->{
  System.out.println("========");
 });
}

public static void main(String[] args) {
 List<Integer> list = new ArrayList<Integer>();
 for (int i = 0; i < 10000; i++) {
  list.add(i);
 }
 Long startTime = System.currentTimeMillis();
 parallelStreamMethod(list);
 Long endTime = System.currentTimeMillis();
 System.out.println("result:" + (endTime - startTime));
}
/**
* stream 并行处理
* @param list
*/
public static void parallelStreamMethod(List<Integer> list){
 list.parallelStream().forEach(i ->{
  System.out.println("========");
 });
}