Java8 new features Stream Streaming thought (a)

And traversing the filter elements in the collection

• Using the element in a conventional manner to traverse the filter and the collection

cn.com.zq.demo01.Stream.test01.Stream Package; 

Import of java.util.ArrayList; 
Import java.util.List; 

/ * 
 * used in a conventional manner to traverse the filter and set 
 * requirements: 
 * 1, the first step in filtration, just to name beginning with "Zhang" 
 * 2, the second step filtration just need to name the names of length 2 
 * * / 
public class Test01Stream { 

    public static void main (String [] args) { 
// create a collection List, store names and filtered according to the requirements 
        List <String> = new new nameList the ArrayList <> (); 
        nameList.add ( "John Doe"); 
        nameList.add ( "John Doe"); 
        nameList.add ( "Wang Wu"); 
        nameList.add ( "Zhao six"); 
        nameList.add ( "Tianqi"); 
        nameList.add ( "bastard");  
        nameList.add ( "Zhang Four");
        nameList.add ( "Chi Master");

// use the traditional way to filter 

// 1, the first step filtration, you need only begin with the name of Zhang 

// need to create a new set of names after the first filter to store 
        List <String> listA = new ArrayList < > (); 
        for (String S: nameList) {// set with enhanced for loop is traversed 
            if (s.startsWith ( "Zhang")) { 
                listA.add (S); // add the result to the filter the new collection 
            } 
        } 

        List <String> = new new listB the ArrayList <> (); 
        for (String S: listA) { 
            IF (s.length () == 2) { 
                listB.add (S); 
            } 
        } 

        for ( S String: listB) { 
            of System.out.print (S + ""); // Double three four final filter results // final filter result sheets three four 
        }
    } 
}

　　

• Use the Stream flow traversing ways and filtration elements in the collection

 

cn.com.zq.demo01.Stream.test01.Stream Package; 

Import of java.util.ArrayList; 
Import java.util.List; 

/ * 
* usage Stream flow through and the collection filter 
* requirements: 
            1, the first step in filtration , just to name "Chang" at the beginning of the 
            2, only the second step filtration, the name is the name of a length 2 
* * / 
public class Test02Stream { 

    public static void main (String [] args) { 
        // create a collection List, store names and filtered according to the requirements 
        List <String> = new new nameList the ArrayList <> (); 
        nameList.add ( "John Doe"); 
        nameList.add ( "John Doe"); 
        nameList.add ( "Wang Wu"); 
        nameList.add ( "Zhao six"); 
        nameList.add ( "Tianqi"); 
        nameList.add ( "bastard");
        nameList.add ( "Zhang Four");
        nameList.add ( "Chi Master"); 

// use Stream flow, to traverse the collection and filtration 
// 1, the first step filtration, need only begin with the name of "Zhang" 

// will be converted to a set of Stream flow a default method called directly interface Collection Stream 
        nameList.stream (). filter (S-> s.startswith ( "Zhang")) 
                         .filter (S-> s.length () == 2) 
                         .forEach (S- > System.out.print (s + "") ); // output: three four sheets 
    } 
}

　　

Original: https: //blog.csdn.net/qq_41319058/article/details/90319707