Java 클래스 라이브러리-Guava-Multimap

일상적인 개발 작업에서는 때때로 Map

[code]import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.junit.Test;

public class MultimapTest {

    Map<String, List<StudentScore>> StudentScoreMap = new HashMap<String, List<StudentScore>>();

    @Test
    public void testStudentScore(){

        for(int i=10;i<20;i++){
            StudentScore studentScore=new StudentScore();
            studentScore.CourseId=1001+i;
            studentScore.score=100-i;
            addStudentScore("peida",studentScore);
        }

        System.out.println("StudentScoreMap:"+StudentScoreMap.size());
        System.out.println("StudentScoreMap:"+StudentScoreMap.containsKey("peida"));

        System.out.println("StudentScoreMap:"+StudentScoreMap.containsKey("jerry"));
        System.out.println("StudentScoreMap:"+StudentScoreMap.size());
        System.out.println("StudentScoreMap:"+StudentScoreMap.get("peida").size());

        List<StudentScore> StudentScoreList=StudentScoreMap.get("peida");
        if(StudentScoreList!=null&&StudentScoreList.size()>0){
            for(StudentScore stuScore:StudentScoreList){
                System.out.println("stuScore one:"+stuScore.CourseId+" score:"+stuScore.score);
            }
        }
    }

    public void addStudentScore(final String stuName,final StudentScore studentScore) {
        List<StudentScore> stuScore = StudentScoreMap.get(stuName);
        if (stuScore == null) {
            stuScore = new ArrayList<StudentScore>();
            StudentScoreMap.put(stuName, stuScore);
        }
        stuScore.add(studentScore);
    }
}

class StudentScore{
    int CourseId;
    int score;
}

과 같은 것을 생성해야 합니다. 참고: Map

[code]　@Test
    public void teststuScoreMultimap(){
        Multimap<String,StudentScore> scoreMultimap = ArrayListMultimap.create(); 
        for(int i=10;i<20;i++){
            StudentScore studentScore=new StudentScore();
            studentScore.CourseId=1001+i;
            studentScore.score=100-i;
            scoreMultimap.put("peida",studentScore);
        }
        System.out.println("scoreMultimap:"+scoreMultimap.size());
        System.out.println("scoreMultimap:"+scoreMultimap.keys());
    }

을 원할 경우 Multimap.get(key)을 호출하면 됩니다. 이 키를 반환합니다. 해당 값의 컬렉션 보기 해당 컬렉션이 없으면 빈 컬렉션이 반환됩니다. ListMultimap의 경우 이 메서드는 List를 반환하고 SetMultimap의 경우 이 메서드는 Set을 반환합니다. 데이터 수정은 기본 Multimap을 수정하여 수행됩니다. 예:

[code]　@Test
public void teststuScoreMultimap(){
Multimap<String,StudentScore> scoreMultimap = ArrayListMultimap.create(); 
for(int i=10;i<20;i++){
StudentScore studentScore=new StudentScore();
studentScore.CourseId=1001+i;
studentScore.score=100-i;
scoreMultimap.put("peida",studentScore);
}
System.out.println("scoreMultimap:"+scoreMultimap.size());
System.out.println("scoreMultimap:"+scoreMultimap.keys());

Collection<StudentScore> studentScore = scoreMultimap.get("peida");
studentScore.clear();
StudentScore studentScoreNew=new StudentScore();
studentScoreNew.CourseId=1034;
studentScoreNew.score=67;
studentScore.add(studentScoreNew);

System.out.println("scoreMultimap:"+scoreMultimap.size());
System.out.println("scoreMultimap:"+scoreMultimap.keys());
}

Multimap은 일련의 강력한 보기 기능도 지원합니다.

1.asMap은 자체 Multimap을 구현합니다.

[code]@Test
    public void teststuScoreMultimap(){
        Multimap<String,StudentScore> scoreMultimap = ArrayListMultimap.create(); 
        for(int i=10;i<20;i++){
            StudentScore studentScore=new StudentScore();
            studentScore.CourseId=1001+i;
            studentScore.score=100-i;
            scoreMultimap.put("peida",studentScore);
        }
        System.out.println("scoreMultimap:"+scoreMultimap.size());
        System.out.println("scoreMultimap:"+scoreMultimap.keys());

        Collection<StudentScore> studentScore = scoreMultimap.get("peida");
        StudentScore studentScore1=new StudentScore();
        studentScore1.CourseId=1034;
        studentScore1.score=67;
        studentScore.add(studentScore1);

        StudentScore studentScore2=new StudentScore();
        studentScore2.CourseId=1045;
        studentScore2.score=56;
        scoreMultimap.put("jerry",studentScore2);

        System.out.println("scoreMultimap:"+scoreMultimap.size());
        System.out.println("scoreMultimap:"+scoreMultimap.keys());

        for(StudentScore stuScore : scoreMultimap.values()) {
            System.out.println("stuScore one:"+stuScore.CourseId+" score:"+stuScore.score);
        }

        scoreMultimap.remove("jerry",studentScore2); 
        System.out.println("scoreMultimap:"+scoreMultimap.size());
        System.out.println("scoreMultimap:"+scoreMultimap.get("jerry"));

        scoreMultimap.put("harry",studentScore2);
        scoreMultimap.removeAll("harry");
        System.out.println("scoreMultimap:"+scoreMultimap.size());
        System.out.println("scoreMultimap:"+scoreMultimap.get("harry"));
    }

Multimap

Multimap은 풍부한 기능을 제공합니다.

위 내용은 Java-Class Library-Guava-Multimap의 내용이며, 더 많은 관련 내용은 PHP 중국어 홈페이지(www. php.cn) !