Dans le travail de développement quotidien, nous devons parfois construire une structure comme 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; }
Remarque : si vous souhaitez appeler Multimap.get(key) pour 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()); }
[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()); }
1.asMap implémente son propre Multimap
[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 fournit une implémentation riche, vous pouvez donc l'utiliser pour remplacer Map dans le programme