Datenpersistierung über Textdateien

src/main/java/university/at/jku/ce/Database.java

-package university.at.jku.ce;
-
-import java.util.HashMap;
-import java.util.Map;
-
-import university.at.jku.ce.model.Student;
-import university.at.jku.ce.model.Study;
-import university.at.jku.ce.model.Subject;
-
-public class Database {
-
-	private static Map<Long ,Student> students=new HashMap<Long,Student>();
-	private static Map<Long ,Subject> subjects=new HashMap<Long,Subject>();
-	private static Map<Long ,Study> studies=new HashMap<Long,Study>();
-	
-	public static Map<Long, Student> getStudents() {
-		return students;
-	}
-	public static Map<Long, Subject> getSubjects() {
-		return subjects;
-	}
-	
-	public static Map<Long, Study> getStudies() {
-		return studies;
-	}
-	
-	
-	
-
-}

src/main/java/university/at/jku/ce/dao/AbstractStudyDao.java

 package university.at.jku.ce.dao;
 
-import java.util.ArrayList;
 import java.util.List;
+import java.util.Map;
 
 import university.at.jku.ce.model.Study;
 
 public abstract class AbstractStudyDao {
 	 
-	abstract List<Study> getAllStudies();
+	public abstract Map<Long,Study> getAllStudies();
 	
-	abstract Study getStudy(Long id);
+	public abstract Study getStudy(Long id);
 	
-	abstract Study addStudy(Study study);
+	public abstract Study addStudy(Study study);
 	
-	abstract Study updateStudy(Study study);
+	public abstract Study updateStudy(Study study);
 	
-	abstract Study removeStudy(long studyId);
+	public abstract void removeStudy(long studyId);
 }

src/main/java/university/at/jku/ce/dao/AbstractSubjectDao.java

@@ -7,7 +7,7 @@ import java.util.Map;
 import university.at.jku.ce.model.Subject;
 
 public abstract class AbstractSubjectDao {
-	public abstract List<Subject> getAllSubjects(long studyId);
+	public abstract Map<Long,Subject> getAllSubjects(Long studyId);
 	
 	public abstract Subject getSubject(long studyId, long id);
 	
@@ -15,5 +15,5 @@ public abstract class AbstractSubjectDao {
 	
 	public abstract Subject updateSubject (long studyId, Subject subject);
 	
-	public abstract Subject removeSubject (long studyId, long id);
+	public abstract void removeSubject (long studyId, long id);
 }

src/main/java/university/at/jku/ce/dao/TextStudyDao.java

+package university.at.jku.ce.dao;
+
+import java.io.BufferedReader;
+import java.io.BufferedWriter;
+import java.io.FileReader;
+import java.io.FileWriter;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.Map;
+
+import university.at.jku.ce.model.Study;
+
+public class TextStudyDao extends AbstractStudyDao {
+
+	Map <Long,Study> studies;
+	
+	@Override
+	public Map<Long,Study> getAllStudies() {
+		ArrayList <String> lineList=new ArrayList<String>();
+		studies=new HashMap<Long,Study>();  
+		try {
+		
+			FileReader fr = new FileReader("C:\\Users\\Michael\\development\\workspace-ce5\\at.jku.ce\\src\\main\\resources\\Studies.txt");
+		    BufferedReader br = new BufferedReader(fr);
+		    String line="";
+		
+		    do{
+		    	line = br.readLine();
+		    	lineList.add(line);
+		    }
+		    while (line != null);
+		    br.close();
+		  } catch (Throwable t) {t.printStackTrace();}
+		  
+		  for(String s: lineList) {
+		    	if (s!=null) {
+			    		int i=0;
+			    		Long studyId;
+			    		String studyName;
+			    		StringBuilder b=new StringBuilder();
+			    		while (s.charAt(i)!='|') {
+			    			b.append(s.charAt(i));
+			    			i++;
+			   			}
+			   			studyId=Long.parseLong(b.toString());
+			   			b=new StringBuilder();
+			   			i++;
+		    			while (i<s.length()) {
+		    				b.append(s.charAt(i));
+		    				i++;			    			
+		    			}
+			    		studyName=b.toString();
+			    		studies.put(studyId, new Study(studyId,studyName));
+			    }		    
+		  	}
+		return studies;	  
+	}
+
+	@Override
+	public Study getStudy(Long id) {
+		studies=getAllStudies();
+		return studies.get(id);
+	}
+
+	@Override
+	public Study addStudy(Study study) {
+		studies=getAllStudies();
+		study.setStudyId(getNextId());
+		studies.put(study.getStudyId(), study);
+		write();
+		return study;
+	}
+
+	@Override
+	public Study updateStudy(Study study) {
+		studies=getAllStudies();
+		if (studies.containsKey(study.getStudyId())) {
+		studies.put(study.getStudyId(), study);
+		}
+		write();
+		return study;
+		
+	}
+
+	@Override
+	public void removeStudy(long studyId) {
+		studies=getAllStudies();
+		studies.remove(studyId);
+		write();
+	}
+
+	
+	void write() {
+		try {
+		FileWriter fw = new FileWriter("C:\\Users\\Michael\\development\\workspace-ce5\\at.jku.ce\\src\\main\\resources\\Studies.txt");
+		BufferedWriter bw = new BufferedWriter(fw);
+		String n = System.getProperty("line.separator"); 
+		ArrayList <String> lineList=new ArrayList<String>();
+		for (Study s:studies.values()) {
+			StringBuilder b=new StringBuilder();
+			b.append(s.getStudyId());
+			b.append("|");
+			b.append(s.getName());
+			lineList.add(b.toString());
+		}
+		
+		for (String s:lineList) {bw.write(s); bw.write(n);}
+		bw.close();
+		} catch (Throwable t) {t.printStackTrace();}
+	}
+	
+	public long getNextId() {
+		long nextId=0;
+		for (Study s:studies.values()) {
+			if (s.getStudyId()>nextId) {
+				nextId=s.getStudyId();
+			}
+		}
+		return nextId+1;
+	}
+
+}

src/main/java/university/at/jku/ce/dao/TextSubjectDao.java

+package university.at.jku.ce.dao;
+
+import java.io.BufferedReader;
+import java.io.BufferedWriter;
+import java.io.FileReader;
+import java.io.FileWriter;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Map.Entry;
+
+import university.at.jku.ce.model.Study;
+import university.at.jku.ce.model.Subject;
+
+public class TextSubjectDao extends AbstractSubjectDao {
+
+Map <Long,Subject> subjects;
+Map <SubjectId,Subject> allSubjects;
+
+class SubjectId{
+	Long studyId;
+	Long subjectId;
+	
+	SubjectId(Long studyId, Long subjectId) {
+		this.studyId=studyId;
+		this.subjectId=subjectId;
+	}
+	
+	@Override
+	public boolean equals (Object o) {
+		if (o instanceof SubjectId) {
+			SubjectId si=(SubjectId)o;
+			if (this.studyId.equals(si.studyId)&&this.subjectId.equals(si.subjectId)) return true;
+		}
+		return false;
+	}
+	
+	@Override
+	public int hashCode() {
+	    int code=(int) (((studyId+subjectId)*(studyId+subjectId+1))/2+subjectId);  
+		return code;
+	    }
+}
+	
+
+
+	@Override
+	public Map<Long,Subject> getAllSubjects(Long studyId) {
+		ArrayList <String> lineList=new ArrayList<String>();
+		allSubjects=new HashMap<SubjectId,Subject>();
+		subjects=new HashMap<Long,Subject>();  
+		try {
+		
+			FileReader fr = new FileReader("C:\\Users\\Michael\\development\\workspace-ce5\\at.jku.ce\\src\\main\\resources\\Subjects.txt");
+		    BufferedReader br = new BufferedReader(fr);
+		    String line="";
+		
+		    do{
+		    	line = br.readLine();
+		    	lineList.add(line);
+		    }
+		    while (line != null);
+		    br.close();
+		  } catch (Throwable t) {t.printStackTrace();}
+		  
+		  for(String s: lineList) {
+		    	if (s!=null) {
+			    		int i=0;
+			    		Long textStudyId;
+			    		Long id;
+			    		String subjectName;
+			    		String subjectDesc;
+			    		StringBuilder b=new StringBuilder();
+			    		while (s.charAt(i)!='|') {
+			    			b.append(s.charAt(i));
+			    			i++;
+			   			}
+			   			textStudyId=Long.parseLong(b.toString());
+			   			b=new StringBuilder();
+			   			i++;
+			   			while (s.charAt(i)!='|') {
+			    			b.append(s.charAt(i));
+			    			i++;
+			   			}
+			   			id=Long.parseLong(b.toString());
+			   			b=new StringBuilder();
+			   			i++;
+			   			while (s.charAt(i)!='|') {
+			    			b.append(s.charAt(i));
+			    			i++;
+			   			}
+			   			subjectName=b.toString();
+			   			b=new StringBuilder();
+			   			i++;
+			   			while (i<s.length()) {
+		    				b.append(s.charAt(i));
+		    				i++;			    			
+		    			}
+			    		subjectDesc=b.toString();
+			    		Subject subject=new Subject(id,subjectName,subjectDesc);
+			    		if(studyId==textStudyId) {
+			    			subjects.put(id, subject);
+			    		}
+			    		allSubjects.put(new SubjectId(textStudyId,id), subject);
+			    }		    
+		  	}
+		return subjects;	  
+	}
+
+	@Override
+	public Subject getSubject(long studyId, long id) {
+		subjects=getAllSubjects(studyId);
+		return subjects.get(id);
+	}
+
+	@Override
+	public Subject addSubject(long studyId, Subject subject) {
+		subjects=getAllSubjects(studyId);
+		subject.setId(getNextId());
+		subjects.put(subject.getId(), subject);
+		allSubjects.put(new SubjectId(studyId,subject.getId()), subject);
+		write();
+		return subject;
+	}
+
+	@Override
+	public Subject updateSubject(long studyId, Subject subject) {
+		subjects=getAllSubjects(studyId);
+		subjects.put(subject.getId(), subject);
+		allSubjects.put(new SubjectId(studyId,subject.getId()), subject);
+		write();
+		return subject;
+	}
+
+	@Override
+	public void removeSubject(long studyId, long id) {
+		subjects=getAllSubjects(studyId);
+		subjects.remove(id);
+		allSubjects.remove(new SubjectId(studyId, id));
+		write();
+	}
+	
+	void write() {
+		ArrayList <String> lineList=new ArrayList<String>();
+		try {
+		FileWriter fw = new FileWriter("C:\\Users\\Michael\\development\\workspace-ce5\\at.jku.ce\\src\\main\\resources\\Subjects.txt");
+		BufferedWriter bw = new BufferedWriter(fw);
+		String n = System.getProperty("line.separator"); 
+		
+		for (Entry<SubjectId, Subject> entry:allSubjects.entrySet()) {
+			StringBuilder b=new StringBuilder();
+			b.append(entry.getKey().studyId);
+			b.append("|");
+			b.append(entry.getValue().getId());
+			b.append("|");
+			b.append(entry.getValue().getName());
+			b.append("|");
+			b.append(entry.getValue().getInfo());
+			lineList.add(b.toString());
+		}
+		for (String st:lineList) {bw.write(st); bw.write(n);}
+		bw.close();
+		} catch (Throwable t) {t.printStackTrace();}
+	}
+	
+	public long getNextId() {
+		long nextId=0;
+		for (Subject s:subjects.values()) {
+			if (s.getId()>nextId) {
+				nextId=s.getId();
+			}
+		}
+		return nextId+1;
+	}
+
+}

src/main/java/university/at/jku/ce/model/Study.java

@@ -22,6 +22,11 @@ public class Study {
 		this.subjects=subjects;
 	}
 	
+	public Study (long studyId, String name) {
+		this.studyId=studyId;
+		this.name=name;
+	}
+	
 	public Study(long studyId, String name, Map<Long, Subject> subjects) {
 		this.name=name;
 		this.studyId=studyId;

src/main/java/university/at/jku/ce/model/Subject.java

@@ -44,4 +44,9 @@ public class Subject {
 	public void setId(long id) {
 		this.id = id;
 	}
+
+
+	
+	
+	
 }

src/main/java/university/at/jku/ce/resource/SubjectResource.java

@@ -40,8 +40,8 @@ public class SubjectResource {
 	
 	@DELETE
 	@Path("/{id}")
-	public Subject removeSubject(@PathParam("studyId")long studyId,@PathParam("id")long id) {
-		return subjectService.removeSubject(studyId, id);
+	public void removeSubject(@PathParam("studyId")long studyId,@PathParam("id")long id) {
+		subjectService.removeSubject(studyId, id);
 	}
 	
 	@GET

src/main/java/university/at/jku/ce/service/StudentService.java

 package university.at.jku.ce.service;
 
 import java.util.ArrayList;
-import university.at.jku.ce.Database;
 import java.util.List;
 import java.util.Map;
 
@@ -12,44 +11,28 @@ import university.at.jku.ce.model.Subject;
 
 
 public class StudentService {
-
-	private Map <Long, Student> students=Database.getStudents();
 	
 	public StudentService() {
-
-		Student s2=new Student(1, "Michael", "Schimpelsberger");
-		Student s1=new Student(2,"Franz", "Reschl");
-		Student s3=new Student(3,"Susanne", "Zaunmayr");
-		
-		students.put(s1.getMatrNr(),s1);
-		students.put(s2.getMatrNr(),s2);
-		students.put(s3.getMatrNr(), s3);
 	}
 	
 	public List<Student> getAllStudents(){
-		return new ArrayList<Student>(students.values());
+		return null;
 	}
 	
 	public Student getStudent(Long id) {
-		return students.get(id);
+		return null;
 	}
 	
 	public Student addStudent(Student student) {
-		if (student!=null) {
-			student.setMatrNr(students.size()+1);
-			students.put(student.getMatrNr(), student);
-		}
-		return student;
+		return null;
 	}
 	
 	public Student updateStudent(Student student) {
-		if (student!=null&&students.containsKey(student.getMatrNr()));
-			students.put(student.getMatrNr(), student);
-		return student;
+		return null;
 	}
 	
 	public Student removeStudent(long matrNr) {
-		 return students.remove(matrNr);
+		 return null;
 	}
 	
 	

src/main/java/university/at/jku/ce/service/StudyService.java

@@ -4,56 +4,40 @@ import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-
-import university.at.jku.ce.Database;
+import university.at.jku.ce.dao.AbstractStudyDao;
+import university.at.jku.ce.dao.TextStudyDao;
 import university.at.jku.ce.model.Study;
 import university.at.jku.ce.model.Subject;
 
 public class StudyService {
-private Map <Long, Study> studies=Database.getStudies();
+
+private AbstractStudyDao studyDao=new TextStudyDao();
 	
 	public StudyService() {
-
-		Map<Long,Subject> win=new HashMap<Long,Subject>();
-		win.put((long)1, new Subject(1,"Einführung Softwareentwicklung","Grundlagen der Softwareentwicklung"));
-		win.put((long)2, new Subject(2,"Datenmodellierung","Datenmodelle und Datenbanksysteme"));
-		
-		Map<Long,Subject> inf=new HashMap<Long,Subject>();
-		inf.put((long)1, new Subject(1,"Einführung Softwareentwicklung","Grundlagen der Softwareentwicklung"));
-		inf.put((long)2, new Subject(2,"Relationale Algebra","Grundlegendes zu Relationalen Algebra"));
-		
-		Study s1=new Study(1,"Wirtschaftsinformatik",win);
-		Study s2=new Study(2,"Informatik", inf);
-		Study s3=new Study(3,"Wirtschaftswissenschaften",null);
-		
-		studies.put(s1.getStudyId(),s1);
-		studies.put(s2.getStudyId(),s2);
-		studies.put(s3.getStudyId(), s3);
 	}
 	
 	public List<Study> getAllStudies(){
-		return new ArrayList<Study>(studies.values());
+		return new ArrayList<Study>(studyDao.getAllStudies().values());
 	}
 	
 	public Study getStudy(Long id) {
-		return studies.get(id);
+		return studyDao.getStudy(id);
 	}
 	
 	public Study addStudy(Study study) {
 		if (study!=null) {
-			study.setStudyId(studies.size()+1);
-			studies.put(study.getStudyId(), study);
+			studyDao.addStudy(study);
 		}
 		return study;