Hi,
i am currently developing an application to view filestructures in a hierarchical way.
Therefore im using a TreeGrid component with lazy load.
When trying to open some nodes on the tree it does load the subfolders, shows them for almost 1 second and then reloads the root and all branches are collapsed again.
Currently i am using Vaadin 8.9.3.
Building the Treegrid
HorizontalLayout horrlayout = new HorizontalLayout();
horrlayout.setSizeFull();
VerticalLayout vertLayout = new VerticalLayout();
selectionState = SelectionState.getInstance();
this.setSizeFull();
List<FolderStatus> folderStatusDD = new ArrayList<>();
folderStatusDD.add(FolderStatus.DS_RELEVANT);
folderStatusDD.add(FolderStatus.NICHT_DS_RELEVANT);
folderStatusDD.add(FolderStatus.KEINE_ARCHIVIERUNG);
folderStatusCB.setWidth(100, Unit.PERCENTAGE);
folderStatusCB.setItems(folderStatusDD);
//Folder dbfolder = OrdnerkennungDAO.getFolderList("c_dsgvo_folders");
final HierarchicalDataProvider<Folder, Void> dataProvider = new AbstractBackEndHierarchicalDataProvider<Folder, Void>() {
/**
*
*/
private static final long serialVersionUID = -2038918474553295909L;
@Override
public int getChildCount(HierarchicalQuery<Folder, Void> query) {
try {
return OrdnerkennungDAO.getChilderFolderCount(query.getParent(), dbConnection);
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return 0;
}
@Override
public boolean hasChildren(Folder item) {
try {
return OrdnerkennungDAO.hasChildrenFolder(item, dbConnection);
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return false;
}
@Override
protected Stream<Folder> fetchChildrenFromBackEnd(HierarchicalQuery<Folder, Void> query) {
try {
return OrdnerkennungDAO.getChildFolder(query.getParent(), dbConnection).stream();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
final List<Folder> list = Collections.emptyList();
return list.stream();
}
};
folderTreeGrid.addColumn(Folder::getDirName).setCaption("M:/");
folderTreeGrid.setDataProvider(dataProvider); // setzten der Werte im Grid
folderTreeGrid.setWidth(100, Unit.PERCENTAGE);
folderTreeGrid.setHeight(100, Unit.PERCENTAGE);
horrlayout.addComponent(folderTreeGrid);
horrlayout.addComponent(vertLayout);
horrlayout.setExpandRatio(folderTreeGrid, 2.0f);
horrlayout.setExpandRatio(vertLayout, 1.0f);
addComponent(horrlayout);
DAO
public static int getChilderFolderCount(Folder folder, DatabaseConnectionManager dbConnection) throws SQLException {
final Integer anzahl;
final Connection conn = dbConnection.getDBConnection().getConnection();
final StringBuilder sb = new StringBuilder();
sb.append("select count(*) as anzahl from C_DSGVO_FOLDERS fold where fold.parent_dir = ?");
try(PreparedStatement stmt = conn.prepareStatement(sb.toString())) {
final Integer parentID = (folder != null) ? folder.getId() : 1;
stmt.setInt(1, parentID);
try(final ResultSet rs = stmt.executeQuery()){
if(rs.next()) {
anzahl = rs.getInt("anzahl");
} else {
anzahl = 0;
}
}
}
System.out.println("folder: "+(folder != null ? folder.getDirName(): "root")+"-> Children: "+anzahl);
return anzahl;
}
public static boolean hasChildrenFolder(Folder folder, DatabaseConnectionManager dbConnection ) throws SQLException {
return OrdnerkennungDAO.getChilderFolderCount(folder, dbConnection) > 0;
}
public static List<Folder> getChildFolder(Folder folder, final DatabaseConnectionManager dbConnection) throws SQLException {
final LinkedList<Folder> folderList = new LinkedList<Folder>();
final StringBuilder sb = new StringBuilder();
sb.append("select folders.id, folders.dir, folders.status, level, folders.parent_dir, folders.user_kommentar from C_DSGVO_FOLDERS folders where folders.parent_dir = ? ")
.append("connect by prior folders.id = folders.parent_dir ")
.append("start with folders.parent_dir is null ")
.append("order siblings by folders.dir ");
final Connection conn = dbConnection.getDBConnection().getConnection();
try(PreparedStatement stmt = conn.prepareStatement(sb.toString())) {
final Integer parentID = (folder != null) ? folder.getId() : 1;
stmt.setInt(1, parentID);
try(final ResultSet rs = stmt.executeQuery()){
while(rs.next()) {
final Integer id = rs.getInt("id");
final Integer status = rs.getInt("status");
final String kommentar = rs.getString("user_kommentar");
final Integer level = rs.getInt("level");
final String dir = rs.getString("dir");
final Folder f = new Folder(dir, folder, id, FolderStatus.getStatus(status), kommentar, level);
folderList.add(f);
}
}
}
return folderList;
}
Folder
public class Folder {
final private String dirName;
final private List<Folder> subFolder;
final private int id;
private FolderStatus status;
private String kommentar;
private Integer level;
private Folder parent;
public Folder(final String path, final Folder parent, final Integer id, final FolderStatus status, final String kommentar, final Integer level) {
super();
this.dirName = path;
this.id = id;
this.parent = parent;
this.status = status;
this.kommentar = kommentar;
this.subFolder = new LinkedList<>();
this.level = level;
}
public FolderStatus getStatus() {
return status;
}
public String getDirName() {
return dirName;
}
public int getId() {
return id;
}
public String getAbsolutePath() {
final StringBuilder sb = new StringBuilder();
if(this.parent != null) {
sb.append(parent.getAbsolutePath());
}
sb.append("\\").append(this.getDirName());
return sb.toString();
}
public void setParent(Folder parent) {
this.parent = parent;
}
public Folder getParent() {
return parent;
}
public List<Folder> getSubFolder() {
return subFolder;
}
public void addSubFolder(final Folder subFolder) {
this.subFolder.add(subFolder);
}
public void setStatus(FolderStatus status) {
this.status = status;
}
public String getKommentar() {
return kommentar;
}
public void setKommentar(String kommentar) {
this.kommentar = kommentar;
}
public Integer getLevel() {
return level;
}
public void setLevel(Integer level) {
this.level = level;
}
@Override
public String toString() {
final StringBuilder sb = new StringBuilder();
sb.append(this.getId()+"-" + dirName);
for (final Folder folder : subFolder) {
sb.append("\n ").append(folder);
}
return sb.toString();
}
@Override
public boolean equals(Object obj) {
if(this == obj) {
return true;
}
if(obj == null) {
return false;
}
if(getClass() != obj.getClass()) {
return false;
}
final Folder f = (Folder) obj;
if(this.dirName.equals(f.dirName) ) {
if(this.getParent() == null && f.getParent() == null) {
return true;
}
if(this.getParent().equals(f.getParent())) {
return true;
} else {
return false;
}
}
return super.equals(obj);
}
final public Folder getRoot() {
if(this.getParent() == null) {
return this;
}
return this.getParent().getRoot();
}
