Refactor: Streamline CityGmlZipEntry filesize calculation

CityDoctorParent/CityDoctorModel/src/main/java/de/hft/stuttgart/citydoctor2/zip/CityGmlZipEntry.java

@@ -68,25 +68,26 @@ public class CityGmlZipEntry implements Serializable {
 
     private boolean entrySizeWithinMemoryLimits() throws IOException {
         long memoryLimit = (long) Math.ceil(((double) Runtime.getRuntime().maxMemory() / MB)*0.9);
-        if (fileSize != -1L) {
-            return memoryLimit > fileSize;
-        }
-        try (CityGmlZipEntryFile entryFile = new CityGmlZipEntryFile(this)){
-            long filesize = entryFile.getFileSize();
-            if (filesize != -1){
-                this.fileSize = filesize;
-                return memoryLimit > fileSize;
-            } else {
-                return false;
+        if (fileSize == -1L) {
+            try (CityGmlZipEntryFile entryFile = new CityGmlZipEntryFile(this)){
+                long filesize = entryFile.getFileSize();
+                if (filesize != -1){
+                    this.fileSize = filesize;
+                } else {
+                    return false;
+                }
+            } catch (Exception e) {
+                throw new IOException(e);
             }
-        } catch (Exception e) {
-            throw new IOException(e);
         }
-
+        return memoryLimit > fileSize;
     }
 
     protected CityGmlZipEntry(ZipEntry entry,CityGmlZipArchive parentArchive, boolean decompressed) {
         this.fileName = entry.getName();
+        if (entry.getSize() != -1){
+            this.fileSize = entry.getSize();
+        }
         this.model = null;
         this.decompressed = decompressed;
         this.parentArchive = parentArchive;
@@ -113,12 +114,11 @@ public class CityGmlZipEntry implements Serializable {
         return model;
     }
 
-    public long getFileSize() throws IOException {
-        if (fileSize == -1L){
-            try(CityGmlZipInputStream cgis = new CityGmlZipInputStream(this)){
-                fileSize = cgis.getFileSize();
-            }
-        }
+    public void setFileSize(long size) {
+        fileSize = size;
+    }
+
+    public long getFileSize(){
         return fileSize;
     }
 }

CityDoctorParent/CityDoctorModel/src/main/java/de/hft/stuttgart/citydoctor2/zip/CityGmlZipEntryFile.java

 package de.hft.stuttgart.citydoctor2.zip;
 
-import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.zip.ZipEntry;
@@ -10,6 +9,7 @@ public class CityGmlZipEntryFile implements AutoCloseable {
 
     private final ZipFile zip;
     private final ZipEntry zipEntry;
+    private final CityGmlZipEntry cgmlZipEntry;
     private boolean closed = false;
     private static final long MB = 1024 * 1024L;
 
@@ -17,6 +17,7 @@ public class CityGmlZipEntryFile implements AutoCloseable {
         CityGmlZipArchive archive = entry.getArchive();
         zip = new ZipFile(archive.getArchivePath().toFile());
         zipEntry = zip.getEntry(entry.getFileName());
+        this.cgmlZipEntry = entry;
     }
 
     public InputStream getInputStream() throws IOException {
@@ -30,15 +31,19 @@ public class CityGmlZipEntryFile implements AutoCloseable {
         if (closed){
             throw new IOException("Stream closed");
         }
-        if (zipEntry.getSize() != -1){
-            return (long) Math.ceil((double) zipEntry.getSize() / MB);
+        if (cgmlZipEntry.getFileSize() == -1L) {
+            if (zipEntry.getSize() == -1) {
+                long bytes = 0;
+                InputStream is = this.getInputStream();
+                for (int i = is.read(); i != -1; i = is.read()) {
+                    bytes++;
+                }
+                cgmlZipEntry.setFileSize((long) Math.ceil((double) bytes / MB));
+            } else {
+                cgmlZipEntry.setFileSize((long) Math.ceil((double) zipEntry.getSize() / MB));
+            }
         }
-        long bytes = 0;
-        InputStream is = this.getInputStream();
-        for(int i = is.read(); i != -1; i=is.read()) {
-            bytes++;
-        }
-        return (long) Math.ceil((double) bytes / MB);
+        return cgmlZipEntry.getFileSize();
     }
 
     @Override