JAVA-5735: Appending a new File to a ZIP file (#13044)

core-java-modules/core-java-io/src/main/java/com/baeldung/zip/ZipAppendFile.java

@@ -0,0 +1,29 @@
+package com.baeldung.zip;
+
+import java.io.*;
+import java.net.URI;
+import java.net.URL;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.*;
+import java.util.*;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+import java.util.zip.ZipEntry;
+import java.util.zip.ZipOutputStream;
+
+import static java.util.stream.Collectors.toList;
+
+public class ZipAppendFile {
+    public static void main(final String[] args) throws IOException {
+        ZipMultipleFiles.main(args);
+        String file3 = ZipAppendFile.class.getClassLoader().getResource("zipTest/file3.txt").getPath();
+        Map<String, String> env = new HashMap<>();
+        env.put("create", "true");
+        Path path = Paths.get(Paths.get(file3).getParent() + "/compressed.zip");
+        URI uri = URI.create("jar:" + path.toUri());
+        try (FileSystem fs = FileSystems.newFileSystem(uri, env)) {
+            Path nf = fs.getPath("newFile3.txt");
+            Files.write(nf, Files.readAllBytes(Paths.get(file3)), StandardOpenOption.CREATE);
+        }
+    }
+}

core-java-modules/core-java-io/src/main/java/com/baeldung/zip/ZipMultipleFiles.java

@@ -4,6 +4,7 @@ import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileOutputStream;
 import java.io.IOException;
+import java.nio.file.Paths;
 import java.util.Arrays;
 import java.util.List;
 import java.util.zip.ZipEntry;
@@ -11,8 +12,11 @@ import java.util.zip.ZipOutputStream;
 
 public class ZipMultipleFiles {
     public static void main(final String[] args) throws IOException {
-        final List<String> srcFiles = Arrays.asList("src/main/resources/zipTest/test1.txt", "src/main/resources/zipTest/test2.txt");
+        String file1 = ZipAppendFile.class.getClassLoader().getResource("zipTest/test1.txt").getPath();
-        final FileOutputStream fos = new FileOutputStream("src/main/resources/multiCompressed.zip");
+        String file2 = ZipAppendFile.class.getClassLoader().getResource("zipTest/test2.txt").getPath();
+        final List<String> srcFiles = Arrays.asList(file1, file2);
+        final FileOutputStream fos =
+                new FileOutputStream(Paths.get(file1).getParent().toAbsolutePath() + "/compressed.zip");
         final ZipOutputStream zipOut = new ZipOutputStream(fos);
         for (final String srcFile : srcFiles) {
             final File fileToZip = new File(srcFile);

core-java-modules/core-java-io/src/main/resources/zipTest/file3.txt

@@ -0,0 +1 @@
+Test3.txt