How to use

zkCreate

method

in

org.apache.hadoop.registry.client.impl.zk.CuratorService

/**
 * Create or update an entry.
 *
 * @param path      path
 * @param data      data
 * @param acl       ACL for path -used when creating a new entry
 * @param overwrite enable overwrite
 * @return true if the entry was created, false if it was simply updated.
 * @throws IOException
 */
public boolean zkSet(String path,
  CreateMode mode,
  byte[] data,
  List<ACL> acl, boolean overwrite) throws IOException {
 Preconditions.checkArgument(data != null, "null data");
 checkServiceLive();
 if (!zkPathExists(path)) {
  zkCreate(path, mode, data, acl);
  return true;
 } else {
  if (overwrite) {
   zkUpdate(path, data);
   return false;
  } else {
   throw new FileAlreadyExistsException(path);
  }
 }
}

@Test
public void testCreateTwice() throws Throwable {
 byte[] buffer = getTestBuffer();
 curatorService.zkCreate("/testcreatetwice",
   CreateMode.PERSISTENT, buffer,
   rootACL);
 try {
  curatorService.zkCreate("/testcreatetwice",
    CreateMode.PERSISTENT, buffer,
    rootACL);
  fail();
 } catch (FileAlreadyExistsException e) {
 }
}

@Test
public void testCreateTwice() throws Throwable {
 byte[] buffer = getTestBuffer();
 curatorService.zkCreate("/testcreatetwice",
   CreateMode.PERSISTENT, buffer,
   rootACL);
 try {
  curatorService.zkCreate("/testcreatetwice",
    CreateMode.PERSISTENT, buffer,
    rootACL);
  fail();
 } catch (FileAlreadyExistsException e) {
 }
}

/**
 * Create or update an entry
 * @param path path
 * @param data data
 * @param acl ACL for path -used when creating a new entry
 * @param overwrite enable overwrite
 * @throws IOException
 * @return true if the entry was created, false if it was simply updated.
 */
public boolean zkSet(String path,
  CreateMode mode,
  byte[] data,
  List<ACL> acl, boolean overwrite) throws IOException {
 Preconditions.checkArgument(data != null, "null data");
 checkServiceLive();
 if (!zkPathExists(path)) {
  zkCreate(path, mode, data, acl);
  return true;
 } else {
  if (overwrite) {
   zkUpdate(path, data);
   return false;
  } else {
   throw new FileAlreadyExistsException(path);
  }
 }
}

@Test
public void testCreate() throws Throwable {
 curatorService.zkCreate("/testcreate",
   CreateMode.PERSISTENT, getTestBuffer(),
   rootACL
 );
 pathMustExist("/testcreate");
}

@Test
public void testCreateUpdate() throws Throwable {
 byte[] buffer = getTestBuffer();
 curatorService.zkCreate("/testcreateupdate",
   CreateMode.PERSISTENT, buffer,
   rootACL
 );
 curatorService.zkUpdate("/testcreateupdate", buffer);
}

@Test
public void testCreate() throws Throwable {
 curatorService.zkCreate("/testcreate",
   CreateMode.PERSISTENT, getTestBuffer(),
   rootACL
 );
 pathMustExist("/testcreate");
}

@Test
public void testCreateUpdate() throws Throwable {
 byte[] buffer = getTestBuffer();
 curatorService.zkCreate("/testcreateupdate",
   CreateMode.PERSISTENT, buffer,
   rootACL
 );
 curatorService.zkUpdate("/testcreateupdate", buffer);
}