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Refactor Datastore example, add example on embedded entities
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‎gcloud-java-examples/README.md‎

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@@ -81,6 +81,7 @@ To run examples from your command line:
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mvn exec:java -Dexec.mainClass="com.google.cloud.examples.datastore.DatastoreExample" -Dexec.args="your-project-id my_name add my\ comment"
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mvn exec:java -Dexec.mainClass="com.google.cloud.examples.datastore.DatastoreExample" -Dexec.args="your-project-id my_name display"
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mvn exec:java -Dexec.mainClass="com.google.cloud.examples.datastore.DatastoreExample" -Dexec.args="your-project-id my_name delete"
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mvn exec:java -Dexec.mainClass="com.google.cloud.examples.datastore.DatastoreExample" -Dexec.args="your-project-id my_name set myname@mydomain.com 1234"
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```
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* Here's an example run of `DnsExample`.

‎gcloud-java-examples/src/main/java/com/google/cloud/examples/datastore/DatastoreExample.java‎

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@@ -38,15 +38,23 @@
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/**
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* An example of using Google Cloud Datastore.
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*
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* <p>This example adds, display or clear comments for a given user.
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* <p>This example adds, displays or clears comments for a given user. This example also sets
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* contact information for a user.
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*
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* <p>Steps needed for running the example:<ol>
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* <li>login using gcloud SDK - {@code gcloud auth login}.</li>
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* <li>compile using maven - {@code mvn compile}</li>
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* <li>run using maven - {@code mvn exec:java
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* -Dexec.mainClass="com.google.cloud.examples.datastore.DatastoreExample"
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* -Dexec.args="[projectId] [user] [delete|display|add comment]"}</li>
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* * <li>run using maven -
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* <pre>{@code mvn exec:java -Dexec.mainClass="com.google.cloud.examples.datastore.DatastoreExample"
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* -Dexec.args="<project_id> <user>
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* delete |
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* display |
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* add <comment> |
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* set <email> <phone>}</pre>
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* </li>
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* </ol>
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*
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* <p>If no action is provided {@code display} is executed.
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*/
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public class DatastoreExample {
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@@ -56,15 +64,24 @@ public class DatastoreExample {
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private static final String DEFAULT_ACTION = "display";
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private static final Map<String, DatastoreAction> ACTIONS = new HashMap<>();
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59-
private interface DatastoreAction {
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void run(Transaction tx, Key userKey, String... args);
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private abstract static class DatastoreAction<T> {
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abstract void run(Transaction tx, Key userKey, T request) throws Exception;
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String getRequiredParams();
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abstract T parse(String... args) throws Exception;
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protected String params() {
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return "";
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}
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}
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private static class DeleteAction implements DatastoreAction {
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/**
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* This class demonstrates how to delete a user. This action also queries the keys of all comments
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* associated with the user and uses them to delete comments.
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*/
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private static class DeleteAction extends DatastoreAction<Void> {
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@Override
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public void run(Transaction tx, Key userKey, String... args) {
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public void run(Transaction tx, Key userKey, Void request) {
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Entity user = tx.get(userKey);
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if (user == null) {
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System.out.println("Nothing to delete, user does not exist.");
@@ -86,19 +103,29 @@ public void run(Transaction tx, Key userKey, String... args) {
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}
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@Override
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public String getRequiredParams() {
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return "";
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Void parse(String... args) throws Exception {
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return null;
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}
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}
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94-
private static class DisplayAction implements DatastoreAction {
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/**
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* This class demonstrates how to get a user. The action also queries all comments associated
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* with a user.
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*/
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private static class DisplayAction extends DatastoreAction<Void> {
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@Override
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public void run(Transaction tx, Key userKey, String... args) {
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public void run(Transaction tx, Key userKey, Void request) {
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Entity user = tx.get(userKey);
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if (user == null) {
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System.out.println("No comments for '" + userKey.name() + "'.");
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System.out.println("User '" + userKey.name() + "' does not exist.");
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return;
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}
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if (user.contains("contact")) {
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FullEntity<IncompleteKey> contact = user.getEntity("contact");
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String email = contact.getString("email");
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String phone = contact.getString("phone");
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System.out.printf("User '%s' email is '%s', phone is '%s'%n", userKey.name(), email, phone);
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}
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System.out.printf("User '%s' has %d comment[s].%n", userKey.name(), user.getLong("count"));
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int limit = 200;
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Map<DateTime, String> sortedComments = new TreeMap<>();
@@ -131,25 +158,37 @@ public void run(Transaction tx, Key userKey, String... args) {
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}
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@Override
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public String getRequiredParams() {
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return "";
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Void parse(String... args) throws Exception {
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return null;
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}
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}
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139-
private static class AddAction implements DatastoreAction {
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/**
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* This class adds a comment for a user. If the user does not exist its entity is created.
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*/
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private static class AddCommentAction extends DatastoreAction<String> {
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@Override
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public void run(Transaction tx, Key userKey, String... args) {
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public void run(Transaction tx, Key userKey, String content) {
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Entity user = tx.get(userKey);
143173
if (user == null) {
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System.out.println("Adding a new user.");
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user = Entity.builder(userKey)
146-
.set("count", 1L)
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.build();
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user = Entity.builder(userKey).set("count", 1L).build();
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tx.add(user);
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} else {
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user = Entity.builder(user).set("count", user.getLong("count") + 1L).build();
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tx.update(user);
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}
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IncompleteKey commentKey = IncompleteKey.builder(userKey, COMMENT_KIND).build();
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FullEntity<IncompleteKey> comment = FullEntity.builder(commentKey)
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.set("content", content)
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.set("timestamp", DateTime.now())
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.build();
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tx.addWithDeferredIdAllocation(comment);
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System.out.println("Adding a comment to user '" + userKey.name() + "'.");
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}
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@Override
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String parse(String... args) throws Exception {
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String content = "No comment.";
154193
if (args.length > 0) {
155194
StringBuilder stBuilder = new StringBuilder();
@@ -159,28 +198,98 @@ public void run(Transaction tx, Key userKey, String... args) {
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stBuilder.setLength(stBuilder.length() - 1);
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content = stBuilder.toString();
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}
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IncompleteKey commentKey = IncompleteKey.builder(userKey, COMMENT_KIND).build();
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FullEntity<IncompleteKey> comment = FullEntity.builder(commentKey)
164-
.set("content", content)
165-
.set("timestamp", DateTime.now())
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return content;
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}
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@Override
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protected String params() {
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return "<comment>";
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}
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}
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/**
211+
* This class sets contact information (email and phone) for a user. If the user does not exist
212+
* its entity is created. Contact information is saved as an entity embedded in the user entity.
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*/
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private static class SetContactAction extends DatastoreAction<SetContactAction.Contact> {
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static final class Contact {
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218+
private final String email;
219+
private final String phone;
220+
221+
Contact(String email, String phone) {
222+
this.email = email;
223+
this.phone = phone;
224+
}
225+
226+
String email() {
227+
return email;
228+
}
229+
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String phone() {
231+
return phone;
232+
}
233+
}
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@Override
236+
public void run(Transaction tx, Key userKey, Contact contact) {
237+
Entity user = tx.get(userKey);
238+
if (user == null) {
239+
System.out.println("Adding a new user.");
240+
user = Entity.builder(userKey).set("count", 0L).build();
241+
tx.add(user);
242+
}
243+
FullEntity<IncompleteKey> contactEntity = FullEntity.builder()
244+
.set("email", contact.email())
245+
.set("phone", contact.phone())
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.build();
167-
tx.addWithDeferredIdAllocation(comment);
168-
System.out.println("Adding a comment to user '" + userKey.name() + "'.");
247+
tx.update(Entity.builder(user).set("contact", contactEntity).build());
248+
System.out.println("Setting contact for user '" + userKey.name() + "'.");
169249
}
170250

171251
@Override
172-
public String getRequiredParams() {
173-
return "comment";
252+
Contact parse(String... args) throws Exception {
253+
String message;
254+
if (args.length == 2) {
255+
return new Contact(args[0], args[1]);
256+
} else if (args.length > 2) {
257+
message = "Too many arguments.";
258+
} else {
259+
message = "Missing required email and phone.";
260+
}
261+
throw new IllegalArgumentException(message);
262+
}
263+
264+
@Override
265+
protected String params() {
266+
return "<email> <phone>";
174267
}
175268
}
176269

177270
static {
178271
ACTIONS.put("delete", new DeleteAction());
179-
ACTIONS.put("add", new AddAction());
272+
ACTIONS.put("add", new AddCommentAction());
273+
ACTIONS.put("set", new SetContactAction());
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ACTIONS.put("display", new DisplayAction());
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}
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183-
public static void main(String... args) {
277+
private static void printUsage() {
278+
StringBuilder actionAndParams = new StringBuilder();
279+
for (Map.Entry<String, DatastoreAction> entry : ACTIONS.entrySet()) {
280+
actionAndParams.append("\n\t").append(entry.getKey());
281+
282+
String param = entry.getValue().params();
283+
if (param != null && !param.isEmpty()) {
284+
actionAndParams.append(' ').append(param.replace("\n", "\n\t\t"));
285+
}
286+
}
287+
System.out.printf("Usage: %s <project_id> <user> operation <args>*%s%n",
288+
DatastoreExample.class.getSimpleName(), actionAndParams);
289+
}
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291+
@SuppressWarnings("unchecked")
292+
public static void main(String... args) throws Exception {
184293
String projectId = args.length > 0 ? args[0] : null;
185294
// If you want to access a local Datastore running via the Google Cloud SDK, do
186295
// DatastoreOptions options = DatastoreOptions.builder()
@@ -197,24 +306,26 @@ public static void main(String... args) {
197306
String actionName = args.length > 2 ? args[2].toLowerCase() : DEFAULT_ACTION;
198307
DatastoreAction action = ACTIONS.get(actionName);
199308
if (action == null) {
200-
StringBuilder actionAndParams = new StringBuilder();
201-
for (Map.Entry<String, DatastoreAction> entry : ACTIONS.entrySet()) {
202-
actionAndParams.append(entry.getKey());
203-
String param = entry.getValue().getRequiredParams();
204-
if (param != null && !param.isEmpty()) {
205-
actionAndParams.append(' ').append(param);
206-
}
207-
actionAndParams.append('|');
208-
}
209-
actionAndParams.setLength(actionAndParams.length() - 1);
210-
System.out.printf("Usage: %s [projectId] [user] [%s]%n",
211-
DatastoreExample.class.getSimpleName(), actionAndParams);
309+
System.out.println("Unrecognized action.");
310+
printUsage();
212311
return;
213312
}
214313
args = args.length > 3 ? Arrays.copyOfRange(args, 3, args.length) : new String []{};
215314
Transaction tx = datastore.newTransaction();
315+
Object request;
316+
try {
317+
request = action.parse(args);
318+
} catch (IllegalArgumentException ex) {
319+
System.out.println("Invalid input for action '" + actionName + "'. " + ex.getMessage());
320+
System.out.println("Expected: " + action.params());
321+
return;
322+
} catch (Exception ex) {
323+
System.out.println("Failed to parse request.");
324+
ex.printStackTrace();
325+
return;
326+
}
216327
try {
217-
action.run(tx, key, args);
328+
action.run(tx, key, request);
218329
tx.commit();
219330
} finally {
220331
if (tx.active()) {

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