AMBARI-11583 - Views : Persistence Data Store Example (tbeerbower)

ambari-views/examples/phone-list-view/src/main/java/org/apache/ambari/view/phonelist/PhoneListServlet.java

@@ -18,7 +18,9 @@
 
 package org.apache.ambari.view.phonelist;
 
+import org.apache.ambari.view.DataStore;
 import org.apache.ambari.view.ViewContext;
+import org.apache.ambari.view.PersistenceException;
 
 import javax.servlet.ServletConfig;
 import javax.servlet.ServletContext;
@@ -28,6 +30,8 @@ import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 import java.io.IOException;
 import java.io.PrintWriter;
+import java.util.Collection;
+import java.util.HashSet;
 import java.util.LinkedHashMap;
 import java.util.Map;
 
@@ -41,54 +45,78 @@ public class PhoneListServlet extends HttpServlet {
    */
   private ViewContext viewContext;
 
+  /**
+   * The view data store.
+   * <code>null</code> indicates that the view properties should be used instead of the data store.
+   */
+  private DataStore dataStore = null;
+
+
+  // ----- GenericServlet ----------------------------------------------------
+
   @Override
   public void init(ServletConfig config) throws ServletException {
     super.init(config);
 
     ServletContext context = config.getServletContext();
     viewContext = (ViewContext) context.getAttribute(ViewContext.CONTEXT_ATTRIBUTE);
+    dataStore = Boolean.parseBoolean(viewContext.getProperties().get("data.store.enabled")) ?
+        viewContext.getDataStore() : null;
   }
 
+
+  // ----- HttpServlet -------------------------------------------------------
+
   @Override
-  protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
+  protected void doPost(HttpServletRequest request, HttpServletResponse response)
+      throws ServletException, IOException {
     String name = request.getParameter("name");
     String phone = request.getParameter("phone");
 
-    if (name != null && name.length() > 0 && phone != null && phone.length() > 0) {
-      if (request.getParameter("add") != null) {
-        if (viewContext.getInstanceData(name) != null) {
-          throw new IllegalArgumentException("A number for " + name + " already exists.");
+    try {
+      if (name != null && name.length() > 0 && phone != null && phone.length() > 0) {
+        if (request.getParameter("add") != null) {
+          addUser(name, phone);
+        } else if (request.getParameter("update") != null) {
+          updateUser(name, phone);
+        } else if (request.getParameter("delete") != null) {
+          removeUser(name, phone);
         }
-        viewContext.putInstanceData(name, phone);
-      } else if (request.getParameter("update") != null) {
-        viewContext.putInstanceData(name, phone);
-      } else if (request.getParameter("delete") != null) {
-        viewContext.removeInstanceData(name);
       }
+      listAll(request, response);
+    } catch (Exception e) {
+      throw new ServletException(e);
     }
-    listAll(request, response);
   }
 
   @Override
-  protected void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException {
+  protected void doGet(HttpServletRequest request, HttpServletResponse response)
+      throws ServletException, IOException {
     response.setContentType("text/html");
     response.setStatus(HttpServletResponse.SC_OK);
 
     PrintWriter writer = response.getWriter();
 
+    try {
+      String name = request.getParameter("name");
+      String phone = getPhone(name);
 
-    String name = request.getParameter("name");
-    String phone = (name == null || name.length() == 0) ? null : viewContext.getInstanceData(name);
-
-    if (phone != null) {
-      editNumber(writer, name, phone);
-    } else {
-      listAll(request, response);
+      if (phone != null) {
+        editNumber(writer, name, phone, request);
+      } else {
+        listAll(request, response);
+      }
+    } catch (PersistenceException e) {
+      throw new ServletException(e);
     }
   }
 
-  private void enterNumber(PrintWriter writer) {
-    writer.println("<form name=\"input\" method=\"POST\">");
+
+  // ----- helper methods ----------------------------------------------------
+
+  // form to add new user
+  private void enterNumber(PrintWriter writer, HttpServletRequest request) {
+    writer.println("<form name=\"input\" action = \""+ request.getRequestURI() +"\" method=\"POST\">");
     writer.println("<table>");
     writer.println("<tr>");
     writer.println("<td>Name:</td><td><input type=\"text\" name=\"name\"></td><br/>");
@@ -101,8 +129,9 @@ public class PhoneListServlet extends HttpServlet {
     writer.println("</form>");
   }
 
-  private void editNumber(PrintWriter writer, String name, String phone) {
-    writer.println("<form name=\"input\" method=\"POST\">");
+  // for to update / delete existing user
+  private void editNumber(PrintWriter writer, String name, String phone, HttpServletRequest request) {
+    writer.println("<form name=\"input\" action = \""+ request.getRequestURI() +"\" method=\"POST\">");
     writer.println("<table>");
     writer.println("<tr>");
     writer.println("<td>Name:</td><td><input type=\"text\" name=\"name\" value=\"" + name + "\" readonly></td><br/>");
@@ -116,8 +145,8 @@ public class PhoneListServlet extends HttpServlet {
     writer.println("</form>");
   }
 
-  private void listAll(HttpServletRequest request, HttpServletResponse response) throws IOException {
-    String name;Map<String, String> data = new LinkedHashMap<String, String>(viewContext.getInstanceData());
+  // list all of the users
+  private void listAll(HttpServletRequest request, HttpServletResponse response) throws IOException, PersistenceException {
 
     PrintWriter writer = response.getWriter();
 
@@ -129,16 +158,80 @@ public class PhoneListServlet extends HttpServlet {
     writer.println("<td>Phone Number</td>");
     writer.println("</tr>");
 
-    for (Map.Entry<String,String> entry : data.entrySet()){
-      name = entry.getKey();
+    Collection<PhoneUser> phoneUsers = getAllUsers();
+    for (PhoneUser phoneUser : phoneUsers) {
+      String name = phoneUser.getName();
       writer.println("<tr>");
       writer.println("<td><A href=" + request.getRequestURI() + "?name=" + name + ">" + name + "</A></td>");
-      writer.println("<td>" + entry.getValue() + "</td>");
+      writer.println("<td>" + phoneUser.getPhone() + "</td>");
       writer.println("</tr>");
     }
+
     writer.println("</table><br/><hr/>");
 
-    enterNumber(writer);
+    enterNumber(writer, request);
+  }
+
+  // determine whether a user has been persisted
+  private boolean userExists(String name) throws PersistenceException {
+    return dataStore != null &&
+        dataStore.find(PhoneUser.class, name) != null || viewContext.getInstanceData(name) != null;
+  }
+
+  // persist a new user
+  private void addUser(String name, String phone) throws PersistenceException {
+    if (userExists(name)) {
+      throw new IllegalArgumentException("A number for " + name + " already exists.");
+    }
+    updateUser(name, phone);
+  }
+
+  // update an existing user
+  private void updateUser(String name, String phone) throws PersistenceException {
+    if (dataStore != null) {
+      dataStore.store(new PhoneUser(name, phone));
+    } else {
+      viewContext.putInstanceData(name, phone);
+    }
+  }
+
+  // remove an existing user
+  private void removeUser(String name, String phone) throws PersistenceException {
+    if (dataStore != null) {
+      dataStore.remove(new PhoneUser(name, phone));
+    } else {
+      viewContext.removeInstanceData(name);
+    }
+  }
+
+  // get the phone for the given name
+  private String getPhone(String name) throws PersistenceException {
+    if (name != null && name.length() > 0) {
+      if (dataStore != null) {
+        PhoneUser phoneUser = dataStore.find(PhoneUser.class, name);
+        if (phoneUser != null) {
+          return phoneUser.getPhone();
+        }
+      } else {
+        return viewContext.getInstanceData(name);
+      }
+    }
+    return null;
+  }
+
+  // get all of the phone users
+  private Collection<PhoneUser> getAllUsers() throws PersistenceException {
+    if (dataStore != null) {
+      return dataStore.findAll(PhoneUser.class, null);
+    }
+    Map<String, String> data = new LinkedHashMap<String, String>(viewContext.getInstanceData());
+    Collection<PhoneUser> users = new HashSet<PhoneUser>();
+
+    for (Map.Entry<String,String> entry : data.entrySet()) {
+      users.add(new PhoneUser(entry.getKey(), entry.getValue()));
+      entry.getKey();
+    }
+    return users;
   }
 }
 

ambari-views/examples/phone-list-view/src/main/java/org/apache/ambari/view/phonelist/PhoneUser.java

@@ -0,0 +1,88 @@
+/* 
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.ambari.view.phonelist;
+
+/**
+ *  Phone user (name/phone number) entity for the phone list view example.
+ */
+public class PhoneUser {
+
+  /**
+   * The user name.
+   */
+  private String name;
+
+  /**
+   * The phone number.
+   */
+  private String phone;
+
+  /**
+   * No-arg constructor required for JPA.
+   */
+  public PhoneUser() {
+  }
+
+  /**
+   * Construct a phone user.
+   *
+   * @param name   the user name
+   * @param phone  the phone number
+   */
+  public PhoneUser(String name, String phone) {
+    this.name  = name;
+    this.phone = phone;
+  }
+
+  /**
+   * Get the user name.
+   *
+   * @return the name
+   */
+  public String getName() {
+    return name;
+  }
+
+  /**
+   * Set the user name.
+   *
+   * @param name  the name
+   */
+  public void setName(String name) {
+    this.name = name;
+  }
+
+  /**
+   * Get the phone number.
+   *
+   * @return the phone number
+   */
+  public String getPhone() {
+    return phone;
+  }
+
+  /**
+   * Set the phone number.
+   *
+   * @param phone  the phone number
+   */
+  public void setPhone(String phone) {
+    this.phone = phone;
+  }
+}

ambari-views/examples/phone-list-view/src/main/resources/view.xml

@@ -18,10 +18,33 @@ limitations under the License. Kerberos, LDAP, Custom. Binary/Htt
   <name>PHONE_LIST</name>
   <label>The Phone List View</label>
   <version>1.0.0</version>
+  <parameter>
+    <name>data.store.enabled</name>
+    <description>
+      Determine whether or not to use the view persistence data store.
+      A value of false indicates that the view properties should be used instead of the data store.
+    </description>
+    <default-value>false</default-value>
+    <required>false</required>
+  </parameter>
+  <persistence>
+    <entity>
+      <class>org.apache.ambari.view.phonelist.PhoneUser</class>
+      <id-property>name</id-property>
+    </entity>
+  </persistence>
   <instance>
     <name>LIST_1</name>
+    <property>
+      <key>data.store.enabled</key>
+      <value>false</value>
+    </property>
   </instance>
   <instance>
     <name>LIST_2</name>
+    <property>
+      <key>data.store.enabled</key>
+      <value>true</value>
+    </property>
   </instance>
 </view>