[ch05] 5.6, Used the data of ServletContext.

Signed-off-by: Dongho Sim <dhsim86@gmail.com>
dhsim86 · Mar 11, 2017 · 7e0cbaf · 7e0cbaf
1 parent 75a5632
commit 7e0cbaf
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Showing 7 changed files with 68 additions and 38 deletions.
diff --git a/src/main/java/AppInitServlet.java b/src/main/java/AppInitServlet.java
@@ -0,0 +1,52 @@
+import javax.servlet.ServletConfig;
+import javax.servlet.ServletContext;
+import javax.servlet.ServletException;
+import javax.servlet.http.HttpServlet;
+import java.sql.Connection;
+import java.sql.DriverManager;
+
+/**
+ * Created by Dongho on 2017. 3. 11..
+ */
+public class AppInitServlet extends HttpServlet {
+
+    @Override
+    public void init(ServletConfig servletConfig) throws ServletException {
+        System.out.println("AppInitServlet.init called");
+        super.init(servletConfig);
+
+        try {
+            ServletContext sc = this.getServletContext();
+            Class.forName(sc.getInitParameter("driver"));
+
+            Connection conn = DriverManager.getConnection(
+                sc.getInitParameter("url"),
+                sc.getInitParameter("username"),
+                sc.getInitParameter("password")
+            );
+
+            sc.setAttribute("conn", conn);
+        }
+        catch (Exception e) {
+            throw new ServletException(e);
+        }
+    }
+
+    @Override
+    public void destroy() {
+        System.out.println("AppInitServlet.destroy called");
+        super.destroy();
+
+        Connection conn =
+            (Connection)this.getServletContext().getAttribute("conn");
+
+        try {
+            if (conn != null && conn.isClosed() == false) {
+                conn.close();
+            }
+        }
+        catch (Exception e) {
+
+        }
+    }
+}
diff --git a/src/main/java/Lesson04/MemberAddServlet.java b/src/main/java/Lesson04/MemberAddServlet.java
@@ -48,12 +48,7 @@ protected void doPost(HttpServletRequest request, HttpServletResponse response)
         try {
             ServletContext sc = this.getServletContext();
 
-            Class.forName(sc.getInitParameter("driver"));
-            conn = DriverManager.getConnection(
-                sc.getInitParameter("url"),
-                sc.getInitParameter("username"),
-                sc.getInitParameter("password")
-            );
+            conn = (Connection) sc.getAttribute("conn");
 
             stmt = conn.prepareStatement(
                 "insert into members(email, pwd, mname, cre_date, mod_date)" +
@@ -81,7 +76,6 @@ protected void doPost(HttpServletRequest request, HttpServletResponse response)
         }
         finally {
             try { if (stmt != null) stmt.close(); } catch (Exception e) {}
-            try { if (conn != null) conn.close(); } catch (Exception e) {}
         }
     }
 }
diff --git a/src/main/java/Lesson04/MemberDeleteServlet.java b/src/main/java/Lesson04/MemberDeleteServlet.java
@@ -28,13 +28,7 @@ protected void doGet(HttpServletRequest request, HttpServletResponse response)
 
             ServletContext sc = this.getServletContext();
 
-            Class.forName(sc.getInitParameter("driver"));
-
-            conn = DriverManager.getConnection(
-                sc.getInitParameter("url"),
-                sc.getInitParameter("username"),
-                sc.getInitParameter("password")
-            );
+            conn = (Connection) sc.getAttribute("conn");
             stmt = conn.prepareStatement(
                 "delete from members" +
                 " where mno = ?"
@@ -49,7 +43,6 @@ protected void doGet(HttpServletRequest request, HttpServletResponse response)
         }
         finally {
             try { if (stmt != null) stmt.close(); } catch (Exception e) {}
-            try { if (conn != null) conn.close(); } catch (Exception e) {}
         }
     }
 }
diff --git a/src/main/java/Lesson04/MemberListServlet.java b/src/main/java/Lesson04/MemberListServlet.java
@@ -30,13 +30,7 @@ protected void doGet(HttpServletRequest request, HttpServletResponse response)
 
             ServletContext sc = this.getServletContext();
 
-            Class.forName(sc.getInitParameter("driver"));
-
-            conn = DriverManager.getConnection(
-                sc.getInitParameter("url"),
-                sc.getInitParameter("username"),
-                sc.getInitParameter("password")
-            );
+            conn = (Connection) sc.getAttribute("conn");
             stmt = conn.createStatement();
             rs = stmt.executeQuery(
                     "select mno, mname, email, cre_date" +
@@ -71,7 +65,6 @@ protected void doGet(HttpServletRequest request, HttpServletResponse response)
         finally {
             try { if (rs != null) rs.close(); } catch (Exception e) {}
             try { if (stmt != null) stmt.close(); } catch (Exception e) {}
-            try { if (conn != null) conn.close(); } catch (Exception e) {}
         }
     }
 }
diff --git a/src/main/java/Lesson04/MemberUpdateServlet.java b/src/main/java/Lesson04/MemberUpdateServlet.java
@@ -84,12 +84,7 @@ protected void doPost(
         try {
             ServletContext sc = this.getServletContext();
 
-            Class.forName(sc.getInitParameter("driver"));
-            conn = DriverManager.getConnection(
-                sc.getInitParameter("url"),
-                sc.getInitParameter("username"),
-                sc.getInitParameter("password")
-            );
+            conn = (Connection) sc.getAttribute("conn");
             stmt = conn.prepareStatement(
                 "update members set email = ?, mname = ?, mod_date = now()" +
                 " where mno = ?"
@@ -106,7 +101,6 @@ protected void doPost(
         }
         finally {
             try { if (stmt != null) stmt.close(); } catch (Exception e) {}
-            try { if (conn != null) conn.close(); } catch (Exception e) {}
         }
     }
 }
diff --git a/src/main/java/Lesson05/MemberListServlet.java b/src/main/java/Lesson05/MemberListServlet.java
@@ -34,13 +34,7 @@ protected void doGet(HttpServletRequest request, HttpServletResponse response)
 
             ServletContext sc = this.getServletContext();
 
-            Class.forName(sc.getInitParameter("driver"));
-
-            conn = DriverManager.getConnection(
-                sc.getInitParameter("url"),
-                sc.getInitParameter("username"),
-                sc.getInitParameter("password")
-            );
+            conn = (Connection) sc.getAttribute("conn");
             stmt = conn.createStatement();
             rs = stmt.executeQuery(
                     "select mno, mname, email, cre_date" +
@@ -78,7 +72,6 @@ protected void doGet(HttpServletRequest request, HttpServletResponse response)
         finally {
             try { if (rs != null) rs.close(); } catch (Exception e) {}
             try { if (stmt != null) stmt.close(); } catch (Exception e) {}
-            try { if (conn != null) conn.close(); } catch (Exception e) {}
         }
     }
 }
diff --git a/src/main/webapp/WEB-INF/web.xml b/src/main/webapp/WEB-INF/web.xml
@@ -41,6 +41,12 @@
     </filter-mapping>
 
     <!-- servlets -->
+    <servlet>
+        <servlet-name>AppInitServlet</servlet-name>
+        <servlet-class>AppInitServlet</servlet-class>
+        <load-on-startup>1</load-on-startup>
+    </servlet>
+
     <servlet>
       <servlet-name>Hello</servlet-name>
       <servlet-class>Lesson03.servlets.HelloWorld</servlet-class>
@@ -74,6 +80,11 @@
     </servlet> -->
 
     <!-- servlet mappings -->
+    <servlet-mapping>
+        <servlet-name>AppInitServlet</servlet-name>
+        <url-pattern>/AppInit</url-pattern>
+    </servlet-mapping>
+
     <servlet-mapping>
       <servlet-name>Hello</servlet-name>
       <url-pattern>/Hello</url-pattern>