[ch04] exercise, added MemberDeleteServlet class.

Signed-off-by: Dongho Sim <dhsim86@gmail.com>

src/main/java/Lesson04/MemberDeleteServlet.java

@@ -0,0 +1,57 @@
+package Lesson04;
+
+import javax.servlet.ServletContext;
+import javax.servlet.ServletException;
+import javax.servlet.annotation.WebServlet;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import java.io.IOException;
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.PreparedStatement;
+import java.sql.Statement;
+
+/**
+ * Created by Dongho on 2017. 3. 7..
+ */
+@WebServlet("/member/delete")
+public class MemberDeleteServlet extends HttpServlet {
+
+    @Override
+    protected void doGet(HttpServletRequest request, HttpServletResponse response)
+        throws ServletException, IOException {
+
+        Connection conn = null;
+        PreparedStatement stmt = null;
+
+        try {
+
+            ServletContext sc = this.getServletContext();
+
+            Class.forName(sc.getInitParameter("driver"));
+
+            conn = DriverManager.getConnection(
+                sc.getInitParameter("url"),
+                sc.getInitParameter("username"),
+                sc.getInitParameter("password")
+            );
+            stmt = conn.prepareStatement(
+                "delete from members" +
+                " where mno = ?"
+            );
+            stmt.setInt(1, Integer.parseInt(request.getParameter("no")));
+
+            stmt.executeUpdate();
+
+            response.sendRedirect("list");
+        }
+        catch (Exception e) {
+            throw new ServletException(e);
+        }
+        finally {
+            try { if (stmt != null) stmt.close(); } catch (Exception e) {}
+            try { if (conn != null) conn.close(); } catch (Exception e) {}
+        }
+    }
+}

src/main/java/Lesson04/MemberListServlet.java

@@ -54,7 +54,9 @@ public void service(ServletRequest request, ServletResponse response)
                         "<a href='update?no=" + rs.getInt("mno") + "'>" +
                         rs.getString("mname") + "</a>, " +
                         rs.getString("email") + ", " +
-                        rs.getDate("cre_date") + "<br>"
+                        rs.getDate("cre_date") +
+                        "<a href='delete?no=" + rs.getInt("mno") + "'>" +
+                        "[delete]" + "</a>" + "<br>"
                 );
             }
             out.println("</body></html>");

src/main/java/Lesson04/MemberUpdateServlet.java

@@ -56,6 +56,8 @@ public void doGet(
                         rs.getString("email") + "'><br>");
             out.println("registered date: " + rs.getDate("cre_date") + "<br>");
             out.println("<input type='submit' value='save'>");
+            out.println("<input type='button' value='delete'" +
+                        " onclick='location.href=\"delete?no=" + request.getParameter("no") + "\"'>");
             out.println("<input type='button' value='cancel'" +
                         " onclick='location.href=\"list\"'>");
             out.println("</form>");