Android——“i 分享”APP開發Day08

主頁上4個Tab的功能基本就已經完善了，接下來準備實現跳轉詳情頁的功能。在此之前，明確一下詳情頁將會實現的功能，優先處理後臺代碼

根據內容ID查找到與內容相關的所有信息——內容簡述、內容詳情、內容作者、點贊數、內容類型
點贊——點擊後，點贊數加一
用戶是否已經收藏該內容——通過傳過來的用戶暱稱和文章內容ID判斷用戶是否已經收藏該內容
取消收藏——從收藏表中將對應的收藏行刪除
添加到我的收藏——將用戶和內容信息插入到收藏表中
評論功能——用戶可以評論
刪除內容——當作者就是用戶時，可以刪除內容，且在刪除文章時對應刪除收藏表的對應行以及評論表對應的內容

1.明確上述幾個後臺處理邏輯之後，首先要在數據庫ishare中新建一張收藏表——focus，還有1張評論表——comment

和之前的用戶表、內容表一樣，在數據庫ishare中新建一張表，命名爲focus具體的表結構如下：
focus_id爲int類型，自增；username對應收藏的用戶；info_id對應收藏的內容

在ishare中新建一張表，命名爲comment，具體表結構設計如下：
comment_id是int類型，自增；comment_user是評論者；comment_info是評論文章的id;comment_detail是評論的具體內容

2. 建好表之後就開始處理通過Id查找內容的servlet文件QueryInfoById.java

和之前新建servlet一樣，在myServlet.data包下新建servlet命名爲QueryInfoById
在web.xml中添加配置：

<servlet>
<servlet-name>QueryInfoById</servlet-name>
<servlet-class>myServlet.data.QueryInfoById</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>QueryInfoById</servlet-name>
<url-pattern>/servlet/QueryInfoById</url-pattern>
</servlet-mapping>

具體實現也是和之前查詢類似，將數據庫返回的內容封裝成JsonArray返回，具體代碼如下

package myServlet.data;

import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

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 org.utils.JdbcUtils;
import org.utils.JsonUtils;

import com.sun.rowset.CachedRowSetImpl;

import net.sf.json.JSONArray;

/**
 * Servlet implementation class QueryInfoById
 */
@WebServlet("/QueryInfoById")
public class QueryInfoById extends HttpServlet {
	private static final long serialVersionUID = 1L;
	CachedRowSetImpl rowSet = null;    //存儲表中全部記錄的行集對象
	int pageSize=10; //每頁加載數量
    int pageNum=1;   //第幾頁
    int totalRecord;  //總記錄數
    
    /**
     * @see HttpServlet#HttpServlet()
     */
    public QueryInfoById() {
        super();
        // TODO Auto-generated constructor stub
    }

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		// TODO Auto-generated method stub
		response.setContentType("text/html;charset=utf-8");
        request.setCharacterEncoding("utf-8");
        response.setCharacterEncoding("utf-8");
        PrintWriter out = response.getWriter();
        String infoId = request.getParameter("infoId");	
        
        if(infoId == null||infoId.length()==0) {
			return;
		}
	
        String condition ="select * from info where info_id="+infoId;   //按id查找
    
	
		Connection connection = null;
		Statement sql = null;
		ResultSet rs = null;

		try {
			connection = JdbcUtils.getConnection();
			sql = connection.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE, ResultSet.CONCUR_READ_ONLY);
			rs = sql.executeQuery(condition);
			
			
			rowSet = new CachedRowSetImpl();  //創建行集對象
			rowSet.populate(rs);
			
			response.setContentType("text/html;charset=utf-8");
			response.setCharacterEncoding("utf-8");
			JSONArray jsonArray = new JSONArray();//存放返回的jsonOjbect數組
			
			//將rowSet的數據提取到Map
			List<Map<String,Object>> data = new ArrayList<Map<String,Object>>();
			try {
				rowSet.last();    //移到隨後一行
	    		totalRecord = rowSet.getRow();
	    		
	    		int index = (pageNum-1)*pageSize+1;
    			rowSet.absolute(index);   //查詢位置移動到查詢頁的起始記錄位置
    			boolean boo = true;
    			
    			for(int i=1; i<=totalRecord&&boo;i++){	
    				int id = rowSet.getInt(1);    //內容ID	    				
    				String infoTitle = rowSet.getString(2);   //內容標題    				
    				String infoDescribe = rowSet.getString(3);   //內容簡述
    				String infoDetail = rowSet.getString("info_detail");   //內容詳情
    				
    				String type = rowSet.getString(5);    //類型：0表示日記，1表示趣事
    				String support = rowSet.getString(6);   //點贊數
    				String infoAuthor = rowSet.getString(7);  //作者     
    				
    				Map<String,Object> map = new HashMap<String,Object>();
    				map.put("infoId", id);
    				map.put("infoTitle", infoTitle);
    				map.put("infoDescribe", infoDescribe);
    				map.put("infoDetail", infoDetail);
    				map.put("infoType", type);
    				map.put("infoSupport", support);
    				map.put("infoAuthor", infoAuthor);
    				
    				data.add(map);
					boo = rowSet.next();
    			}
    			jsonArray = JsonUtils.formatRsToJsonArray(data);
    			
    			out.println(jsonArray.toString());  //返回json
    			
			}catch(Exception e) {
				out.println("null"); 
			}
		} catch (Exception e) {	
			out.println(condition+"異常："+e.toString());
			e.printStackTrace();
		}finally {
			//5.釋放資源 connection prepareStatement
			JdbcUtils.statementClose(connection, sql, rs);
		}
	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		doGet(request, response);
	}

}

3. 實現點贊，對應servlet文件AddSupport.java

一樣在myServlet.data包下新建servlet文件,命名爲AddSupport
在web.xml中配置：

<servlet>
<servlet-name>AddSupport</servlet-name>
<servlet-class>myServlet.data.AddSupport</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>AddSupport</servlet-name>
<url-pattern>/servlet/AddSupport</url-pattern>
</servlet-mapping>

AddSupport.java通過參數獲取到info_id，查詢到info表中的對應點贊數，然後在當前點贊數的基礎上加一之後更新到info表對應的內容點贊數中，具體代碼如下：

package myServlet.data;

import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

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 org.utils.JdbcUtils;
import org.utils.JsonUtils;

import net.sf.json.JSONArray;

/**
 * Servlet implementation class AddSupport
 */
@WebServlet("/AddSupport")
public class AddSupport extends HttpServlet {
	private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public AddSupport() {
        super();
        // TODO Auto-generated constructor stub
    }

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		response.setContentType("text/html;charset=utf-8");
        request.setCharacterEncoding("utf-8");
        response.setCharacterEncoding("utf-8");
        PrintWriter out = response.getWriter();
       
		String infoId = request.getParameter("InfoId").trim();
/*		String supportNum = request.getParameter("supportNum").trim();*/
		
		if(infoId == null) {
			infoId = "";
		}
		
	 	Connection connection = null;
		PreparedStatement prepareStatement = null;
		PreparedStatement prepareStatement2 = null;
		ResultSet rs = null;
		ResultSet rs2 =null;
		
		String backnews="";
		boolean boo = false;
		
		boo = infoId.length()>0;
		
		try {
			connection = JdbcUtils.getConnection();
		
			//3.獲取statement
			String sql ="select * from info where info_id=?";
			prepareStatement = connection.prepareStatement(sql);
			prepareStatement.setString(1, infoId);
			
			if(boo) {
    			//4.執行sql
    			rs = prepareStatement.executeQuery();
    			boolean m = rs.next();
    			int support = rs.getInt(6);
    			support = support+1;
    			
    			
    			if(m==true) {
    				//查詢成功
    				String changeSql = "update info set info_support=? where info_id=?";
    				prepareStatement2 = connection.prepareStatement(changeSql);
    				prepareStatement2.setInt(1, support);
    				prepareStatement2.setString(2, infoId);
    				
    			    prepareStatement2.execute();
    			    
					JSONArray jsonArray = new JSONArray();//存放返回的jsonOjbect數組
    				List<Map<String,Object>> data = new ArrayList<Map<String,Object>>();
 
    			
    				Map<String,Object> map = new HashMap<String,Object>();
    				map.put("addOk", true);
			
					data.add(map);
					jsonArray = JsonUtils.formatRsToJsonArray(data);
					out.println(jsonArray.toString());  //返回json
    				
    				
    			}else {
    				JSONArray jsonArray = new JSONArray();//存放返回的jsonOjbect數組
    				List<Map<String,Object>> data = new ArrayList<Map<String,Object>>();
 
    			
    				Map<String,Object> map = new HashMap<String,Object>();
    				map.put("addOk", false);
			
					data.add(map);
					jsonArray = JsonUtils.formatRsToJsonArray(data);
					out.println(jsonArray.toString());  //返回json
    			}
			}else {
				JSONArray jsonArray = new JSONArray();//存放返回的jsonOjbect數組
				List<Map<String,Object>> data = new ArrayList<Map<String,Object>>();

			
				Map<String,Object> map = new HashMap<String,Object>();
				map.put("addOk", false);
		
				data.add(map);
				jsonArray = JsonUtils.formatRsToJsonArray(data);
				out.println(jsonArray.toString());  //返回json
			}
			out.print(backnews.toString());
		} catch (Exception e) {
			backnews="修改失敗"+e.toString();
			out.print(backnews); 
			e.printStackTrace();
		
		}finally {
			//5.釋放資源 connection prepareStatement
			JdbcUtils.close(connection, prepareStatement, rs);
			JdbcUtils.close(connection, prepareStatement2, rs2);
		}
	     out.flush();
	     out.close();
	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		doGet(request, response);
	}

}

4.判斷用戶是否已經收藏內容——IfAddFocus.java

在myServlet.java包下新建servlet命名爲IfAddFocus
在web.xml中配置：

<servlet>
<servlet-name>IfAddFocus</servlet-name>
<servlet-class>myServlet.data.IfAddFocus</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>IfAddFocus</servlet-name>
<url-pattern>/servlet/IfAddFocus</url-pattern>
</servlet-mapping>

通過參數獲取到用戶名和內容id，根據用戶名和id查詢focu表是否已經存在該信息，若是則返回true，具體代碼如下：

package myServlet.data;

import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

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 org.utils.JdbcUtils;
import org.utils.JsonUtils;

import net.sf.json.JSONArray;

/**
 * Servlet implementation class IfAddlike
 */
@WebServlet("/IfAddlike")
public class IfAddFocus extends HttpServlet {
	private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public IfAddFocus() {
        super();
        // TODO Auto-generated constructor stub
    }

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		response.setContentType("text/html;charset=utf-8");
        request.setCharacterEncoding("utf-8");
        response.setCharacterEncoding("utf-8");
        PrintWriter out = response.getWriter();
	          
		String username = request.getParameter("username").trim();
		String infoId = request.getParameter("infoId").trim();
		int focusId = 0;

        
		if(username == null) {
			username = "";
		}
		
		if(infoId == null) {
			infoId = "";
		}
      
	 	Connection connection = null;
		PreparedStatement prepareStatement = null;
		ResultSet rs = null;
		boolean boo = false;
		
		boo = username.length()>0&&infoId.length()>0;
		
		try {
			connection = JdbcUtils.getConnection();
			
			//3.獲取statement
			//String sql ="insert into user(logname,password,phone,address,realname) value(?,?,?,?,?) ";
			String sql ="select * from focus where username=? and info_id=?";
			prepareStatement = connection.prepareStatement(sql);
			prepareStatement.setString(1, username);
			prepareStatement.setString(2, infoId);
			
			if(boo) {
    			//4.執行sql
				boolean m =false;
				
    			rs = prepareStatement.executeQuery();
    			while(rs.next()) {
    				m = true;
    				focusId = rs.getInt(1);
    			}
    			
    			if(m==true) {
    			
    				success(request,response,focusId);
    				
    			}else {
    				fail(request,response);
    			}
			}else {
				fail(request,response);
			}
			
  
		} catch (Exception e) {
			e.printStackTrace();
			fail(request,response);
		}finally {
			//5.釋放資源 connection prepareStatement
			JdbcUtils.close(connection, prepareStatement, rs);
		}
	     out.flush();
	     out.close();
	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		doGet(request, response);
	}
	
	public void success(HttpServletRequest request, HttpServletResponse response, int focusId) {
		try {
			JSONArray jsonArray = new JSONArray();//存放返回的jsonOjbect數組
			List<Map<String,Object>> data = new ArrayList<Map<String,Object>>();
			
			PrintWriter out = response.getWriter();
	
			Map<String,Object> map = new HashMap<String,Object>();
			map.put("isFocus", true);
			map.put("focusId", focusId);
	
			data.add(map);
			jsonArray = JsonUtils.formatRsToJsonArray(data);
			out.println(jsonArray.toString());  //返回json
		}catch(IOException e) {
			e.printStackTrace();
		}
	}
	
	public void fail(HttpServletRequest request, HttpServletResponse response) {
		response.setContentType("text/html;charset=utf-8");
		try {
			JSONArray jsonArray = new JSONArray();//存放返回的jsonOjbect數組
			List<Map<String,Object>> data = new ArrayList<Map<String,Object>>();
			
			PrintWriter out = response.getWriter();
	
			Map<String,Object> map = new HashMap<String,Object>();
			map.put("isFocus", false);
	
			data.add(map);
			jsonArray = JsonUtils.formatRsToJsonArray(data);
			out.println(jsonArray.toString());  //返回json
		}catch(IOException e) {
			e.printStackTrace();
		}
	}

}

5.取消收藏——RemoveFocus.java

在myServlet.data包下創建servlet並命名爲RemoveFocus
在web.xml添加配置

<servlet>
<servlet-name>RemoveFocus</servlet-name>
<servlet-class>myServlet.data.RemoveFocus</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>RemoveFocus</servlet-name>
<url-pattern>/servlet/RemoveFocus</url-pattern>
</servlet-mapping>

通過獲取到用戶名和內容Id，將focus表中對應的收藏信息刪除，具體代碼如下：

package myServlet.data;

import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

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 org.utils.JdbcUtils;
import org.utils.JsonUtils;

import net.sf.json.JSONArray;

/**
 * Servlet implementation class RemoveFocus
 */
@WebServlet("/RemoveFocus")
public class RemoveFocus extends HttpServlet {
	private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public RemoveFocus() {
        super();
        // TODO Auto-generated constructor stub
    }

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		response.setContentType("text/html;charset=utf-8");
        request.setCharacterEncoding("utf-8");
        response.setCharacterEncoding("utf-8");
        PrintWriter out = response.getWriter();
        
      
		String focusId = request.getParameter("focusId").trim();
		
		if(focusId == null||focusId == "") {
			return;
		}
	
		
	 	Connection connection = null;
		PreparedStatement prepareStatement = null;
		ResultSet rs = null;

		
		boolean boo = false;
		
		boo = focusId.length()>0;
		
		try {
			connection = JdbcUtils.getConnection();
		
			//3.獲取statement
			String sql ="delete from focus where focus_id=?";
			prepareStatement = connection.prepareStatement(sql);
			prepareStatement.setString(1, focusId);
			
			if(boo) {
    			//4.執行sql
    			prepareStatement.execute();
    			   
				JSONArray jsonArray = new JSONArray();//存放返回的jsonOjbect數組
				List<Map<String,Object>> data = new ArrayList<Map<String,Object>>();
				Map<String,Object> map = new HashMap<String,Object>();
				map.put("removeOk", true);
		
				data.add(map);
				jsonArray = JsonUtils.formatRsToJsonArray(data);
				out.println(jsonArray.toString());  //返回json		
    		
			}else {
				JSONArray jsonArray = new JSONArray();//存放返回的jsonOjbect數組
				List<Map<String,Object>> data = new ArrayList<Map<String,Object>>();

			
				Map<String,Object> map = new HashMap<String,Object>();
				map.put("removeOk", false);
		
				data.add(map);
				jsonArray = JsonUtils.formatRsToJsonArray(data);
				out.println(jsonArray.toString());  //返回json
			}
			
		} catch (Exception e) {
			JSONArray jsonArray = new JSONArray();//存放返回的jsonOjbect數組
			List<Map<String,Object>> data = new ArrayList<Map<String,Object>>();

		
			Map<String,Object> map = new HashMap<String,Object>();
			map.put("removeOk", false);
	
			data.add(map);
			jsonArray = JsonUtils.formatRsToJsonArray(data);
			out.println(jsonArray.toString());  //返回json
		
		}finally {
			//5.釋放資源 connection prepareStatement
			JdbcUtils.close(connection, prepareStatement, rs);
		}
	     out.flush();
	     out.close();
	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		doGet(request, response);
	}

}

6.添加到我的收藏

在myServlet.data下新建文件AddFocus.java
在web.xml下添加配置：

<servlet>
<servlet-name>AddFocus</servlet-name>
<servlet-class>myServlet.data.AddFocus</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>AddFocus</servlet-name>
<url-pattern>/servlet/AddFocus</url-pattern>
</servlet-mapping>

通過參數獲取到用戶名和內容ID，將信息插入到收藏表focus中，具體代碼如下：

package myServlet.data;

import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

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 org.utils.JdbcUtils;
import org.utils.JsonUtils;

import net.sf.json.JSONArray;

/**
 * Servlet implementation class AddFocus
 */
@WebServlet("/AddFocus")
public class AddFocus extends HttpServlet {
	private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public AddFocus() {
        super();
        // TODO Auto-generated constructor stub
    }

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		response.setContentType("text/html;charset=utf-8");
        request.setCharacterEncoding("utf-8");
        response.setCharacterEncoding("utf-8");
        PrintWriter out = response.getWriter();
        
      
		String infoId = request.getParameter("InfoId").trim();
		String username = request.getParameter("username").trim();
		
		if(infoId == null||infoId == "") {
			return;
		}
		
		if(username == null||username == "") {
			return;
		}
		
	 	Connection connection = null;
		PreparedStatement prepareStatement = null;
		PreparedStatement prepareStatement2 = null;
		ResultSet rs = null;
		ResultSet rs2 =null;
		
		String backnews="";
		boolean boo = false;
		
		boo = infoId.length()>0;
		
		try {
			connection = JdbcUtils.getConnection();
		
			//3.獲取statement
			String sql ="select * from focus where info_id=? and username=?";
			prepareStatement = connection.prepareStatement(sql);
			prepareStatement.setString(1, infoId);
			prepareStatement.setString(2, username);
			
			if(boo) {
    			//4.執行sql
    			rs = prepareStatement.executeQuery();
    			boolean m = rs.next();
    			
    			if(m!=true) {
    				String changeSql = "INSERT INTO focus VALUES(?,?,?)";
    				prepareStatement2 = connection.prepareStatement(changeSql);
    				prepareStatement2.setInt(1, 0);
    				prepareStatement2.setString(2, username);
    				prepareStatement2.setString(3, infoId);
    				
    			    prepareStatement2.execute();
    			    
					JSONArray jsonArray = new JSONArray();//存放返回的jsonOjbect數組
    				List<Map<String,Object>> data = new ArrayList<Map<String,Object>>();
    				Map<String,Object> map = new HashMap<String,Object>();
    				map.put("addOk", true);
			
					data.add(map);
					jsonArray = JsonUtils.formatRsToJsonArray(data);
					out.println(jsonArray.toString());  //返回json
    				
    			}else {
    				JSONArray jsonArray = new JSONArray();//存放返回的jsonOjbect數組
    				List<Map<String,Object>> data = new ArrayList<Map<String,Object>>();
 
    			
    				Map<String,Object> map = new HashMap<String,Object>();
    				map.put("addOk", false);
			
					data.add(map);
					jsonArray = JsonUtils.formatRsToJsonArray(data);
					out.println(jsonArray.toString());  //返回json
    			}
			}else {
				JSONArray jsonArray = new JSONArray();//存放返回的jsonOjbect數組
				List<Map<String,Object>> data = new ArrayList<Map<String,Object>>();

			
				Map<String,Object> map = new HashMap<String,Object>();
				map.put("addOk", false);
		
				data.add(map);
				jsonArray = JsonUtils.formatRsToJsonArray(data);
				out.println(jsonArray.toString());  //返回json
			}
			out.print(backnews.toString());
		} catch (Exception e) {
			backnews="修改失敗"+e.toString();
			out.print(backnews); 
			e.printStackTrace();
		
		}finally {
			//5.釋放資源 connection prepareStatement
			JdbcUtils.close(connection, prepareStatement, rs);
			JdbcUtils.close(connection, prepareStatement2, rs2);
		}
	     out.flush();
	     out.close();
	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		doGet(request, response);
	}

}

7.評論內容

在myServlet.data下新建servlet並命名爲AddComment
在web.xml中添加配置

<servlet>
<servlet-name>AddComment</servlet-name>
<servlet-class>myServlet.data.AddComment</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>AddComment</servlet-name>
<url-pattern>/servlet/AddComment</url-pattern>
</servlet-mapping>

同參數獲取到用戶的ID、內容ID、評論的內容插入到評論表中，具體代碼如下

package myServlet.data;

import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

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 org.utils.JdbcUtils;
import org.utils.JsonUtils;

import net.sf.json.JSONArray;

/**
 * Servlet implementation class AddComment
 */
@WebServlet("/AddComment")
public class AddComment extends HttpServlet {
	private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public AddComment() {
        super();
        // TODO Auto-generated constructor stub
    }

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		response.setContentType("text/html;charset=utf-8");
        request.setCharacterEncoding("utf-8");
        response.setCharacterEncoding("utf-8");
        PrintWriter out = response.getWriter();
        
        Integer commentId =0;    //內容ID,默認設置爲0
        String infoIdStr = request.getParameter("infoId");   //內容標題
        String commentUser =request.getParameter("commentUser");   //內容簡述
        String commentDetail = request.getParameter("commentDetail");   //內容詳情

        if(infoIdStr == null||infoIdStr == "") {
        	infoIdStr = "";
		}
        
        if(commentUser == null||commentUser == "") {
        	commentUser = "";
		}
        
        if(commentDetail == null||commentDetail == "") {
        	commentDetail = "";
		}
      
        
        Boolean m = infoIdStr.length()>0&&commentUser.length()>0&&commentDetail.length()>0;
        
        int infoId = 0;
        try {
        	infoId = Integer.parseInt(infoIdStr);    //內容類型
        } catch (NumberFormatException e) {
            e.printStackTrace();
        }       
		 
	 	Connection connection = null;
		PreparedStatement prepareStatement = null;
		try {
			connection = JdbcUtils.getConnection();
			//3.獲取statement
			String sql ="INSERT INTO comment VALUES(?,?,?,?)";
			prepareStatement = connection.prepareStatement(sql);
			
			if(m) {
				prepareStatement.setInt(1, commentId);  //自增
				prepareStatement.setString(2, commentUser);
				prepareStatement.setInt(3, infoId);
				prepareStatement.setString(4, commentDetail);
				
				//4.執行sql
				prepareStatement.execute();
				JSONArray jsonArray = new JSONArray();//存放返回的jsonOjbect數組
				List<Map<String,Object>> data = new ArrayList<Map<String,Object>>();
				Map<String,Object> map = new HashMap<String,Object>();
				map.put("addOk", true);
		
				data.add(map);
				jsonArray = JsonUtils.formatRsToJsonArray(data);
				out.println(jsonArray.toString());  //返回json
				
			}else {
				JSONArray jsonArray = new JSONArray();//存放返回的jsonOjbect數組
				List<Map<String,Object>> data = new ArrayList<Map<String,Object>>();
				Map<String,Object> map = new HashMap<String,Object>();
				map.put("addOk", false);
		
				data.add(map);
				jsonArray = JsonUtils.formatRsToJsonArray(data);
				out.println(jsonArray.toString());  //返回json
			}
			
  
		} catch (Exception e) {
			JSONArray jsonArray = new JSONArray();//存放返回的jsonOjbect數組
			List<Map<String,Object>> data = new ArrayList<Map<String,Object>>();
			Map<String,Object> map = new HashMap<String,Object>();
			map.put("addOk", false);
	
			data.add(map);
			jsonArray = JsonUtils.formatRsToJsonArray(data);
			out.println(jsonArray.toString());  //返回json
			
		}finally {
			//5.釋放資源 connection prepareStatement
			JdbcUtils.close(connection, prepareStatement, null);
		}
	     out.flush();
	     out.close();
	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		doGet(request, response);
	}

}

8.刪除分享內容

在myServlet.data下新建servlet並命名爲DeleteInfo
在web.xml中添加配置：

<servlet>
<servlet-name>DeleteInfo</servlet-name>
<servlet-class>myServlet.data.DeleteInfo</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>DeleteInfo</servlet-name>
<url-pattern>/servlet/DeleteInfo</url-pattern>
</servlet-mapping>

通過參數獲取到內容ID，對應刪除收藏表中的相關內容，然後再刪除info表中的內容，具體代碼如下：

package myServlet.data;

import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

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 org.utils.JdbcUtils;
import org.utils.JsonUtils;

import net.sf.json.JSONArray;

/**
 * Servlet implementation class DeleteInfo
 */
@WebServlet("/DeleteInfo")
public class DeleteInfo extends HttpServlet {
	private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public DeleteInfo() {
        super();
        // TODO Auto-generated constructor stub
    }

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		response.setContentType("text/html;charset=utf-8");
        request.setCharacterEncoding("utf-8");
        response.setCharacterEncoding("utf-8");
        PrintWriter out = response.getWriter();
        
      
		String infoId = request.getParameter("infoId").trim();
		
		if(infoId == null||infoId == "") {
			return;
		}
	
		
	 	Connection connection = null;
		PreparedStatement prepareStatement = null;
		ResultSet rs = null;
		


		PreparedStatement prepareStatement3 = null;
		ResultSet rs3 =null;
		String backnews="";
		boolean boo = false;
		
		boo = infoId.length()>0;
		
		try {
			connection = JdbcUtils.getConnection();
		
			//3.獲取statement
			String sql ="delete from focus where info_id=?";
			prepareStatement = connection.prepareStatement(sql);
			prepareStatement.setString(1, infoId);
			
			if(boo) {
    			//4.執行sql
    			prepareStatement.execute();
    		
    			
    			String changeSql = "delete from info where info_id=?";
				prepareStatement3 = connection.prepareStatement(changeSql);
				prepareStatement3.setString(1, infoId);
				prepareStatement3.execute();
				
				JSONArray jsonArray = new JSONArray();//存放返回的jsonOjbect數組
				List<Map<String,Object>> data = new ArrayList<Map<String,Object>>();
				Map<String,Object> map = new HashMap<String,Object>();
				map.put("deleteOk", true);
		
				data.add(map);
				jsonArray = JsonUtils.formatRsToJsonArray(data);
				out.println(jsonArray.toString());  //返回json		
    		
			}else {
				JSONArray jsonArray = new JSONArray();//存放返回的jsonOjbect數組
				List<Map<String,Object>> data = new ArrayList<Map<String,Object>>();

			
				Map<String,Object> map = new HashMap<String,Object>();
				map.put("deleteOk", false);
		
				data.add(map);
				jsonArray = JsonUtils.formatRsToJsonArray(data);
				out.println(jsonArray.toString());  //返回json
			}
			out.print(backnews.toString());
		} catch (Exception e) {
			backnews="修改失敗"+e.toString();
			out.print(backnews); 
			e.printStackTrace();
		
		}finally {
			//5.釋放資源 connection prepareStatement
			JdbcUtils.close(connection, prepareStatement, rs);
			JdbcUtils.close(connection, prepareStatement2, rs2);
			JdbcUtils.close(connection, prepareStatement3, rs3);
		}
	     out.flush();
	     out.close();
	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		doGet(request, response);
	}

}

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