1
                package
                 com.etc.utils;

                  2
                  3
                import
                 java.sql.Connection;

                  4
                import
                 java.sql.DriverManager;

                  5
                import
                 java.sql.PreparedStatement;

                  6
                import
                 java.sql.ResultSet;

                  7
                import
                 java.sql.SQLException;

                  8
                  9
                import
                 javax.sql.rowset.CachedRowSet;

                 10
                 11
                import
                 com.sun.rowset.CachedRowSetImpl;

                 12
                 13
                /**
                 14
                 * 数据库访问的通用类

                 15
                 * 

                 16
                 * 
                @author
                 Administrator

                 17
                 * 

                 18
                */
                 19
                public
                class
                 DBUtil {

                 20
                private
                final
                static String URL = "jdbc:mysql://localhost/day07";
 21privatefinalstatic String USER = "root";
 22privatefinalstatic String PASSWORD = "123456";
 23privatefinalstatic String DRIVER = "com.mysql.jdbc.Driver";
 24 25/** 26     * 定义方法返回一个连接(Connection)对象
 27     * 
 28     * @return 返回值就是一个连接对象
 29*/ 30privatestatic Connection getConnection() {
 31         Connection conn = null;
 32try {
 33            Class.forName(DRIVER);
 34             conn = DriverManager.getConnection(URL, USER, PASSWORD);
 35         } catch (ClassNotFoundException e) {
 36            e.printStackTrace();
 37         } // 低版本的jdbc jar包 38catch (SQLException e) {
 39            e.printStackTrace();
 40        }
 41return conn;
 42    }
 43 44/** 45     * 一个方法来做增加删除和修改
 46     * 
 47     * @param sql   要执行的sql
 48     * @param param 执行的sql中包含的参数的实际值
 49     * @return int 表示的是受影响的行
 50*/ 51publicstaticint execUpdate(String sql, Object... param) {
 52         Connection conn = getConnection();
 53         PreparedStatement pstmt = null;
 54int result = 0;
 55try {
 56             pstmt = conn.prepareStatement(sql);
 57for (int i = 0; i < param.length; i++) {
 58                 pstmt.setObject(i + 1, param[i]);
 59            }
 60             result = pstmt.executeUpdate();
 61         } catch (SQLException e) {
 62            e.printStackTrace();
 63         } finally {
 64             closeAll(null, pstmt, conn);
 65        }
 66return result;
 67    }
 68 69/** 70     * 一个方法来做查询
 71     * 
 72     * @param sql   要执行查询的sql语句
 73     * @param param 要执行sql对应的参数
 74     * @return CachedRowSet 缓存的结果集
 75*/ 76publicstatic CachedRowSet execQuery(String sql, Object... param) {
 77         Connection conn = getConnection();
 78         PreparedStatement pstmt = null;
 79         ResultSet rs = null;
 80// 实例化CachedRowSetImpl 81         CachedRowSetImpl crs = null;
 82try {
 83             crs = new CachedRowSetImpl();
 84             pstmt = conn.prepareStatement(sql);
 85// 可以吧param当成是一个数组 86            System.out.println(param.length);
 87 88for (int i = 0; i < param.length; i++) {
 89                 pstmt.setObject(i + 1, param[i]);
 90            }
 91             rs = pstmt.executeQuery();
 92// 建立rs和crs关系，可以将rs的数据行缓存到crs中了 93            crs.populate(rs);
 94         } catch (SQLException e) {
 95            e.printStackTrace();
 96         } finally {
 97// 释放资源等 此处代码省略 98            closeAll(rs, pstmt, conn);
 99        }
100return crs;
101    }
102103/**104     * 释放资源
105     * 
106     * @param rs    结果集兑现
107     * @param pstmt 预处理语句对象
108     * @param conn  连接对象
109*/110privatestaticvoid closeAll(ResultSet rs, PreparedStatement pstmt, Connection conn) {
111try {
112if (rs != null)
113                rs.close();
114         } catch (SQLException e) {
115            e.printStackTrace();
116        }
117try {
118if (pstmt != null)
119                pstmt.close();
120         } catch (SQLException e) {
121            e.printStackTrace();
122        }
123try {
124if (conn != null)
125                conn.close();
126         } catch (SQLException e) {
127            e.printStackTrace();
128        }
129    }
130131 }

                 1
                package
                 com.etc.utils;

                 2
                 3
                import
                 java.util.ArrayList;

                 4
                import
                 java.util.List;

                 5
                 6
                public
                class Page<T> {
 7// 总页数 8privateint totalPageCount = 1;
 9// 页面大小，即每页显示记录数10privateint pageSize = 10;
11// 记录总数12privateint totalCount = 0;
13// 当前页码14privateint currPageNo = 1;
15// 每页集合16         List<T> list = new ArrayList<>();
1718publicint getTotalPageCount() {
19return totalPageCount;
20        }
21publicvoid setTotalPageCount(int totalPageCount) {
22this.totalPageCount = totalPageCount;
23        }
24publicint getPageSize() {
25return pageSize;
26        }
27publicvoid setPageSize(int pageSize) {
28this.pageSize = pageSize;
29        }
30publicint getTotalCount() {
31return totalCount;
32        }
33publicvoid setTotalCount(int totalCount) {
34this.totalCount = totalCount;
35        }
36publicint getCurrPageNo() {
37return currPageNo;
38        }
39publicvoid setCurrPageNo(int currPageNo) {
40this.currPageNo = currPageNo;
41        }
42public List<T> getList() {
43return list;
44        }
45publicvoid setList(List<T> list) {
46this.list = list;
47        }
484950 }

                 1
                package
                 com.etc.entity;

                 2
                 3
                public
                class
                 User {

                 4
                private
                int uid=0;
 5private String username;
 6private String password;
 7 8public User(int uid, String username, String password) {
 9super();
10this.uid = uid;
11this.username = username;
12this.password = password;
13    }
1415public User() {
16super();
17    }
1819publicint getUid() {
20return uid;
21    }
2223publicvoid setUid(int uid) {
24this.uid = uid;
25    }
2627public String getUsername() {
28return username;
29    }
3031publicvoid setUsername(String username) {
32this.username = username;
33    }
3435public String getPassword() {
36return password;
37    }
3839publicvoid setPassword(String password) {
40this.password = password;
41    }
42434445 }