1 package com.at221.jdbc;
  2 
  3 import java.io.IOException;
  4 import java.io.InputStream;
  5 import java.sql.*;
  6 import java.util.Properties;
  7 
  8 import com.mysql.jdbc.Connection;
  9 
 10 public class JDBCTools {
 11     public static void release(Statement sta,java.sql.Connection con,ResultSet rs){
 12         if(sta != null){
 13             try{
 14                 sta.close();
 15             }catch(Exception e){
 16                 e.getStackTrace();
 17             }
 18         }
 19         
 20         if(con != null){
 21             try{
 22                 con.close();
 23             }catch(Exception e){
 24                 e.getStackTrace();
 25             }
 26         }
 27         
 28         if(rs != null){
 29             try {
 30                 rs.close();
 31             } catch (SQLException e) {
 32                 // TODO Auto-generated catch block
 33                 e.printStackTrace();
 34             }
 35         }
 36             
 37     }
 38     
 39     public static void release(Statement sta,java.sql.Connection con){
 40         if(sta != null){
 41             try{
 42                 sta.close();
 43             }catch(Exception e){
 44                 e.getStackTrace();
 45             }
 46         }
 47         
 48         if(con != null){
 49             try{
 50                 con.close();
 51             }catch(Exception e){
 52                 e.getStackTrace();
 53             }
 54         }
 55             
 56     }
 57     
 58     public static Connection getConnec() throws SQLException, IOException, ClassNotFoundException, 
 59     InstantiationException, IllegalAccessException{
 60         String driverClass = null;
 61         String jdbcUrl = null;
 62         String user = null;
 63         String password = null;
 64         
 65         //利用配置文件,来更改数据库的配置
 66         InputStream is = JDBCTools.class.getClassLoader().getResourceAsStream("jdbc.properties");
 67         Properties p = new Properties();
 68         p.load(is);
 69         driverClass = p.getProperty("driver");
 70 //        System.out.println(driverClass);
 71         
 72         jdbcUrl = p.getProperty("jdbcUrl");
 73 //        System.out.println(jdbcUrl);
 74         
 75         user = p.getProperty("user");
 76 //        System.out.println(driverClass);
 77         
 78         password = p.getProperty("password");
 79 //        System.out.println(password);
 80         
 81         Properties info = new Properties();
 82         info.put("user", user);
 83         info.put("password", password);
 84         DriverManager.registerDriver((Driver)Class.forName(driverClass).newInstance());
 85         
 86         Connection connec = (Connection)DriverManager.getConnection(jdbcUrl, user, password);
 87 //        System.out.println(connec);
 88         return connec;
 89     }
 90 }
 91 
 92 
 93 
 94 package com.at221.jdbc;
 95 
 96 import java.sql.Connection;
 97 import java.sql.PreparedStatement;
 98 import java.sql.ResultSet;
 99 import java.util.HashMap;
100 import java.util.Map;
101 
102 import org.junit.Test;
103 
104 import com.mysql.jdbc.ResultSetMetaData;
105 
106 public class TestReflection {
107     @Test
108     public void test(){
109         String sql = "SELECT id Id,name Name,birth Birth,email Email from student where id = ?";
110         Student s = (Student)getStudent(Student.class,sql,3);
111         System.out.println(s);
112     }
113     public <T> Object getStudent(Class<T> clazz,String sql,Object ... args ){
114         Connection conn = null;
115         PreparedStatement ps = null;
116         ResultSet rs = null;
117         ResultSetMetaData rsmd = null;
118         T entity = null;
119         try {
120             //1.SQL语句进行配置
121             conn = JDBCTools.getConnec();
122             ps = conn.prepareStatement(sql);
123             //①给SQL语句中的通配符赋值
124             
125             for(int i = 0; i < args.length; i++){
126                 ps.setObject(i+1, args[i]);
127             }
128             //②利用SQL进行查询得到结果集
129             rs = ps.executeQuery();
130             //2.创建类的对象
131             entity = clazz.newInstance();
132             //3.利用jdbc元数据来获得列的别名,为map中的键值对进行赋值
133             rsmd = (ResultSetMetaData)rs.getMetaData();
134             
135             Map<String, Object> value = new HashMap<String, Object>();
136             if(rs.next()){
137                 for(int i = 0; i < rsmd.getColumnCount(); i++){
138                     String key = rsmd.getColumnLabel(i+1);
139                     Object obj = rs.getObject(i+1);
140                     value.put(key, obj);
141                 }    
142             }
143             //4.利用得到的map进行对创建的对象进行赋值
144             if(value.size() > 0){
145                 for(Map.Entry<String, Object> entry : value.entrySet()){
146                     String column = entry.getKey();
147                     Object columnValue = entry.getValue();
148                     RecflectionUtils.setFieldValue(entity, column, columnValue);
149                 }
150             }
151             
152             
153         } catch(Exception e){
154             e.printStackTrace();
155         }finally {
156             JDBCTools.release(ps, conn);
157             
158         }
159         return entity;
160     }
161 }
162 
163 
164 
165 package com.at221.jdbc;
166 
167 import java.sql.Date;
168 
169 public class Student {
170     private int id;
171     private String name = null;
172     private Date birth = null;
173     private String email = null;
174     
175     public Student(int id, String name, Date birth, String email) {
176         super();
177         this.id = id;
178         this.name = name;
179         this.birth = birth;
180         this.email = email;
181     }
182 
183     public Student() {
184         super();
185     }
186     
187     public int getId() {
188         return id;
189     }
190 
191     public void setId(Integer id) {
192         this.id = id.intValue();
193     }
194 
195     public String getName() {
196         return name;
197     }
198 
199     public void setName(String name) {
200         this.name = name;
201     }
202 
203     public Date getBirth() {
204         return birth;
205     }
206 
207     public void setBirth(Date birth) {
208         this.birth = birth;
209     }
210 
211     public String getEmail() {
212         return email;
213     }
214 
215     public void setEmail(String email) {
216         this.email = email;
217     }
218 
219     @Override
220     public String toString() {
221         return "Student [id=" + id + ", name=" + name 
222                 + ", birth=" + birth + ", email=" + email + "]";
223     }
224     
225     
226 }