jredis 返回集合 jdbc返回结果集

1. package jdbc.chap05;  
2.   
3. import java.sql.Connection;  
4. import java.sql.PreparedStatement;  
5. import java.sql.ResultSet;  
6. import java.util.ArrayList;  
7. import java.util.List;  
8.   
9. import jdbc.util.DbUtil;  
10. import model.Person;  
11.   
12. public class sec01 {  
13.   
14. private static DbUtil dbUtil=new DbUtil();  
15. /** 
16.      * 遍历查询结果1 
17.      * @throws Exception 
18.      */  
19. private static void listPerson()throws Exception{  
20. //获取连接  
21. "select * from t_student";  
22.         PreparedStatement pstmt=con.prepareStatement(sql);  
23. //返回2维结果集ResultSet  
24. while (rs.next()){  
25. int id=rs.getInt(1);//获取第一个列的值 编号ID  
26. 2);//获取第二个列的值 编号 name  
27. int age=rs.getInt(3);//获取第三列的值 编号age  
28. "学生编号："+id+"学生姓名："+name+"学生年龄："+age);  
29. "========================================================");  
30.               
31.         }  
32.     }  
33. /** 
34.      * 遍历查询结果2 
35.      * @throws Exception 
36.      */  
37. private static void listPerson2()throws Exception{  
38. //获取连接  
39. "select * from t_student";  
40.         PreparedStatement pstmt=con.prepareStatement(sql);  
41. //返回2维结果集ResultSet  
42. while (rs.next()){  
43. int id=rs.getInt("id");//获取第一个列的值 编号ID  
44. "name");//获取第二个列的值 编号 name  
45. int age=rs.getInt("age");//获取第三列的值 编号age  
46. "学生编号："+id+"学生姓名："+name+"学生年龄："+age);  
47. "========================================================");  
48.               
49.         }  
50.     }  
51. private static List<Person> listPerson3()throws Exception{  
52. new ArrayList<Person>();    
53. //获取连接  
54. "select * from t_student";  
55.         PreparedStatement pstmt=con.prepareStatement(sql);  
56. //返回2维结果集ResultSet  
57. while (rs.next()){  
58. int id=rs.getInt("id");//获取第一个列的值 编号ID  
59. "name");//获取第二个列的值 编号 name  
60. int age=rs.getInt("age");//获取第三列的值 编号age  
61. new Person(id, personName, age);  
62.         personlist.add(person);  
63.           
64.               
65.         }  
66. return personlist;  
67.             
68.     }  
69. public static void main(String[] args) throws Exception {  
70.   
71. //      listPerson();  
72. //      listPerson2();  
73.         List<Person> personList=listPerson3();  
74. for (Person person:personList){  
75.             System.out.println(person.toString());  
76.         }  
77.     }  
78. }

关键点：重写ToString

1. package model;  
2. /** 
3.  * 个人信息  
4.  * @author MC-DS 
5.  * 
6.  */  
7.   
8. public class Person {  
9.   
10. private int id;  
11. private String personName;  
12. private int age;  
13.       
14.       
15.       
16. public Person(int id, String personName, int age) {  
17. super();  
18. this.id = id;  
19. this.personName = personName;  
20. this.age = age;  
21.     }  
22. public Person(String personName, int age) {  
23. super();  
24. this.personName = personName;  
25. this.age = age;  
26.     }  
27. public int getId() {      
28. return id;  
29.     }  
30. public void setId(int id) {  
31. this.id = id;  
32.     }  
33. public String getPersonName() {  
34. return personName;  
35.     }  
36. public void setPersonName(String personName) {  
37. this.personName = personName;  
38.     }  
39. public Integer getAge() {  
40. return age;  
41.     }  
42. public void setAge(int age) {  
43. this.age = age;  
44.     }  
45. @Override  
46. public String toString() {  
47. // TODO Auto-generated method stub  
48. return "["+this.id+","+this.personName+","+this.age+"]";  
49.     }  
50.       
51. }

写前：

1. model.Person@27d43d30  
2. model.Person@5efd2ebd  
3. model.Person@4007ab03  
4. model.Person@376c72cc  
5. model.Person@30e4cb81  
6. model.Person@7cec9b3a  
7. model.Person@11c33ce9  
8. model.Person@28d3ee1b  
9. model.Person@71b5438d  
10. model.Person@3366184d  
11. model.Person@73c58197  
12. model.Person@2bbf1be2

写后：

1. [1,ling,18]  
2. [2,李小龍,18]  
3. [6,劉德華,17]  
4. [7,古天樂,37]  
5. [8,李小龍,18]  
6. [22,李小龍,18]  
7. [222,李小龍,18]  
8. [233,李小龍,18]  
9. [656,李小龍,18]  
10. [658,李小龍,18]  
11. [659,郑伊健,37]  
12. [661,陈小春,32]