? ? 做項(xiàng)目的過程中,對數(shù)據(jù)表建立一對多的關(guān)聯(lián)關(guān)系時(shí),以前都是用MyEclipse自動(dòng)生成配置文件,數(shù)據(jù)集合都是使用默認(rèn)生成的Set, Set是無序的,保存數(shù)據(jù)沒有按順序存儲(chǔ),而我需要把數(shù)據(jù)按保存時(shí)的順序讀取出來時(shí),數(shù)據(jù)的順序全亂了,看來想偷懶都不行,呵呵,修改hbm.xml配置文件,把Set換成list.
?數(shù)據(jù)表語句,
create?table?student(
id?int?primary?key,
name?varchar(30),
age?int,
sex?varchar(8));
create?table?course(
id?int?primary?key,
cid?int?,
cname?varchar(20),
idx?int,
student_id?int,
foreign?key?course(student_id)?references?student(id)
);映射文件與持久類
Student.hbm.xml
?1?<?xml?version="1.0"?encoding="utf-8"?>
?2?<!DOCTYPE?hibernate-mapping?PUBLIC?"-//Hibernate/Hibernate?Mapping?DTD?3.0//EN"
?3?"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
?4?<!--?
?5?????Mapping?file?autogenerated?by?MyEclipse?Persistence?Tools
?6?-->
?7?<hibernate-mapping>
?8?????<class?name="com.dragon.datamodel.Student"?table="student"?>
?9?????????<id?name="id"?type="java.lang.Integer">
10?????????????<column?name="id"?/>
11?????????????<generator?class="increment"?/>
12?????????</id>
13?????????<property?name="name"?type="java.lang.String">
14?????????????<column?name="name"?length="30"?not-null="true"?/>
15?????????</property>
16?????????<property?name="age"?type="java.lang.Integer">
17?????????????<column?name="age"?/>
18?????????</property>
19?????????<property?name="sex"?type="java.lang.String">
20?????????????<column?name="sex"?length="8"?/>
21?????????</property>
22?????????
23?????????<list?name="courses"?table="course"?cascade="all">
24????????????<key?column="student_id"??></key>
25????????????<!--?idx?字段用來記錄?保存的數(shù)據(jù)的順序??-->
26????????????<index?column="idx"?type="java.lang.Integer"></index>
27????????????<one-to-many?class="com.dragon.datamodel.Course"?/>
28?????????</list>
29?????????
30?????</class>
31?</hibernate-mapping>
32?Student.java
??1?package?com.dragon.datamodel;
??2?
??3?
??4?
??5?import?java.util.ArrayList;
??6?
??7?import?java.util.List;
??8?
??9?
?10?
?11?/**
?12?
?13??*?Student?generated?by?MyEclipse?Persistence?Tools
?14?
?15??*/
?16?
?17?
?18?
?19?public?class?Student?implements?java.io.Serializable?{
?20?
?21?
?22?
?23?????//?Fields
?24?
?25?
?26?
?27?????/**
?28?
?29??????*?
?30?
?31??????*/
?32?
?33?????private?static?final?long?serialVersionUID?=?1L;
?34?
?35?
?36?
?37?????private?Integer?id;
?38?
?39?
?40?
?41?????private?String?name;
?42?
?43?
?44?
?45?????private?Integer?age;
?46?
?47?
?48?
?49?????private?String?sex;
?50?
?51?????
?52?
?53?????private?List?courses?=?new?ArrayList();
?54?
?55?
?56?
?57?????//?Constructors
?58?
?59?
?60?
?61?????/**?default?constructor?*/
?62?
?63?????public?Student()?{
?64?
?65?????}
?66?
?67?
?68?
?69?????/**?minimal?constructor?*/
?70?
?71?????public?Student(String?name)?{
?72?
?73?????????this.name?=?name;
?74?
?75?????}
?76?
?77?
?78?
?79?????/**?full?constructor?*/
?80?
?81?????public?Student(String?name,?Integer?age,?String?sex)?{
?82?
?83?????????this.name?=?name;
?84?
?85?????????this.age?=?age;
?86?
?87?????????this.sex?=?sex;
?88?
?89?????}
?90?
?91?
?92?
?93?????//?Property?accessors
?94?
?95?
?96?
?97?????public?Integer?getId()?{
?98?
?99?????????return?this.id;
100?
101?????}
102?
103?
104?
105?????public?void?setId(Integer?id)?{
106?
107?????????this.id?=?id;
108?
109?????}
110?
111?
112?
113?????public?String?getName()?{
114?
115?????????return?this.name;
116?
117?????}
118?
119?
120?
121?????public?void?setName(String?name)?{
122?
123?????????this.name?=?name;
124?
125?????}
126?
127?
128?
129?????public?Integer?getAge()?{
130?
131?????????return?this.age;
132?
133?????}
134?
135?
136?
137?????public?void?setAge(Integer?age)?{
138?
139?????????this.age?=?age;
140?
141?????}
142?
143?
144?
145?????public?String?getSex()?{
146?
147?????????return?this.sex;
148?
149?????}
150?
151?
152?
153?????public?void?setSex(String?sex)?{
154?
155?????????this.sex?=?sex;
156?
157?????}
158?
159?
160?
161?????public?List?getCourses()?{
162?
163?????????return?courses;
164?
165?????}
166?
167?
168?
169?????public?void?setCourses(List?courses)?{
170?
171?????????this.courses?=?courses;
172?
173?????}
174?
175?????
176?
177?????public?void?addCourses(Course?course){
178?
179?????????this.courses.add(course);
180?
181?????}
182?
183?????
184?
185?
186?
187?}Course.hbm.xml
?1?<?xml?version="1.0"?encoding="utf-8"?>
?2?<!DOCTYPE?hibernate-mapping?PUBLIC?"-//Hibernate/Hibernate?Mapping?DTD?3.0//EN"
?3?"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
?4?<!--?
?5?????Mapping?file?autogenerated?by?MyEclipse?Persistence?Tools
?6?-->
?7?<hibernate-mapping>
?8?????<class?name="com.dragon.datamodel.Course"?table="course"?>
?9?????????<id?name="id"?type="java.lang.Integer">
10?????????????<column?name="id"?/>
11?????????????<generator?class="increment"?/>
12?????????</id>
13?????????<property?name="cid"?type="java.lang.Integer">
14?????????????<column?name="cid"?/>
15?????????</property>
16?????????<property?name="cname"?type="java.lang.String">
17?????????????<column?name="cname"?length="20"?/>
18?????????</property>
19?????
20?????</class>
21?</hibernate-mapping>
22?Course.java
?1?package?com.dragon.datamodel;
?2?
?3?/**
?4??*?Course?generated?by?MyEclipse?Persistence?Tools
?5??*/
?6?
?7?public?class?Course?implements?java.io.Serializable?{
?8?
?9?????//?Fields
10?
11?????/**
12??????*?
13??????*/
14?????private?static?final?long?serialVersionUID?=?1L;
15?
16?????private?Integer?id;
17?
18?????private?Integer?cid;
19?
20?????private?String?cname;
21?
22?//????private?Integer?studentId;
23?
24?????//?Constructors
25?
26?
27?????/**?default?constructor?*/
28?????public?Course()?{
29?????}
30?
31?????/**?full?constructor?*/
32?????public?Course(Integer?cid,?String?cname,?Integer?studentId)?{
33?????????this.cid?=?cid;
34?????????this.cname?=?cname;
35?//????????this.studentId?=?studentId;
36?????}
37?
38?????//?Property?accessors
39?
40?????public?Integer?getId()?{
41?????????return?this.id;
42?????}
43?
44?????public?void?setId(Integer?id)?{
45?????????this.id?=?id;
46?????}
47?
48?????public?Integer?getCid()?{
49?????????return?this.cid;
50?????}
51?
52?????public?void?setCid(Integer?cid)?{
53?????????this.cid?=?cid;
54?????}
55?
56?????public?String?getCname()?{
57?????????return?this.cname;
58?????}
59?
60?????public?void?setCname(String?cname)?{
61?????????this.cname?=?cname;
62?????}
63?
64?//????public?Integer?getStudentId()?{
65?//????????return?this.studentId;
66?//????}
67?//
68?//????public?void?setStudentId(Integer?studentId)?{
69?//????????this.studentId?=?studentId;
70?//????}
71?
72?}測試類
TestList.java
?1?/**
?2??*?
?3??*/
?4?package?com.test;
?5?
?6?import?java.util.List;
?7?
?8?import?org.hibernate.Session;
?9?import?org.hibernate.Transaction;
10?import?org.junit.After;
11?import?org.junit.Before;
12?import?org.junit.Test;
13?
14?import?com.dragon.datamodel.Course;
15?import?com.dragon.datamodel.HibernateSessionFactory;
16?import?com.dragon.datamodel.Student;
17?
18?/**
19??*?@author?dragon
20??*
21??*/
22?public?class?TestList?{
23?????
24?????private?Session?session;
25?????private?Transaction?tx;
26?????
27?????@Before
28?????public?void?setup(){
29?????????session?=?HibernateSessionFactory.getSession();
30?????????tx?=?session.beginTransaction();
31?????}
32?????
33?//????@Test
34?????public?void?saveStundetInfo(){
35?????????Student?stu?=?new?Student();
36?????????stu.setName("dragon");
37?????????stu.setAge(23);
38?????????stu.setSex("男");
39?????????String?k?;
40?????????
41?????????Course?c1?=?new?Course();
42?????????c1.setCid(3);
43?????????c1.setCname("j2ee?應(yīng)用");
44?????????
45?????????Course?c2?=?new?Course();
46?????????c2.setCid(21);
47?????????c2.setCname("C#?基礎(chǔ)");
48?????????
49?????????Course?c3?=?new?Course();
50?????????c3.setCid(22);
51?????????c3.setCname("軟件工程");
52?????????
53?????????stu.addCourses(c1);
54?????????stu.addCourses(c2);
55?????????stu.addCourses(c3);
56?????????
57?????????session.save(stu);
58?????????
59?????????
60?????????
61?????}
62?????
63?????
64????@Test
65????public?void?LoadStudentInfo(){
66????????List?list?=?session.createQuery("from?Student").list();
67????????
68????????for?(int?i?=0;?i?<?list.size();?i++){
69????????????Student?stu?=?(Student)?list.get(i);
70????????????System.out.println(stu.getName());
71????????????List?courses?=?stu.getCourses();
72????????????for?(int?j?=?0;?j?<?courses.size();?j++){
73????????????????Course?cors?=?(Course)?courses.get(j);
74????????????????System.out.print("????"+cors.getCname());
75????????????}
76????????????System.out.println();
77????????}
78????????
79????}
80?????
81?????
82?????
83?????@After
84?????public?void?closeSession(){
85?????????tx.commit();
86?????????session.close();
87?????}
88?????
89?}
90?posted on 2007-07-04 18:17
javadragon 閱讀(7822)
評論(3) 編輯 收藏